diff options
| author | Matthias Melcher <fltk@matthiasm.com> | 2012-04-22 00:06:25 +0000 |
|---|---|---|
| committer | Matthias Melcher <fltk@matthiasm.com> | 2012-04-22 00:06:25 +0000 |
| commit | 4f7f902a00678be6a3028f12037fa2e337baf881 (patch) | |
| tree | 3b773e84a8250c7a3e5bd04ad170d72155fe7c61 /png | |
| parent | 1b01c3a94ca2be1a35ecd59e3e524142157aa7c6 (diff) | |
Updated PNG library to current version 1.5.10
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@9370 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
Diffstat (limited to 'png')
| -rw-r--r-- | png/ANNOUNCE | 112 | ||||
| -rw-r--r-- | png/CHANGES | 647 | ||||
| -rw-r--r-- | png/CMakeLists.txt | 357 | ||||
| -rw-r--r-- | png/LICENSE | 4 | ||||
| -rw-r--r-- | png/README | 13 | ||||
| -rw-r--r-- | png/libpng-manual.txt | 1022 | ||||
| -rw-r--r-- | png/libpng.3 | 1124 | ||||
| -rw-r--r-- | png/libpngpf.3 | 10 | ||||
| -rw-r--r-- | png/png.5 | 2 | ||||
| -rw-r--r-- | png/png.c | 922 | ||||
| -rw-r--r-- | png/png.h | 898 | ||||
| -rw-r--r-- | png/pngconf.h | 172 | ||||
| -rw-r--r-- | png/pngerror.c | 278 | ||||
| -rw-r--r-- | png/pngget.c | 120 | ||||
| -rw-r--r-- | png/pnginfo.h | 1 | ||||
| -rw-r--r-- | png/pnglibconf.h | 267 | ||||
| -rw-r--r-- | png/pngmem.c | 37 | ||||
| -rw-r--r-- | png/pngpread.c | 778 | ||||
| -rw-r--r-- | png/pngpriv.h | 748 | ||||
| -rw-r--r-- | png/pngread.c | 527 | ||||
| -rw-r--r-- | png/pngrtran.c | 2508 | ||||
| -rw-r--r-- | png/pngrutil.c | 1531 | ||||
| -rw-r--r-- | png/pngset.c | 144 | ||||
| -rw-r--r-- | png/pngstruct.h | 103 | ||||
| -rw-r--r-- | png/pngtrans.c | 352 | ||||
| -rw-r--r-- | png/pngwrite.c | 256 | ||||
| -rw-r--r-- | png/pngwtran.c | 30 | ||||
| -rw-r--r-- | png/pngwutil.c | 581 |
28 files changed, 9168 insertions, 4376 deletions
diff --git a/png/ANNOUNCE b/png/ANNOUNCE index 4a3b01888..dbc2ed173 100644 --- a/png/ANNOUNCE +++ b/png/ANNOUNCE @@ -1,5 +1,5 @@ -Libpng 1.5.1 - February 3, 2011 +Libpng 1.5.10 - March 29, 2012 This is a public release of libpng, intended for use in production codes. @@ -8,89 +8,57 @@ Files available for download: Source files with LF line endings (for Unix/Linux) and with a "configure" script - libpng-1.5.1.tar.xz (LZMA-compressed, recommended) - libpng-1.5.1.tar.gz - libpng-1.5.1.tar.bz2 + libpng-1.5.10.tar.xz (LZMA-compressed, recommended) + libpng-1.5.10.tar.gz + libpng-1.5.10.tar.bz2 Source files with CRLF line endings (for Windows), without the "configure" script - lpng151.7z (LZMA-compressed, recommended) - lpng151.zip + lpng1510.7z (LZMA-compressed, recommended) + lpng1510.zip Other information: - libpng-1.5.1-README.txt - libpng-1.5.1-LICENSE.txt + libpng-1.5.10-README.txt + libpng-1.5.10-LICENSE.txt -Changes since the last public release (1.5.0): +Changes since the last public release (1.5.9): - Added description of png_set_crc_action() to the manual. - Added a note in the manual that the type of the iCCP profile was changed - from png_charpp to png_bytepp in png_get_iCCP(). Similarly, - it was changed from png_charpp to png_const_bytepp in png_set_iCCP(). - Ensure that png_rgb_to_gray ignores palette mapped images, if libpng - internally happens to call it with one. - Fixed the failure to handle palette mapped images correctly. - Fixed a bug in handling of interlaced images (bero at arklinux.org). - Updated CMakeLists.txt (Clifford Yapp) - Fixed typecasting of some png_debug() statements (Cosmin) - Updated documentation of png_set|get_tRNS() (Thomas Klausner). - Mentioned in the documentation that applications must #include "zlib.h" - if they need access to anything in zlib.h, and that a number of - macros such as png_memset() are no longer accessible by applications. - Corrected pngvalid gamma test "sample" function to access all of the color - samples of each pixel, instead of sampling the red channel three times. - Changed variable names index, div, exp, and gamma to char_index, divisor, - exp_b10, and gamma_val, respectively, to avoid "shadow" warnings. - Prevent png_push_crc_skip() from hanging while reading an unknown chunk - or an over-large compressed zTXt chunk with the progressive reader. - Eliminated more GCC "shadow" warnings. - Revised png_fixed() in png.c to avoid compiler warning about reaching the - end without returning anything. - In the manual, describe the png_get_IHDR() arguments in the correct order. - Added const_png_structp and const_png_infop types, and used them in - prototypes for most png_get_*() functions. - Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name() - Added synopses for the IO_STATE functions and other missing synopses - to the manual. Removed the synopses from libpngpf.3 because they - were out of date and no longer useful. Better information can be - obtained by reading the prototypes and comments in pngpriv.h - Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build - Added a make macro DFNCPP that is a CPP that will accept the tokens in - a .dfn file and adds configure stuff to test for such a CPP. ./configure - should fail if one is not available. - Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace. - Added png_get_current_row_number and png_get_current_pass_number for the - benefit of the user transform callback. - Added png_process_data_pause and png_process_data_skip for the benefit of - progressive readers that need to stop data processing or want to optimize - skipping of unread data (e.g. if the reader marks a chunk to be skipped.) - Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error. - pngvalid contains tests of transforms, which tests are currently disabled - because they are incompletely tested. gray_to_rgb was failing to expand - the bit depth for smaller bit depth images; this seems to be a long - standing error and resulted, apparently, in invalid output. The - documentation did not accurately describe what libpng really does when - converting RGB to gray. - Fixed incorrect examples of callback prototypes in the manual, that were - introduced in libpng-1.0.0. - In addition the order of the png_get_uint macros with respect to the - relevant function definitions has been reversed. This helps the - preprocessing of the symbol files be more robust. Furthermore, the - symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when - the library may actually be built with PNG_USE_READ_MACROS; this stops - the read macros interfering with the symbol file format. - Made the manual, synopses, and function prototypes use the function - argument names file_gamma, int_file_gamma, and srgb_intent consistently. - Changed PNG_UNUSED from "param=param;" to "(void)param;". - Added transform tests to pngvalid and simplified the arguments. - Added a request in the manual that applications do not use "png_" or - "PNG_" to begin any of their own symbols. + Removed two useless #ifdef directives from pngread.c and one from pngrutil.c + Always put the CMAKE_LIBRARY in "lib" (removed special WIN32 case). + Removed empty vstudio/pngstest directory (Clifford Yapp). + Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from + pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c; + now that png_ptr->buffer is inaccessible to applications, the special + handling is no longer useful. + Fixed bug with png_handle_hIST with odd chunk length (Frank Busse). + Added PNG_SAFE_LIMITS feature to pnglibconf.dfa and code in pngconf.h + to reset the user limits to safe ones if PNG_SAFE_LIMITS is defined. + To enable, use "CPPFLAGS=-DPNG_SAFE_LIMITS_SUPPORTED" on the configure + command or put "#define PNG_SAFE_LIMITS_SUPPORTED" in pnglibconf.h. + Revised the SAFE_LIMITS feature to be the same as the feature in libpng16. + Added information about the new limits in the manual. + Updated Makefile.in + Removed unused "current_text" members of png_struct and the png_free() + of png_ptr->current_text from pngread.c + Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition. + Fixed CMF optimization of non-IDAT compressed chunks, which was added at + libpng-1.5.4. It sometimes produced too small of a window. + Reject all iCCP chunks after the first, even if the first one is invalid. + Added palette-index checking. Issue a png_benign_error() if an invalid + index is found. + Revised example.c to put text strings in a temporary character array + instead of directly assigning string constants to png_textp members. + This avoids compiler warnings when -Wwrite-strings is enabled. + Prevent PNG_EXPAND+PNG_SHIFT doing the shift twice. + Revised png_set_text_2() to avoid potential memory corruption (fixes + CVE-2011-3048). Send comments/corrections/commendations to png-mng-implement at lists.sf.net (subscription required; visit https://lists.sourceforge.net/lists/listinfo/png-mng-implement -to subscribe) or to glennrp at users.sourceforge.net +to subscribe) +or to glennrp at users.sourceforge.net Glenn R-P diff --git a/png/CHANGES b/png/CHANGES index fa5f2aae7..70af8273e 100644 --- a/png/CHANGES +++ b/png/CHANGES @@ -1,5 +1,4 @@ #if 0 -libpng_changes(){ /* CHANGES - changes for libpng Version 0.2 @@ -15,7 +14,7 @@ Version 0.3 fixed some bugs in writer interfaced with zlib 0.5 added K&R support - added check for 64 KB blocks for 16 bit machines + added check for 64 KB blocks for 16-bit machines Version 0.4 cleaned up code and commented code @@ -74,7 +73,7 @@ Version 0.82 [September, 1995] Version 0.85 [December, 1995] added more medium model code (almost everything's a far) added i/o, error, and memory callback functions - fixed some bugs (16 bit, 4 bit interlaced, etc.) + fixed some bugs (16-bit, 4-bit interlaced, etc.) added first run progressive reader (barely tested) Version 0.86 [January, 1996] @@ -180,7 +179,7 @@ Version 0.96 [May, 1997] Fixed serious bug with < 8bpp images introduced in 0.95 Fixed 256-color transparency bug (Greg Roelofs) Fixed up documentation (Greg Roelofs, Laszlo Nyul) - Fixed "error" in pngconf.h for Linux setjmp() behaviour + Fixed "error" in pngconf.h for Linux setjmp() behavior Fixed DOS medium model support (Tim Wegner) Fixed png_check_keyword() for case with error in static string text Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul) @@ -197,18 +196,20 @@ Version 0.97 [January, 1998] Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P) Minor corrections in libpng.txt Added simple sRGB support (Glenn R-P) - Easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED; + Easier conditional compiling, e.g., + define PNG_READ/WRITE_NOT_FULLY_SUPPORTED; all configurable options can be selected from command-line instead of having to edit pngconf.h (Glenn R-P) Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P) Added more conditions for png_do_background, to avoid changing black pixels to background when a background is supplied and no pixels are transparent - Repaired PNG_NO_STDIO behaviour - Tested NODIV support and made it default behaviour (Greg Roelofs) + Repaired PNG_NO_STDIO behavior + Tested NODIV support and made it default behavior (Greg Roelofs) Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler) Regularized version numbering scheme and bumped shared-library major - version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs) + version number to 2 to avoid problems with libpng 0.89 apps + (Greg Roelofs) Version 0.98 [January, 1998] Cleaned up some typos in libpng.txt and in code documentation @@ -1778,7 +1779,7 @@ Version 1.2.13beta1 [October 2, 2006] Removed AC_FUNC_MALLOC from configure.ac Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h Change "logical" to "bitwise" throughout documentation. - Detect and fix attempt to write wrong iCCP profile length. + Detect and fix attempt to write wrong iCCP profile length (CVE-2006-7244) Version 1.0.21, 1.2.13 [November 14, 2006] Fix potential buffer overflow in sPLT chunk handler. @@ -2361,7 +2362,7 @@ Version 1.4.0beta72 [August 1, 2009] Version 1.4.0beta73 [August 1, 2009] Reject attempt to write iCCP chunk with negative embedded profile length - (JD Chen) + (JD Chen) (CVE-2009-5063). Version 1.4.0beta74 [August 8, 2009] Changed png_ptr and info_ptr member "trans" to "trans_alpha". @@ -2935,7 +2936,7 @@ Version 1.5.0beta36 [July 29, 2010] PNG_INTERLACE transform and to get the number of rows in the current pass. A new test program, pngvalid.c, validates the gamma code. - Errors in the 16 bit gamma correction (overflows) have been corrected. + Errors in the 16-bit gamma correction (overflows) have been corrected. cHRM chunk testing is done consistently (previously the floating point API bypassed it, because the test really didn't work on FP, now the test is performed on the actual values to be stored in the PNG file so it @@ -3149,8 +3150,8 @@ version 1.5.1beta01 [January 8, 2011] in version 1.5.0beta36 but is not noted in the CHANGES. Similarly, it was changed from png_charpp to png_const_bytepp in png_set_iCCP(). Ensure that png_rgb_to_gray ignores palette mapped images, if libpng - internally happens to call it with one. - Fixed a failure to handle palette mapped images correctly. + internally happens to call it with one, and fixed a failure to handle + palette mapped images correctly. This fixes CVE-2690. Version 1.5.1beta02 [January 14, 2011] Fixed a bug in handling of interlaced images (bero at arklinux.org). @@ -3208,9 +3209,9 @@ Version 1.5.1beta09 [January 24, 2011] pngvalid contains tests of transforms, which tests are currently disabled because they are incompletely tested. gray_to_rgb was failing to expand the bit depth for smaller bit depth images; this seems to be a long - standing error and resulted, apparently, in invalid output. The - documentation did not accurately describe what libpng really does when - converting RGB to gray. + standing error and resulted, apparently, in invalid output + (CVE-2011-0408, CERT VU#643140). The documentation did not accurately + describe what libpng really does when converting RGB to gray. Version 1.5.1beta10 [January 27, 2010] Fixed incorrect examples of callback prototypes in the manual, that were @@ -3227,7 +3228,7 @@ Version 1.5.1beta10 [January 27, 2010] Version 1.5.1beta11 [January 28, 2011] Changed PNG_UNUSED from "param=param;" to "{if(param){}}". Corrected local variable type in new API png_process_data_skip() - The type was self-evidently incorrect but only causes problems on 64 bit + The type was self-evidently incorrect but only causes problems on 64-bit architectures. Added transform tests to pngvalid and simplified the arguments. @@ -3242,6 +3243,617 @@ Version 1.5.1rc02 [January 31, 2011] Version 1.5.1 [February 3, 2011] No changes. +Version 1.5.2beta01 [February 13, 2011] + More -Wshadow fixes for older gcc compilers. Older gcc versions apparently + check formal parameters names in function declarations (as well as + definitions) to see if they match a name in the global namespace. + Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the + old VisualC++ preprocessor. + Turned on interlace handling in png_read_png(). + Fixed gcc pendantic warnings. + Handle longjmp in Cygwin. + Fixed png_get_current_row_number() in the interlaced case. + Cleaned up ALPHA flags and transformations. + Implemented expansion to 16 bits. + +Version 1.5.2beta02 [February 19, 2011] + Fixed mistake in the descriptions of user read_transform and write_transform + function prototypes in the manual. The row_info struct is png_row_infop. + Reverted png_get_current_row_number() to previous (1.5.2beta01) behavior. + Corrected png_get_current_row_number documentation + Fixed the read/write row callback documentation. + This documents the current behavior, where the callback is called after + every row with information pertaining to the next row. + +Version 1.5.2beta03 [March 3, 2011] + Fixed scripts/makefile.vcwin32 + Updated contrib/pngsuite/README to add the word "modify". + Define PNG_ALLOCATED to blank when _MSC_VER<1300. + +Version 1.5.2rc01 [March 19, 2011] + Define remaining attributes to blank when MSC_VER<1300. + ifdef out mask arrays in pngread.c when interlacing is not supported. + +Version 1.5.2rc02 [March 22, 2011] + Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak + and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip" + from the makefiles. + Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail + to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill) + +Version 1.5.2rc03 [March 24, 2011] + Don't include standard header files in png.h while building the symbol table, + to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro). + +Version 1.5.2 [March 31, 2011] + No changes. + +Version 1.5.3beta01 [April 1, 2011] + Re-initialize the zlib compressor before compressing non-IDAT chunks. + Added API functions (png_set_text_compression_level() and four others) to + set parameters for zlib compression of non-IDAT chunks. + +Version 1.5.3beta02 [April 3, 2011] + Updated scripts/symbols.def with new API functions. + Only compile the new zlib re-initializing code when text or iCCP is + supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro. + Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03). + Optimize the zlib CMF byte in non-IDAT compressed chunks + +Version 1.5.3beta03 [April 16, 2011] + Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have + snprintf, and the "__STRICT_ANSI__" detects that condition more reliably + than __STDC__ (John Bowler). + Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells + the compiler that a user supplied callback (the error handler) does not + return, yet there is no guarantee in practice that the application code + will correctly implement the error handler because the compiler only + issues a warning if there is a mistake (John Bowler). + Removed the no-longer-used PNG_DEPSTRUCT macro. + Updated the zlib version to 1.2.5 in the VStudio project. + Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in + pngwutil.c (John Bowler). + Fixed bug with stripping the filler or alpha channel when writing, that + was introduced in libpng-1.5.2beta01 (bug report by Andrew Church). + +Version 1.5.3beta04 [April 27, 2011] + Updated pngtest.png with the new zlib CMF optimization. + Cleaned up conditional compilation code and of background/gamma handling + Internal changes only except a new option to avoid compiling the + png_build_grayscale_palette API (which is not used at all internally.) + The main change is to move the transform tests (READ_TRANSFORMS, + WRITE_TRANSFORMS) up one level to the caller of the APIs. This avoids + calls to spurious functions if all transforms are disabled and slightly + simplifies those functions. Pngvalid modified to handle this. + A minor change is to stop the strip_16 and expand_16 interfaces from + disabling each other; this allows the future alpha premultiplication + code to use 16-bit intermediate values while still producing 8-bit output. + png_do_background and png_do_gamma have been simplified to take a single + pointer to the png_struct rather than pointers to every item required + from the png_struct. This makes no practical difference to the internal + code. + A serious bug in the pngvalid internal routine 'standard_display_init' has + been fixed - this failed to initialize the red channel and accidentally + initialized the alpha channel twice. + Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to + avoid a possible clash with the png_jmpbuf macro on some platforms. + +Version 1.5.3beta05 [May 6, 2011] + Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the + correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and + pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs. + Removed png_snprintf and added formatted warning messages. This change adds + internal APIs to allow png_warning messages to have parameters without + requiring the host OS to implement snprintf. As a side effect the + dependency of the tIME-supporting RFC1132 code on stdio is removed and + PNG_NO_WARNINGS does actually work now. + Pass "" instead of '\0' to png_default_error() in png_err(). This mistake + was introduced in libpng-1.2.20beta01. This fixes CVE-2011-2691. + Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte + optimization configureable. + IDAT compression failed if preceded by a compressed text chunk (bug + introduced in libpng-1.5.3beta01-02). This was because the attempt to + reset the zlib stream in png_write_IDAT happened after the first IDAT + chunk had been deflated - much too late. In this change internal + functions were added to claim/release the z_stream and, hopefully, make + the code more robust. Also deflateEnd checking is added - previously + libpng would ignore an error at the end of the stream. + +Version 1.5.3beta06 [May 8, 2011] + Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt + Implemented premultiplied alpha support: png_set_alpha_mode API + +Version 1.5.3beta07 [May 11, 2011] + Added expand_16 support to the high level interface. + Added named value and 'flag' gamma support to png_set_gamma. Made a minor + change from the previous (unreleased) ABI/API to hide the exact value used + for Macs - it's not a good idea to embed this in the ABI! + Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT + from pngpriv.h to png.h because they must be visible to applications + that call png_set_unknown_chunks(). + Check for up->location !PNG_AFTER_IDAT when writing unknown chunks + before IDAT. + +Version 1.5.3beta08 [May 16, 2011] + Improved "pngvalid --speed" to exclude more of pngvalid from the time. + Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt + The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative + parameters are supplied by the caller), while in the absence of cHRM + sRGB/Rec 709 values are still used. This introduced a divide-by-zero + bug in png_handle_cHRM(). + The bKGD chunk no longer overwrites the background value set by + png_set_background(), allowing the latter to be used before the file + header is read. It never performed any useful function to override + the default anyway. + Added memory overwrite and palette image checks to pngvalid.c + Previously palette image code was poorly checked. Since the transformation + code has a special palette path in most cases this was a severe weakness. + Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When + expanding an indexed image, always expand to RGBA if transparency is + present. + +Version 1.5.3beta09 [May 17, 2011] + Reversed earlier 1.5.3 change of transformation order; move png_expand_16 + back where it was. The change doesn't work because it requires 16-bit + gamma tables when the code only generates 8-bit ones. This fails + silently; the libpng code just doesn't do any gamma correction. Moving + the tests back leaves the old, inaccurate, 8-bit gamma calculations, but + these are clearly better than none! + +Version 1.5.3beta10 [May 20, 2011] + + png_set_background() and png_expand_16() did not work together correctly. + This problem is present in 1.5.2; if png_set_background is called with + need_expand false and the matching 16 bit color libpng erroneously just + treats it as an 8-bit color because of where png_do_expand_16 is in the + transform list. This simple fix reduces the supplied colour to 8-bits, + so it gets smashed, but this is better than the current behavior. + Added tests for expand16, more fixes for palette image tests to pngvalid. + Corrects the code for palette image tests and disables attempts to + validate palette colors. + +Version 1.5.3rc01 [June 3, 2011] + No changes. + +Version 1.5.3rc02 [June 8, 2011] + Fixed uninitialized memory read in png_format_buffer() (Bug report by + Frank Busse, CVE-2011-2501, related to CVE-2004-0421). + +Version 1.5.3beta11 [June 11, 2011] + Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692. + Added sCAL to pngtest.png + Revised documentation about png_set_user_limits() to say that it also affects + png writing. + Revised handling of png_set_user_limits() so that it can increase the + limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only + reduce it. + Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is + wrong (high by one) 25% of the time. Dividing by 257 with rounding is + wrong in 128 out of 65536 cases. Getting the right answer all the time + without division is easy. + Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro. + Added projects/owatcom, an IDE project for OpenWatcom to replace + scripts/makefile.watcom. This project works with OpenWatcom 1.9. The + IDE autogenerates appropriate makefiles (libpng.mk) for batch processing. + The project is configurable, unlike the Visual Studio project, so long + as the developer has an awk. + Changed png_set_gAMA to limit the gamma value range so that the inverse + of the stored value cannot overflow the fixed point representation, + and changed other things OpenWatcom warns about. + Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows + pngvalid to build when ALPHA_MODE is not supported, which is required if + it is to build on libpng 1.4. + Removed string/memory macros that are no longer used and are not + necessarily fully supportable, particularly png_strncpy and png_snprintf. + Added log option to pngvalid.c and attempted to improve gamma messages. + +Version 1.5.3 [omitted] + People found the presence of a beta release following an rc release + to be confusing; therefore we bump the version to libpng-1.5.4beta01 + and there will be no libpng-1.5.3 release. + +Version 1.5.4beta01 [June 14, 2011] + Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED + to get the same (inaccurate) output as libpng-1.5.2 and earlier. + Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE + outside of an unknown-chunk block in png.h because they are also + needed for other uses. + +Version 1.5.4beta02 [June 14, 2011] + Fixed and clarified LEGACY 16-to-8 scaling code. + Added png_set_chop_16() API, to match inaccurate results from previous + libpng versions. + Removed the ACCURATE and LEGACY options (they are no longer useable) + Use the old scaling method for background if png_set_chop_16() was + called. + Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED + +Version 1.5.4beta03 [June 15, 2011] + Fixed a problem in png_do_expand_palette() exposed by optimization in + 1.5.3beta06 + Also removed a spurious and confusing "trans" member ("trans") from png_info. + The palette expand optimization prevented expansion to an intermediate RGBA + form if tRNS was present but alpha was marked to be stripped; this exposed + a check for tRNS in png_do_expand_palette() which is inconsistent with the + code elsewhere in libpng. + Correction to the expand_16 code; removed extra instance of + png_set_scale_16_to_8 from pngpriv.h + +Version 1.5.4beta04 [June 16, 2011] + Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c + Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms. + Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again. If this is + not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built. + Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8 + +Version 1.5.4beta05 [June 16, 2011] + Renamed png_set_strip_16() to png_set_scale_16() and renamed + png_set_chop_16() to png_set_strip(16) in an attempt to minimize the + behavior changes between libpng14 and libpng15. + +Version 1.5.4beta06 [June 18, 2011] + Fixed new bug that was causing both strip_16 and scale_16 to be applied. + +Version 1.5.4beta07 [June 19, 2011] + Fixed pngvalid, simplified macros, added checking for 0 in sCAL. + The ACCURATE scale macro is no longer defined in 1.5 - call the + png_scale_16_to_8 API. Made sure that PNG_READ_16_TO_8 is still defined + if the png_strip_16_to_8 API is present. png_check_fp_number now + maintains some state so that positive, negative and zero values are + identified. sCAL uses these to be strictly spec conformant. + +Version 1.5.4beta08 [June 23, 2011] + Fixed pngvalid if ACCURATE_SCALE is defined. + Updated scripts/pnglibconf.h.prebuilt. + +Version 1.5.4rc01 [June 30, 2011] + Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400. + +Version 1.5.4 [July 7, 2011] + No changes. + +Version 1.5.5beta01 [July 13, 2011] + Fixed some typos and made other minor changes in the manual. + Updated contrib/pngminus/makefile.std (Samuli Souminen) + +Version 1.5.5beta02 [July 14, 2011] + Revised Makefile.am and Makefile.in to look in the right directory for + pnglibconf.h.prebuilt + +Version 1.5.5beta03 [July 27, 2011] + Enabled compilation with g++ compiler. This compiler does not recognize + the file extension, so it always compiles with C++ rules. Made minor + changes to pngrutil.c to cast results where C++ expects it but C does not. + Minor editing of libpng.3 and libpng-manual.txt. + +Version 1.5.5beta04 [July 29, 2011] + Revised CMakeLists.txt (Clifford Yapp) + Updated commentary about the png_rgb_to_gray() default coefficients + in the manual and in pngrtran.c + +Version 1.5.5beta05 [August 17, 2011] + Prevent unexpected API exports from non-libpng DLLs on Windows. The "_DLL" + is removed from the test of whether a DLL is being built (this erroneously + caused the libpng APIs to be marked as DLL exports in static builds under + Microsoft Visual Studio). Almost all of the libpng building configuration + is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in + pngconf.h, though, so that it is colocated with the import definition (it + is no longer used anywhere in the installed headers). The VStudio project + definitions have been cleaned up: "_USRDLL" has been removed from the + static library builds (this was incorrect), and PNG_USE_DLL has been added + to pngvalid to test the functionality (pngtest does not supply it, + deliberately). The spurious "_EXPORTS" has been removed from the + libpng build (all these errors were a result of copy/paste between project + configurations.) + Added new types and internal functions for CIE RGB end point handling to + pngpriv.h (functions yet to be implemented). + +Version 1.5.5beta06 [August 26, 2011] + Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt + (Clifford Yap) + Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler): + The rgb_to_gray code had errors when combined with gamma correction. + Some pixels were treated as true grey when they weren't and such pixels + and true grey ones were not gamma corrected (the original value of the + red component was used instead). APIs to get and set cHRM using color + space end points have been added and the rgb_to_gray code that defaults + based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT + VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected. + A considerable number of tests has been added to pngvalid for the + rgb_to_gray transform. + Arithmetic errors in rgb_to_gray whereby the calculated gray value was + truncated to the bit depth rather than rounded have been fixed except in + the 8-bit non-gamma-corrected case (where consistency seems more important + than correctness.) The code still has considerable inaccuracies in the + 8-bit case because 8-bit linear arithmetic is used. + +Version 1.5.5beta07 [September 7, 2011] + Added "$(ARCH)" option to makefile.darwin + Added SunOS support to configure.ac and Makefile.am + Changed png_chunk_benign_error() to png_warning() in png.c, in + png_XYZ_from_xy_checked(). + +Version 1.5.5beta08 [September 10, 2011] + Fixed 64-bit compilation errors (gcc). The errors fixed relate + to conditions where types that are 32 bits in the GCC 32-bit + world (uLong and png_size_t) become 64 bits in the 64-bit + world. This produces potential truncation errors which the + compiler correctly flags. + Relocated new HAVE_SOLARIS_LD definition in configure.ac + Constant changes for 64-bit compatibility (removal of L suffixes). The + 16-bit cases still use "L" as we don't have a 16-bit test system. + +Version 1.5.5rc01 [September 15, 2011] + Removed "L" suffixes in pngpriv.h + +Version 1.5.5 [September 22, 2011] + No changes. + +Version 1.5.6beta01 [September 22, 2011] + Fixed some 64-bit type conversion warnings in pngrtran.c + Moved row_info from png_struct to a local variable. + The various interlace mask arrays have been made into arrays of + bytes and made PNG_CONST and static (previously some arrays were + marked PNG_CONST and some weren't). + Additional checks have been added to the transform code to validate the + pixel depths after the transforms on both read and write. + Removed some redundant code from pngwrite.c, in png_destroy_write_struct(). + Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4]. + This removes the need to allocate temporary strings for chunk names on + the stack in the read/write code. Unknown chunk handling still uses the + string form because this is exposed in the API. + +Version 1.5.6beta02 [September 26, 2011] + Added a note in the manual the png_read_update_info() must be called only + once with a particular info_ptr. + Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro. + +Version 1.5.6beta03 [September 28, 2011] + Revised test-pngtest.sh to report FAIL when pngtest fails. + Added "--strict" option to pngtest, to report FAIL when the failure is + only because the resulting valid files are different. + Revised CMakeLists.txt to work with mingw and removed some material from + CMakeLists.txt that is no longer useful in libpng-1.5. + +Version 1.5.6beta04 [October 5, 2011] + Fixed typo in Makefile.in and Makefile.am ("-M Wl" should be "-M -Wl")." + +Version 1.5.6beta05 [October 12, 2011] + Speed up png_combine_row() for interlaced images. This reduces the generality + of the code, allowing it to be optimized for Adam7 interlace. The masks + passed to png_combine_row() are now generated internally, avoiding + some code duplication and localizing the interlace handling somewhat. + Align png_struct::row_buf - previously it was always unaligned, caused by + a bug in the code that attempted to align it; the code needs to subtract + one from the pointer to take account of the filter byte prepended to + each row. + Optimized png_combine_row() when rows are aligned. This gains a small + percentage for 16-bit and 32-bit pixels in the typical case where the + output row buffers are appropriately aligned. The optimization was not + previously possible because the png_struct buffer was always misaligned. + Fixed bug in png_write_chunk_header() debug print, introduced in 1.5.6beta01. + +Version 1.5.6beta06 [October 17, 2011] + Removed two redundant tests for unitialized row. + Fixed a relatively harmless memory overwrite in compressed text writing + with a 1 byte zlib buffer. + Add ability to call png_read_update_info multiple times to pngvalid.c. + Fixes for multiple calls to png_read_update_info. These fixes attend to + most of the errors revealed in pngvalid, however doing the gamma work + twice results in inaccuracies that can't be easily fixed. There is now + a warning in the code if this is going to happen. + Turned on multiple png_read_update_info in pngvalid transform tests. + Prevent libpng from overwriting unused bits at the end of the image when + it is not byte aligned, while reading. Prior to libpng-1.5.6 libpng would + overwrite the partial byte at the end of each row if the row width was not + an exact multiple of 8 bits and the image is not interlaced. + +Version 1.5.6beta07 [October 21, 2011] + Made png_ptr->prev_row an aligned pointer into png_ptr->big_prev_row + (Mans Rullgard). + +Version 1.5.6rc01 [October 26, 2011] + Changed misleading "Missing PLTE before cHRM" warning to "Out of place cHRM" + +Version 1.5.6rc02 [October 27, 2011] + Added LSR() macro to defend against buggy compilers that evaluate non-taken + code branches and complain about out-of-range shifts. + +Version 1.5.6rc03 [October 28, 2011] + Renamed the LSR() macro to PNG_LSR() and added PNG_LSL() macro. + Fixed compiler warnings with Intel and MSYS compilers. The logical shift + fix for Microsoft Visual C is required by other compilers, so this + enables that fix for all compilers when using compile-time constants. + Under MSYS 'byte' is a name declared in a system header file, so we + changed the name of a local variable to avoid the warnings that result. + Added #define PNG_ALIGN_TYPE PNG_ALIGN_NONE to contrib/pngminim/*/pngusr.h + +Version 1.5.6 [November 3, 2011] + No changes. + +Version 1.5.7beta01 [November 4, 2011] + Added support for ARM processor (Mans Rullgard) + Fixed bug in pngvalid on early allocation failure; fixed type cast in + pngmem.c; pngvalid would attempt to call png_error() if the allocation + of a png_struct or png_info failed. This would probably have led to a + crash. The pngmem.c implementation of png_malloc() included a cast + to png_size_t which would fail on large allocations on 16-bit systems. + Fix for the preprocessor of the Intel C compiler. The preprocessor + splits adjacent @ signs with a space; this changes the concatentation + token from @-@-@ to PNG_JOIN; that should work with all compiler + preprocessors. + Paeth filter speed improvements from work by Siarhei Siamashka. This + changes the 'Paeth' reconstruction function to improve the GCC code + generation on x86. The changes are only part of the suggested ones; + just the changes that definitely improve speed and remain simple. + The changes also slightly increase the clarity of the code. + +Version 1.5.7beta02 [November 11, 2011] + Check compression_type parameter in png_get_iCCP and remove spurious + casts. The compression_type parameter is always assigned to, so must + be non-NULL. The cast of the profile length potentially truncated the + value unnecessarily on a 16-bit int system, so the cast of the (byte) + compression type to (int) is specified by ANSI-C anyway. + Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left + the sBIT fields in the test pixel as 0, which resulted in a floating + point division by zero which was irrelevant but causes systems where + FP exceptions cause a crash. Added code to pngvalid to turn on FP + exceptions if the appropriate glibc support is there to ensure this is + tested in the future. + Updated scripts/pnglibconf.mak and scripts/makefile.std to handle the + new PNG_JOIN macro. + Added versioning to pnglibconf.h comments. + Simplified read/write API initial version; basic read/write tested on + a variety of images, limited documentation (in the header file.) + Installed more accurate linear to sRGB conversion tables. The slightly + modified tables reduce the number of 16-bit values that + convert to an off-by-one 8-bit value. The "makesRGB.c" code that was used + to generate the tables is now in a contrib/sRGBtables sub-directory. + +Version 1.5.7beta03 [November 17, 2011] + Removed PNG_CONST from the sRGB table declarations in pngpriv.h and png.c + Added run-time detection of NEON support. + Added contrib/libtests; includes simplified API test and timing test and + a color conversion utility for rapid checking of failed 'pngstest' results. + Multiple transform bug fixes plus a work-round for double gamma correction. + libpng does not support more than one transform that requires linear data + at once - if this is tried typically the results is double gamma + correction. Since the simplified APIs can need rgb to gray combined with + a compose operation it is necessary to do one of these outside the main + libpng transform code. This check-in also contains fixes to various bugs + in the simplified APIs themselves and to some bugs in compose and rgb to + gray (on palette) itself. + Fixes for C++ compilation using g++ When libpng source is compiled + using g++. The compiler imposes C++ rules on the C source; thus it + is desireable to make the source work with either C or C++ rules + without throwing away useful error information. This change adds + png_voidcast to allow C semantic (void*) cases or the corresponding + C++ static_cast operation, as appropriate. + Added --noexecstack to assembler file compilation. GCC does not set + this on assembler compilation, even though it does on C compilation. + This creates security issues if assembler code is enabled; the + work-around is to set it by default in the flags for $(CCAS) + Work around compilers that don't support declaration of const data. Some + compilers fault 'extern const' data declarations (because the data is + not initialized); this turns on const-ness only for compilers where + this is known to work. + +Version 1.5.7beta04 [November 17, 2011] + Since the gcc driver does not recognize the --noexecstack flag, we must + use the -Wa prefix to have it passed through to the assembler. + Also removed a duplicate setting of this flag. + Added files that were omitted from the libpng-1.5.7beta03 zip distribution. + +Version 1.5.7beta05 [November 25, 2011] + Removed "zTXt" from warning in generic chunk decompression function. + Validate time settings passed to pngset() and png_convert_to_rfc1123() + (Frank Busse). + Added MINGW support to CMakeLists.txt + Reject invalid compression flag or method when reading the iTXt chunk. + Backed out 'simplified' API changes. The API seems too complex and there + is a lack of consensus or enthusiasm for the proposals. The API also + reveals significant bugs inside libpng (double gamma correction and the + known bug of being unable to retrieve a corrected palette). It seems + better to wait until the bugs, at least, are corrected. + Moved pngvalid.c into contrib/libtests + Rebuilt Makefile.in, configure, etc., with autoconf-2.68 + +Version 1.5.7rc01 [December 1, 2011] + Replaced an "#if" with "#ifdef" in pngrtran.c + Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else) + +Version 1.5.7rc02 [December 5, 2011] + Revised project files and contrib/pngvalid/pngvalid.c to account for + the relocation of pngvalid into contrib/libtests. + Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400, + as in libpng-1.5.4. + Put CRLF line endings in the owatcom project files. + +Version 1.5.7rc03 [December 7, 2011] + Updated CMakeLists.txt to account for the relocation of pngvalid.c + +Version 1.5.7 [December 15, 2011] + Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings + reported by earlier versions. + +Version 1.5.8beta01 [January 15, 2011] + Removed '#include config.h"' from contrib/libtests/pngvalid.c. It's not + needed and causes trouble for VPATH building. + Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper + location in configure.ac (Gilles Espinasse). + Fix bug in pngerror.c: some long warnings were being improperly truncated + (CVE-2011-3464, bug introduced in libpng-1.5.3beta05). + +Version 1.5.8rc01 [January 21, 2012] + No changes. + +Version 1.5.8rc02 [January 25, 2012] + Fixed Min/GW uninstall to remove libpng.dll.a + Conditionalize the install rules for MINGW and CYGWIN in CMakeLists.txt + +Version 1.5.8 [February 1, 2012] + No changes. + +Version 1.5.9beta01 [February 3, 2012] + Rebuilt configure scripts in the tar distributions. + +Version 1.5.9beta02 [February 16, 2012] + Removed two unused definitions from scripts/pnglibconf.h.prebuilt + Removed some unused arrays (with #ifdef) from png_read_push_finish_row(). + Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h + +Version 1.5.9rc01 [February 17, 2012] + Fixed CVE-2011-3026 buffer overrun bug. This bug was introduced when + iCCP chunk support was added at libpng-1.0.6. Deal more correctly with the + test on iCCP chunk length. Also removed spurious casts that may hide + problems on 16-bit systems. + +Version 1.5.9 [February 18, 2012] + No changes. + +Version 1.5.10beta01 [February 24, 2012] + Removed two useless #ifdef directives from pngread.c and one from pngrutil.c + Always put the CMAKE_LIBRARY in "lib" (removed special WIN32 case). + Removed empty vstudio/pngstest directory (Clifford Yapp). + Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from + pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c; + now that png_ptr->buffer is inaccessible to applications, the special + handling is no longer useful. + Fixed bug with png_handle_hIST with odd chunk length (Frank Busse). + Added PNG_SAFE_LIMITS feature to pnglibconf.dfa and code in pngconf.h + to reset the user limits to safe ones if PNG_SAFE_LIMITS is defined. + To enable, use "CPPFLAGS=-DPNG_SAFE_LIMITS_SUPPORTED" on the configure + command or put "#define PNG_SAFE_LIMITS_SUPPORTED" in pnglibconf.h. + Revised the SAFE_LIMITS feature to be the same as the feature in libpng16. + Added information about the new limits in the manual. + +Version 1.5.10beta02 [February 27, 2012] + Updated Makefile.in + +Version 1.5.10beta03 [March 6, 2012] + Removed unused "current_text" members of png_struct and the png_free() + of png_ptr->current_text from pngread.c + Added palette-index checking. Issue a png_warning() if an invalid index is + found. + +Version 1.5.10beta04 [March 10, 2012] + Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition. + Fixed CMF optimization of non-IDAT compressed chunks, which was added at + libpng-1.5.4. It sometimes produced too small of a window. + +Version 1.5.10beta05 [March 10, 2012] + Reject all iCCP chunks after the first, even if the first one is invalid. + Issue a png_benign_error() instead of png_warning() about bad palette index. + Fixed an off-by-one error in the palette index checking function. + Revised example.c to put text strings in a temporary character array + instead of directly assigning string constants to png_textp members. + This avoids compiler warnings when -Wwrite-strings is enabled. + +Version 1.5.10 [March 29, 2012] + Prevent PNG_EXPAND+PNG_SHIFT doing the shift twice. + Revised png_set_text_2() to avoid potential memory corruption (fixes + CVE-2011-3048). + Send comments/corrections/commendations to png-mng-implement at lists.sf.net (subscription required; visit https://lists.sourceforge.net/lists/listinfo/png-mng-implement @@ -3249,5 +3861,4 @@ to subscribe) or to glennrp at users.sourceforge.net Glenn R-P -*/ } #endif diff --git a/png/CMakeLists.txt b/png/CMakeLists.txt index 8cd41114f..b5117891d 100644 --- a/png/CMakeLists.txt +++ b/png/CMakeLists.txt @@ -1,35 +1,344 @@ -project(FLTKPNG) -include_regular_expression("^png.*[.][c|h]$") +# CMakeLists.txt -include_directories(${FLTKZLIB_SOURCE_DIR}) +# Copyright (C) 2007-2011 Glenn Randers-Pehrson + +# This code is released under the libpng license. +# For conditions of distribution and use, see the disclaimer +# and license in png.h + +cmake_minimum_required(VERSION 2.4.4) +set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true) + +if(UNIX AND NOT DEFINED CMAKE_BUILD_TYPE) + if(CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION EQUAL 4) + # workaround CMake 2.4.x bug + set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING + "Choose the type of build, options are: + None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) + Debug + Release + RelWithDebInfo + MinSizeRel.") + else() + set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING + "Choose the type of build, options are: + None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) + Debug + Release + RelWithDebInfo + MinSizeRel.") + endif() +endif() + +project(libpng C) +enable_testing() + +set(PNGLIB_MAJOR 1) +set(PNGLIB_MINOR 5) +set(PNGLIB_RELEASE 10) +set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR}) +set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE}) + +# needed packages +find_package(ZLIB REQUIRED) include_directories(${ZLIB_INCLUDE_DIR}) -include_directories(${FLTKPNG_SOURCE_DIR}) -include_directories(${FLTKPNG_BINARY_DIR}) +if(NOT WIN32) + find_library(M_LIBRARY + NAMES m + PATHS /usr/lib /usr/local/lib + ) + if(NOT M_LIBRARY) + message(STATUS + "math library 'libm' not found - floating point support disabled") + endif() +else() + # not needed on windows + set(M_LIBRARY "") +endif() + +# COMMAND LINE OPTIONS +if(DEFINED PNG_SHARED) + option(PNG_SHARED "Build shared lib" ${PNG_SHARED}) +else() + option(PNG_SHARED "Build shared lib" ON) +endif() +if(DEFINED PNG_STATIC) + option(PNG_STATIC "Build static lib" ${PNG_STATIC}) +else() + option(PNG_STATIC "Build static lib" ON) +endif() + +option(PNG_TESTS "Build libpng tests" YES) -# source files for png -set(PNG_SRCS - pngget.c pngrio.c pngwrite.c - png.c pngmem.c pngrtran.c pngtrans.c pngwtran.c - pngerror.c pngpread.c pngrutil.c pngwutil.c - pngread.c pngset.c pngwio.c +# Many more configuration options could be added here +option(PNG_DEBUG "Build with debug output" NO) +option(PNGARG "Disable ANSI-C prototypes" NO) + +# SET LIBNAME +set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR}) + +# to distinguish between debug and release lib +set(CMAKE_DEBUG_POSTFIX "d") + +# Use the prebuilt pnglibconf.h file from the scripts folder +# TODO: fix this by building with awk; without this no cmake build can be +# configured directly (to do so indirectly use your local awk to build a +# pnglibconf.h in the build directory.) +configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt + ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h) +include_directories(${CMAKE_CURRENT_BINARY_DIR}) + +# OUR SOURCES +set(libpng_public_hdrs + png.h + pngconf.h + ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h +) +set(libpng_sources + ${libpng_public_hdrs} + pngdebug.h + pnginfo.h + pngpriv.h + pngstruct.h + png.c + pngerror.c + pngget.c + pngmem.c + pngpread.c + pngread.c + pngrio.c + pngrtran.c + pngrutil.c + pngset.c + pngtrans.c + pngwio.c + pngwrite.c + pngwtran.c + pngwutil.c +) +set(pngtest_sources + pngtest.c ) +set(pngvalid_sources + contrib/libtests/pngvalid.c +) +# SOME NEEDED DEFINITIONS -####################################################################### -add_library(fltk_png ${PNG_SRCS}) +add_definitions(-DPNG_CONFIGURE_LIBPNG) if(MSVC) - set_target_properties(fltk_png PROPERTIES OUTPUT_NAME fltkpng) - if(OPTION_LARGE_FILE) - set_target_properties(fltk_png PROPERTIES LINK_FLAGS /LARGEADDRESSAWARE) - endif(OPTION_LARGE_FILE) -else() - set_target_properties(fltk_png PROPERTIES OUTPUT_NAME fltk_png) + add_definitions(-D_CRT_SECURE_NO_DEPRECATE) endif(MSVC) -target_link_libraries(fltk_png ${FLTK_ZLIB_LIBRARIES}) +if(PNG_DEBUG) + add_definitions(-DPNG_DEBUG) +endif() + +# NOW BUILD OUR TARGET +include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR}) + +if(PNG_SHARED) + add_library(${PNG_LIB_NAME} SHARED ${libpng_sources}) + if(MSVC) + # msvc does not append 'lib' - do it here to have consistent name + set_target_properties(${PNG_LIB_NAME} PROPERTIES PREFIX "lib") + set_target_properties(${PNG_LIB_NAME} PROPERTIES IMPORT_PREFIX "lib") + endif() + target_link_libraries(${PNG_LIB_NAME} ${ZLIB_LIBRARY} ${M_LIBRARY}) +endif() + +if(PNG_STATIC) +# does not work without changing name + set(PNG_LIB_NAME_STATIC ${PNG_LIB_NAME}_static) + add_library(${PNG_LIB_NAME_STATIC} STATIC ${libpng_sources}) + if(MSVC) + # msvc does not append 'lib' - do it here to have consistent name + set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES PREFIX "lib") + endif() + target_link_libraries(${PNG_LIB_NAME_STATIC} ${ZLIB_LIBRARY} ${M_LIBRARY}) +endif() + +if(PNG_SHARED AND WIN32) + set_target_properties(${PNG_LIB_NAME} PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL) +endif() + +if(PNG_TESTS AND PNG_SHARED) + # does not work with msvc due to png_lib_ver issue + add_executable(pngtest ${pngtest_sources}) + target_link_libraries(pngtest ${PNG_LIB_NAME}) + add_test(pngtest ./pngtest ${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png) + # + add_executable(pngvalid ${pngvalid_sources}) + target_link_libraries(pngvalid ${PNG_LIB_NAME}) + add_test(pngvalid ./pngvalid) +endif() + +# Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set +IF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY) + SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib") +ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY) + +# Set a variable with CMake code which: +# Creates a symlink from src to dest (if possible) or alternatively +# copies if different. +macro(CREATE_SYMLINK SRC_FILE DEST_FILE) + FILE(REMOVE ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}) + if(WIN32 AND NOT CYGWIN AND NOT MINGW) + ADD_CUSTOM_COMMAND( + OUTPUT ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE} + COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_BINARY_DIR}/${SRC_FILE} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} + COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_BINARY_DIR}/${SRC_FILE} ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE} + DEPENDS ${PNG_LIB_NAME} ${PNG_LIB_NAME_STATIC} + ) + ADD_CUSTOM_TARGET(${DEST_FILE}_COPY ALL DEPENDS ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}) + else(WIN32 AND NOT CYGWIN AND NOT MINGW) + execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${SRC_FILE} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}) + execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${SRC_FILE} ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}) + endif(WIN32 AND NOT CYGWIN AND NOT MINGW) +endmacro() + +# libpng is a library so default to 'lib' +if(NOT DEFINED CMAKE_INSTALL_LIBDIR) + set(CMAKE_INSTALL_LIBDIR lib) +endif(NOT DEFINED CMAKE_INSTALL_LIBDIR) + +# CREATE PKGCONFIG FILES +# we use the same files like ./configure, so we have to set its vars +# Only do this on Windows for Cygwin - the files don't make much sense outside +# a UNIX look alike +if(NOT WIN32 OR CYGWIN OR MINGW) + set(prefix ${CMAKE_INSTALL_PREFIX}) + set(exec_prefix ${CMAKE_INSTALL_PREFIX}) + set(libdir ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}) + set(includedir ${CMAKE_INSTALL_PREFIX}/include) + set(LIBS "-lz -lm") + configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in + ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY) + CREATE_SYMLINK(${PNGLIB_NAME}.pc libpng.pc) + + configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in + ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY) + CREATE_SYMLINK(${PNGLIB_NAME}-config libpng-config) +endif(NOT WIN32 OR CYGWIN OR MINGW) + +# SET UP LINKS +if(PNG_SHARED) + set_target_properties(${PNG_LIB_NAME} PROPERTIES +# VERSION 15.${PNGLIB_RELEASE}.1.5.10 + VERSION 15.${PNGLIB_RELEASE}.0 + SOVERSION 15 + CLEAN_DIRECT_OUTPUT 1) +endif() +if(PNG_STATIC) + # MSVC doesn't use a different file extension for shared vs. static + # libs. We are able to change OUTPUT_NAME to remove the _static + # for all other platforms. + if(NOT MSVC) + set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES + OUTPUT_NAME ${PNG_LIB_NAME} + CLEAN_DIRECT_OUTPUT 1) + endif() +endif() + +# If CMake > 2.4.x, we set a variable used below to export +# targets to an export file. +# TODO: Use VERSION_GREATER after our cmake_minimum_required >= 2.6.2 +if(CMAKE_MAJOR_VERSION GREATER 1 AND CMAKE_MINOR_VERSION GREATER 4) + set(PNG_EXPORT_RULE EXPORT libpng) +elseif(CMAKE_MAJOR_VERSION GREATER 2) # future proof + set(PNG_EXPORT_RULE EXPORT libpng) +endif() + +# INSTALL +if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL ) + if(PNG_SHARED) + install(TARGETS ${PNG_LIB_NAME} + ${PNG_EXPORT_RULE} + RUNTIME DESTINATION bin + LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR} + ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}) + + # Create a symlink for libpng.dll.a => libpng15.dll.a on Cygwin + if(CYGWIN OR MINGW) + get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE}) + get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME) + CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}) + install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} + DESTINATION ${CMAKE_INSTALL_LIBDIR}) + endif(CYGWIN OR MINGW) + + if(NOT WIN32) + get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE}) + get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME) + CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_SHARED_LIBRARY_SUFFIX}) + install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX} + DESTINATION ${CMAKE_INSTALL_LIBDIR}) + endif(NOT WIN32) + endif(PNG_SHARED) + + if(PNG_STATIC) + install(TARGETS ${PNG_LIB_NAME_STATIC} + ${PNG_EXPORT_RULE} + LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR} + ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}) + if(NOT WIN32 OR CYGWIN OR MINGW) + get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME_STATIC} LOCATION_${CMAKE_BUILD_TYPE}) + get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME) + CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_STATIC_LIBRARY_SUFFIX}) + install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX} + DESTINATION ${CMAKE_INSTALL_LIBDIR}) + endif(NOT WIN32 OR CYGWIN OR MINGW) + endif() +endif() + +if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL ) + install(FILES ${libpng_public_hdrs} DESTINATION include) + install(FILES ${libpng_public_hdrs} DESTINATION include/${PNGLIB_NAME}) +endif() +if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL ) + if(NOT WIN32 OR CYGWIN OR MINGW) + install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin) + install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config + DESTINATION bin) + endif(NOT WIN32 OR CYGWIN OR MINGW) +endif() + +if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL ) + # Install man pages + if(NOT PNG_MAN_DIR) + set(PNG_MAN_DIR "share/man") + endif() + install(FILES libpng.3 libpngpf.3 DESTINATION ${PNG_MAN_DIR}/man3) + install(FILES png.5 DESTINATION ${PNG_MAN_DIR}/man5) + # Install pkg-config files + if(NOT WIN32 OR CYGWIN OR MINGW) + install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc + DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig) + install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config + DESTINATION bin) + install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc + DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig) + install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config + DESTINATION bin) + endif(NOT WIN32 OR CYGWIN OR MINGW) +endif() + +# On versions of CMake that support it, create an export file CMake +# users can include() to import our targets +if(PNG_EXPORT_RULE AND NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL ) + install(EXPORT libpng DESTINATION lib/libpng FILE lib${PNG_LIB_NAME}.cmake) +endif() + +# what's with libpng-$VER%.txt and all the extra files? + +# UNINSTALL +# do we need this? + +# DIST +# do we need this? + +# to create msvc import lib for mingw compiled shared lib +# pexports libpng.dll > libpng.def +# lib /def:libpng.def /machine:x86 -install(TARGETS fltk_png - EXPORT fltk-install - DESTINATION ${PREFIX_LIB} -) diff --git a/png/LICENSE b/png/LICENSE index b28f15c74..b72d1258e 100644 --- a/png/LICENSE +++ b/png/LICENSE @@ -10,7 +10,7 @@ this sentence. This code is released under the libpng license. -libpng versions 1.2.6, August 15, 2004, through 1.5.1, February 3, 2011, are +libpng versions 1.2.6, August 15, 2004, through 1.5.10, March 29, 2012, are Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are distributed according to the same disclaimer and license as libpng-1.2.5 with the following individual added to the list of Contributing Authors @@ -108,4 +108,4 @@ certification mark of the Open Source Initiative. Glenn Randers-Pehrson glennrp at users.sourceforge.net -February 3, 2011 +March 29, 2012 diff --git a/png/README b/png/README index 9dd6745f0..e821ee4c8 100644 --- a/png/README +++ b/png/README @@ -1,4 +1,4 @@ -README for libpng version 1.5.1 - February 3, 2011 (shared library 15.0) +README for libpng version 1.5.10 - March 29, 2012 (shared library 15.0) See the note about version numbers near the top of png.h See INSTALL for instructions on how to install libpng. @@ -114,19 +114,16 @@ given in previous versions of this document. He and Andreas will read mail addressed to the png-implement list, however. Please do not send general questions about PNG. Send them to -the (png-list at ccrc.wustl.edu, subscription required, write to -majordomo at ccrc.wustl.edu with "subscribe png-list" in your message). -On the other hand, -please do not send libpng questions to that address, send them to me -or to the png-implement list. I'll -get them in the end anyway. If you have a question about something +png-mng-misc at lists.sf.net (subscription required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-misc to +subscribe). If you have a question about something in the PNG specification that is related to using libpng, send it to me. Send me any questions that start with "I was using libpng, and ...". If in doubt, send questions to me. I'll bounce them to others, if necessary. Please do not send suggestions on how to change PNG. We have -been discussing PNG for nine years now, and it is official and +been discussing PNG for sixteen years now, and it is official and finished. If you have suggestions for libpng, however, I'll gladly listen. Even if your suggestion is not used immediately, it may be used later. diff --git a/png/libpng-manual.txt b/png/libpng-manual.txt index 77adf7aec..d55e80a00 100644 --- a/png/libpng-manual.txt +++ b/png/libpng-manual.txt @@ -1,6 +1,6 @@ libpng-manual.txt - A description on how to use and modify libpng - libpng version 1.5.1 - February 3, 2011 + libpng version 1.5.10 - March 29, 2012 Updated and distributed by Glenn Randers-Pehrson <glennrp at users.sourceforge.net> Copyright (c) 1998-2011 Glenn Randers-Pehrson @@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng Based on: - libpng versions 0.97, January 1998, through 1.5.1 - February 3, 2011 + libpng versions 0.97, January 1998, through 1.5.10 - March 29, 2012 Updated and distributed by Glenn Randers-Pehrson Copyright (c) 1998-2011 Glenn Randers-Pehrson @@ -107,7 +107,8 @@ PNG file. At one time, the fields of png_info were intended to be directly accessible to the user. However, this tended to cause problems with applications using dynamically loaded libraries, and as a result a set of interface functions for png_info (the png_get_*() and png_set_*() -functions) was developed. +functions) was developed, and direct access to the png_info fields was +deprecated.. The png_struct structure is the object used by the library to decode a single image. As of 1.5.0 this structure is also not exposed. @@ -116,14 +117,23 @@ Almost all libpng APIs require a pointer to a png_struct as the first argument. Many (in particular the png_set and png_get APIs) also require a pointer to png_info as the second argument. Some application visible macros defined in png.h designed for basic data access (reading and writing -integers in the PNG format) break this rule, but it's almost always safe -to assume that a (png_struct*) has to be passed to call an API function. +integers in the PNG format) don't take a png_info pointer, but it's almost +always safe to assume that a (png_struct*) has to be passed to call an API +function. + +You can have more than one png_info structure associated with an image, +as illustrated in pngtest.c, one for information valid prior to the +IDAT chunks and another (called "end_info" below) for things after them. The png.h header file is an invaluable reference for programming with libpng. And while I'm on the topic, make sure you include the libpng header file: #include <png.h> +and also (as of libpng-1.5.0) the zlib header file, if you need it: + +#include <zlib.h> + Types The png.h header file defines a number of integral types used by the @@ -137,9 +147,9 @@ the value by multiplying by 100,000. As of libpng 1.5.0 a convenience macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point) which is simply (png_int_32). -All APIs that take (double) arguments also have an matching API that +All APIs that take (double) arguments also have a matching API that takes the corresponding fixed point integer arguments. The fixed point -API has the same name as the floating point one with _fixed appended. +API has the same name as the floating point one with "_fixed" appended. The actual range of values permitted in the APIs is frequently less than the full range of (png_fixed_point) (-21474 to +21474). When APIs require a non-negative argument the type is recorded as png_uint_32 above. Consult @@ -157,6 +167,10 @@ preprocessing directives of the form: #ifdef PNG_feature_SUPPORTED declare-function #endif + ... + #ifdef PNG_feature_SUPPORTED + use-function + #endif The library can be built without support for these APIs, although a standard build will have all implemented APIs. Application programs @@ -165,7 +179,7 @@ portability. From libpng 1.5.0 the feature macros set during the build of libpng are recorded in the header file "pnglibconf.h" and this file is always included by png.h. -If you don't need to change the library configuration from the default skip to +If you don't need to change the library configuration from the default, skip to the next section ("Reading"). Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all @@ -197,24 +211,25 @@ A variety of methods exist to build libpng. Not all of these support reconfiguration of pnglibconf.h. To reconfigure pnglibconf.h it must either be rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand. -Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt and changing -the lines defining the supported features, paying very close attention to the -'option' information in scripts/pnglibconf.dfa that describes those features and -their requirements. This is easy to get wrong. +Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt to +pnglibconf.h and changing the lines defining the supported features, paying +very close attention to the 'option' information in scripts/pnglibconf.dfa +that describes those features and their requirements. This is easy to get +wrong. B. Configuration using DFA_XTRA Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later variant such as 'nawk' or 'gawk', is available. The configure build will automatically find an appropriate awk and build pnglibconf.h. -scripts/pnglibconf.mak contains a set of make rules for doing the same thing if -configure is not used, and many of the makefiles in the scripts directory use -this approach. +The scripts/pnglibconf.mak file contains a set of make rules for doing the +same thing if configure is not used, and many of the makefiles in the scripts +directory use this approach. -When rebuilding simply write new file containing changed options and set +When rebuilding simply write a new file containing changed options and set DFA_XTRA to the name of this file. This causes the build to append the new file -to the end of scripts/pnglibconf.dfa. pngusr.dfa should contain lines of the -following forms: +to the end of scripts/pnglibconf.dfa. The pngusr.dfa file should contain lines +of the following forms: everything = off @@ -238,12 +253,16 @@ source code. Most of these values have performance implications for the library but most of them have no visible effect on the API. Some can also be overridden from the API. +This method of building a customized pnglibconf.h is illustrated in +contrib/pngminim/*. See the "$(PNGCONF):" target in the makefile and +pngusr.dfa in these directories. + C. Configuration using PNG_USR_CONFIG If -DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file pngusr.h will automatically be included before the options in -scripts/pnglibconf.dfa are processed. pngusr.h should contain only macro -definitions turning features on or off or setting settings. +scripts/pnglibconf.dfa are processed. Your pngusr.h file should contain only +macro definitions turning features on or off or setting settings. Apart from the global setting "everything = off" all the options listed above can be set using macros in pngusr.h: @@ -274,6 +293,9 @@ examine the intermediate file pnglibconf.dfn to find the full set of dependency information for each setting and option. Simply locate the feature in the file and read the C comments that precede it. +This method is also illustrated in the contrib/pngminim/* makefiles and +pngusr.h. + III. Reading We'll now walk you through the possible functions to call when reading @@ -348,21 +370,12 @@ create the structure, so your application should check for that. return (ERROR); } - png_infop end_info = png_create_info_struct(png_ptr); - - if (!end_info) - { - png_destroy_read_struct(&png_ptr, &info_ptr, - (png_infopp)NULL); - return (ERROR); - } - If you want to use your own memory allocation routines, use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use png_create_read_struct_2() instead of png_create_read_struct(): png_structp png_ptr = png_create_read_struct_2 - (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, user_error_fn, user_warning_fn, (png_voidp) user_mem_ptr, user_malloc_fn, user_free_fn); @@ -374,7 +387,7 @@ handling and memory alloc/free functions. When libpng encounters an error, it expects to longjmp back to your routine. Therefore, you will need to call setjmp and pass your png_jmpbuf(png_ptr). If you read the file from different -routines, you will need to update the jmpbuf field every time you enter +routines, you will need to update the longjmp buffer every time you enter a new routine that will call a png_*() function. See your documentation of setjmp/longjmp for your compiler for more @@ -392,6 +405,9 @@ free any memory. return (ERROR); } +Pass (png_infopp)NULL instead of &end_info if you didn't create +an end_info structure. + If you would rather avoid the complexity of setjmp/longjmp issues, you can compile libpng with PNG_NO_SETJMP, in which case errors will result in a call to PNG_ABORT() which defaults to abort(). @@ -513,6 +529,19 @@ To inform libpng about your function, use png_set_read_status_fn(png_ptr, read_row_callback); +When this function is called the row has already been completely processed and +the 'row' and 'pass' refer to the next row to be handled. For the +non-interlaced case the row that was just handled is simply one less than the +passed in row number, and pass will always be 0. For the interlaced case the +same applies unless the row value is 0, in which case the row just handled was +the last one from one of the preceding passes. Because interlacing may skip a +pass you cannot be sure that the preceding pass is just 'pass-1', if you really +need to know what the last pass is record (row,pass) from the callback and use +the last recorded value each time. + +As with the user transform you can find the output row using the +PNG_ROW_FROM_PASS_ROW macro. + Unknown-chunk handling Now you get to set the way the library processes unknown chunks in the @@ -550,6 +579,8 @@ according to the "keep" directive. If a chunk is named in successive instances of png_set_keep_unknown_chunks(), the final instance will take precedence. The IHDR and IEND chunks should not be named in chunk_list; if they are, libpng will process them normally anyway. +If you know that your application will never make use of some particular +chunks, use PNG_HANDLE_CHUNK_NEVER (or 1) as demonstrated below. Here is an example of the usage of png_set_keep_unknown_chunks(), where the private "vpAg" chunk will later be processed by a user chunk @@ -590,7 +621,7 @@ large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns. Since very few applications really need to process such large images, we have imposed an arbitrary 1-million limit on rows and columns. Larger images will be rejected immediately with a png_error() call. If -you wish to override this limit, you can use +you wish to change this limit, you can use png_set_user_limits(png_ptr, width_max, height_max); @@ -600,6 +631,10 @@ anyway because of potential buffer overflow conditions). You should put this statement after you create the PNG structure and before calling png_read_info(), png_read_png(), or png_process_data(). + +When writing a PNG datastream, put this statement before calling +png_write_info() or png_write_png(). + If you need to retrieve the limits that are being applied, use width_max = png_get_user_width_max(png_ptr); @@ -630,6 +665,242 @@ and you can retrieve the limit with Any chunks that would cause either of these limits to be exceeded will be ignored. +Information about your system + +If you intend to display the PNG or to incorporate it in other image data you +need to tell libpng information about your display or drawing surface so that +libpng can convert the values in the image to match the display. + +From libpng-1.5.4 this information can be set before reading the PNG file +header. In earlier versions png_set_gamma() existed but behaved incorrectly if +called before the PNG file header had been read and png_set_alpha_mode() did not +exist. + +If you need to support versions prior to libpng-1.5.4 test the version number +as illustrated below using "PNG_LIBPNG_VER >= 10504" and follow the procedures +described in the appropriate manual page. + +You give libpng the encoding expected by your system expressed as a 'gamma' +value. You can also specify a default encoding for the PNG file in +case the required information is missing from the file. By default libpng +assumes that the PNG data matches your system, to keep this default call: + + png_set_gamma(png_ptr, screen_gamma, 1/screen_gamma/*file gamma*/); + +or you can use the fixed point equivalent: + + png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma); + +If you don't know the gamma for your system it is probably 2.2 - a good +approximation to the IEC standard for display systems (sRGB). If images are +too contrasty or washed out you got the value wrong - check your system +documentation! + +Many systems permit the system gamma to be changed via a lookup table in the +display driver, a few systems, including older Macs, change the response by +default. As of 1.5.4 three special values are available to handle common +situations: + + PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1 + standard. This matches almost all systems. + PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6) + Apple Macintosh system with the default settings. + PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the + system expects data with no gamma encoding. + +You would use the linear (unencoded) value if you need to process the pixel +values further because this avoids the need to decode and reencode each +component value whenever arithmetic is performed. A lot of graphics software +uses linear values for this reason, often with higher precision component values +to preserve overall accuracy. + +The second thing you may need to tell libpng about is how your system handles +alpha channel information. Some, but not all, PNG files contain an alpha +channel. To display these files correctly you need to compose the data onto a +suitable background, as described in the PNG specification. + +Libpng only supports composing onto a single color (using png_set_background; +see below). Otherwise you must do the composition yourself and, in this case, +you may need to call png_set_alpha_mode: + +#if PNG_LIBPNG_VER >= 10504 + png_set_alpha_mode(png_ptr, mode, screen_gamma); +#else + png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma); +#endif + +The screen_gamma value is the same as the argument to png_set_gamma; however, +how it affects the output depends on the mode. png_set_alpha_mode() sets the +file gamma default to 1/screen_gamma, so normally you don't need to call +png_set_gamma. If you need different defaults call png_set_gamma() before +png_set_alpha_mode() - if you call it after it will override the settings made +by png_set_alpha_mode(). + +The mode is as follows: + + PNG_ALPHA_PNG: The data is encoded according to the PNG specification. Red, +green and blue, or gray, components are gamma encoded color +values and are not premultiplied by the alpha value. The +alpha value is a linear measure of the contribution of the +pixel to the corresponding final output pixel. + +You should normally use this format if you intend to perform +color correction on the color values; most, maybe all, color +correction software has no handling for the alpha channel and, +anyway, the math to handle pre-multiplied component values is +unnecessarily complex. + +Before you do any arithmetic on the component values you need +to remove the gamma encoding and multiply out the alpha +channel. See the PNG specification for more detail. It is +important to note that when an image with an alpha channel is +scaled, linear encoded, pre-multiplied component values must +be used! + +The remaining modes assume you don't need to do any further color correction or +that if you do, your color correction software knows all about alpha (it +probably doesn't!) + + PNG_ALPHA_STANDARD: The data libpng produces +is encoded in the standard way +assumed by most correctly written graphics software. +The gamma encoding will be removed by libpng and the +linear component values will be pre-multiplied by the +alpha channel. + +With this format the final image must be re-encoded to +match the display gamma before the image is displayed. +If your system doesn't do that, yet still seems to +perform arithmetic on the pixels without decoding them, +it is broken - check out the modes below. + +With PNG_ALPHA_STANDARD libpng always produces linear +component values, whatever screen_gamma you supply. The +screen_gamma value is, however, used as a default for +the file gamma if the PNG file has no gamma information. + +If you call png_set_gamma() after png_set_alpha_mode() you +will override the linear encoding. Instead the +pre-multiplied pixel values will be gamma encoded but +the alpha channel will still be linear. This may +actually match the requirements of some broken software, +but it is unlikely. + +While linear 8-bit data is often used it has +insufficient precision for any image with a reasonable +dynamic range. To avoid problems, and if your software +supports it, use png_set_expand_16() to force all +components to 16 bits. + + PNG_ALPHA_OPTIMIZED: This mode is the same +as PNG_ALPHA_STANDARD except that +completely opaque pixels are gamma encoded according to +the screen_gamma value. Pixels with alpha less than 1.0 +will still have linear components. + +Use this format if you have control over your +compositing software and do don't do other arithmetic +(such as scaling) on the data you get from libpng. Your +compositing software can simply copy opaque pixels to +the output but still has linear values for the +non-opaque pixels. + +In normal compositing, where the alpha channel encodes +partial pixel coverage (as opposed to broad area +translucency), the inaccuracies of the 8-bit +representation of non-opaque pixels are irrelevant. + +You can also try this format if your software is broken; +it might look better. + + PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD; +however, all component values, +including the alpha channel are gamma encoded. This is +an appropriate format to try if your software, or more +likely hardware, is totally broken, i.e., if it performs +linear arithmetic directly on gamma encoded values. + +In most cases of broken software or hardware the bug in the final display +manifests as a subtle halo around composited parts of the image. You may not +even perceive this as a halo; the composited part of the image may simply appear +separate from the background, as though it had been cut out of paper and pasted +on afterward. + +If you don't have to deal with bugs in software or hardware, or if you can fix +them, there are three recommended ways of using png_set_alpha_mode(): + + png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG, + screen_gamma); + +You can do color correction on the result (libpng does not currently +support color correction internally). When you handle the alpha channel +you need to undo the gamma encoding and multiply out the alpha. + + png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD, + screen_gamma); + png_set_expand_16(png_ptr); + +If you are using the high level interface, don't call png_set_expand_16(); +instead pass PNG_TRANSFORM_EXPAND_16 to the interface. + +With this mode you can't do color correction, but you can do arithmetic, +including composition and scaling, on the data without further processing. + + png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED, + screen_gamma); + +You can avoid the expansion to 16-bit components with this mode, but you +lose the ability to scale the image or perform other linear arithmetic. +All you can do is compose the result onto a matching output. Since this +mode is libpng-specific you also need to write your own composition +software. + +If you don't need, or can't handle, the alpha channel you can call +png_set_background() to remove it by compositing against a fixed color. Don't +call png_set_strip_alpha() to do this - it will leave spurious pixel values in +transparent parts of this image. + + png_set_background(png_ptr, &background_color, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1); + +The background_color is an RGB or grayscale value according to the data format +libpng will produce for you. Because you don't yet know the format of the PNG +file, if you call png_set_background at this point you must arrange for the +format produced by libpng to always have 8-bit or 16-bit components and then +store the color as an 8-bit or 16-bit color as appropriate. The color contains +separate gray and RGB component values, so you can let libpng produce gray or +RGB output according to the input format, but low bit depth grayscale images +must always be converted to at least 8-bit format. (Even though low bit depth +grayscale images can't have an alpha channel they can have a transparent +color!) + +You set the transforms you need later, either as flags to the high level +interface or libpng API calls for the low level interface. For reference the +settings and API calls required are: + +8-bit values: + PNG_TRANSFORM_SCALE_16 | PNG_EXPAND + png_set_expand(png_ptr); png_set_scale_16(png_ptr); + + If you must get exactly the same inaccurate results + produced by default in versions prior to libpng-1.5.4, + use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr) + instead. + +16-bit values: + PNG_TRANSFORM_EXPAND_16 + png_set_expand_16(png_ptr); + +In either case palette image data will be expanded to RGB. If you just want +color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr) +to the list. + +Calling png_set_background before the PNG file header is read will not work +prior to libpng-1.5.4. Because the failure may result in unexpected warnings or +errors it is therefore much safer to call png_set_background after the head has +been read. Unfortunately this means that prior to libpng-1.5.4 it cannot be +used with the high level interface. + The high-level read interface At this point there are two ways to proceed; through the high-level @@ -639,8 +910,10 @@ the entire image into memory, and (b) the input transformations you want to do are limited to the following set: PNG_TRANSFORM_IDENTITY No transformation - PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to - 8 bits + PNG_TRANSFORM_SCALE_16 Strip 16-bit samples to + 8-bit accurately + PNG_TRANSFORM_STRIP_16 Chop 16-bit samples to + 8-bit less accurately PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit samples to bytes @@ -659,6 +932,7 @@ you want to do are limited to the following set: PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples to RGB (or GA to RGBA) + PNG_TRANSFORM_EXPAND_16 Expand samples to 16 bits (This excludes setting a background color, doing gamma transformation, quantizing, and setting filler.) If this is the case, simply do this: @@ -727,6 +1001,22 @@ call to png_read_info(). This will process all chunks up to but not including the image data. +This also copies some of the data from the PNG file into the decode structure +for use in later transformations. Important information copied in is: + +1) The PNG file gamma from the gAMA chunk. This overwrites the default value +provided by an earlier call to png_set_gamma or png_set_alpha_mode. + +2) Prior to libpng-1.5.4 the background color from a bKGd chunk. This +damages the information provided by an earlier call to png_set_background +resulting in unexpected behavior. Libpng-1.5.4 no longer does this. + +3) The number of significant bits in each component value. Libpng uses this to +optimize gamma handling by reducing the internal lookup table sizes. + +4) The transparent color information from a tRNS chunk. This can be modified by +a later call to png_set_tRNS. + Querying the info structure Functions are used to get the information from the info_ptr once it @@ -857,6 +1147,28 @@ pointer into the info_ptr is returned for any complex types. int_file_gamma - 100,000 times the gamma at which the file is written + png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x, &red_y, + &green_x, &green_y, &blue_x, &blue_y) + png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, &green_X, + &green_Y, &green_Z, &blue_X, &blue_Y, &blue_Z) + png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, &int_white_y, + &int_red_x, &int_red_y, &int_green_x, &int_green_y, + &int_blue_x, &int_blue_y) + png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y, + &int_red_Z, &int_green_X, &int_green_Y, &int_green_Z, + &int_blue_X, &int_blue_Y, &int_blue_Z) + + {white,red,green,blue}_{x,y} + A color space encoding specified using the chromaticities + of the end points and the white point. (PNG_INFO_cHRM) + + {red,green,blue}_{X,Y,Z} + A color space encoding specified using the encoding end + points - the CIE tristimulus specification of the intended + color of the red, green and blue channels in the PNG RGB + data. The white point is simply the sum of the three end + points. (PNG_INFO_cHRM) + png_get_sRGB(png_ptr, info_ptr, &srgb_intent); file_srgb_intent - the rendering intent (PNG_INFO_sRGB) @@ -915,7 +1227,8 @@ pointer into the info_ptr is returned for any complex types. png_get_bKGD(png_ptr, info_ptr, &background); - background - background color (PNG_VALID_bKGD) + background - background color (of type + png_color_16p) (PNG_VALID_bKGD) valid 16-bit red, green and blue values, regardless of color_type @@ -952,8 +1265,13 @@ pointer into the info_ptr is returned for any complex types. (empty string for unknown). Note that the itxt_length, lang, and lang_key - members of the text_ptr structure only exist - when the library is built with iTXt chunk support. + members of the text_ptr structure only exist when the + library is built with iTXt chunk support. Prior to + libpng-1.4.0 the library was built by default without + iTXt support. Also note that when iTXt is supported, + they contain NULL pointers when the "compression" + field contains PNG_TEXT_COMPRESSION_NONE or + PNG_TEXT_COMPRESSION_zTXt. num_text - number of comments (same as num_comments; you can put NULL here @@ -978,10 +1296,10 @@ pointer into the info_ptr is returned for any complex types. &unit_type); offset_x - positive offset from the left edge - of the screen + of the screen (can be negative) offset_y - positive offset from the top edge - of the screen + of the screen (can be negative) unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER @@ -1013,6 +1331,7 @@ pointer into the info_ptr is returned for any complex types. unit - physical scale units (an integer) width - width of a pixel in physical scale units + (expressed as a string) height - height of a pixel in physical scale units (width and height are strings like "2.54") @@ -1035,6 +1354,12 @@ pointer into the info_ptr is returned for any complex types. chunks were read from the PNG file or inserted with the png_set_unknown_chunks() function. + The value of "location" is a bitwise "or" of + + PNG_HAVE_IHDR (0x01) + PNG_HAVE_PLTE (0x02) + PNG_AFTER_IDAT (0x08) + The data from the pHYs chunk can be retrieved in several convenient forms: @@ -1069,7 +1394,7 @@ forms: 72 dpi is stored as 0.28346 pixels/meter, and when this is retrieved it is 71.9988 dpi, so be sure to round the returned value appropriately - if you want to display a reasonable-looking result. + if you want to display a reasonable-looking result. The data from the oFFs chunk can be retrieved in several convenient forms: @@ -1090,7 +1415,7 @@ forms: converted to microns and back without some loss of precision. -For more information, see the png_info definition in png.h and the +For more information, see the PNG specification for chunk contents. Be careful with trusting rowbytes, as some of the transformations could increase the space needed to hold a row (expand, filler, gray_to_rgb, etc.). @@ -1125,17 +1450,20 @@ to handle any special transformations of the image data. The various ways to transform the data will be described in the order that they should occur. This is important, as some of these change the color type and/or bit depth of the data, and some others only work on -certain color types and bit depths. Even though each transformation -checks to see if it has data that it can do something with, you should -make sure to only enable a transformation if it will be valid for the -data. For example, don't swap red and blue on grayscale data. +certain color types and bit depths. + +Transformations you request are ignored if they don't have any meaning for a +particular input data format. However some transformations can have an effect +as a result of a previous transformation. If you specify a contradictory set of +transformations, for example both adding and removing the alpha channel, you +cannot predict the final result. -The colors used for the background and transparency values should be -supplied in the same format/depth as the current image data. They -are stored in the same format/depth as the image data in a bKGD or tRNS -chunk, so this is what libpng expects for this data. The colors are -transformed to keep in sync with the image data when an application -calls the png_read_update_info() routine (see below). +The color used for the transparency values should be supplied in the same +format/depth as the current image data. It is stored in the same format/depth +as the image data in a tRNS chunk, so this is what libpng expects for this data. + +The color used for the background value depends on the need_expand argument as +described below. Data will be decoded into the supplied row buffers packed into bytes unless the library has been told to transform it into another format. @@ -1145,12 +1473,12 @@ byte, unless png_set_packing() is called. 8-bit RGB data will be stored in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha() is called to insert filler bytes, either before or after each RGB triplet. 16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant -byte of the color value first, unless png_set_strip_16() is called to +byte of the color value first, unless png_set_scale_16() is called to transform it to regular RGB RGB triplets, or png_set_filler() or png_set_add alpha() is called to insert filler bytes, either before or after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can -be modified with -png_set_filler(), png_set_add_alpha(), or png_set_strip_16(). +be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(), +or png_set_scale_16(). The following code transforms grayscale images of less than 8 to 8 bits, changes paletted images to RGB, and adds a full alpha channel if there is @@ -1161,13 +1489,13 @@ viewing application that wishes to treat all images in the same way. if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_palette_to_rgb(png_ptr); - if (color_type == PNG_COLOR_TYPE_GRAY && - bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); - if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr); -These three functions are actually aliases for png_set_expand(), added + if (color_type == PNG_COLOR_TYPE_GRAY && + bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); + +The first two functions are actually aliases for png_set_expand(), added in libpng version 1.0.4, with the function names expanded to improve code readability. In some future version they may actually do different things. @@ -1175,56 +1503,91 @@ things. As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was added. It expands the sample depth without changing tRNS to alpha. -As of libpng version 1.5.1, not all possible expansions are supported. +As of libpng version 1.5.2, png_set_expand_16() was added. It behaves as +png_set_expand(); however, the resultant channels have 16 bits rather than 8. +Use this when the output color or gray channels are made linear to avoid fairly +severe accuracy loss. + + if (bit_depth < 16) + png_set_expand_16(png_ptr); + +PNG can have files with 16 bits per channel. If you only can handle +8 bits per channel, this will strip the pixels down to 8-bit. + + if (bit_depth == 16) +#if PNG_LIBPNG_VER >= 10504 + png_set_scale_16(png_ptr); +#else + png_set_strip_16(png_ptr); +#endif + +(The more accurate "png_set_scale_16()" API became available in libpng version +1.5.4). + +If you need to process the alpha channel on the image separately from the image +data (for example if you convert it to a bitmap mask) it is possible to have +libpng strip the channel leaving just RGB or gray data: + + if (color_type & PNG_COLOR_MASK_ALPHA) + png_set_strip_alpha(png_ptr); + +If you strip the alpha channel you need to find some other way of dealing with +the information. If, instead, you want to convert the image to an opaque +version with no alpha channel use png_set_background; see below. + +As of libpng version 1.5.2, almost all useful expansions are supported, the +major ommissions are conversion of grayscale to indexed images (which can be +done trivially in the application) and conversion of indexed to grayscale (which +can be done by a trivial manipulation of the palette.) In the following table, the 01 means grayscale with depth<8, 31 means indexed with depth<8, other numerals represent the color type, "T" means the tRNS chunk is present, A means an alpha channel is present, and O means tRNS or alpha is present but all pixels in the image are opaque. - FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O + FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O TO - 01 - - 31 - - 0 1 - - 0T - - 0O - - 2 GX - - 2T - - 2O - - 3 1 - - 3T - - 3O - - 4A T - - 4O - - 6A GX TX TX - - 6O GX TX - + 01 - [G] - - - - - - - - - - - - - + 31 [Q] Q [Q] [Q] [Q] Q Q Q Q Q Q [Q] [Q] Q Q + 0 1 G + . . G G G G G G B B GB GB + 0T lt Gt t + . Gt G G Gt G G Bt Bt GBt GBt + 0O lt Gt t . + Gt Gt G Gt Gt G Bt Bt GBt GBt + 2 C P C C C + . . C - - CB CB B B + 2T Ct - Ct C C t + t - - - CBt CBt Bt Bt + 2O Ct - Ct C C t t + - - - CBt CBt Bt Bt + 3 [Q] p [Q] [Q] [Q] Q Q Q + . . [Q] [Q] Q Q + 3T [Qt] p [Qt][Q] [Q] Qt Qt Qt t + t [Qt][Qt] Qt Qt + 3O [Qt] p [Qt][Q] [Q] Qt Qt Qt t t + [Qt][Qt] Qt Qt + 4A lA G A T T GA GT GT GA GT GT + BA G GBA + 4O lA GBA A T T GA GT GT GA GT GT BA + GBA G + 6A CA PA CA C C A T tT PA P P C CBA + BA + 6O CA PBA CA C C A tT T PA P P CBA C BA + Within the matrix, + "+" identifies entries where 'from' and 'to' are the same. "-" means the transformation is not supported. + "." means nothing is necessary (a tRNS chunk can just be ignored). + "t" means the transformation is obtained by png_set_tRNS. + "A" means the transformation is obtained by png_set_add_alpha(). "X" means the transformation is obtained by png_set_expand(). "1" means the transformation is obtained by - png_set_expand_gray_1_2_4_to_8 - "G" means the transformation is obtained by - png_set_gray_to_rgb(). + png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() if there + is no transparency in the original or the final format). + "C" means the transformation is obtained by png_set_gray_to_rgb(). + "G" means the transformation is obtained by png_set_rgb_to_gray(). "P" means the transformation is obtained by png_set_expand_palette_to_rgb(). - "T" means the transformation is obtained by - png_set_tRNS_to_alpha(). - -PNG can have files with 16 bits per channel. If you only can handle -8 bits per channel, this will strip the pixels down to 8 bit. - - if (bit_depth == 16) - png_set_strip_16(png_ptr); - -If, for some reason, you don't need the alpha channel on an image, -and you want to remove it rather than combining it with the background -(but the image author certainly had in mind that you *would* combine -it with the background, so that's what you should probably do): - - if (color_type & PNG_COLOR_MASK_ALPHA) - png_set_strip_alpha(png_ptr); + "p" means the transformation is obtained by png_set_packing(). + "Q" means the transformation is obtained by png_set_quantize(). + "T" means the transformation is obtained by png_set_tRNS_to_alpha(). + "B" means the transformation is obtained by png_set_background(), or + png_strip_alpha(). + +When an entry has multiple transforms listed all are required to cause the +right overall transformation. When two transforms are separated by a comma +either will do the job. When transforms are enclosed in [] the transform should +do the job but this is currently unimplemented - a different format will result +if the suggested transformations are used. In PNG files, the alpha channel in an image is the level of opacity. If you need the alpha channel in an image to @@ -1303,8 +1666,8 @@ with alpha. if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) - png_set_rgb_to_gray_fixed(png_ptr, error_action, - int red_weight, int green_weight); + png_set_rgb_to_gray(png_ptr, error_action, double red_weight, + double green_weight); error_action = 1: silently do the conversion @@ -1317,122 +1680,98 @@ with alpha. image has any pixel where red != green or red != blue - red_weight: weight of red component times 100000 + red_weight: weight of red component - green_weight: weight of green component times 100000 + green_weight: weight of green component If either weight is negative, default - weights (21268, 71514) are used. + weights are used. + +In the corresponding fixed point API the red_weight and green_weight values are +simply scaled by 100,000: + + png_set_rgb_to_gray(png_ptr, error_action, png_fixed_point red_weight, + png_fixed_point green_weight); If you have set error_action = 1 or 2, you can later check whether the image really was gray, after processing the image rows, with the png_get_rgb_to_gray_status(png_ptr) function. It will return a png_byte that is zero if the image was gray or -1 if there were any non-gray pixels. bKGD and sBIT data +1 if there were any non-gray pixels. Background and sBIT data will be silently converted to grayscale, using the green channel -data, regardless of the error_action setting. +data for sBIT, regardless of the error_action setting. -With red_weight+green_weight<=100000, -the normalized graylevel is computed: +The default values come from the PNG file cHRM chunk if present; otherwise, the +defaults correspond to the ITU-R recommendation 709, and also the sRGB color +space, as recommended in the Charles Poynton's Colour FAQ, +<http://www.poynton.com/>, in section 9: - int rw = red_weight * 65536; - int gw = green_weight * 65536; - int bw = 65536 - (rw + gw); - gray = (rw*red + gw*green + bw*blue)/65536; + <http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9> -The default values approximate those recommended in the Charles -Poynton's Color FAQ, <http://www.inforamp.net/~poynton/> -Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net> + Y = 0.2126 * R + 0.7152 * G + 0.0722 * B + +Previous versions of this document, 1998 through 2002, recommended a slightly +different formula: Y = 0.212671 * R + 0.715160 * G + 0.072169 * B -Libpng approximates this with integers scaled by 32768: +Libpng uses an integer approximation: Y = (6968 * R + 23434 * G + 2366 * B)/32768 The calculation is done in a linear colorspace, if the image gamma can be determined. -If you have a grayscale and you are using png_set_expand_depth(), -png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to -a higher bit-depth, you must either supply the background color as a gray -value at the original file bit-depth (need_expand = 1) or else supply the -background color as an RGB triplet at the final, expanded bit depth -(need_expand = 0). Similarly, if you are reading a paletted image, you -must either supply the background color as a palette index (need_expand = 1) -or as an RGB triplet that may or may not be in the palette (need_expand = 0). +The png_set_background() function has been described already; it tells libpng to +composite images with alpha or simple transparency against the supplied +background color. For compatibility with versions of libpng earlier than +libpng-1.5.4 it is recommended that you call the function after reading the file +header, even if you don't want to use the color in a bKGD chunk, if one exists. + +If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), +you may use this color, or supply another color more suitable for +the current display (e.g., the background color from a web page). You +need to tell libpng how the color is represented, both the format of the +component values in the color (the number of bits) and the gamma encoding of the +color. The function takes two arguments, background_gamma_mode and need_expand +to convey this information, however only two combinations are likely to be +useful: png_color_16 my_background; png_color_16p image_background; if (png_get_bKGD(png_ptr, info_ptr, &image_background)) png_set_background(png_ptr, image_background, - PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); + PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1); else png_set_background(png_ptr, &my_background, - PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); - -The png_set_background() function tells libpng to composite images -with alpha or simple transparency against the supplied background -color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), -you may use this color, or supply another color more suitable for -the current display (e.g., the background color from a web page). You -need to tell libpng whether the color is in the gamma space of the -display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file -(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one -that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't -know why anyone would use this, but it's here). - -To properly display PNG images on any kind of system, the application needs -to know what the display gamma is. Ideally, the user will know this, and -the application will allow them to set it. One method of allowing the user -to set the display gamma separately for each system is to check for a -SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be -correctly set. - -Note that display_gamma is the overall gamma correction required to produce -pleasing results, which depends on the lighting conditions in the surrounding -environment. In a dim or brightly lit room, no compensation other than -the physical gamma exponent of the monitor is needed, while in a dark room -a slightly smaller exponent is better. - - double gamma, screen_gamma; - - if (/* We have a user-defined screen - gamma value */) - { - screen_gamma = user_defined_screen_gamma; - } - - /* One way that applications can share the same - screen gamma value */ - else if ((gamma_str = getenv("SCREEN_GAMMA")) - != NULL) - { - screen_gamma = (double)atof(gamma_str); - } - - /* If we don't have another value */ - else - { - screen_gamma = 2.2; /* A good guess for a - PC monitor in a bright office or a dim room */ - - screen_gamma = 2.0; /* A good guess for a - PC monitor in a dark room */ - - screen_gamma = 1.7 or 1.0; /* A good - guess for Mac systems */ - } - -The functions png_set_gamma() and its fixed point equivalent -png_set_gamma_fixed() handle gamma transformations of the data. -Pass both the file gamma and the current screen_gamma. If the file does -not have a gamma value, you can pass one anyway if you have an idea what -it is (usually 0.45455 is a good guess for GIF images on PCs). Note -that file gammas are inverted from screen gammas. See the discussions -on gamma in the PNG specification for an excellent description of what -gamma is, and why all applications should support it. It is strongly -recommended that PNG viewers support gamma correction. + PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1); + +The second call was described above - my_background is in the format of the +final, display, output produced by libpng. Because you now know the format of +the PNG it is possible to avoid the need to choose either 8-bit or 16-bit +output and to retain palette images (the palette colors will be modified +appropriately and the tRNS chunk removed.) However, if you are doing this, +take great care not to ask for transformations without checking first that +they apply! + +In the first call the background color has the original bit depth and color type +of the PNG file. So, for palette images the color is supplied as a palette +index and for low bit greyscale images the color is a reduced bit value in +image_background->gray. + +If you didn't call png_set_gamma() before reading the file header, for example +if you need your code to remain compatible with older versions of libpng prior +to libpng-1.5.4, this is the place to call it. + +Do not call it if you called png_set_alpha_mode(); doing so will damage the +settings put in place by png_set_alpha_mode(). (If png_set_alpha_mode() is +supported then you can certainly do png_set_gamma() before reading the PNG +header.) + +This API unconditionally sets the screen and file gamma values, so it will +override the value in the PNG file unless it is called before the PNG file +reading starts. For this reason you must always call it with the PNG file +value when you call it in this position: if (png_get_gAMA(png_ptr, info_ptr, &file_gamma)) png_set_gamma(png_ptr, screen_gamma, file_gamma); @@ -1445,9 +1784,9 @@ file has more entries then will fit on your screen, png_set_quantize() will do that. Note that this is a simple match quantization that merely finds the closest color available. This should work fairly well with optimized palettes, but fairly badly with linear color cubes. If you -pass a palette that is larger then maximum_colors, the file will +pass a palette that is larger than maximum_colors, the file will reduce the number of colors in the palette so it will fit into -maximum_colors. If there is a histogram, it will use it to make +maximum_colors. If there is a histogram, libpng will use it to make more intelligent choices when reducing the palette. If there is no histogram, it may not do as good a job. @@ -1488,7 +1827,7 @@ This function can also be used to invert grayscale and gray-alpha images: color_type == PNG_COLOR_TYPE_GRAY_ALPHA) png_set_invert_mono(png_ptr); -PNG files store 16 bit pixels in network byte order (big-endian, +PNG files store 16-bit pixels in network byte order (big-endian, ie. most significant bits first). This code changes the storage to the other way (little-endian, i.e. least significant bits first, the way PCs store them): @@ -1511,7 +1850,7 @@ with You must supply the function - void read_transform_fn(png_structp png_ptr, row_info_ptr + void read_transform_fn(png_structp png_ptr, png_row_infop row_info, png_bytep data) See pngtest.c for a working example. Your function will be called @@ -1519,7 +1858,7 @@ after all of the other transformations have been processed. Take care with interlaced images if you do the interlace yourself - the width of the row is the width in 'row_info', not the overall image width. -If supported libpng provides two information routines that you can use to find +If supported, libpng provides two information routines that you can use to find where you are in processing the image: png_get_current_pass_number(png_structp png_ptr); @@ -1530,6 +1869,14 @@ supported if user transforms are supported, secondly they may well return unexpected results unless the row is actually being processed at the moment they are called. +With interlaced +images the value returned is the row in the input sub-image image. Use +PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to +find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass). + +The discussion of interlace handling above contains more information on how to +use these values. + You can also set up a pointer to a user structure for use by your callback function, and you can inform libpng that your transform function will change the number of channels or bit depth with the @@ -1555,13 +1902,16 @@ of the interlaced image. After setting the transformations, libpng can update your png_info structure to reflect any transformations you've requested with this -call. This is most useful to update the info structure's rowbytes -field so you can use it to allocate your image memory. This function -will also update your palette with the correct screen_gamma and -background if these have been given with the calls above. +call. png_read_update_info(png_ptr, info_ptr); +This is most useful to update the info structure's rowbytes +field so you can use it to allocate your image memory. This function +will also update your palette with the correct screen_gamma and +background if these have been given with the calls above. You may +only call png_read_update_info() once with a particular info_ptr. + After you call png_read_update_info(), you can allocate any memory you need to hold the image. The row data is simply raw byte data for all forms of images. As the actual allocation @@ -1570,7 +1920,7 @@ are allocating one large chunk, you will need to build an array of pointers to each row, as it will be needed for some of the functions below. -Remember: Before you call png_read_update_info(), the png_get_ +Remember: Before you call png_read_update_info(), the png_get_*() functions return the values corresponding to the original PNG image. After you call png_read_update_info the values refer to the image that libpng will output. Consequently you must call all the png_set_ @@ -1762,7 +2112,7 @@ to load the whole file into memory when it is interlaced. libpng includes a test program, pngvalid, that illustrates reading and writing of interlaced images. If you can't get interlacing to work in your -code and don't want to leave it to libpng (the recommended approach) see +code and don't want to leave it to libpng (the recommended approach), see how pngvalid.c does it. Finishing a sequential read @@ -1772,15 +2122,39 @@ low-level interface, you can finish reading the file. If you are interested in comments or time, which may be stored either before or after the image data, you should pass the separate png_info struct if you want to keep the comments from before and after the image -separate. If you are not interested, you can pass NULL. +separate. + + png_infop end_info = png_create_info_struct(png_ptr); + + if (!end_info) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return (ERROR); + } png_read_end(png_ptr, end_info); +If you are not interested, you should still call png_read_end() +but you can pass NULL, avoiding the need to create an end_info structure. + + png_read_end(png_ptr, (png_infop)NULL); + +If you don't call png_read_end(), then your file pointer will be +left pointing to the first chunk after the last IDAT, which is probably +not what you want if you expect to read something beyond the end of +the PNG datastream. + When you are done, you can free all memory allocated by libpng like this: png_destroy_read_struct(&png_ptr, &info_ptr, &end_info); +or, if you didn't create an end_info structure, + + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + It is also possible to individually free the info_ptr members that point to libpng-allocated storage with the following function: @@ -2183,6 +2557,20 @@ To inform libpng about your function, use png_set_write_status_fn(png_ptr, write_row_callback); +When this function is called the row has already been completely processed and +it has also been written out. The 'row' and 'pass' refer to the next row to be +handled. For the +non-interlaced case the row that was just handled is simply one less than the +passed in row number, and pass will always be 0. For the interlaced case the +same applies unless the row value is 0, in which case the row just handled was +the last one from one of the preceding passes. Because interlacing may skip a +pass you cannot be sure that the preceding pass is just 'pass-1', if you really +need to know what the last pass is record (row,pass) from the callback and use +the last recorded value each time. + +As with the user transform you can find the output row using the +PNG_ROW_FROM_PASS_ROW macro. + You now have the option of modifying how the compression library will run. The following functions are mainly for testing, but may be useful in some cases, like if you need to write PNG files extremely fast and @@ -2227,11 +2615,13 @@ which changes how much time zlib spends on trying to compress the image data. See the Compression Library (zlib.h and algorithm.txt, distributed with zlib) for details on the compression levels. - /* set the zlib compression level */ + #include zlib.h + + /* Set the zlib compression level */ png_set_compression_level(png_ptr, Z_BEST_COMPRESSION); - /* set other zlib parameters */ + /* Set other zlib parameters for compressing IDAT */ png_set_compression_mem_level(png_ptr, 8); png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY); @@ -2239,7 +2629,15 @@ with zlib) for details on the compression levels. png_set_compression_method(png_ptr, 8); png_set_compression_buffer_size(png_ptr, 8192) -extern PNG_EXPORT(void,png_set_zbuf_size) + /* Set zlib parameters for text compression + * If you don't call these, the parameters + * fall back on those defined for IDAT chunks + */ + png_set_text_compression_mem_level(png_ptr, 8); + png_set_text_compression_strategy(png_ptr, + Z_DEFAULT_STRATEGY); + png_set_text_compression_window_bits(png_ptr, 15); + png_set_text_compression_method(png_ptr, 8); Setting the contents of info for output @@ -2327,6 +2725,28 @@ width, height, bit_depth, and color_type must be the same in each call. int_file_gamma - 100,000 times the gamma at which the image was created + png_set_cHRM(png_ptr, info_ptr, white_x, white_y, red_x, red_y, + green_x, green_y, blue_x, blue_y) + png_set_cHRM_XYZ(png_ptr, info_ptr, red_X, red_Y, red_Z, green_X, + green_Y, green_Z, blue_X, blue_Y, blue_Z) + png_set_cHRM_fixed(png_ptr, info_ptr, int_white_x, int_white_y, + int_red_x, int_red_y, int_green_x, int_green_y, + int_blue_x, int_blue_y) + png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, int_red_X, int_red_Y, + int_red_Z, int_green_X, int_green_Y, int_green_Z, + int_blue_X, int_blue_Y, int_blue_Z) + + {white,red,green,blue}_{x,y} + A color space encoding specified using the chromaticities + of the end points and the white point. + + {red,green,blue}_{X,Y,Z} + A color space encoding specified using the encoding end + points - the CIE tristimulus specification of the intended + color of the red, green and blue channels in the PNG RGB + data. The white point is simply the sum of the three end + points. + png_set_sRGB(png_ptr, info_ptr, srgb_intent); srgb_intent - the rendering intent @@ -2387,14 +2807,14 @@ width, height, bit_depth, and color_type must be the same in each call. trans_alpha - array of alpha (transparency) entries for palette (PNG_INFO_tRNS) + num_trans - number of transparent entries + (PNG_INFO_tRNS) + trans_color - graylevel or color sample values (in order red, green, blue) of the single transparent color for non-paletted images (PNG_INFO_tRNS) - num_trans - number of transparent entries - (PNG_INFO_tRNS) - png_set_hIST(png_ptr, info_ptr, hist); hist - histogram of palette (array of @@ -2407,7 +2827,8 @@ width, height, bit_depth, and color_type must be the same in each call. png_set_bKGD(png_ptr, info_ptr, background); - background - background color (PNG_VALID_bKGD) + background - background color (of type + png_color_16p) (PNG_VALID_bKGD) png_set_text(png_ptr, info_ptr, text_ptr, num_text); @@ -2431,9 +2852,15 @@ width, height, bit_depth, and color_type must be the same in each call. empty for unknown). text_ptr[i].translated_keyword - keyword in UTF-8 (NULL or empty for unknown). + Note that the itxt_length, lang, and lang_key - members of the text_ptr structure only exist - when the library is built with iTXt chunk support. + members of the text_ptr structure only exist when the + library is built with iTXt chunk support. Prior to + libpng-1.4.0 the library was built by default without + iTXt support. Also note that when iTXt is supported, + they contain NULL pointers when the "compression" + field contains PNG_TEXT_COMPRESSION_NONE or + PNG_TEXT_COMPRESSION_zTXt. num_text - number of comments @@ -2483,6 +2910,7 @@ width, height, bit_depth, and color_type must be the same in each call. unit - physical scale units (an integer) width - width of a pixel in physical scale units + expressed as a string height - height of a pixel in physical scale units (width and height are strings like "2.54") @@ -2524,7 +2952,7 @@ Because tEXt and zTXt chunks don't have a language field, if you specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt any language code or translated keyword will not be written out. -Until text gets around 1000 bytes, it is not worth compressing it. +Until text gets around a few hundred bytes, it is not worth compressing it. After the text has been written out to the file, the compression type is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR, so that it isn't written out again at the end (in case you are calling @@ -2745,7 +3173,7 @@ is required by PNG. png_set_shift(png_ptr, &sig_bit); -PNG files store 16 bit pixels in network byte order (big-endian, +PNG files store 16-bit pixels in network byte order (big-endian, ie. most significant bits first). This code would be used if they are supplied the other way (little-endian, i.e. least significant bits first, the way PCs store them): @@ -2779,8 +3207,8 @@ with You must supply the function - void write_transform_fn(png_structp png_ptr ptr, - row_info_ptr row_info, png_bytep data) + void write_transform_fn(png_structp png_ptr, png_row_infop + row_info, png_bytep data) See pngtest.c for a working example. Your function will be called before any of the other transformations are processed. If supported @@ -2788,9 +3216,15 @@ libpng also supplies an information routine that may be called from your callback: png_get_current_row_number(png_ptr); + png_get_current_pass_number(png_ptr); -This returns the current row passed to the transform. Even with interlaced -images the value returned is the row in the final output image. +This returns the current row passed to the transform. With interlaced +images the value returned is the row in the input sub-image image. Use +PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to +find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass). + +The discussion of interlace handling above contains more information on how to +use these values. You can also set up a pointer to a user structure for use by your callback function. @@ -3128,7 +3562,8 @@ However, there are some uncertainties about the status of local variables after a longjmp, so the user may want to be careful about doing anything after setjmp returns non-zero besides returning itself. Consult your compiler documentation for more details. For an alternative approach, you -may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net). +may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net), +which is illustrated in pngvalid.c and in contrib/visupng. Custom chunks @@ -3146,8 +3581,11 @@ and look at how other chunks were designed, so you can do things similarly. Second, check out the sections of libpng that read and write chunks. Try to find a chunk that is similar to yours and use it as a template. More details can be found in the comments inside -the code. It is best to handle unknown chunks in a generic method, -via callback functions, instead of by modifying libpng functions. +the code. It is best to handle private or unknown chunks in a generic method, +via callback functions, instead of by modifying libpng functions. This +is illustrated in pngtest.c, which uses a callback function to handle a +private "vpAg" chunk and the new "sTER" chunk, which are both unknown to +libpng. If you wish to write your own transformation for the data, look through the part of the code that does the transformations, and check out some of @@ -3155,7 +3593,7 @@ the simpler ones to get an idea of how they work. Try to find a similar transformation to the one you want to add and copy off of it. More details can be found in the comments inside the code itself. -Configuring for 16 bit platforms +Configuring for 16-bit platforms You will want to look into zconf.h to tell zlib (and thus libpng) that it cannot allocate more then 64K at a time. Even if you can, the memory @@ -3175,8 +3613,8 @@ defined, and FAR gets defined to far in pngconf.h, and you should be all set. Everything in the library (except for zlib's structure) is expecting far data. You must use the typedefs with the p or pp on the end for pointers (or at least look at them and be careful). Make -note that the rows of data are defined as png_bytepp, which is an -unsigned char far * far *. +note that the rows of data are defined as png_bytepp, which is +an "unsigned char far * far *". Configuring for gui/windowing platforms: @@ -3194,7 +3632,10 @@ or delete an include, this is the place to do it. The includes that are not needed outside libpng are placed in pngpriv.h, which is only used by the routines inside libpng itself. The files in libpng proper only include pngpriv.h and png.h, which -in turn includes pngconf.h. +in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h. +As of libpng-1.5.0, pngpriv.h also includes three other private header +files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material +that previously appeared in the public headers. Configuring zlib: @@ -3210,6 +3651,7 @@ specify no compression (Z_NO_COMPRESSION = 0), but this would create files larger than just storing the raw bitmap. You can specify the compression level by calling: + #include zlib.h png_set_compression_level(png_ptr, level); Another useful one is to reduce the memory level used by the library. @@ -3220,12 +3662,14 @@ other things, lower levels will result in sections of incompressible data being emitted in smaller stored blocks, with a correspondingly larger relative overhead of up to 15% in the worst case. + #include zlib.h png_set_compression_mem_level(png_ptr, level); The other functions are for configuring zlib. They are not recommended for normal use and may result in writing an invalid PNG file. See zlib.h for more information on what these mean. + #include zlib.h png_set_compression_strategy(png_ptr, strategy); @@ -3233,8 +3677,28 @@ zlib.h for more information on what these mean. window_bits); png_set_compression_method(png_ptr, method); + png_set_compression_buffer_size(png_ptr, size); +As of libpng version 1.5.4, additional APIs became +available to set these separately for non-IDAT +compressed chunks such as zTXt, iTXt, and iCCP: + + #include zlib.h + #if PNG_LIBPNG_VER <= 10504 + png_set_text_compression_level(png_ptr, level); + + png_set_text_compression_mem_level(png_ptr, level); + + png_set_text_compression_strategy(png_ptr, + strategy); + + png_set_text_compression_window_bits(png_ptr, + window_bits); + + png_set_text_compression_method(png_ptr, method); + #endif + Controlling row filtering If you want to control whether libpng uses filtering or not, which @@ -3340,8 +3804,8 @@ capability, which you'll still have). All the reading and writing specific code are in separate files, so the linker should only grab the files it needs. However, if you want to make sure, or if you are building a stand alone library, all the -reading files start with pngr and all the writing files start with -pngw. The files that don't match either (like png.c, pngtrans.c, etc.) +reading files start with "pngr" and all the writing files start with "pngw". +The files that don't match either (like png.c, pngtrans.c, etc.) are used for both reading and writing, and always need to be included. The progressive reader is in pngpread.c @@ -3460,6 +3924,9 @@ The number libpng_vn is constructed from the major version, minor version with leading zero, and release number with leading zero, (e.g., libpng_vn for version 1.0.7 is 10007). +Note that this function does not take a png_ptr, so you can call it +before you've created one. + You can also check which version of png.h you used when compiling your application: @@ -3623,12 +4090,12 @@ and memset(), respectively. The function png_set_gray_1_2_4_to_8() was removed. It has been deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with png_set_expand_gray_1_2_4_to_8() because the former function also -expanded palette images. +expanded any tRNS chunk to an alpha channel. Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32 were added and are used by default instead of the corresponding functions. Unfortunately, -from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. We changed the prototype for png_malloc() from @@ -3658,7 +4125,8 @@ The png_zalloc() function no longer zeroes out the memory that it allocates. Support for dithering was disabled by default in libpng-1.4.0, because -been well tested and doesn't actually "dither". The code was not +it has not been well tested and doesn't actually "dither". +The code was not removed, however, and could be enabled by building libpng with PNG_READ_DITHER_SUPPORTED defined. In libpng-1.4.2, this support was reenabled, but the function was renamed png_set_quantize() to @@ -3671,9 +4139,19 @@ We removed the trailing '.' from the warning and error messages. X. Changes to Libpng from version 1.4.x to 1.5.x -From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. +Checking for invalid palette index on read or write was added at libpng +1.5.10. When an invalid index is found, libpng issues a benign error. +This is enabled by default but can be disabled in each png_ptr with + + png_set_check_for_invalid_index(png_ptr, allowed); + + allowed - one of + 0: disable + 1: enable + A. Changes that affect users of libpng There are no substantial API changes between the non-deprecated parts of @@ -3695,10 +4173,9 @@ In png_get_iCCP, the type of "profile" was changed from png_charpp to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep. There are changes of form in png.h, including new and changed macros to -declare -parts of the API. Some API functions with arguments that are pointers to -data not modified within the function have been corrected to declare -these arguments with PNG_CONST. +declare parts of the API. Some API functions with arguments that are +pointers to data not modified within the function have been corrected to +declare these arguments with PNG_CONST. Much of the internal use of C macros to control the library build has also changed and some of this is visible in the exported header files, in @@ -3708,7 +4185,8 @@ application code. (It is extremely rare for an application to do this.) Any program that compiled against libpng 1.4 and did not use deprecated features or access internal library structures should compile and work -against libpng 1.5. +against libpng 1.5, except for the change in the prototype for +png_get_iCCP() and png_set_iCCP() API functions mentioned above. libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of interlaced images. The macros return the number of rows and columns in @@ -3716,10 +4194,10 @@ each pass and information that can be used to de-interlace and (if absolutely necessary) interlace an image. libpng 1.5.0 adds an API png_longjmp(png_ptr, value). This API calls -the application provided png_longjmp_ptr on the internal, but application -initialized, jmpbuf. It is provided as a convenience to avoid the need -to use the png_jmpbuf macro, which had the unnecessary side effect of -resetting the internal png_longjmp_ptr value. +the application-provided png_longjmp_ptr on the internal, but application +initialized, longjmp buffer. It is provided as a convenience to avoid +the need to use the png_jmpbuf macro, which had the unnecessary side +effect of resetting the internal png_longjmp_ptr value. libpng 1.5.0 includes a complete fixed point API. By default this is present along with the corresponding floating point API. In general the @@ -3762,7 +4240,7 @@ reset by pngusr.h or by explicit settings on the compiler command line. These settings may produce compiler warnings or errors in 1.5.0 because of macro redefinition. -From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. libpng 1.5.0 is consistent with the implementation in 1.4.5 and 1.2.x (where the macro did not exist.) @@ -3771,14 +4249,47 @@ Applications can now choose whether to use these macros or to call the corresponding function by defining PNG_USE_READ_MACROS or PNG_NO_USE_READ_MACROS before including png.h. Notice that this is only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0 - will lead to a link failure. +will lead to a link failure. + +Prior to libpng-1.5.4, the zlib compressor used the same set of parameters +when compressing the IDAT data and textual data such as zTXt and iCCP. +In libpng-1.5.4 we reinitialized the zlib stream for each type of data. +We added five png_set_text_*() functions for setting the parameters to +use with textual data. + +Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED +option was off by default, and slightly inaccurate scaling occurred. +This option can no longer be turned off, and the choice of accurate +or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8() +API for accurate scaling or the old png_set_strip_16_to_8() API for simple +chopping. + +Prior to libpng-1.5.4, the png_set_user_limits() function could only be +used to reduce the width and height limits from the value of +PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said +that it could be used to override them. Now this function will reduce or +increase the limits. + +Starting in libpng-1.5.10, the user limits can be set en masse with the +configuration option PNG_SAFE_LIMITS_SUPPORTED. If this option is enabled, +a set of "safe" limits is applied in pngpriv.h. These can be overridden by +application calls to png_set_user_limits(), png_set_user_chunk_cache_max(), +and/or png_set_user_malloc_max() that increase or decrease the limits. Also, +in libpng-1.5.10 the default width and height limits were increased +from 1,000,000 to 0x7ffffff (i.e., made unlimited). Therefore, the +limits are now + default safe + png_user_width_max 0x7fffffff 1,000,000 + png_user_height_max 0x7fffffff 1,000,000 + png_user_chunk_cache_max 0 (unlimited) 128 + png_user_chunk_malloc_max 0 (unlimited) 8,000,000 B. Changes to the build and configuration of libpng Details of internal changes to the library code can be found in the CHANGES -file. These will be of no concern to the vast majority of library users or -builders, however the few who configure libpng to a non-default feature -set may need to change how this is done. +file and in the GIT repository logs. These will be of no concern to the vast +majority of library users or builders, however the few who configure libpng +to a non-default feature set may need to change how this is done. There should be no need for library builders to alter build scripts if these use the distributed build support - configure or the makefiles - @@ -3787,14 +4298,14 @@ to build pnglibconf.h where the corresponding makefile does not do so. Building libpng with a non-default configuration has changed completely. The old method using pngusr.h should still work correctly even though the -way pngusr.h is used in the build has been changed, however library +way pngusr.h is used in the build has been changed; however, library builders will probably want to examine the changes to take advantage of new capabilities and to simplify their build system. B.1 Specific changes to library configuration capabilities The library now supports a complete fixed point implementation and can -thus be used on systems which have no floating point support or very +thus be used on systems that have no floating point support or very limited or slow support. Previously gamma correction, an essential part of complete PNG support, required reasonably fast floating point. @@ -3810,14 +4321,14 @@ pnglibconf.h As part of this the mechanism used to choose procedure call standards on those systems that allow a choice has been changed. At present this only affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems -running on Intel processors. As before PNGAPI is defined where required +running on Intel processors. As before, PNGAPI is defined where required to control the exported API functions; however, two new macros, PNGCBAPI and PNGCAPI, are used instead for callback functions (PNGCBAPI) and (PNGCAPI) for functions that must match a C library prototype (currently only png_longjmp_ptr, which must match the C longjmp function.) The new approach is documented in pngconf.h -Despite these changes libpng 1.5.0 only supports the native C function +Despite these changes, libpng 1.5.0 only supports the native C function calling standard on those platforms tested so far (__cdecl on Microsoft Windows). This is because the support requirements for alternative calling conventions seem to no longer exist. Developers who find it @@ -3850,8 +4361,10 @@ if the feature is supported or: /*#undef PNG_feature_SUPPORTED*/ if it is not. Library code consistently checks for the 'SUPPORTED' macro. -It does not, and should not, check for the 'NO' macro which will not -normally be defined even if the feature is not supported. +It does not, and libpng applications should not, check for the 'NO' macro +which will not normally be defined even if the feature is not supported. +The 'NO' macros are only used internally for setting or not setting the +corresponding 'SUPPORTED' macros. Compatibility with the old names is provided as follows: @@ -3908,10 +4421,10 @@ application built without PNG_USER_CONFIG defined would see the unmodified, default, libpng API and thus would probably fail to link. These mechanisms still work in the configure build and in any makefile -build that builds pnglibconf.h although the feature selection macros +build that builds pnglibconf.h, although the feature selection macros have changed somewhat as described above. In 1.5.0, however, pngusr.h is processed only once, when the exported header file pnglibconf.h is built. -pngconf.h no longer includes pngusr.h, therefore it is ignored after the +pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the build of pnglibconf.h and it is never included in an application build. The rarely used alternative of adding a list of feature macros to the @@ -3925,7 +4438,7 @@ scripts/pnglibconf.dfa. This requires the program awk. Brian Kernighan and all known later implementations (often called by subtly different names - nawk and gawk for example) are adequate to build pnglibconf.h. The Sun Microsystems (now Oracle) program 'awk' is an earlier version -and does not work, this may also apply to other systems that have a +and does not work; this may also apply to other systems that have a functioning awk called 'nawk'. Configuration options are now documented in scripts/pnglibconf.dfa. This @@ -3967,8 +4480,8 @@ the libpng bug tracker at We also accept patches built from the tar or zip distributions, and simple verbal discriptions of bug fixes, reported either to the -SourceForge bug tracker or to the png-mng-implement at lists.sf.net -mailing list. +SourceForge bug tracker, to the png-mng-implement at lists.sf.net +mailing list, or directly to glennrp. XIII. Coding style @@ -4056,8 +4569,8 @@ above the comment that says /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */ To avoid polluting the global namespace, the names of all exported -functions and variables begin with "png_", and all publicly visible C -preprocessor macros begin with "PNG_". We request that applications that +functions and variables begin with "png_", and all publicly visible C +preprocessor macros begin with "PNG". We request that applications that use libpng *not* begin any of their own symbols with either of these strings. We put a space after each comma and after each semicolon @@ -4073,6 +4586,9 @@ left parenthesis that follows it: We prefer #ifdef and #ifndef to #if defined() and if !defined() when there is only one macro being tested. +We prefer to express integers that are used as bit masks in hex format, +with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100). + We do not use the TAB character for indentation in the C sources. Lines do not exceed 80 characters. @@ -4081,13 +4597,13 @@ Other rules can be inferred by inspecting the libpng source. XIV. Y2K Compliance in libpng -February 3, 2011 +March 29, 2012 Since the PNG Development group is an ad-hoc body, we can't make an official declaration. This is your unofficial assurance that libpng from version 0.71 and -upward through 1.5.1 are Y2K compliant. It is my belief that earlier +upward through 1.5.10 are Y2K compliant. It is my belief that earlier versions were also Y2K compliant. Libpng only has three year fields. One is a 2-byte unsigned integer that diff --git a/png/libpng.3 b/png/libpng.3 index ecc42777b..bba25afa7 100644 --- a/png/libpng.3 +++ b/png/libpng.3 @@ -1,6 +1,6 @@ -.TH LIBPNG 3 "February 3, 2011" +.TH LIBPNG 3 "March 29, 2012" .SH NAME -libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 +libpng \- Portable Network Graphics (PNG) Reference Library 1.5.10 .SH SYNOPSIS \fI\fB @@ -128,10 +128,22 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 \fI\fB -\fBpng_uint_32 png_get_chunk_cache_max (png_const_structp \fIpng_ptr\fP\fB);\fP +\fBpng_uint_32 png_get_cHRM_XYZ (png_structp \fIpng_ptr, + +\fBpng_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*red_X\fP\fB, double \fP\fI*red_Y\fP\fB, double \fI*red_Z, + +\fBdouble \fP\fI*green_X\fP\fB, double \fP\fI*green_Y\fP\fB, double \fP\fI*green_Z\fP\fB, double \fI*blue_X, + +\fBdouble \fP\fI*blue_Y\fP\fB, double \fI*blue_Z\fP\fB);\fP \fI\fB +\fBpng_uint_32 png_get_cHRM_XYZ_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_fixed_point \fP\fI*int_red_X\fP\fB, png_fixed_point \fP\fI*int_red_Y\fP\fB, png_fixed_point \fP\fI*int_red_Z\fP\fB, png_fixed_point \fP\fI*int_green_X\fP\fB, png_fixed_point \fP\fI*int_green_Y\fP\fB, png_fixed_point \fP\fI*int_green_Z\fP\fB, png_fixed_point \fP\fI*int_blue_X\fP\fB, png_fixed_point \fP\fI*int_blue_Y\fP\fB, png_fixed_point \fI*int_blue_Z\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_chunk_cache_max (png_const_structp \fIpng_ptr\fP\fB);\fP + \fI\fB \fBpng_alloc_size_t png_get_chunk_malloc_max (png_const_structp \fIpng_ptr\fP\fB);\fP @@ -512,6 +524,14 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 \fI\fB +\fBvoid png_set_alpha_mode (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, double \fIoutput_gamma\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_alpha_mode_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, png_fixed_point \fIoutput_gamma\fP\fB);\fP + +\fI\fB + \fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP \fI\fB @@ -532,6 +552,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 \fI\fB +\fBvoid png_set_check_for_invalid_index(png_structrp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP + +\fI\fB + \fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP \fI\fB @@ -540,6 +564,16 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 \fI\fB +\fBvoid png_set_cHRM_XYZ (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIred_X\fP\fB, double \fP\fIred_Y\fP\fB, double \fP\fIred_Z\fP\fB, double \fP\fIgreen_X\fP\fB, double \fIgreen_Y, + +\fBdouble \fP\fIgreen_Z\fP\fB, double \fP\fIblue_X\fP\fB, double \fP\fIblue_Y\fP\fB, double \fIblue_Z\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_cHRM_XYZ_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_fixed_point \fP\fIint_red_X\fP\fB, png_fixed_point \fP\fIint_red_Y\fP\fB, png_fixed_point \fP\fIint_red_Z\fP\fB, png_fixed_point \fP\fIint_green_X\fP\fB, png_fixed_point \fP\fIint_green_Y\fP\fB, png_fixed_point \fP\fIint_green_Z\fP\fB, png_fixed_point \fP\fIint_blue_X\fP\fB, png_fixed_point \fP\fIint_blue_Y\fP\fB, png_fixed_point \fIint_blue_Z\fP\fB);\fP + +\fI\fB + \fBvoid png_set_chunk_cache_max (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIuser_chunk_cache_max\fP\fB);\fP \fI\fB @@ -576,6 +610,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 \fI\fB +\fBvoid png_set_expand_16 (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + \fBvoid png_set_expand_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP \fI\fB @@ -752,6 +790,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 \fI\fB +\fBvoid png_set_scale_16 (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + \fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP \fI\fB @@ -796,6 +838,26 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 \fI\fB +\fBvoid png_set_text_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_text_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_text_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_text_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP + +\fI\fB + +\fBvoid \fP\fIpng_set_text_compression_method\fP\fB, (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod)\fP\fB);\fP + +\fI\fB + \fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP \fI\fB @@ -919,7 +981,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng. .SH LIBPNG.TXT libpng-manual.txt - A description on how to use and modify libpng - libpng version 1.5.1 - February 3, 2011 + libpng version 1.5.10 - March 29, 2012 Updated and distributed by Glenn Randers-Pehrson <glennrp at users.sourceforge.net> Copyright (c) 1998-2011 Glenn Randers-Pehrson @@ -930,7 +992,7 @@ libpng-manual.txt - A description on how to use and modify libpng Based on: - libpng versions 0.97, January 1998, through 1.5.1 - February 3, 2011 + libpng versions 0.97, January 1998, through 1.5.10 - March 29, 2012 Updated and distributed by Glenn Randers-Pehrson Copyright (c) 1998-2011 Glenn Randers-Pehrson @@ -1026,7 +1088,8 @@ PNG file. At one time, the fields of png_info were intended to be directly accessible to the user. However, this tended to cause problems with applications using dynamically loaded libraries, and as a result a set of interface functions for png_info (the png_get_*() and png_set_*() -functions) was developed. +functions) was developed, and direct access to the png_info fields was +deprecated.. The png_struct structure is the object used by the library to decode a single image. As of 1.5.0 this structure is also not exposed. @@ -1035,14 +1098,23 @@ Almost all libpng APIs require a pointer to a png_struct as the first argument. Many (in particular the png_set and png_get APIs) also require a pointer to png_info as the second argument. Some application visible macros defined in png.h designed for basic data access (reading and writing -integers in the PNG format) break this rule, but it's almost always safe -to assume that a (png_struct*) has to be passed to call an API function. +integers in the PNG format) don't take a png_info pointer, but it's almost +always safe to assume that a (png_struct*) has to be passed to call an API +function. + +You can have more than one png_info structure associated with an image, +as illustrated in pngtest.c, one for information valid prior to the +IDAT chunks and another (called "end_info" below) for things after them. The png.h header file is an invaluable reference for programming with libpng. And while I'm on the topic, make sure you include the libpng header file: #include <png.h> +and also (as of libpng-1.5.0) the zlib header file, if you need it: + +#include <zlib.h> + .SS Types The png.h header file defines a number of integral types used by the @@ -1056,9 +1128,9 @@ the value by multiplying by 100,000. As of libpng 1.5.0 a convenience macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point) which is simply (png_int_32). -All APIs that take (double) arguments also have an matching API that +All APIs that take (double) arguments also have a matching API that takes the corresponding fixed point integer arguments. The fixed point -API has the same name as the floating point one with _fixed appended. +API has the same name as the floating point one with "_fixed" appended. The actual range of values permitted in the APIs is frequently less than the full range of (png_fixed_point) (-21474 to +21474). When APIs require a non-negative argument the type is recorded as png_uint_32 above. Consult @@ -1076,6 +1148,10 @@ preprocessing directives of the form: #ifdef PNG_feature_SUPPORTED declare-function #endif + ... + #ifdef PNG_feature_SUPPORTED + use-function + #endif The library can be built without support for these APIs, although a standard build will have all implemented APIs. Application programs @@ -1084,7 +1160,7 @@ portability. From libpng 1.5.0 the feature macros set during the build of libpng are recorded in the header file "pnglibconf.h" and this file is always included by png.h. -If you don't need to change the library configuration from the default skip to +If you don't need to change the library configuration from the default, skip to the next section ("Reading"). Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all @@ -1116,24 +1192,25 @@ A variety of methods exist to build libpng. Not all of these support reconfiguration of pnglibconf.h. To reconfigure pnglibconf.h it must either be rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand. -Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt and changing -the lines defining the supported features, paying very close attention to the -'option' information in scripts/pnglibconf.dfa that describes those features and -their requirements. This is easy to get wrong. +Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt to +pnglibconf.h and changing the lines defining the supported features, paying +very close attention to the 'option' information in scripts/pnglibconf.dfa +that describes those features and their requirements. This is easy to get +wrong. B. Configuration using DFA_XTRA Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later variant such as 'nawk' or 'gawk', is available. The configure build will automatically find an appropriate awk and build pnglibconf.h. -scripts/pnglibconf.mak contains a set of make rules for doing the same thing if -configure is not used, and many of the makefiles in the scripts directory use -this approach. +The scripts/pnglibconf.mak file contains a set of make rules for doing the +same thing if configure is not used, and many of the makefiles in the scripts +directory use this approach. -When rebuilding simply write new file containing changed options and set +When rebuilding simply write a new file containing changed options and set DFA_XTRA to the name of this file. This causes the build to append the new file -to the end of scripts/pnglibconf.dfa. pngusr.dfa should contain lines of the -following forms: +to the end of scripts/pnglibconf.dfa. The pngusr.dfa file should contain lines +of the following forms: everything = off @@ -1157,12 +1234,16 @@ source code. Most of these values have performance implications for the library but most of them have no visible effect on the API. Some can also be overridden from the API. +This method of building a customized pnglibconf.h is illustrated in +contrib/pngminim/*. See the "$(PNGCONF):" target in the makefile and +pngusr.dfa in these directories. + C. Configuration using PNG_USR_CONFIG If -DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file pngusr.h will automatically be included before the options in -scripts/pnglibconf.dfa are processed. pngusr.h should contain only macro -definitions turning features on or off or setting settings. +scripts/pnglibconf.dfa are processed. Your pngusr.h file should contain only +macro definitions turning features on or off or setting settings. Apart from the global setting "everything = off" all the options listed above can be set using macros in pngusr.h: @@ -1193,6 +1274,9 @@ examine the intermediate file pnglibconf.dfn to find the full set of dependency information for each setting and option. Simply locate the feature in the file and read the C comments that precede it. +This method is also illustrated in the contrib/pngminim/* makefiles and +pngusr.h. + .SH III. Reading We'll now walk you through the possible functions to call when reading @@ -1267,21 +1351,12 @@ create the structure, so your application should check for that. return (ERROR); } - png_infop end_info = png_create_info_struct(png_ptr); - - if (!end_info) - { - png_destroy_read_struct(&png_ptr, &info_ptr, - (png_infopp)NULL); - return (ERROR); - } - If you want to use your own memory allocation routines, use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use png_create_read_struct_2() instead of png_create_read_struct(): png_structp png_ptr = png_create_read_struct_2 - (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, user_error_fn, user_warning_fn, (png_voidp) user_mem_ptr, user_malloc_fn, user_free_fn); @@ -1293,7 +1368,7 @@ handling and memory alloc/free functions. When libpng encounters an error, it expects to longjmp back to your routine. Therefore, you will need to call setjmp and pass your png_jmpbuf(png_ptr). If you read the file from different -routines, you will need to update the jmpbuf field every time you enter +routines, you will need to update the longjmp buffer every time you enter a new routine that will call a png_*() function. See your documentation of setjmp/longjmp for your compiler for more @@ -1311,6 +1386,9 @@ free any memory. return (ERROR); } +Pass (png_infopp)NULL instead of &end_info if you didn't create +an end_info structure. + If you would rather avoid the complexity of setjmp/longjmp issues, you can compile libpng with PNG_NO_SETJMP, in which case errors will result in a call to PNG_ABORT() which defaults to abort(). @@ -1432,6 +1510,19 @@ To inform libpng about your function, use png_set_read_status_fn(png_ptr, read_row_callback); +When this function is called the row has already been completely processed and +the 'row' and 'pass' refer to the next row to be handled. For the +non-interlaced case the row that was just handled is simply one less than the +passed in row number, and pass will always be 0. For the interlaced case the +same applies unless the row value is 0, in which case the row just handled was +the last one from one of the preceding passes. Because interlacing may skip a +pass you cannot be sure that the preceding pass is just 'pass-1', if you really +need to know what the last pass is record (row,pass) from the callback and use +the last recorded value each time. + +As with the user transform you can find the output row using the +PNG_ROW_FROM_PASS_ROW macro. + .SS Unknown-chunk handling Now you get to set the way the library processes unknown chunks in the @@ -1469,6 +1560,8 @@ according to the "keep" directive. If a chunk is named in successive instances of png_set_keep_unknown_chunks(), the final instance will take precedence. The IHDR and IEND chunks should not be named in chunk_list; if they are, libpng will process them normally anyway. +If you know that your application will never make use of some particular +chunks, use PNG_HANDLE_CHUNK_NEVER (or 1) as demonstrated below. Here is an example of the usage of png_set_keep_unknown_chunks(), where the private "vpAg" chunk will later be processed by a user chunk @@ -1509,7 +1602,7 @@ large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns. Since very few applications really need to process such large images, we have imposed an arbitrary 1-million limit on rows and columns. Larger images will be rejected immediately with a png_error() call. If -you wish to override this limit, you can use +you wish to change this limit, you can use png_set_user_limits(png_ptr, width_max, height_max); @@ -1519,6 +1612,10 @@ anyway because of potential buffer overflow conditions). You should put this statement after you create the PNG structure and before calling png_read_info(), png_read_png(), or png_process_data(). + +When writing a PNG datastream, put this statement before calling +png_write_info() or png_write_png(). + If you need to retrieve the limits that are being applied, use width_max = png_get_user_width_max(png_ptr); @@ -1549,6 +1646,242 @@ and you can retrieve the limit with Any chunks that would cause either of these limits to be exceeded will be ignored. +.SS Information about your system + +If you intend to display the PNG or to incorporate it in other image data you +need to tell libpng information about your display or drawing surface so that +libpng can convert the values in the image to match the display. + +From libpng-1.5.4 this information can be set before reading the PNG file +header. In earlier versions png_set_gamma() existed but behaved incorrectly if +called before the PNG file header had been read and png_set_alpha_mode() did not +exist. + +If you need to support versions prior to libpng-1.5.4 test the version number +as illustrated below using "PNG_LIBPNG_VER >= 10504" and follow the procedures +described in the appropriate manual page. + +You give libpng the encoding expected by your system expressed as a 'gamma' +value. You can also specify a default encoding for the PNG file in +case the required information is missing from the file. By default libpng +assumes that the PNG data matches your system, to keep this default call: + + png_set_gamma(png_ptr, screen_gamma, 1/screen_gamma/*file gamma*/); + +or you can use the fixed point equivalent: + + png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma); + +If you don't know the gamma for your system it is probably 2.2 - a good +approximation to the IEC standard for display systems (sRGB). If images are +too contrasty or washed out you got the value wrong - check your system +documentation! + +Many systems permit the system gamma to be changed via a lookup table in the +display driver, a few systems, including older Macs, change the response by +default. As of 1.5.4 three special values are available to handle common +situations: + + PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1 + standard. This matches almost all systems. + PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6) + Apple Macintosh system with the default settings. + PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the + system expects data with no gamma encoding. + +You would use the linear (unencoded) value if you need to process the pixel +values further because this avoids the need to decode and reencode each +component value whenever arithmetic is performed. A lot of graphics software +uses linear values for this reason, often with higher precision component values +to preserve overall accuracy. + +The second thing you may need to tell libpng about is how your system handles +alpha channel information. Some, but not all, PNG files contain an alpha +channel. To display these files correctly you need to compose the data onto a +suitable background, as described in the PNG specification. + +Libpng only supports composing onto a single color (using png_set_background; +see below). Otherwise you must do the composition yourself and, in this case, +you may need to call png_set_alpha_mode: + +#if PNG_LIBPNG_VER >= 10504 + png_set_alpha_mode(png_ptr, mode, screen_gamma); +#else + png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma); +#endif + +The screen_gamma value is the same as the argument to png_set_gamma; however, +how it affects the output depends on the mode. png_set_alpha_mode() sets the +file gamma default to 1/screen_gamma, so normally you don't need to call +png_set_gamma. If you need different defaults call png_set_gamma() before +png_set_alpha_mode() - if you call it after it will override the settings made +by png_set_alpha_mode(). + +The mode is as follows: + + PNG_ALPHA_PNG: The data is encoded according to the PNG specification. Red, +green and blue, or gray, components are gamma encoded color +values and are not premultiplied by the alpha value. The +alpha value is a linear measure of the contribution of the +pixel to the corresponding final output pixel. + +You should normally use this format if you intend to perform +color correction on the color values; most, maybe all, color +correction software has no handling for the alpha channel and, +anyway, the math to handle pre-multiplied component values is +unnecessarily complex. + +Before you do any arithmetic on the component values you need +to remove the gamma encoding and multiply out the alpha +channel. See the PNG specification for more detail. It is +important to note that when an image with an alpha channel is +scaled, linear encoded, pre-multiplied component values must +be used! + +The remaining modes assume you don't need to do any further color correction or +that if you do, your color correction software knows all about alpha (it +probably doesn't!) + + PNG_ALPHA_STANDARD: The data libpng produces +is encoded in the standard way +assumed by most correctly written graphics software. +The gamma encoding will be removed by libpng and the +linear component values will be pre-multiplied by the +alpha channel. + +With this format the final image must be re-encoded to +match the display gamma before the image is displayed. +If your system doesn't do that, yet still seems to +perform arithmetic on the pixels without decoding them, +it is broken - check out the modes below. + +With PNG_ALPHA_STANDARD libpng always produces linear +component values, whatever screen_gamma you supply. The +screen_gamma value is, however, used as a default for +the file gamma if the PNG file has no gamma information. + +If you call png_set_gamma() after png_set_alpha_mode() you +will override the linear encoding. Instead the +pre-multiplied pixel values will be gamma encoded but +the alpha channel will still be linear. This may +actually match the requirements of some broken software, +but it is unlikely. + +While linear 8-bit data is often used it has +insufficient precision for any image with a reasonable +dynamic range. To avoid problems, and if your software +supports it, use png_set_expand_16() to force all +components to 16 bits. + + PNG_ALPHA_OPTIMIZED: This mode is the same +as PNG_ALPHA_STANDARD except that +completely opaque pixels are gamma encoded according to +the screen_gamma value. Pixels with alpha less than 1.0 +will still have linear components. + +Use this format if you have control over your +compositing software and do don't do other arithmetic +(such as scaling) on the data you get from libpng. Your +compositing software can simply copy opaque pixels to +the output but still has linear values for the +non-opaque pixels. + +In normal compositing, where the alpha channel encodes +partial pixel coverage (as opposed to broad area +translucency), the inaccuracies of the 8-bit +representation of non-opaque pixels are irrelevant. + +You can also try this format if your software is broken; +it might look better. + + PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD; +however, all component values, +including the alpha channel are gamma encoded. This is +an appropriate format to try if your software, or more +likely hardware, is totally broken, i.e., if it performs +linear arithmetic directly on gamma encoded values. + +In most cases of broken software or hardware the bug in the final display +manifests as a subtle halo around composited parts of the image. You may not +even perceive this as a halo; the composited part of the image may simply appear +separate from the background, as though it had been cut out of paper and pasted +on afterward. + +If you don't have to deal with bugs in software or hardware, or if you can fix +them, there are three recommended ways of using png_set_alpha_mode(): + + png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG, + screen_gamma); + +You can do color correction on the result (libpng does not currently +support color correction internally). When you handle the alpha channel +you need to undo the gamma encoding and multiply out the alpha. + + png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD, + screen_gamma); + png_set_expand_16(png_ptr); + +If you are using the high level interface, don't call png_set_expand_16(); +instead pass PNG_TRANSFORM_EXPAND_16 to the interface. + +With this mode you can't do color correction, but you can do arithmetic, +including composition and scaling, on the data without further processing. + + png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED, + screen_gamma); + +You can avoid the expansion to 16-bit components with this mode, but you +lose the ability to scale the image or perform other linear arithmetic. +All you can do is compose the result onto a matching output. Since this +mode is libpng-specific you also need to write your own composition +software. + +If you don't need, or can't handle, the alpha channel you can call +png_set_background() to remove it by compositing against a fixed color. Don't +call png_set_strip_alpha() to do this - it will leave spurious pixel values in +transparent parts of this image. + + png_set_background(png_ptr, &background_color, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1); + +The background_color is an RGB or grayscale value according to the data format +libpng will produce for you. Because you don't yet know the format of the PNG +file, if you call png_set_background at this point you must arrange for the +format produced by libpng to always have 8-bit or 16-bit components and then +store the color as an 8-bit or 16-bit color as appropriate. The color contains +separate gray and RGB component values, so you can let libpng produce gray or +RGB output according to the input format, but low bit depth grayscale images +must always be converted to at least 8-bit format. (Even though low bit depth +grayscale images can't have an alpha channel they can have a transparent +color!) + +You set the transforms you need later, either as flags to the high level +interface or libpng API calls for the low level interface. For reference the +settings and API calls required are: + +8-bit values: + PNG_TRANSFORM_SCALE_16 | PNG_EXPAND + png_set_expand(png_ptr); png_set_scale_16(png_ptr); + + If you must get exactly the same inaccurate results + produced by default in versions prior to libpng-1.5.4, + use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr) + instead. + +16-bit values: + PNG_TRANSFORM_EXPAND_16 + png_set_expand_16(png_ptr); + +In either case palette image data will be expanded to RGB. If you just want +color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr) +to the list. + +Calling png_set_background before the PNG file header is read will not work +prior to libpng-1.5.4. Because the failure may result in unexpected warnings or +errors it is therefore much safer to call png_set_background after the head has +been read. Unfortunately this means that prior to libpng-1.5.4 it cannot be +used with the high level interface. + .SS The high-level read interface At this point there are two ways to proceed; through the high-level @@ -1558,8 +1891,10 @@ the entire image into memory, and (b) the input transformations you want to do are limited to the following set: PNG_TRANSFORM_IDENTITY No transformation - PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to - 8 bits + PNG_TRANSFORM_SCALE_16 Strip 16-bit samples to + 8-bit accurately + PNG_TRANSFORM_STRIP_16 Chop 16-bit samples to + 8-bit less accurately PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit samples to bytes @@ -1578,6 +1913,7 @@ you want to do are limited to the following set: PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples to RGB (or GA to RGBA) + PNG_TRANSFORM_EXPAND_16 Expand samples to 16 bits (This excludes setting a background color, doing gamma transformation, quantizing, and setting filler.) If this is the case, simply do this: @@ -1646,6 +1982,22 @@ call to png_read_info(). This will process all chunks up to but not including the image data. +This also copies some of the data from the PNG file into the decode structure +for use in later transformations. Important information copied in is: + +1) The PNG file gamma from the gAMA chunk. This overwrites the default value +provided by an earlier call to png_set_gamma or png_set_alpha_mode. + +2) Prior to libpng-1.5.4 the background color from a bKGd chunk. This +damages the information provided by an earlier call to png_set_background +resulting in unexpected behavior. Libpng-1.5.4 no longer does this. + +3) The number of significant bits in each component value. Libpng uses this to +optimize gamma handling by reducing the internal lookup table sizes. + +4) The transparent color information from a tRNS chunk. This can be modified by +a later call to png_set_tRNS. + .SS Querying the info structure Functions are used to get the information from the info_ptr once it @@ -1776,6 +2128,28 @@ pointer into the info_ptr is returned for any complex types. int_file_gamma - 100,000 times the gamma at which the file is written + png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x, &red_y, + &green_x, &green_y, &blue_x, &blue_y) + png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, &green_X, + &green_Y, &green_Z, &blue_X, &blue_Y, &blue_Z) + png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, &int_white_y, + &int_red_x, &int_red_y, &int_green_x, &int_green_y, + &int_blue_x, &int_blue_y) + png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y, + &int_red_Z, &int_green_X, &int_green_Y, &int_green_Z, + &int_blue_X, &int_blue_Y, &int_blue_Z) + + {white,red,green,blue}_{x,y} + A color space encoding specified using the chromaticities + of the end points and the white point. (PNG_INFO_cHRM) + + {red,green,blue}_{X,Y,Z} + A color space encoding specified using the encoding end + points - the CIE tristimulus specification of the intended + color of the red, green and blue channels in the PNG RGB + data. The white point is simply the sum of the three end + points. (PNG_INFO_cHRM) + png_get_sRGB(png_ptr, info_ptr, &srgb_intent); file_srgb_intent - the rendering intent (PNG_INFO_sRGB) @@ -1834,7 +2208,8 @@ pointer into the info_ptr is returned for any complex types. png_get_bKGD(png_ptr, info_ptr, &background); - background - background color (PNG_VALID_bKGD) + background - background color (of type + png_color_16p) (PNG_VALID_bKGD) valid 16-bit red, green and blue values, regardless of color_type @@ -1871,8 +2246,13 @@ pointer into the info_ptr is returned for any complex types. (empty string for unknown). Note that the itxt_length, lang, and lang_key - members of the text_ptr structure only exist - when the library is built with iTXt chunk support. + members of the text_ptr structure only exist when the + library is built with iTXt chunk support. Prior to + libpng-1.4.0 the library was built by default without + iTXt support. Also note that when iTXt is supported, + they contain NULL pointers when the "compression" + field contains PNG_TEXT_COMPRESSION_NONE or + PNG_TEXT_COMPRESSION_zTXt. num_text - number of comments (same as num_comments; you can put NULL here @@ -1897,10 +2277,10 @@ pointer into the info_ptr is returned for any complex types. &unit_type); offset_x - positive offset from the left edge - of the screen + of the screen (can be negative) offset_y - positive offset from the top edge - of the screen + of the screen (can be negative) unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER @@ -1932,6 +2312,7 @@ pointer into the info_ptr is returned for any complex types. unit - physical scale units (an integer) width - width of a pixel in physical scale units + (expressed as a string) height - height of a pixel in physical scale units (width and height are strings like "2.54") @@ -1954,6 +2335,12 @@ pointer into the info_ptr is returned for any complex types. chunks were read from the PNG file or inserted with the png_set_unknown_chunks() function. + The value of "location" is a bitwise "or" of + + PNG_HAVE_IHDR (0x01) + PNG_HAVE_PLTE (0x02) + PNG_AFTER_IDAT (0x08) + The data from the pHYs chunk can be retrieved in several convenient forms: @@ -1988,7 +2375,7 @@ forms: 72 dpi is stored as 0.28346 pixels/meter, and when this is retrieved it is 71.9988 dpi, so be sure to round the returned value appropriately - if you want to display a reasonable-looking result. + if you want to display a reasonable-looking result. The data from the oFFs chunk can be retrieved in several convenient forms: @@ -2009,7 +2396,7 @@ forms: converted to microns and back without some loss of precision. -For more information, see the png_info definition in png.h and the +For more information, see the PNG specification for chunk contents. Be careful with trusting rowbytes, as some of the transformations could increase the space needed to hold a row (expand, filler, gray_to_rgb, etc.). @@ -2044,17 +2431,20 @@ to handle any special transformations of the image data. The various ways to transform the data will be described in the order that they should occur. This is important, as some of these change the color type and/or bit depth of the data, and some others only work on -certain color types and bit depths. Even though each transformation -checks to see if it has data that it can do something with, you should -make sure to only enable a transformation if it will be valid for the -data. For example, don't swap red and blue on grayscale data. +certain color types and bit depths. + +Transformations you request are ignored if they don't have any meaning for a +particular input data format. However some transformations can have an effect +as a result of a previous transformation. If you specify a contradictory set of +transformations, for example both adding and removing the alpha channel, you +cannot predict the final result. + +The color used for the transparency values should be supplied in the same +format/depth as the current image data. It is stored in the same format/depth +as the image data in a tRNS chunk, so this is what libpng expects for this data. -The colors used for the background and transparency values should be -supplied in the same format/depth as the current image data. They -are stored in the same format/depth as the image data in a bKGD or tRNS -chunk, so this is what libpng expects for this data. The colors are -transformed to keep in sync with the image data when an application -calls the png_read_update_info() routine (see below). +The color used for the background value depends on the need_expand argument as +described below. Data will be decoded into the supplied row buffers packed into bytes unless the library has been told to transform it into another format. @@ -2064,12 +2454,12 @@ byte, unless png_set_packing() is called. 8-bit RGB data will be stored in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha() is called to insert filler bytes, either before or after each RGB triplet. 16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant -byte of the color value first, unless png_set_strip_16() is called to +byte of the color value first, unless png_set_scale_16() is called to transform it to regular RGB RGB triplets, or png_set_filler() or png_set_add alpha() is called to insert filler bytes, either before or after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can -be modified with -png_set_filler(), png_set_add_alpha(), or png_set_strip_16(). +be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(), +or png_set_scale_16(). The following code transforms grayscale images of less than 8 to 8 bits, changes paletted images to RGB, and adds a full alpha channel if there is @@ -2080,13 +2470,13 @@ viewing application that wishes to treat all images in the same way. if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_palette_to_rgb(png_ptr); - if (color_type == PNG_COLOR_TYPE_GRAY && - bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); - if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr); -These three functions are actually aliases for png_set_expand(), added + if (color_type == PNG_COLOR_TYPE_GRAY && + bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); + +The first two functions are actually aliases for png_set_expand(), added in libpng version 1.0.4, with the function names expanded to improve code readability. In some future version they may actually do different things. @@ -2094,56 +2484,91 @@ things. As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was added. It expands the sample depth without changing tRNS to alpha. -As of libpng version 1.5.1, not all possible expansions are supported. +As of libpng version 1.5.2, png_set_expand_16() was added. It behaves as +png_set_expand(); however, the resultant channels have 16 bits rather than 8. +Use this when the output color or gray channels are made linear to avoid fairly +severe accuracy loss. + + if (bit_depth < 16) + png_set_expand_16(png_ptr); + +PNG can have files with 16 bits per channel. If you only can handle +8 bits per channel, this will strip the pixels down to 8-bit. + + if (bit_depth == 16) +#if PNG_LIBPNG_VER >= 10504 + png_set_scale_16(png_ptr); +#else + png_set_strip_16(png_ptr); +#endif + +(The more accurate "png_set_scale_16()" API became available in libpng version +1.5.4). + +If you need to process the alpha channel on the image separately from the image +data (for example if you convert it to a bitmap mask) it is possible to have +libpng strip the channel leaving just RGB or gray data: + + if (color_type & PNG_COLOR_MASK_ALPHA) + png_set_strip_alpha(png_ptr); + +If you strip the alpha channel you need to find some other way of dealing with +the information. If, instead, you want to convert the image to an opaque +version with no alpha channel use png_set_background; see below. + +As of libpng version 1.5.2, almost all useful expansions are supported, the +major ommissions are conversion of grayscale to indexed images (which can be +done trivially in the application) and conversion of indexed to grayscale (which +can be done by a trivial manipulation of the palette.) In the following table, the 01 means grayscale with depth<8, 31 means indexed with depth<8, other numerals represent the color type, "T" means the tRNS chunk is present, A means an alpha channel is present, and O means tRNS or alpha is present but all pixels in the image are opaque. - FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O + FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O TO - 01 - - 31 - - 0 1 - - 0T - - 0O - - 2 GX - - 2T - - 2O - - 3 1 - - 3T - - 3O - - 4A T - - 4O - - 6A GX TX TX - - 6O GX TX - + 01 - [G] - - - - - - - - - - - - - + 31 [Q] Q [Q] [Q] [Q] Q Q Q Q Q Q [Q] [Q] Q Q + 0 1 G + . . G G G G G G B B GB GB + 0T lt Gt t + . Gt G G Gt G G Bt Bt GBt GBt + 0O lt Gt t . + Gt Gt G Gt Gt G Bt Bt GBt GBt + 2 C P C C C + . . C - - CB CB B B + 2T Ct - Ct C C t + t - - - CBt CBt Bt Bt + 2O Ct - Ct C C t t + - - - CBt CBt Bt Bt + 3 [Q] p [Q] [Q] [Q] Q Q Q + . . [Q] [Q] Q Q + 3T [Qt] p [Qt][Q] [Q] Qt Qt Qt t + t [Qt][Qt] Qt Qt + 3O [Qt] p [Qt][Q] [Q] Qt Qt Qt t t + [Qt][Qt] Qt Qt + 4A lA G A T T GA GT GT GA GT GT + BA G GBA + 4O lA GBA A T T GA GT GT GA GT GT BA + GBA G + 6A CA PA CA C C A T tT PA P P C CBA + BA + 6O CA PBA CA C C A tT T PA P P CBA C BA + Within the matrix, + "+" identifies entries where 'from' and 'to' are the same. "-" means the transformation is not supported. + "." means nothing is necessary (a tRNS chunk can just be ignored). + "t" means the transformation is obtained by png_set_tRNS. + "A" means the transformation is obtained by png_set_add_alpha(). "X" means the transformation is obtained by png_set_expand(). "1" means the transformation is obtained by - png_set_expand_gray_1_2_4_to_8 - "G" means the transformation is obtained by - png_set_gray_to_rgb(). + png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() if there + is no transparency in the original or the final format). + "C" means the transformation is obtained by png_set_gray_to_rgb(). + "G" means the transformation is obtained by png_set_rgb_to_gray(). "P" means the transformation is obtained by png_set_expand_palette_to_rgb(). - "T" means the transformation is obtained by - png_set_tRNS_to_alpha(). - -PNG can have files with 16 bits per channel. If you only can handle -8 bits per channel, this will strip the pixels down to 8 bit. - - if (bit_depth == 16) - png_set_strip_16(png_ptr); - -If, for some reason, you don't need the alpha channel on an image, -and you want to remove it rather than combining it with the background -(but the image author certainly had in mind that you *would* combine -it with the background, so that's what you should probably do): - - if (color_type & PNG_COLOR_MASK_ALPHA) - png_set_strip_alpha(png_ptr); + "p" means the transformation is obtained by png_set_packing(). + "Q" means the transformation is obtained by png_set_quantize(). + "T" means the transformation is obtained by png_set_tRNS_to_alpha(). + "B" means the transformation is obtained by png_set_background(), or + png_strip_alpha(). + +When an entry has multiple transforms listed all are required to cause the +right overall transformation. When two transforms are separated by a comma +either will do the job. When transforms are enclosed in [] the transform should +do the job but this is currently unimplemented - a different format will result +if the suggested transformations are used. In PNG files, the alpha channel in an image is the level of opacity. If you need the alpha channel in an image to @@ -2222,8 +2647,8 @@ with alpha. if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) - png_set_rgb_to_gray_fixed(png_ptr, error_action, - int red_weight, int green_weight); + png_set_rgb_to_gray(png_ptr, error_action, double red_weight, + double green_weight); error_action = 1: silently do the conversion @@ -2236,122 +2661,98 @@ with alpha. image has any pixel where red != green or red != blue - red_weight: weight of red component times 100000 + red_weight: weight of red component - green_weight: weight of green component times 100000 + green_weight: weight of green component If either weight is negative, default - weights (21268, 71514) are used. + weights are used. + +In the corresponding fixed point API the red_weight and green_weight values are +simply scaled by 100,000: + + png_set_rgb_to_gray(png_ptr, error_action, png_fixed_point red_weight, + png_fixed_point green_weight); If you have set error_action = 1 or 2, you can later check whether the image really was gray, after processing the image rows, with the png_get_rgb_to_gray_status(png_ptr) function. It will return a png_byte that is zero if the image was gray or -1 if there were any non-gray pixels. bKGD and sBIT data +1 if there were any non-gray pixels. Background and sBIT data will be silently converted to grayscale, using the green channel -data, regardless of the error_action setting. +data for sBIT, regardless of the error_action setting. + +The default values come from the PNG file cHRM chunk if present; otherwise, the +defaults correspond to the ITU-R recommendation 709, and also the sRGB color +space, as recommended in the Charles Poynton's Colour FAQ, +<http://www.poynton.com/>, in section 9: -With red_weight+green_weight<=100000, -the normalized graylevel is computed: + <http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9> - int rw = red_weight * 65536; - int gw = green_weight * 65536; - int bw = 65536 - (rw + gw); - gray = (rw*red + gw*green + bw*blue)/65536; + Y = 0.2126 * R + 0.7152 * G + 0.0722 * B -The default values approximate those recommended in the Charles -Poynton's Color FAQ, <http://www.inforamp.net/~poynton/> -Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net> +Previous versions of this document, 1998 through 2002, recommended a slightly +different formula: Y = 0.212671 * R + 0.715160 * G + 0.072169 * B -Libpng approximates this with integers scaled by 32768: +Libpng uses an integer approximation: Y = (6968 * R + 23434 * G + 2366 * B)/32768 The calculation is done in a linear colorspace, if the image gamma can be determined. -If you have a grayscale and you are using png_set_expand_depth(), -png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to -a higher bit-depth, you must either supply the background color as a gray -value at the original file bit-depth (need_expand = 1) or else supply the -background color as an RGB triplet at the final, expanded bit depth -(need_expand = 0). Similarly, if you are reading a paletted image, you -must either supply the background color as a palette index (need_expand = 1) -or as an RGB triplet that may or may not be in the palette (need_expand = 0). +The png_set_background() function has been described already; it tells libpng to +composite images with alpha or simple transparency against the supplied +background color. For compatibility with versions of libpng earlier than +libpng-1.5.4 it is recommended that you call the function after reading the file +header, even if you don't want to use the color in a bKGD chunk, if one exists. + +If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), +you may use this color, or supply another color more suitable for +the current display (e.g., the background color from a web page). You +need to tell libpng how the color is represented, both the format of the +component values in the color (the number of bits) and the gamma encoding of the +color. The function takes two arguments, background_gamma_mode and need_expand +to convey this information, however only two combinations are likely to be +useful: png_color_16 my_background; png_color_16p image_background; if (png_get_bKGD(png_ptr, info_ptr, &image_background)) png_set_background(png_ptr, image_background, - PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); + PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1); else png_set_background(png_ptr, &my_background, - PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); - -The png_set_background() function tells libpng to composite images -with alpha or simple transparency against the supplied background -color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), -you may use this color, or supply another color more suitable for -the current display (e.g., the background color from a web page). You -need to tell libpng whether the color is in the gamma space of the -display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file -(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one -that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't -know why anyone would use this, but it's here). - -To properly display PNG images on any kind of system, the application needs -to know what the display gamma is. Ideally, the user will know this, and -the application will allow them to set it. One method of allowing the user -to set the display gamma separately for each system is to check for a -SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be -correctly set. - -Note that display_gamma is the overall gamma correction required to produce -pleasing results, which depends on the lighting conditions in the surrounding -environment. In a dim or brightly lit room, no compensation other than -the physical gamma exponent of the monitor is needed, while in a dark room -a slightly smaller exponent is better. - - double gamma, screen_gamma; - - if (/* We have a user-defined screen - gamma value */) - { - screen_gamma = user_defined_screen_gamma; - } - - /* One way that applications can share the same - screen gamma value */ - else if ((gamma_str = getenv("SCREEN_GAMMA")) - != NULL) - { - screen_gamma = (double)atof(gamma_str); - } - - /* If we don't have another value */ - else - { - screen_gamma = 2.2; /* A good guess for a - PC monitor in a bright office or a dim room */ - - screen_gamma = 2.0; /* A good guess for a - PC monitor in a dark room */ - - screen_gamma = 1.7 or 1.0; /* A good - guess for Mac systems */ - } - -The functions png_set_gamma() and its fixed point equivalent -png_set_gamma_fixed() handle gamma transformations of the data. -Pass both the file gamma and the current screen_gamma. If the file does -not have a gamma value, you can pass one anyway if you have an idea what -it is (usually 0.45455 is a good guess for GIF images on PCs). Note -that file gammas are inverted from screen gammas. See the discussions -on gamma in the PNG specification for an excellent description of what -gamma is, and why all applications should support it. It is strongly -recommended that PNG viewers support gamma correction. + PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1); + +The second call was described above - my_background is in the format of the +final, display, output produced by libpng. Because you now know the format of +the PNG it is possible to avoid the need to choose either 8-bit or 16-bit +output and to retain palette images (the palette colors will be modified +appropriately and the tRNS chunk removed.) However, if you are doing this, +take great care not to ask for transformations without checking first that +they apply! + +In the first call the background color has the original bit depth and color type +of the PNG file. So, for palette images the color is supplied as a palette +index and for low bit greyscale images the color is a reduced bit value in +image_background->gray. + +If you didn't call png_set_gamma() before reading the file header, for example +if you need your code to remain compatible with older versions of libpng prior +to libpng-1.5.4, this is the place to call it. + +Do not call it if you called png_set_alpha_mode(); doing so will damage the +settings put in place by png_set_alpha_mode(). (If png_set_alpha_mode() is +supported then you can certainly do png_set_gamma() before reading the PNG +header.) + +This API unconditionally sets the screen and file gamma values, so it will +override the value in the PNG file unless it is called before the PNG file +reading starts. For this reason you must always call it with the PNG file +value when you call it in this position: if (png_get_gAMA(png_ptr, info_ptr, &file_gamma)) png_set_gamma(png_ptr, screen_gamma, file_gamma); @@ -2364,9 +2765,9 @@ file has more entries then will fit on your screen, png_set_quantize() will do that. Note that this is a simple match quantization that merely finds the closest color available. This should work fairly well with optimized palettes, but fairly badly with linear color cubes. If you -pass a palette that is larger then maximum_colors, the file will +pass a palette that is larger than maximum_colors, the file will reduce the number of colors in the palette so it will fit into -maximum_colors. If there is a histogram, it will use it to make +maximum_colors. If there is a histogram, libpng will use it to make more intelligent choices when reducing the palette. If there is no histogram, it may not do as good a job. @@ -2407,7 +2808,7 @@ This function can also be used to invert grayscale and gray-alpha images: color_type == PNG_COLOR_TYPE_GRAY_ALPHA) png_set_invert_mono(png_ptr); -PNG files store 16 bit pixels in network byte order (big-endian, +PNG files store 16-bit pixels in network byte order (big-endian, ie. most significant bits first). This code changes the storage to the other way (little-endian, i.e. least significant bits first, the way PCs store them): @@ -2430,7 +2831,7 @@ with You must supply the function - void read_transform_fn(png_structp png_ptr, row_info_ptr + void read_transform_fn(png_structp png_ptr, png_row_infop row_info, png_bytep data) See pngtest.c for a working example. Your function will be called @@ -2438,7 +2839,7 @@ after all of the other transformations have been processed. Take care with interlaced images if you do the interlace yourself - the width of the row is the width in 'row_info', not the overall image width. -If supported libpng provides two information routines that you can use to find +If supported, libpng provides two information routines that you can use to find where you are in processing the image: png_get_current_pass_number(png_structp png_ptr); @@ -2449,6 +2850,14 @@ supported if user transforms are supported, secondly they may well return unexpected results unless the row is actually being processed at the moment they are called. +With interlaced +images the value returned is the row in the input sub-image image. Use +PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to +find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass). + +The discussion of interlace handling above contains more information on how to +use these values. + You can also set up a pointer to a user structure for use by your callback function, and you can inform libpng that your transform function will change the number of channels or bit depth with the @@ -2474,13 +2883,16 @@ of the interlaced image. After setting the transformations, libpng can update your png_info structure to reflect any transformations you've requested with this -call. This is most useful to update the info structure's rowbytes -field so you can use it to allocate your image memory. This function -will also update your palette with the correct screen_gamma and -background if these have been given with the calls above. +call. png_read_update_info(png_ptr, info_ptr); +This is most useful to update the info structure's rowbytes +field so you can use it to allocate your image memory. This function +will also update your palette with the correct screen_gamma and +background if these have been given with the calls above. You may +only call png_read_update_info() once with a particular info_ptr. + After you call png_read_update_info(), you can allocate any memory you need to hold the image. The row data is simply raw byte data for all forms of images. As the actual allocation @@ -2489,7 +2901,7 @@ are allocating one large chunk, you will need to build an array of pointers to each row, as it will be needed for some of the functions below. -Remember: Before you call png_read_update_info(), the png_get_ +Remember: Before you call png_read_update_info(), the png_get_*() functions return the values corresponding to the original PNG image. After you call png_read_update_info the values refer to the image that libpng will output. Consequently you must call all the png_set_ @@ -2681,7 +3093,7 @@ to load the whole file into memory when it is interlaced. libpng includes a test program, pngvalid, that illustrates reading and writing of interlaced images. If you can't get interlacing to work in your -code and don't want to leave it to libpng (the recommended approach) see +code and don't want to leave it to libpng (the recommended approach), see how pngvalid.c does it. .SS Finishing a sequential read @@ -2691,15 +3103,39 @@ low-level interface, you can finish reading the file. If you are interested in comments or time, which may be stored either before or after the image data, you should pass the separate png_info struct if you want to keep the comments from before and after the image -separate. If you are not interested, you can pass NULL. +separate. + + png_infop end_info = png_create_info_struct(png_ptr); + + if (!end_info) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return (ERROR); + } png_read_end(png_ptr, end_info); +If you are not interested, you should still call png_read_end() +but you can pass NULL, avoiding the need to create an end_info structure. + + png_read_end(png_ptr, (png_infop)NULL); + +If you don't call png_read_end(), then your file pointer will be +left pointing to the first chunk after the last IDAT, which is probably +not what you want if you expect to read something beyond the end of +the PNG datastream. + When you are done, you can free all memory allocated by libpng like this: png_destroy_read_struct(&png_ptr, &info_ptr, &end_info); +or, if you didn't create an end_info structure, + + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + It is also possible to individually free the info_ptr members that point to libpng-allocated storage with the following function: @@ -3102,6 +3538,20 @@ To inform libpng about your function, use png_set_write_status_fn(png_ptr, write_row_callback); +When this function is called the row has already been completely processed and +it has also been written out. The 'row' and 'pass' refer to the next row to be +handled. For the +non-interlaced case the row that was just handled is simply one less than the +passed in row number, and pass will always be 0. For the interlaced case the +same applies unless the row value is 0, in which case the row just handled was +the last one from one of the preceding passes. Because interlacing may skip a +pass you cannot be sure that the preceding pass is just 'pass-1', if you really +need to know what the last pass is record (row,pass) from the callback and use +the last recorded value each time. + +As with the user transform you can find the output row using the +PNG_ROW_FROM_PASS_ROW macro. + You now have the option of modifying how the compression library will run. The following functions are mainly for testing, but may be useful in some cases, like if you need to write PNG files extremely fast and @@ -3146,11 +3596,13 @@ which changes how much time zlib spends on trying to compress the image data. See the Compression Library (zlib.h and algorithm.txt, distributed with zlib) for details on the compression levels. - /* set the zlib compression level */ + #include zlib.h + + /* Set the zlib compression level */ png_set_compression_level(png_ptr, Z_BEST_COMPRESSION); - /* set other zlib parameters */ + /* Set other zlib parameters for compressing IDAT */ png_set_compression_mem_level(png_ptr, 8); png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY); @@ -3158,7 +3610,15 @@ with zlib) for details on the compression levels. png_set_compression_method(png_ptr, 8); png_set_compression_buffer_size(png_ptr, 8192) -extern PNG_EXPORT(void,png_set_zbuf_size) + /* Set zlib parameters for text compression + * If you don't call these, the parameters + * fall back on those defined for IDAT chunks + */ + png_set_text_compression_mem_level(png_ptr, 8); + png_set_text_compression_strategy(png_ptr, + Z_DEFAULT_STRATEGY); + png_set_text_compression_window_bits(png_ptr, 15); + png_set_text_compression_method(png_ptr, 8); .SS Setting the contents of info for output @@ -3246,6 +3706,28 @@ width, height, bit_depth, and color_type must be the same in each call. int_file_gamma - 100,000 times the gamma at which the image was created + png_set_cHRM(png_ptr, info_ptr, white_x, white_y, red_x, red_y, + green_x, green_y, blue_x, blue_y) + png_set_cHRM_XYZ(png_ptr, info_ptr, red_X, red_Y, red_Z, green_X, + green_Y, green_Z, blue_X, blue_Y, blue_Z) + png_set_cHRM_fixed(png_ptr, info_ptr, int_white_x, int_white_y, + int_red_x, int_red_y, int_green_x, int_green_y, + int_blue_x, int_blue_y) + png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, int_red_X, int_red_Y, + int_red_Z, int_green_X, int_green_Y, int_green_Z, + int_blue_X, int_blue_Y, int_blue_Z) + + {white,red,green,blue}_{x,y} + A color space encoding specified using the chromaticities + of the end points and the white point. + + {red,green,blue}_{X,Y,Z} + A color space encoding specified using the encoding end + points - the CIE tristimulus specification of the intended + color of the red, green and blue channels in the PNG RGB + data. The white point is simply the sum of the three end + points. + png_set_sRGB(png_ptr, info_ptr, srgb_intent); srgb_intent - the rendering intent @@ -3306,14 +3788,14 @@ width, height, bit_depth, and color_type must be the same in each call. trans_alpha - array of alpha (transparency) entries for palette (PNG_INFO_tRNS) + num_trans - number of transparent entries + (PNG_INFO_tRNS) + trans_color - graylevel or color sample values (in order red, green, blue) of the single transparent color for non-paletted images (PNG_INFO_tRNS) - num_trans - number of transparent entries - (PNG_INFO_tRNS) - png_set_hIST(png_ptr, info_ptr, hist); hist - histogram of palette (array of @@ -3326,7 +3808,8 @@ width, height, bit_depth, and color_type must be the same in each call. png_set_bKGD(png_ptr, info_ptr, background); - background - background color (PNG_VALID_bKGD) + background - background color (of type + png_color_16p) (PNG_VALID_bKGD) png_set_text(png_ptr, info_ptr, text_ptr, num_text); @@ -3350,9 +3833,15 @@ width, height, bit_depth, and color_type must be the same in each call. empty for unknown). text_ptr[i].translated_keyword - keyword in UTF-8 (NULL or empty for unknown). + Note that the itxt_length, lang, and lang_key - members of the text_ptr structure only exist - when the library is built with iTXt chunk support. + members of the text_ptr structure only exist when the + library is built with iTXt chunk support. Prior to + libpng-1.4.0 the library was built by default without + iTXt support. Also note that when iTXt is supported, + they contain NULL pointers when the "compression" + field contains PNG_TEXT_COMPRESSION_NONE or + PNG_TEXT_COMPRESSION_zTXt. num_text - number of comments @@ -3402,6 +3891,7 @@ width, height, bit_depth, and color_type must be the same in each call. unit - physical scale units (an integer) width - width of a pixel in physical scale units + expressed as a string height - height of a pixel in physical scale units (width and height are strings like "2.54") @@ -3443,7 +3933,7 @@ Because tEXt and zTXt chunks don't have a language field, if you specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt any language code or translated keyword will not be written out. -Until text gets around 1000 bytes, it is not worth compressing it. +Until text gets around a few hundred bytes, it is not worth compressing it. After the text has been written out to the file, the compression type is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR, so that it isn't written out again at the end (in case you are calling @@ -3664,7 +4154,7 @@ is required by PNG. png_set_shift(png_ptr, &sig_bit); -PNG files store 16 bit pixels in network byte order (big-endian, +PNG files store 16-bit pixels in network byte order (big-endian, ie. most significant bits first). This code would be used if they are supplied the other way (little-endian, i.e. least significant bits first, the way PCs store them): @@ -3698,8 +4188,8 @@ with You must supply the function - void write_transform_fn(png_structp png_ptr ptr, - row_info_ptr row_info, png_bytep data) + void write_transform_fn(png_structp png_ptr, png_row_infop + row_info, png_bytep data) See pngtest.c for a working example. Your function will be called before any of the other transformations are processed. If supported @@ -3707,9 +4197,15 @@ libpng also supplies an information routine that may be called from your callback: png_get_current_row_number(png_ptr); + png_get_current_pass_number(png_ptr); + +This returns the current row passed to the transform. With interlaced +images the value returned is the row in the input sub-image image. Use +PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to +find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass). -This returns the current row passed to the transform. Even with interlaced -images the value returned is the row in the final output image. +The discussion of interlace handling above contains more information on how to +use these values. You can also set up a pointer to a user structure for use by your callback function. @@ -4047,7 +4543,8 @@ However, there are some uncertainties about the status of local variables after a longjmp, so the user may want to be careful about doing anything after setjmp returns non-zero besides returning itself. Consult your compiler documentation for more details. For an alternative approach, you -may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net). +may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net), +which is illustrated in pngvalid.c and in contrib/visupng. .SS Custom chunks @@ -4065,8 +4562,11 @@ and look at how other chunks were designed, so you can do things similarly. Second, check out the sections of libpng that read and write chunks. Try to find a chunk that is similar to yours and use it as a template. More details can be found in the comments inside -the code. It is best to handle unknown chunks in a generic method, -via callback functions, instead of by modifying libpng functions. +the code. It is best to handle private or unknown chunks in a generic method, +via callback functions, instead of by modifying libpng functions. This +is illustrated in pngtest.c, which uses a callback function to handle a +private "vpAg" chunk and the new "sTER" chunk, which are both unknown to +libpng. If you wish to write your own transformation for the data, look through the part of the code that does the transformations, and check out some of @@ -4074,7 +4574,7 @@ the simpler ones to get an idea of how they work. Try to find a similar transformation to the one you want to add and copy off of it. More details can be found in the comments inside the code itself. -.SS Configuring for 16 bit platforms +.SS Configuring for 16-bit platforms You will want to look into zconf.h to tell zlib (and thus libpng) that it cannot allocate more then 64K at a time. Even if you can, the memory @@ -4094,8 +4594,8 @@ defined, and FAR gets defined to far in pngconf.h, and you should be all set. Everything in the library (except for zlib's structure) is expecting far data. You must use the typedefs with the p or pp on the end for pointers (or at least look at them and be careful). Make -note that the rows of data are defined as png_bytepp, which is an -unsigned char far * far *. +note that the rows of data are defined as png_bytepp, which is +an "unsigned char far * far *". .SS Configuring for gui/windowing platforms: @@ -4113,7 +4613,11 @@ or delete an include, this is the place to do it. The includes that are not needed outside libpng are placed in pngpriv.h, which is only used by the routines inside libpng itself. The files in libpng proper only include pngpriv.h and png.h, which -in turn includes pngconf.h. +%14%in turn includes pngconf.h. +in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h. +As of libpng-1.5.0, pngpriv.h also includes three other private header +files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material +that previously appeared in the public headers. .SS Configuring zlib: @@ -4129,6 +4633,7 @@ specify no compression (Z_NO_COMPRESSION = 0), but this would create files larger than just storing the raw bitmap. You can specify the compression level by calling: + #include zlib.h png_set_compression_level(png_ptr, level); Another useful one is to reduce the memory level used by the library. @@ -4139,12 +4644,14 @@ other things, lower levels will result in sections of incompressible data being emitted in smaller stored blocks, with a correspondingly larger relative overhead of up to 15% in the worst case. + #include zlib.h png_set_compression_mem_level(png_ptr, level); The other functions are for configuring zlib. They are not recommended for normal use and may result in writing an invalid PNG file. See zlib.h for more information on what these mean. + #include zlib.h png_set_compression_strategy(png_ptr, strategy); @@ -4152,8 +4659,28 @@ zlib.h for more information on what these mean. window_bits); png_set_compression_method(png_ptr, method); + png_set_compression_buffer_size(png_ptr, size); +As of libpng version 1.5.4, additional APIs became +available to set these separately for non-IDAT +compressed chunks such as zTXt, iTXt, and iCCP: + + #include zlib.h + #if PNG_LIBPNG_VER <= 10504 + png_set_text_compression_level(png_ptr, level); + + png_set_text_compression_mem_level(png_ptr, level); + + png_set_text_compression_strategy(png_ptr, + strategy); + + png_set_text_compression_window_bits(png_ptr, + window_bits); + + png_set_text_compression_method(png_ptr, method); + #endif + .SS Controlling row filtering If you want to control whether libpng uses filtering or not, which @@ -4259,8 +4786,8 @@ capability, which you'll still have). All the reading and writing specific code are in separate files, so the linker should only grab the files it needs. However, if you want to make sure, or if you are building a stand alone library, all the -reading files start with pngr and all the writing files start with -pngw. The files that don't match either (like png.c, pngtrans.c, etc.) +reading files start with "pngr" and all the writing files start with "pngw". +The files that don't match either (like png.c, pngtrans.c, etc.) are used for both reading and writing, and always need to be included. The progressive reader is in pngpread.c @@ -4379,6 +4906,9 @@ The number libpng_vn is constructed from the major version, minor version with leading zero, and release number with leading zero, (e.g., libpng_vn for version 1.0.7 is 10007). +Note that this function does not take a png_ptr, so you can call it +before you've created one. + You can also check which version of png.h you used when compiling your application: @@ -4542,12 +5072,12 @@ and memset(), respectively. The function png_set_gray_1_2_4_to_8() was removed. It has been deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with png_set_expand_gray_1_2_4_to_8() because the former function also -expanded palette images. +expanded any tRNS chunk to an alpha channel. Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32 were added and are used by default instead of the corresponding functions. Unfortunately, -from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. We changed the prototype for png_malloc() from @@ -4577,7 +5107,8 @@ The png_zalloc() function no longer zeroes out the memory that it allocates. Support for dithering was disabled by default in libpng-1.4.0, because -been well tested and doesn't actually "dither". The code was not +it has not been well tested and doesn't actually "dither". +The code was not removed, however, and could be enabled by building libpng with PNG_READ_DITHER_SUPPORTED defined. In libpng-1.4.2, this support was reenabled, but the function was renamed png_set_quantize() to @@ -4590,9 +5121,19 @@ We removed the trailing '.' from the warning and error messages. .SH X. Changes to Libpng from version 1.4.x to 1.5.x -From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. +Checking for invalid palette index on read or write was added at libpng +1.5.10. When an invalid index is found, libpng issues a benign error. +This is enabled by default but can be disabled in each png_ptr with + + png_set_check_for_invalid_index(png_ptr, allowed); + + allowed - one of + 0: disable + 1: enable + A. Changes that affect users of libpng There are no substantial API changes between the non-deprecated parts of @@ -4614,10 +5155,9 @@ In png_get_iCCP, the type of "profile" was changed from png_charpp to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep. There are changes of form in png.h, including new and changed macros to -declare -parts of the API. Some API functions with arguments that are pointers to -data not modified within the function have been corrected to declare -these arguments with PNG_CONST. +declare parts of the API. Some API functions with arguments that are +pointers to data not modified within the function have been corrected to +declare these arguments with PNG_CONST. Much of the internal use of C macros to control the library build has also changed and some of this is visible in the exported header files, in @@ -4627,7 +5167,8 @@ application code. (It is extremely rare for an application to do this.) Any program that compiled against libpng 1.4 and did not use deprecated features or access internal library structures should compile and work -against libpng 1.5. +against libpng 1.5, except for the change in the prototype for +png_get_iCCP() and png_set_iCCP() API functions mentioned above. libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of interlaced images. The macros return the number of rows and columns in @@ -4635,10 +5176,10 @@ each pass and information that can be used to de-interlace and (if absolutely necessary) interlace an image. libpng 1.5.0 adds an API png_longjmp(png_ptr, value). This API calls -the application provided png_longjmp_ptr on the internal, but application -initialized, jmpbuf. It is provided as a convenience to avoid the need -to use the png_jmpbuf macro, which had the unnecessary side effect of -resetting the internal png_longjmp_ptr value. +the application-provided png_longjmp_ptr on the internal, but application +initialized, longjmp buffer. It is provided as a convenience to avoid +the need to use the png_jmpbuf macro, which had the unnecessary side +effect of resetting the internal png_longjmp_ptr value. libpng 1.5.0 includes a complete fixed point API. By default this is present along with the corresponding floating point API. In general the @@ -4681,7 +5222,7 @@ reset by pngusr.h or by explicit settings on the compiler command line. These settings may produce compiler warnings or errors in 1.5.0 because of macro redefinition. -From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. libpng 1.5.0 is consistent with the implementation in 1.4.5 and 1.2.x (where the macro did not exist.) @@ -4690,14 +5231,47 @@ Applications can now choose whether to use these macros or to call the corresponding function by defining PNG_USE_READ_MACROS or PNG_NO_USE_READ_MACROS before including png.h. Notice that this is only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0 - will lead to a link failure. +will lead to a link failure. + +Prior to libpng-1.5.4, the zlib compressor used the same set of parameters +when compressing the IDAT data and textual data such as zTXt and iCCP. +In libpng-1.5.4 we reinitialized the zlib stream for each type of data. +We added five png_set_text_*() functions for setting the parameters to +use with textual data. + +Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED +option was off by default, and slightly inaccurate scaling occurred. +This option can no longer be turned off, and the choice of accurate +or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8() +API for accurate scaling or the old png_set_strip_16_to_8() API for simple +chopping. + +Prior to libpng-1.5.4, the png_set_user_limits() function could only be +used to reduce the width and height limits from the value of +PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said +that it could be used to override them. Now this function will reduce or +increase the limits. + +Starting in libpng-1.5.10, the user limits can be set en masse with the +configuration option PNG_SAFE_LIMITS_SUPPORTED. If this option is enabled, +a set of "safe" limits is applied in pngpriv.h. These can be overridden by +application calls to png_set_user_limits(), png_set_user_chunk_cache_max(), +and/or png_set_user_malloc_max() that increase or decrease the limits. Also, +in libpng-1.5.10 the default width and height limits were increased +from 1,000,000 to 0x7ffffff (i.e., made unlimited). Therefore, the +limits are now + default safe + png_user_width_max 0x7fffffff 1,000,000 + png_user_height_max 0x7fffffff 1,000,000 + png_user_chunk_cache_max 0 (unlimited) 128 + png_user_chunk_malloc_max 0 (unlimited) 8,000,000 B. Changes to the build and configuration of libpng Details of internal changes to the library code can be found in the CHANGES -file. These will be of no concern to the vast majority of library users or -builders, however the few who configure libpng to a non-default feature -set may need to change how this is done. +file and in the GIT repository logs. These will be of no concern to the vast +majority of library users or builders, however the few who configure libpng +to a non-default feature set may need to change how this is done. There should be no need for library builders to alter build scripts if these use the distributed build support - configure or the makefiles - @@ -4706,14 +5280,14 @@ to build pnglibconf.h where the corresponding makefile does not do so. Building libpng with a non-default configuration has changed completely. The old method using pngusr.h should still work correctly even though the -way pngusr.h is used in the build has been changed, however library +way pngusr.h is used in the build has been changed; however, library builders will probably want to examine the changes to take advantage of new capabilities and to simplify their build system. B.1 Specific changes to library configuration capabilities The library now supports a complete fixed point implementation and can -thus be used on systems which have no floating point support or very +thus be used on systems that have no floating point support or very limited or slow support. Previously gamma correction, an essential part of complete PNG support, required reasonably fast floating point. @@ -4729,14 +5303,14 @@ pnglibconf.h As part of this the mechanism used to choose procedure call standards on those systems that allow a choice has been changed. At present this only affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems -running on Intel processors. As before PNGAPI is defined where required +running on Intel processors. As before, PNGAPI is defined where required to control the exported API functions; however, two new macros, PNGCBAPI and PNGCAPI, are used instead for callback functions (PNGCBAPI) and (PNGCAPI) for functions that must match a C library prototype (currently only png_longjmp_ptr, which must match the C longjmp function.) The new approach is documented in pngconf.h -Despite these changes libpng 1.5.0 only supports the native C function +Despite these changes, libpng 1.5.0 only supports the native C function calling standard on those platforms tested so far (__cdecl on Microsoft Windows). This is because the support requirements for alternative calling conventions seem to no longer exist. Developers who find it @@ -4769,8 +5343,10 @@ if the feature is supported or: /*#undef PNG_feature_SUPPORTED*/ if it is not. Library code consistently checks for the 'SUPPORTED' macro. -It does not, and should not, check for the 'NO' macro which will not -normally be defined even if the feature is not supported. +It does not, and libpng applications should not, check for the 'NO' macro +which will not normally be defined even if the feature is not supported. +The 'NO' macros are only used internally for setting or not setting the +corresponding 'SUPPORTED' macros. Compatibility with the old names is provided as follows: @@ -4827,10 +5403,10 @@ application built without PNG_USER_CONFIG defined would see the unmodified, default, libpng API and thus would probably fail to link. These mechanisms still work in the configure build and in any makefile -build that builds pnglibconf.h although the feature selection macros +build that builds pnglibconf.h, although the feature selection macros have changed somewhat as described above. In 1.5.0, however, pngusr.h is processed only once, when the exported header file pnglibconf.h is built. -pngconf.h no longer includes pngusr.h, therefore it is ignored after the +pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the build of pnglibconf.h and it is never included in an application build. The rarely used alternative of adding a list of feature macros to the @@ -4844,7 +5420,7 @@ scripts/pnglibconf.dfa. This requires the program awk. Brian Kernighan and all known later implementations (often called by subtly different names - nawk and gawk for example) are adequate to build pnglibconf.h. The Sun Microsystems (now Oracle) program 'awk' is an earlier version -and does not work, this may also apply to other systems that have a +and does not work; this may also apply to other systems that have a functioning awk called 'nawk'. Configuration options are now documented in scripts/pnglibconf.dfa. This @@ -4886,8 +5462,8 @@ the libpng bug tracker at We also accept patches built from the tar or zip distributions, and simple verbal discriptions of bug fixes, reported either to the -SourceForge bug tracker or to the png-mng-implement at lists.sf.net -mailing list. +SourceForge bug tracker, to the png-mng-implement at lists.sf.net +mailing list, or directly to glennrp. .SH XIII. Coding style @@ -4975,8 +5551,8 @@ above the comment that says /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */ To avoid polluting the global namespace, the names of all exported -functions and variables begin with "png_", and all publicly visible C -preprocessor macros begin with "PNG_". We request that applications that +functions and variables begin with "png_", and all publicly visible C +preprocessor macros begin with "PNG". We request that applications that use libpng *not* begin any of their own symbols with either of these strings. We put a space after each comma and after each semicolon @@ -4992,6 +5568,9 @@ left parenthesis that follows it: We prefer #ifdef and #ifndef to #if defined() and if !defined() when there is only one macro being tested. +We prefer to express integers that are used as bit masks in hex format, +with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100). + We do not use the TAB character for indentation in the C sources. Lines do not exceed 80 characters. @@ -5000,13 +5579,13 @@ Other rules can be inferred by inspecting the libpng source. .SH XIV. Y2K Compliance in libpng -February 3, 2011 +March 29, 2012 Since the PNG Development group is an ad-hoc body, we can't make an official declaration. This is your unofficial assurance that libpng from version 0.71 and -upward through 1.5.1 are Y2K compliant. It is my belief that earlier +upward through 1.5.10 are Y2K compliant. It is my belief that earlier versions were also Y2K compliant. Libpng only has three year fields. One is a 2-byte unsigned integer that @@ -5192,6 +5771,33 @@ the first widely used release: 1.5.1beta01-11 15 10501 15.so.15.1[.0] 1.5.1rc01-02 15 10501 15.so.15.1[.0] 1.5.1 15 10501 15.so.15.1[.0] + 1.5.2beta01-03 15 10502 15.so.15.2[.0] + 1.5.2rc01-03 15 10502 15.so.15.2[.0] + 1.5.2 15 10502 15.so.15.2[.0] + 1.5.3beta01-10 15 10503 15.so.15.3[.0] + 1.5.3rc01-02 15 10503 15.so.15.3[.0] + 1.5.3beta11 15 10503 15.so.15.3[.0] + 1.5.3 [omitted] + 1.5.4beta01-08 15 10504 15.so.15.4[.0] + 1.5.4rc01 15 10504 15.so.15.4[.0] + 1.5.4 15 10504 15.so.15.4[.0] + 1.5.5beta01-08 15 10505 15.so.15.5[.0] + 1.5.5rc01 15 10505 15.so.15.5[.0] + 1.5.5 15 10505 15.so.15.5[.0] + 1.5.6beta01-07 15 10506 15.so.15.6[.0] + 1.5.6rc01-03 15 10506 15.so.15.6[.0] + 1.5.6 15 10506 15.so.15.6[.0] + 1.5.7beta01-05 15 10507 15.so.15.7[.0] + 1.5.7rc01-03 15 10507 15.so.15.7[.0] + 1.5.7 15 10507 15.so.15.7[.0] + 1.5.8beta01 15 10508 15.so.15.8[.0] + 1.5.8rc01 15 10508 15.so.15.8[.0] + 1.5.8 15 10508 15.so.15.8[.0] + 1.5.9beta01-02 15 10509 15.so.15.9[.0] + 1.5.9rc01 15 10509 15.so.15.9[.0] + 1.5.9 15 10509 15.so.15.9[.0] + 1.5.10beta01-05 15 10510 15.so.15.10[.0] + 1.5.10 15 10510 15.so.15.10[.0] Henceforth the source version will match the shared-library minor and patch numbers; the shared-library major version number will be @@ -5248,7 +5854,7 @@ possible without all of you. Thanks to Frank J. T. Wojcik for helping with the documentation. -Libpng version 1.5.1 - February 3, 2011: +Libpng version 1.5.10 - March 29, 2012: Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc. Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net). @@ -5271,7 +5877,7 @@ this sentence. This code is released under the libpng license. -libpng versions 1.2.6, August 15, 2004, through 1.5.1, February 3, 2011, are +libpng versions 1.2.6, August 15, 2004, through 1.5.10, March 29, 2012, are Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are distributed according to the same disclaimer and license as libpng-1.2.5 with the following individual added to the list of Contributing Authors @@ -5370,7 +5976,7 @@ certification mark of the Open Source Initiative. Glenn Randers-Pehrson glennrp at users.sourceforge.net -February 3, 2011 +March 29, 2012 .\" end of man page diff --git a/png/libpngpf.3 b/png/libpngpf.3 index ff6e1641e..8449f173f 100644 --- a/png/libpngpf.3 +++ b/png/libpngpf.3 @@ -1,6 +1,6 @@ -.TH LIBPNGPF 3 "February 3, 2011" +.TH LIBPNGPF 3 "March 29, 2012" .SH NAME -libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 +libpng \- Portable Network Graphics (PNG) Reference Library 1.5.10 (private functions) .SH SYNOPSIS \fB#include \fI"pngpriv.h" @@ -18,11 +18,9 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 \fI\fB .SH DESCRIPTION -The functions previously listed here are used privately by libpng +The functions previously listed here are used privately by libpng and are not recommended for use by applications. They are -not "exported" to applications using shared libraries. They -are listed alphabetically here as an aid to libpng maintainers. -See pngpriv.h for more information on these functions. +not "exported" to applications using shared libraries. .SH SEE ALSO .BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5) @@ -1,4 +1,4 @@ -.TH PNG 5 "February 3, 2011" +.TH PNG 5 "March 29, 2012" .SH NAME png \- Portable Network Graphics (PNG) format .SH DESCRIPTION @@ -1,8 +1,8 @@ /* png.c - location for general purpose libpng functions * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -14,7 +14,7 @@ #include "pngpriv.h" /* Generate a compiler error if there is an old png.h in the search path. */ -typedef png_libpng_version_1_5_1 Your_png_h_is_not_version_1_5_1; +typedef png_libpng_version_1_5_10 Your_png_h_is_not_version_1_5_10; /* Tells libpng that we have already handled the first "num_bytes" bytes * of the PNG file signature. If the PNG data is embedded into another @@ -43,7 +43,7 @@ png_set_sig_bytes(png_structp png_ptr, int num_bytes) * can simply check the remaining bytes for extra assurance. Returns * an integer less than, equal to, or greater than zero if sig is found, * respectively, to be less than, to match, or be greater than the correct - * PNG signature (this is the same behaviour as strcmp, memcmp, etc). + * PNG signature (this is the same behavior as strcmp, memcmp, etc). */ int PNGAPI png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check) @@ -107,7 +107,8 @@ png_zfree(voidpf png_ptr, voidpf ptr) void /* PRIVATE */ png_reset_crc(png_structp png_ptr) { - png_ptr->crc = crc32(0, Z_NULL, 0); + /* The cast is safe because the crc is a 32 bit value. */ + png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0); } /* Calculate the CRC over a section of data. We can only pass as @@ -120,21 +121,103 @@ png_calculate_crc(png_structp png_ptr, png_const_bytep ptr, png_size_t length) { int need_crc = 1; - if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name)) { if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) need_crc = 0; } - else /* critical */ + else /* critical */ { if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) need_crc = 0; } - if (need_crc) - png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length); + /* 'uLong' is defined as unsigned long, this means that on some systems it is + * a 64 bit value. crc32, however, returns 32 bits so the following cast is + * safe. 'uInt' may be no more than 16 bits, so it is necessary to perform a + * loop here. + */ + if (need_crc && length > 0) + { + uLong crc = png_ptr->crc; /* Should never issue a warning */ + + do + { + uInt safeLength = (uInt)length; + if (safeLength == 0) + safeLength = (uInt)-1; /* evil, but safe */ + + crc = crc32(crc, ptr, safeLength); + + /* The following should never issue compiler warnings, if they do the + * target system has characteristics that will probably violate other + * assumptions within the libpng code. + */ + ptr += safeLength; + length -= safeLength; + } + while (length > 0); + + /* And the following is always safe because the crc is only 32 bits. */ + png_ptr->crc = (png_uint_32)crc; + } +} + +/* Check a user supplied version number, called from both read and write + * functions that create a png_struct + */ +int +png_user_version_check(png_structp png_ptr, png_const_charp user_png_ver) +{ + if (user_png_ver) + { + int i = 0; + + do + { + if (user_png_ver[i] != png_libpng_ver[i]) + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + } while (png_libpng_ver[i++]); + } + + else + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + + if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) + { + /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so + * we must recompile any applications that use any older library version. + * For versions after libpng 1.0, we will be compatible, so we need + * only check the first digit. + */ + if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || + (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || + (user_png_ver[0] == '0' && user_png_ver[2] < '9')) + { +#ifdef PNG_WARNINGS_SUPPORTED + size_t pos = 0; + char m[128]; + + pos = png_safecat(m, sizeof m, pos, "Application built with libpng-"); + pos = png_safecat(m, sizeof m, pos, user_png_ver); + pos = png_safecat(m, sizeof m, pos, " but running with "); + pos = png_safecat(m, sizeof m, pos, png_libpng_ver); + + png_warning(png_ptr, m); +#endif + +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + png_ptr->flags = 0; +#endif + + return 0; + } + } + + /* Success return. */ + return 1; } /* Allocate the memory for an info_struct for the application. We don't @@ -291,12 +374,10 @@ png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask, /* Free any sCAL entry */ if ((mask & PNG_FREE_SCAL) & info_ptr->free_me) { -#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) png_free(png_ptr, info_ptr->scal_s_width); png_free(png_ptr, info_ptr->scal_s_height); info_ptr->scal_s_width = NULL; info_ptr->scal_s_height = NULL; -#endif info_ptr->valid &= ~PNG_INFO_sCAL; } #endif @@ -489,8 +570,8 @@ png_get_io_ptr(png_structp png_ptr) /* Initialize the default input/output functions for the PNG file. If you * use your own read or write routines, you can call either png_set_read_fn() * or png_set_write_fn() instead of png_init_io(). If you have defined - * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't - * necessarily available. + * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a + * function of your own because "FILE *" isn't necessarily available. */ void PNGAPI png_init_io(png_structp png_ptr, png_FILE_p fp) @@ -518,28 +599,47 @@ png_convert_to_rfc1123(png_structp png_ptr, png_const_timep ptime) if (png_ptr == NULL) return (NULL); - if (png_ptr->time_buffer == NULL) + if (ptime->year > 9999 /* RFC1123 limitation */ || + ptime->month == 0 || ptime->month > 12 || + ptime->day == 0 || ptime->day > 31 || + ptime->hour > 23 || ptime->minute > 59 || + ptime->second > 60) { - png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29* - png_sizeof(char))); + png_warning(png_ptr, "Ignoring invalid time value"); + return (NULL); } -# ifdef USE_FAR_KEYWORD { - char near_time_buf[29]; - png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000", - ptime->day % 32, short_months[(ptime->month - 1) % 12], - ptime->year, ptime->hour % 24, ptime->minute % 60, - ptime->second % 61); - png_memcpy(png_ptr->time_buffer, near_time_buf, - 29*png_sizeof(char)); + size_t pos = 0; + char number_buf[5]; /* enough for a four-digit year */ + +# define APPEND_STRING(string)\ + pos = png_safecat(png_ptr->time_buffer, sizeof png_ptr->time_buffer,\ + pos, (string)) +# define APPEND_NUMBER(format, value)\ + APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value))) +# define APPEND(ch)\ + if (pos < (sizeof png_ptr->time_buffer)-1)\ + png_ptr->time_buffer[pos++] = (ch) + + APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day); + APPEND(' '); + APPEND_STRING(short_months[(ptime->month - 1)]); + APPEND(' '); + APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year); + APPEND(' '); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour); + APPEND(':'); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute); + APPEND(':'); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second); + APPEND_STRING(" +0000"); /* This reliably terminates the buffer */ + +# undef APPEND +# undef APPEND_NUMBER +# undef APPEND_STRING } -# else - png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000", - ptime->day % 32, short_months[(ptime->month - 1) % 12], - ptime->year, ptime->hour % 24, ptime->minute % 60, - ptime->second % 61); -# endif + return png_ptr->time_buffer; } # endif /* PNG_TIME_RFC1123_SUPPORTED */ @@ -555,13 +655,13 @@ png_get_copyright(png_const_structp png_ptr) #else # ifdef __STDC__ return PNG_STRING_NEWLINE \ - "libpng version 1.5.1 - February 3, 2011" PNG_STRING_NEWLINE \ + "libpng version 1.5.10 - March 29, 2012" PNG_STRING_NEWLINE \ "Copyright (c) 1998-2011 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \ "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \ "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \ PNG_STRING_NEWLINE; # else - return "libpng version 1.5.1 - February 3, 2011\ + return "libpng version 1.5.10 - March 29, 2012\ Copyright (c) 1998-2011 Glenn Randers-Pehrson\ Copyright (c) 1996-1997 Andreas Dilger\ Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc."; @@ -608,25 +708,43 @@ png_get_header_version(png_const_structp png_ptr) #endif } -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) -# ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED int PNGAPI png_handle_as_unknown(png_structp png_ptr, png_const_bytep chunk_name) { /* Check chunk_name and return "keep" value if it's on the list, else 0 */ - int i; - png_bytep p; - if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0) - return 0; + png_const_bytep p, p_end; + + if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list <= 0) + return PNG_HANDLE_CHUNK_AS_DEFAULT; - p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5; - for (i = png_ptr->num_chunk_list; i; i--, p -= 5) + p_end = png_ptr->chunk_list; + p = p_end + png_ptr->num_chunk_list*5; /* beyond end */ + + /* The code is the fifth byte after each four byte string. Historically this + * code was always searched from the end of the list, so it should continue + * to do so in case there are duplicated entries. + */ + do /* num_chunk_list > 0, so at least one */ + { + p -= 5; if (!png_memcmp(chunk_name, p, 4)) - return ((int)*(p + 4)); - return 0; + return p[4]; + } + while (p > p_end); + + return PNG_HANDLE_CHUNK_AS_DEFAULT; } -# endif -#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ + +int /* PRIVATE */ +png_chunk_unknown_handling(png_structp png_ptr, png_uint_32 chunk_name) +{ + png_byte chunk_string[5]; + + PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name); + return png_handle_as_unknown(png_ptr, chunk_string); +} +#endif #ifdef PNG_READ_SUPPORTED /* This function, added to libpng-1.0.6g, is untested. */ @@ -651,18 +769,9 @@ png_access_version_number(void) #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) -# ifdef PNG_SIZE_T -/* Added at libpng version 1.2.6 */ - PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size)); -png_size_t PNGAPI -png_convert_size(size_t size) -{ - if (size > (png_size_t)-1) - PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */ - - return ((png_size_t)size); -} -# endif /* PNG_SIZE_T */ +/* png_convert_size: a PNGAPI but no longer in png.h, so deleted + * at libpng 1.5.5! + */ /* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */ # ifdef PNG_CHECK_cHRM_SUPPORTED @@ -681,6 +790,13 @@ png_check_cHRM_fixed(png_structp png_ptr, if (png_ptr == NULL) return 0; + /* (x,y,z) values are first limited to 0..100000 (PNG_FP_1), the white + * y must also be greater than 0. To test for the upper limit calculate + * (PNG_FP_1-y) - x must be <= to this for z to be >= 0 (and the expression + * cannot overflow.) At this point we know x and y are >= 0 and (x+y) is + * <= PNG_FP_1. The previous test on PNG_MAX_UINT_31 is removed because it + * pointless (and it produces compiler warnings!) + */ if (white_x < 0 || white_y <= 0 || red_x < 0 || red_y < 0 || green_x < 0 || green_y < 0 || @@ -690,38 +806,26 @@ png_check_cHRM_fixed(png_structp png_ptr, "Ignoring attempt to set negative chromaticity value"); ret = 0; } - if (white_x > (png_fixed_point)PNG_UINT_31_MAX || - white_y > (png_fixed_point)PNG_UINT_31_MAX || - red_x > (png_fixed_point)PNG_UINT_31_MAX || - red_y > (png_fixed_point)PNG_UINT_31_MAX || - green_x > (png_fixed_point)PNG_UINT_31_MAX || - green_y > (png_fixed_point)PNG_UINT_31_MAX || - blue_x > (png_fixed_point)PNG_UINT_31_MAX || - blue_y > (png_fixed_point)PNG_UINT_31_MAX ) - { - png_warning(png_ptr, - "Ignoring attempt to set chromaticity value exceeding 21474.83"); - ret = 0; - } - if (white_x > 100000L - white_y) + /* And (x+y) must be <= PNG_FP_1 (so z is >= 0) */ + if (white_x > PNG_FP_1 - white_y) { png_warning(png_ptr, "Invalid cHRM white point"); ret = 0; } - if (red_x > 100000L - red_y) + if (red_x > PNG_FP_1 - red_y) { png_warning(png_ptr, "Invalid cHRM red point"); ret = 0; } - if (green_x > 100000L - green_y) + if (green_x > PNG_FP_1 - green_y) { png_warning(png_ptr, "Invalid cHRM green point"); ret = 0; } - if (blue_x > 100000L - blue_y) + if (blue_x > PNG_FP_1 - blue_y) { png_warning(png_ptr, "Invalid cHRM blue point"); ret = 0; @@ -741,6 +845,326 @@ png_check_cHRM_fixed(png_structp png_ptr, } # endif /* PNG_CHECK_cHRM_SUPPORTED */ +#ifdef PNG_cHRM_SUPPORTED +/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for + * cHRM, as opposed to using chromaticities. These internal APIs return + * non-zero on a parameter error. The X, Y and Z values are required to be + * positive and less than 1.0. + */ +int png_xy_from_XYZ(png_xy *xy, png_XYZ XYZ) +{ + png_int_32 d, dwhite, whiteX, whiteY; + + d = XYZ.redX + XYZ.redY + XYZ.redZ; + if (!png_muldiv(&xy->redx, XYZ.redX, PNG_FP_1, d)) return 1; + if (!png_muldiv(&xy->redy, XYZ.redY, PNG_FP_1, d)) return 1; + dwhite = d; + whiteX = XYZ.redX; + whiteY = XYZ.redY; + + d = XYZ.greenX + XYZ.greenY + XYZ.greenZ; + if (!png_muldiv(&xy->greenx, XYZ.greenX, PNG_FP_1, d)) return 1; + if (!png_muldiv(&xy->greeny, XYZ.greenY, PNG_FP_1, d)) return 1; + dwhite += d; + whiteX += XYZ.greenX; + whiteY += XYZ.greenY; + + d = XYZ.blueX + XYZ.blueY + XYZ.blueZ; + if (!png_muldiv(&xy->bluex, XYZ.blueX, PNG_FP_1, d)) return 1; + if (!png_muldiv(&xy->bluey, XYZ.blueY, PNG_FP_1, d)) return 1; + dwhite += d; + whiteX += XYZ.blueX; + whiteY += XYZ.blueY; + + /* The reference white is simply the same of the end-point (X,Y,Z) vectors, + * thus: + */ + if (!png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite)) return 1; + if (!png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite)) return 1; + + return 0; +} + +int png_XYZ_from_xy(png_XYZ *XYZ, png_xy xy) +{ + png_fixed_point red_inverse, green_inverse, blue_scale; + png_fixed_point left, right, denominator; + + /* Check xy and, implicitly, z. Note that wide gamut color spaces typically + * have end points with 0 tristimulus values (these are impossible end + * points, but they are used to cover the possible colors.) + */ + if (xy.redx < 0 || xy.redx > PNG_FP_1) return 1; + if (xy.redy < 0 || xy.redy > PNG_FP_1-xy.redx) return 1; + if (xy.greenx < 0 || xy.greenx > PNG_FP_1) return 1; + if (xy.greeny < 0 || xy.greeny > PNG_FP_1-xy.greenx) return 1; + if (xy.bluex < 0 || xy.bluex > PNG_FP_1) return 1; + if (xy.bluey < 0 || xy.bluey > PNG_FP_1-xy.bluex) return 1; + if (xy.whitex < 0 || xy.whitex > PNG_FP_1) return 1; + if (xy.whitey < 0 || xy.whitey > PNG_FP_1-xy.whitex) return 1; + + /* The reverse calculation is more difficult because the original tristimulus + * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8 + * derived values were recorded in the cHRM chunk; + * (red,green,blue,white)x(x,y). This loses one degree of freedom and + * therefore an arbitrary ninth value has to be introduced to undo the + * original transformations. + * + * Think of the original end-points as points in (X,Y,Z) space. The + * chromaticity values (c) have the property: + * + * C + * c = --------- + * X + Y + Z + * + * For each c (x,y,z) from the corresponding original C (X,Y,Z). Thus the + * three chromaticity values (x,y,z) for each end-point obey the + * relationship: + * + * x + y + z = 1 + * + * This describes the plane in (X,Y,Z) space that intersects each axis at the + * value 1.0; call this the chromaticity plane. Thus the chromaticity + * calculation has scaled each end-point so that it is on the x+y+z=1 plane + * and chromaticity is the intersection of the vector from the origin to the + * (X,Y,Z) value with the chromaticity plane. + * + * To fully invert the chromaticity calculation we would need the three + * end-point scale factors, (red-scale, green-scale, blue-scale), but these + * were not recorded. Instead we calculated the reference white (X,Y,Z) and + * recorded the chromaticity of this. The reference white (X,Y,Z) would have + * given all three of the scale factors since: + * + * color-C = color-c * color-scale + * white-C = red-C + green-C + blue-C + * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale + * + * But cHRM records only white-x and white-y, so we have lost the white scale + * factor: + * + * white-C = white-c*white-scale + * + * To handle this the inverse transformation makes an arbitrary assumption + * about white-scale: + * + * Assume: white-Y = 1.0 + * Hence: white-scale = 1/white-y + * Or: red-Y + green-Y + blue-Y = 1.0 + * + * Notice the last statement of the assumption gives an equation in three of + * the nine values we want to calculate. 8 more equations come from the + * above routine as summarised at the top above (the chromaticity + * calculation): + * + * Given: color-x = color-X / (color-X + color-Y + color-Z) + * Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0 + * + * This is 9 simultaneous equations in the 9 variables "color-C" and can be + * solved by Cramer's rule. Cramer's rule requires calculating 10 9x9 matrix + * determinants, however this is not as bad as it seems because only 28 of + * the total of 90 terms in the various matrices are non-zero. Nevertheless + * Cramer's rule is notoriously numerically unstable because the determinant + * calculation involves the difference of large, but similar, numbers. It is + * difficult to be sure that the calculation is stable for real world values + * and it is certain that it becomes unstable where the end points are close + * together. + * + * So this code uses the perhaps slighly less optimal but more understandable + * and totally obvious approach of calculating color-scale. + * + * This algorithm depends on the precision in white-scale and that is + * (1/white-y), so we can immediately see that as white-y approaches 0 the + * accuracy inherent in the cHRM chunk drops off substantially. + * + * libpng arithmetic: a simple invertion of the above equations + * ------------------------------------------------------------ + * + * white_scale = 1/white-y + * white-X = white-x * white-scale + * white-Y = 1.0 + * white-Z = (1 - white-x - white-y) * white_scale + * + * white-C = red-C + green-C + blue-C + * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale + * + * This gives us three equations in (red-scale,green-scale,blue-scale) where + * all the coefficients are now known: + * + * red-x*red-scale + green-x*green-scale + blue-x*blue-scale + * = white-x/white-y + * red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1 + * red-z*red-scale + green-z*green-scale + blue-z*blue-scale + * = (1 - white-x - white-y)/white-y + * + * In the last equation color-z is (1 - color-x - color-y) so we can add all + * three equations together to get an alternative third: + * + * red-scale + green-scale + blue-scale = 1/white-y = white-scale + * + * So now we have a Cramer's rule solution where the determinants are just + * 3x3 - far more tractible. Unfortunately 3x3 determinants still involve + * multiplication of three coefficients so we can't guarantee to avoid + * overflow in the libpng fixed point representation. Using Cramer's rule in + * floating point is probably a good choice here, but it's not an option for + * fixed point. Instead proceed to simplify the first two equations by + * eliminating what is likely to be the largest value, blue-scale: + * + * blue-scale = white-scale - red-scale - green-scale + * + * Hence: + * + * (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale = + * (white-x - blue-x)*white-scale + * + * (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale = + * 1 - blue-y*white-scale + * + * And now we can trivially solve for (red-scale,green-scale): + * + * green-scale = + * (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale + * ----------------------------------------------------------- + * green-x - blue-x + * + * red-scale = + * 1 - blue-y*white-scale - (green-y - blue-y) * green-scale + * --------------------------------------------------------- + * red-y - blue-y + * + * Hence: + * + * red-scale = + * ( (green-x - blue-x) * (white-y - blue-y) - + * (green-y - blue-y) * (white-x - blue-x) ) / white-y + * ------------------------------------------------------------------------- + * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x) + * + * green-scale = + * ( (red-y - blue-y) * (white-x - blue-x) - + * (red-x - blue-x) * (white-y - blue-y) ) / white-y + * ------------------------------------------------------------------------- + * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x) + * + * Accuracy: + * The input values have 5 decimal digits of accuracy. The values are all in + * the range 0 < value < 1, so simple products are in the same range but may + * need up to 10 decimal digits to preserve the original precision and avoid + * underflow. Because we are using a 32-bit signed representation we cannot + * match this; the best is a little over 9 decimal digits, less than 10. + * + * The approach used here is to preserve the maximum precision within the + * signed representation. Because the red-scale calculation above uses the + * difference between two products of values that must be in the range -1..+1 + * it is sufficient to divide the product by 7; ceil(100,000/32767*2). The + * factor is irrelevant in the calculation because it is applied to both + * numerator and denominator. + * + * Note that the values of the differences of the products of the + * chromaticities in the above equations tend to be small, for example for + * the sRGB chromaticities they are: + * + * red numerator: -0.04751 + * green numerator: -0.08788 + * denominator: -0.2241 (without white-y multiplication) + * + * The resultant Y coefficients from the chromaticities of some widely used + * color space definitions are (to 15 decimal places): + * + * sRGB + * 0.212639005871510 0.715168678767756 0.072192315360734 + * Kodak ProPhoto + * 0.288071128229293 0.711843217810102 0.000085653960605 + * Adobe RGB + * 0.297344975250536 0.627363566255466 0.075291458493998 + * Adobe Wide Gamut RGB + * 0.258728243040113 0.724682314948566 0.016589442011321 + */ + /* By the argument, above overflow should be impossible here. The return + * value of 2 indicates an internal error to the caller. + */ + if (!png_muldiv(&left, xy.greenx-xy.bluex, xy.redy - xy.bluey, 7)) return 2; + if (!png_muldiv(&right, xy.greeny-xy.bluey, xy.redx - xy.bluex, 7)) return 2; + denominator = left - right; + + /* Now find the red numerator. */ + if (!png_muldiv(&left, xy.greenx-xy.bluex, xy.whitey-xy.bluey, 7)) return 2; + if (!png_muldiv(&right, xy.greeny-xy.bluey, xy.whitex-xy.bluex, 7)) return 2; + + /* Overflow is possible here and it indicates an extreme set of PNG cHRM + * chunk values. This calculation actually returns the reciprocal of the + * scale value because this allows us to delay the multiplication of white-y + * into the denominator, which tends to produce a small number. + */ + if (!png_muldiv(&red_inverse, xy.whitey, denominator, left-right) || + red_inverse <= xy.whitey /* r+g+b scales = white scale */) + return 1; + + /* Similarly for green_inverse: */ + if (!png_muldiv(&left, xy.redy-xy.bluey, xy.whitex-xy.bluex, 7)) return 2; + if (!png_muldiv(&right, xy.redx-xy.bluex, xy.whitey-xy.bluey, 7)) return 2; + if (!png_muldiv(&green_inverse, xy.whitey, denominator, left-right) || + green_inverse <= xy.whitey) + return 1; + + /* And the blue scale, the checks above guarantee this can't overflow but it + * can still produce 0 for extreme cHRM values. + */ + blue_scale = png_reciprocal(xy.whitey) - png_reciprocal(red_inverse) - + png_reciprocal(green_inverse); + if (blue_scale <= 0) return 1; + + + /* And fill in the png_XYZ: */ + if (!png_muldiv(&XYZ->redX, xy.redx, PNG_FP_1, red_inverse)) return 1; + if (!png_muldiv(&XYZ->redY, xy.redy, PNG_FP_1, red_inverse)) return 1; + if (!png_muldiv(&XYZ->redZ, PNG_FP_1 - xy.redx - xy.redy, PNG_FP_1, + red_inverse)) + return 1; + + if (!png_muldiv(&XYZ->greenX, xy.greenx, PNG_FP_1, green_inverse)) return 1; + if (!png_muldiv(&XYZ->greenY, xy.greeny, PNG_FP_1, green_inverse)) return 1; + if (!png_muldiv(&XYZ->greenZ, PNG_FP_1 - xy.greenx - xy.greeny, PNG_FP_1, + green_inverse)) + return 1; + + if (!png_muldiv(&XYZ->blueX, xy.bluex, blue_scale, PNG_FP_1)) return 1; + if (!png_muldiv(&XYZ->blueY, xy.bluey, blue_scale, PNG_FP_1)) return 1; + if (!png_muldiv(&XYZ->blueZ, PNG_FP_1 - xy.bluex - xy.bluey, blue_scale, + PNG_FP_1)) + return 1; + + return 0; /*success*/ +} + +int png_XYZ_from_xy_checked(png_structp png_ptr, png_XYZ *XYZ, png_xy xy) +{ + switch (png_XYZ_from_xy(XYZ, xy)) + { + case 0: /* success */ + return 1; + + case 1: + /* The chunk may be technically valid, but we got png_fixed_point + * overflow while trying to get XYZ values out of it. This is + * entirely benign - the cHRM chunk is pretty extreme. + */ + png_warning(png_ptr, + "extreme cHRM chunk cannot be converted to tristimulus values"); + break; + + default: + /* libpng is broken; this should be a warning but if it happens we + * want error reports so for the moment it is an error. + */ + png_error(png_ptr, "internal error in png_XYZ_from_xy"); + break; + } + + /* ERROR RETURN */ + return 0; +} +#endif + void /* PRIVATE */ png_check_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, @@ -763,7 +1187,7 @@ png_check_IHDR(png_structp png_ptr, } # ifdef PNG_SET_USER_LIMITS_SUPPORTED - if (width > png_ptr->user_width_max || width > PNG_USER_WIDTH_MAX) + if (width > png_ptr->user_width_max) # else if (width > PNG_USER_WIDTH_MAX) @@ -774,7 +1198,7 @@ png_check_IHDR(png_structp png_ptr, } # ifdef PNG_SET_USER_LIMITS_SUPPORTED - if (height > png_ptr->user_height_max || height > PNG_USER_HEIGHT_MAX) + if (height > png_ptr->user_height_max) # else if (height > PNG_USER_HEIGHT_MAX) # endif @@ -889,16 +1313,9 @@ png_check_IHDR(png_structp png_ptr, /* Check an ASCII formated floating point value, see the more detailed * comments in pngpriv.h */ -/* The following is used internally to preserve the 'valid' flag */ +/* The following is used internally to preserve the sticky flags */ #define png_fp_add(state, flags) ((state) |= (flags)) -#define png_fp_set(state, value)\ - ((state) = (value) | ((state) & PNG_FP_WAS_VALID)) - -/* Internal type codes: bits above the base state! */ -#define PNG_FP_SIGN 0 /* [+-] */ -#define PNG_FP_DOT 4 /* . */ -#define PNG_FP_DIGIT 8 /* [0123456789] */ -#define PNG_FP_E 12 /* [Ee] */ +#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY)) int /* PRIVATE */ png_check_fp_number(png_const_charp string, png_size_t size, int *statep, @@ -911,55 +1328,55 @@ png_check_fp_number(png_const_charp string, png_size_t size, int *statep, { int type; /* First find the type of the next character */ + switch (string[i]) { - char ch = string[i]; - - if (ch >= 48 && ch <= 57) - type = PNG_FP_DIGIT; - - else switch (ch) - { - case 43: case 45: type = PNG_FP_SIGN; break; - case 46: type = PNG_FP_DOT; break; - case 69: case 101: type = PNG_FP_E; break; - default: goto PNG_FP_End; - } + case 43: type = PNG_FP_SAW_SIGN; break; + case 45: type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break; + case 46: type = PNG_FP_SAW_DOT; break; + case 48: type = PNG_FP_SAW_DIGIT; break; + case 49: case 50: case 51: case 52: + case 53: case 54: case 55: case 56: + case 57: type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break; + case 69: + case 101: type = PNG_FP_SAW_E; break; + default: goto PNG_FP_End; } /* Now deal with this type according to the current * state, the type is arranged to not overlap the * bits of the PNG_FP_STATE. */ - switch ((state & PNG_FP_STATE) + type) + switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY)) { - case PNG_FP_INTEGER + PNG_FP_SIGN: + case PNG_FP_INTEGER + PNG_FP_SAW_SIGN: if (state & PNG_FP_SAW_ANY) goto PNG_FP_End; /* not a part of the number */ - png_fp_add(state, PNG_FP_SAW_SIGN); + png_fp_add(state, type); break; - case PNG_FP_INTEGER + PNG_FP_DOT: + case PNG_FP_INTEGER + PNG_FP_SAW_DOT: /* Ok as trailer, ok as lead of fraction. */ if (state & PNG_FP_SAW_DOT) /* two dots */ goto PNG_FP_End; else if (state & PNG_FP_SAW_DIGIT) /* trailing dot? */ - png_fp_add(state, PNG_FP_SAW_DOT); + png_fp_add(state, type); else - png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT); + png_fp_set(state, PNG_FP_FRACTION | type); break; - case PNG_FP_INTEGER + PNG_FP_DIGIT: + case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT: if (state & PNG_FP_SAW_DOT) /* delayed fraction */ png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT); - png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID); + png_fp_add(state, type | PNG_FP_WAS_VALID); break; - case PNG_FP_INTEGER + PNG_FP_E: + + case PNG_FP_INTEGER + PNG_FP_SAW_E: if ((state & PNG_FP_SAW_DIGIT) == 0) goto PNG_FP_End; @@ -967,17 +1384,17 @@ png_check_fp_number(png_const_charp string, png_size_t size, int *statep, break; - /* case PNG_FP_FRACTION + PNG_FP_SIGN: - goto PNG_FP_End; ** no sign in exponent */ + /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN: + goto PNG_FP_End; ** no sign in fraction */ - /* case PNG_FP_FRACTION + PNG_FP_DOT: + /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT: goto PNG_FP_End; ** Because SAW_DOT is always set */ - case PNG_FP_FRACTION + PNG_FP_DIGIT: - png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID); + case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT: + png_fp_add(state, type | PNG_FP_WAS_VALID); break; - case PNG_FP_FRACTION + PNG_FP_E: + case PNG_FP_FRACTION + PNG_FP_SAW_E: /* This is correct because the trailing '.' on an * integer is handled above - so we can only get here * with the sequence ".E" (with no preceding digits). @@ -989,7 +1406,7 @@ png_check_fp_number(png_const_charp string, png_size_t size, int *statep, break; - case PNG_FP_EXPONENT + PNG_FP_SIGN: + case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN: if (state & PNG_FP_SAW_ANY) goto PNG_FP_End; /* not a part of the number */ @@ -997,15 +1414,15 @@ png_check_fp_number(png_const_charp string, png_size_t size, int *statep, break; - /* case PNG_FP_EXPONENT + PNG_FP_DOT: + /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT: goto PNG_FP_End; */ - case PNG_FP_EXPONENT + PNG_FP_DIGIT: - png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID); + case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT: + png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID); break; - /* case PNG_FP_EXPONEXT + PNG_FP_E: + /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E: goto PNG_FP_End; */ default: goto PNG_FP_End; /* I.e. break 2 */ @@ -1033,8 +1450,11 @@ png_check_fp_string(png_const_charp string, png_size_t size) int state=0; png_size_t char_index=0; - return png_check_fp_number(string, size, &state, &char_index) && - (char_index == size || string[char_index] == 0); + if (png_check_fp_number(string, size, &state, &char_index) && + (char_index == size || string[char_index] == 0)) + return state /* must be non-zero - see above */; + + return 0; /* i.e. fail */ } #endif /* pCAL or sCAL */ @@ -1047,7 +1467,7 @@ static double png_pow10(int power) { int recip = 0; - double d = 1; + double d = 1.0; /* Handle negative exponent with a reciprocal at the end because * 10 is exact whereas .1 is inexact in base 2 @@ -1061,7 +1481,7 @@ png_pow10(int power) if (power > 0) { /* Decompose power bitwise. */ - double mult = 10; + double mult = 10.0; do { if (power & 1) d *= mult; @@ -1102,7 +1522,7 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, if (fp < 0) { fp = -fp; - *ascii++ = 45; /* '-' PLUS 1 TOTAL 1*/ + *ascii++ = 45; /* '-' PLUS 1 TOTAL 1 */ --size; } @@ -1180,7 +1600,8 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, { double d; - fp *= 10; + fp *= 10.0; + /* Use modf here, not floor and subtract, so that * the separation is done in one step. At the end * of the loop don't break the number into parts so @@ -1193,7 +1614,7 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, { d = floor(fp + .5); - if (d > 9) + if (d > 9.0) { /* Rounding up to 10, handle that here. */ if (czero > 0) @@ -1201,9 +1622,10 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, --czero, d = 1; if (cdigits == 0) --clead; } + else { - while (cdigits > 0 && d > 9) + while (cdigits > 0 && d > 9.0) { int ch = *--ascii; @@ -1228,7 +1650,7 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, * exponent but take into account the leading * decimal point. */ - if (d > 9) /* cdigits == 0 */ + if (d > 9.0) /* cdigits == 0 */ { if (exp_b10 == (-1)) { @@ -1249,18 +1671,19 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, ++exp_b10; /* In all cases we output a '1' */ - d = 1; + d = 1.0; } } } fp = 0; /* Guarantees termination below. */ } - if (d == 0) + if (d == 0.0) { ++czero; if (cdigits == 0) ++clead; } + else { /* Included embedded zeros in the digit count. */ @@ -1288,6 +1711,7 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, above */ --exp_b10; } + *ascii++ = (char)(48 + (int)d), ++cdigits; } } @@ -1329,19 +1753,31 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, */ size -= cdigits; - *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision*/ - if (exp_b10 < 0) + *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision */ + + /* The following use of an unsigned temporary avoids ambiguities in + * the signed arithmetic on exp_b10 and permits GCC at least to do + * better optimization. + */ { - *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */ - exp_b10 = -exp_b10; - } + unsigned int uexp_b10; - cdigits = 0; + if (exp_b10 < 0) + { + *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */ + uexp_b10 = -exp_b10; + } - while (exp_b10 > 0) - { - exponent[cdigits++] = (char)(48 + exp_b10 % 10); - exp_b10 /= 10; + else + uexp_b10 = exp_b10; + + cdigits = 0; + + while (uexp_b10 > 0) + { + exponent[cdigits++] = (char)(48 + uexp_b10 % 10); + uexp_b10 /= 10; + } } /* Need another size check here for the exponent digits, so @@ -1399,9 +1835,9 @@ png_ascii_from_fixed(png_structp png_ptr, png_charp ascii, png_size_t size, else num = fp; - if (num <= 0x80000000U) /* else overflowed */ + if (num <= 0x80000000) /* else overflowed */ { - unsigned int ndigits = 0, first = 16/*flag value*/; + unsigned int ndigits = 0, first = 16 /* flag value */; char digits[10]; while (num) @@ -1495,7 +1931,7 @@ png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times, r /= divisor; r = floor(r+.5); - /* A png_fixed_point is a 32 bit integer. */ + /* A png_fixed_point is a 32-bit integer. */ if (r <= 2147483647. && r >= -2147483648.) { *res = (png_fixed_point)r; @@ -1540,7 +1976,7 @@ png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times, if (s32 < D) /* else overflow */ { - /* s32.s00 is now the 64 bit product, do a standard + /* s32.s00 is now the 64-bit product, do a standard * division, we know that s32 < D, so the maximum * required shift is 31. */ @@ -1683,7 +2119,7 @@ png_reciprocal2(png_fixed_point a, png_fixed_point b) * 2010: moved from pngset.c) */ /* * Multiply two 32-bit numbers, V1 and V2, using 32-bit - * arithmetic, to produce a 64 bit result in the HI/LO words. + * arithmetic, to produce a 64-bit result in the HI/LO words. * * A B * x C D @@ -1727,24 +2163,24 @@ png_64bit_product (long v1, long v2, unsigned long *hi_product, /* Fixed point gamma. * * To calculate gamma this code implements fast log() and exp() calls using only - * fixed point arithmetic. This code has sufficient precision for either 8 or - * 16 bit sample values. + * fixed point arithmetic. This code has sufficient precision for either 8-bit + * or 16-bit sample values. * * The tables used here were calculated using simple 'bc' programs, but C double * precision floating point arithmetic would work fine. The programs are given * at the head of each table. * - * 8 bit log table + * 8-bit log table * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to - * 255, so it's the base 2 logarithm of a normalized 8 bit floating point - * mantissa. The numbers are 32 bit fractions. + * 255, so it's the base 2 logarithm of a normalized 8-bit floating point + * mantissa. The numbers are 32-bit fractions. */ static png_uint_32 png_8bit_l2[128] = { -# if PNG_DO_BC +# ifdef PNG_DO_BC for (i=128;i<256;++i) { .5 - l(i/255)/l(2)*65536*65536; } -# endif +# else 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U, 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U, 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U, @@ -1767,11 +2203,13 @@ png_8bit_l2[128] = 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U, 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U, 24347096U, 0U +# endif + #if 0 - /* The following are the values for 16 bit tables - these work fine for the 8 - * bit conversions but produce very slightly larger errors in the 16 bit log - * (about 1.2 as opposed to 0.7 absolute error in the final value). To use - * these all the shifts below must be adjusted appropriately. + /* The following are the values for 16-bit tables - these work fine for the + * 8-bit conversions but produce very slightly larger errors in the 16-bit + * log (about 1.2 as opposed to 0.7 absolute error in the final value). To + * use these all the shifts below must be adjusted appropriately. */ 65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054, 57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803, @@ -1788,7 +2226,7 @@ png_8bit_l2[128] = #endif }; -static png_int_32 +PNG_STATIC png_int_32 png_log8bit(unsigned int x) { unsigned int lg2 = 0; @@ -1814,11 +2252,11 @@ png_log8bit(unsigned int x) return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16)); } -/* The above gives exact (to 16 binary places) log2 values for 8 bit images, - * for 16 bit images we use the most significant 8 bits of the 16 bit value to +/* The above gives exact (to 16 binary places) log2 values for 8-bit images, + * for 16-bit images we use the most significant 8 bits of the 16-bit value to * get an approximation then multiply the approximation by a correction factor * determined by the remaining up to 8 bits. This requires an additional step - * in the 16 bit case. + * in the 16-bit case. * * We want log2(value/65535), we have log2(v'/255), where: * @@ -1827,8 +2265,8 @@ png_log8bit(unsigned int x) * * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128 * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less - * than 258. The final factor also needs to correct for the fact that our 8 bit - * value is scaled by 255, whereas the 16 bit values must be scaled by 65535. + * than 258. The final factor also needs to correct for the fact that our 8-bit + * value is scaled by 255, whereas the 16-bit values must be scaled by 65535. * * This gives a final formula using a calculated value 'x' which is value/v' and * scaling by 65536 to match the above table: @@ -1838,13 +2276,13 @@ png_log8bit(unsigned int x) * Since these numbers are so close to '1' we can use simple linear * interpolation between the two end values 256/257 (result -368.61) and 258/257 * (result 367.179). The values used below are scaled by a further 64 to give - * 16 bit precision in the interpolation: + * 16-bit precision in the interpolation: * * Start (256): -23591 * Zero (257): 0 * End (258): 23499 */ -static png_int_32 +PNG_STATIC png_int_32 png_log16bit(png_uint_32 x) { unsigned int lg2 = 0; @@ -1865,7 +2303,7 @@ png_log16bit(png_uint_32 x) if ((x & 0x8000) == 0) lg2 += 1, x <<= 1; - /* Calculate the base logarithm from the top 8 bits as a 28 bit fractional + /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional * value. */ lg2 <<= 28; @@ -1895,34 +2333,35 @@ png_log16bit(png_uint_32 x) return (png_int_32)((lg2 + 2048) >> 12); } -/* The 'exp()' case must invert the above, taking a 20 bit fixed point - * logarithmic value and returning a 16 or 8 bit number as appropriate. In +/* The 'exp()' case must invert the above, taking a 20-bit fixed point + * logarithmic value and returning a 16 or 8-bit number as appropriate. In * each case only the low 16 bits are relevant - the fraction - since the * integer bits (the top 4) simply determine a shift. * - * The worst case is the 16 bit distinction between 65535 and 65534, this - * requires perhaps spurious accuracty in the decoding of the logarithm to + * The worst case is the 16-bit distinction between 65535 and 65534, this + * requires perhaps spurious accuracy in the decoding of the logarithm to * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance * of getting this accuracy in practice. * * To deal with this the following exp() function works out the exponent of the - * frational part of the logarithm by using an accurate 32 bit value from the + * frational part of the logarithm by using an accurate 32-bit value from the * top four fractional bits then multiplying in the remaining bits. */ static png_uint_32 png_32bit_exp[16] = { -# if PNG_DO_BC +# ifdef PNG_DO_BC for (i=0;i<16;++i) { .5 + e(-i/16*l(2))*2^32; } -# endif - /* NOTE: the first entry is deliberately set to the maximum 32 bit value. */ +# else + /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */ 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U, 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U, 2553802834U, 2445529972U, 2341847524U, 2242560872U +# endif }; /* Adjustment table; provided to explain the numbers in the code below. */ -#if PNG_DO_BC +#ifdef PNG_DO_BC for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"} 11 44937.64284865548751208448 10 45180.98734845585101160448 @@ -1938,12 +2377,12 @@ for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"} 0 45425.85339951654943850496 #endif -static png_uint_32 +PNG_STATIC png_uint_32 png_exp(png_fixed_point x) { if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */ { - /* Obtain a 4 bit approximation */ + /* Obtain a 4-bit approximation */ png_uint_32 e = png_32bit_exp[(x >> 12) & 0xf]; /* Incorporate the low 12 bits - these decrease the returned value by @@ -1986,13 +2425,13 @@ png_exp(png_fixed_point x) return 0; } -static png_byte +PNG_STATIC png_byte png_exp8bit(png_fixed_point lg2) { - /* Get a 32 bit value: */ + /* Get a 32-bit value: */ png_uint_32 x = png_exp(lg2); - /* Convert the 32 bit value to 0..255 by multiplying by 256-1, note that the + /* Convert the 32-bit value to 0..255 by multiplying by 256-1, note that the * second, rounding, step can't overflow because of the first, subtraction, * step. */ @@ -2000,13 +2439,13 @@ png_exp8bit(png_fixed_point lg2) return (png_byte)((x + 0x7fffffU) >> 24); } -static png_uint_16 +PNG_STATIC png_uint_16 png_exp16bit(png_fixed_point lg2) { - /* Get a 32 bit value: */ + /* Get a 32-bit value: */ png_uint_32 x = png_exp(lg2); - /* Convert the 32 bit value to 0..65535 by multiplying by 65536-1: */ + /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */ x -= x >> 16; return (png_uint_16)((x + 32767U) >> 16); } @@ -2059,9 +2498,9 @@ png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val) } /* This does the right thing based on the bit_depth field of the - * png_struct, interpreting values as 8 or 16 bit. While the result - * is nominally a 16 bit value if bit depth is 8 then the result is - * 8 bit (as are the arguments.) + * png_struct, interpreting values as 8-bit or 16-bit. While the result + * is nominally a 16-bit value if bit depth is 8 then the result is + * 8-bit (as are the arguments.) */ png_uint_16 /* PRIVATE */ png_gamma_correct(png_structp png_ptr, unsigned int value, @@ -2084,8 +2523,8 @@ png_gamma_significant(png_fixed_point gamma_val) gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED; } -/* Internal function to build a single 16 bit table - the table consists of - * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount +/* Internal function to build a single 16-bit table - the table consists of + * 'num' 256-entry subtables, where 'num' is determined by 'shift' - the amount * to shift the input values right (or 16-number_of_signifiant_bits). * * The caller is responsible for ensuring that the table gets cleaned up on @@ -2111,7 +2550,7 @@ png_build_16bit_table(png_structp png_ptr, png_uint_16pp *ptable, (png_uint_16p)png_malloc(png_ptr, 256 * png_sizeof(png_uint_16)); /* The 'threshold' test is repeated here because it can arise for one of - * the 16 bit tables even if the others don't hit it. + * the 16-bit tables even if the others don't hit it. */ if (png_gamma_significant(gamma_val)) { @@ -2172,9 +2611,9 @@ png_build_16to8_table(png_structp png_ptr, png_uint_16pp *ptable, png_uint_16pp table = *ptable = (png_uint_16pp)png_calloc(png_ptr, num * png_sizeof(png_uint_16p)); - /* 'num' is the number of tables and also the number of low bits of low - * bits of the input 16 bit value used to select a table. Each table is - * itself index by the high 8 bits of the value. + /* 'num' is the number of tables and also the number of low bits of the + * input 16-bit value used to select a table. Each table is itself indexed + * by the high 8 bits of the value. */ for (i = 0; i < num; i++) table[i] = (png_uint_16p)png_malloc(png_ptr, @@ -2183,24 +2622,24 @@ png_build_16to8_table(png_structp png_ptr, png_uint_16pp *ptable, /* 'gamma_val' is set to the reciprocal of the value calculated above, so * pow(out,g) is an *input* value. 'last' is the last input value set. * - * In the loop 'i' is used to find output values. Since the output is 8 - * bit there are only 256 possible values. The tables are set up to + * In the loop 'i' is used to find output values. Since the output is + * 8-bit there are only 256 possible values. The tables are set up to * select the closest possible output value for each input by finding * the input value at the boundary between each pair of output values * and filling the table up to that boundary with the lower output * value. * - * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9 bit - * values the code below uses a 16 bit value in i; the values start at + * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9-bit + * values the code below uses a 16-bit value in i; the values start at * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last * entries are filled with 255). Start i at 128 and fill all 'last' * table entries <= 'max' */ last = 0; - for (i = 0; i < 255; ++i) /* 8 bit output value */ + for (i = 0; i < 255; ++i) /* 8-bit output value */ { /* Find the corresponding maximum input value */ - png_uint_16 out = (png_uint_16)(i * 257U); /* 16 bit output value */ + png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */ /* Find the boundary value in 16 bits: */ png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val); @@ -2223,9 +2662,9 @@ png_build_16to8_table(png_structp png_ptr, png_uint_16pp *ptable, } } -/* Build a single 8 bit table: same as the 16 bit case but much simpler (and +/* Build a single 8-bit table: same as the 16-bit case but much simpler (and * typically much faster). Note that libpng currently does no sBIT processing - * (apparently contrary to the spec) so a 256 entry table is always generated. + * (apparently contrary to the spec) so a 256-entry table is always generated. */ static void png_build_8bit_table(png_structp png_ptr, png_bytepp ptable, @@ -2241,6 +2680,60 @@ png_build_8bit_table(png_structp png_ptr, png_bytepp ptable, table[i] = (png_byte)i; } +/* Used from png_read_destroy and below to release the memory used by the gamma + * tables. + */ +void /* PRIVATE */ +png_destroy_gamma_table(png_structp png_ptr) +{ + png_free(png_ptr, png_ptr->gamma_table); + png_ptr->gamma_table = NULL; + + if (png_ptr->gamma_16_table != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_table[i]); + } + png_free(png_ptr, png_ptr->gamma_16_table); + png_ptr->gamma_16_table = NULL; + } + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + png_free(png_ptr, png_ptr->gamma_from_1); + png_ptr->gamma_from_1 = NULL; + png_free(png_ptr, png_ptr->gamma_to_1); + png_ptr->gamma_to_1 = NULL; + + if (png_ptr->gamma_16_from_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_from_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_from_1); + png_ptr->gamma_16_from_1 = NULL; + } + if (png_ptr->gamma_16_to_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_to_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_to_1); + png_ptr->gamma_16_to_1 = NULL; + } +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ +} + /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit * tables, we don't make a full table if we are reducing to 8-bit in * the future. Note also how the gamma_16 tables are segmented so that @@ -2251,6 +2744,18 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) { png_debug(1, "in png_build_gamma_table"); + /* Remove any existing table; this copes with multiple calls to + * png_read_update_info. The warning is because building the gamma tables + * multiple times is a performance hit - it's harmless but the ability to call + * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible + * to warn if the app introduces such a hit. + */ + if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL) + { + png_warning(png_ptr, "gamma table being rebuilt"); + png_destroy_gamma_table(png_ptr); + } + if (bit_depth <= 8) { png_build_8bit_table(png_ptr, &png_ptr->gamma_table, @@ -2258,8 +2763,9 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) png_ptr->screen_gamma) : PNG_FP_1); #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY)) + if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) { png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, png_reciprocal(png_ptr->gamma)); @@ -2268,7 +2774,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : png_ptr->gamma/* Probably doing rgb_to_gray */); } -#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ } else { @@ -2287,14 +2793,14 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) else sig_bit = png_ptr->sig_bit.gray; - /* 16 bit gamma code uses this equation: + /* 16-bit gamma code uses this equation: * * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8] * * Where 'iv' is the input color value and 'ov' is the output value - * pow(iv, gamma). * - * Thus the gamma table consists of up to 256 256 entry tables. The table + * Thus the gamma table consists of up to 256 256-entry tables. The table * is selected by the (8-gamma_shift) most significant of the low 8 bits of * the color value then indexed by the upper 8 bits: * @@ -2302,7 +2808,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) * * So the table 'n' corresponds to all those 'iv' of: * - * <all high 8 bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1> + * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1> * */ if (sig_bit > 0 && sig_bit < 16U) @@ -2311,7 +2817,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) else shift = 0; /* keep all 16 bits */ - if (png_ptr->transformations & PNG_16_TO_8) + if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) { /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively * the significant bits in the *input* when the output will @@ -2327,7 +2833,12 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) png_ptr->gamma_shift = shift; #ifdef PNG_16BIT_SUPPORTED - if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND)) + /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now + * PNG_COMPOSE). This effectively smashed the background calculation for + * 16-bit output because the 8-bit table assumes the result will be reduced + * to 8 bits. + */ + if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) #endif png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift, png_ptr->screen_gamma > 0 ? png_product2(png_ptr->gamma, @@ -2341,8 +2852,9 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) #endif #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY)) + if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) { png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift, png_reciprocal(png_ptr->gamma)); @@ -2355,7 +2867,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth) png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : png_ptr->gamma/* Probably doing rgb_to_gray */); } -#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ } } #endif /* READ_GAMMA */ @@ -1,8 +1,8 @@ /* png.h - header file for PNG reference library * - * libpng version 1.5.1 - February 3, 2011 - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * libpng version 1.5.10 - March 29, 2012 + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -11,7 +11,7 @@ * Authors and maintainers: * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger - * libpng versions 0.97, January 1998, through 1.5.1 - February 3, 2011: Glenn + * libpng versions 0.97, January 1998, through 1.5.10 - March 29, 2012: Glenn * See also "Contributing Authors", below. * * Note about libpng version numbers: @@ -147,6 +147,33 @@ * 1.5.1beta01-11 15 10501 15.so.15.1[.0] * 1.5.1rc01-02 15 10501 15.so.15.1[.0] * 1.5.1 15 10501 15.so.15.1[.0] + * 1.5.2beta01-03 15 10502 15.so.15.2[.0] + * 1.5.2rc01-03 15 10502 15.so.15.2[.0] + * 1.5.2 15 10502 15.so.15.2[.0] + * 1.5.3beta01-10 15 10503 15.so.15.3[.0] + * 1.5.3rc01-02 15 10503 15.so.15.3[.0] + * 1.5.3beta11 15 10503 15.so.15.3[.0] + * 1.5.3 [omitted] + * 1.5.4beta01-08 15 10504 15.so.15.4[.0] + * 1.5.4rc01 15 10504 15.so.15.4[.0] + * 1.5.4 15 10504 15.so.15.4[.0] + * 1.5.5beta01-08 15 10505 15.so.15.5[.0] + * 1.5.5rc01 15 10505 15.so.15.5[.0] + * 1.5.5 15 10505 15.so.15.5[.0] + * 1.5.6beta01-07 15 10506 15.so.15.6[.0] + * 1.5.6rc01-03 15 10506 15.so.15.6[.0] + * 1.5.6 15 10506 15.so.15.6[.0] + * 1.5.7beta01-05 15 10507 15.so.15.7[.0] + * 1.5.7rc01-03 15 10507 15.so.15.7[.0] + * 1.5.7 15 10507 15.so.15.7[.0] + * 1.5.8beta01 15 10508 15.so.15.8[.0] + * 1.5.8rc01 15 10508 15.so.15.8[.0] + * 1.5.8 15 10508 15.so.15.8[.0] + * 1.5.9beta01-02 15 10509 15.so.15.9[.0] + * 1.5.9rc01 15 10509 15.so.15.9[.0] + * 1.5.9 15 10509 15.so.15.9[.0] + * 1.5.10beta01-05 15 10510 15.so.15.10[.0] + * 1.5.10 15 10510 15.so.15.10[.0] * * Henceforth the source version will match the shared-library major * and minor numbers; the shared-library major version number will be @@ -156,7 +183,7 @@ * to the source version x.y.z (leading zeros in y and z). Beta versions * were given the previous public release number plus a letter, until * version 1.0.6j; from then on they were given the upcoming public - * release number plus "betaNN" or "rcN". + * release number plus "betaNN" or "rcNN". * * Binary incompatibility exists only when applications make direct access * to the info_ptr or png_ptr members through png.h, and the compiled @@ -178,8 +205,8 @@ * * This code is released under the libpng license. * - * libpng versions 1.2.6, August 15, 2004, through 1.5.1, February 3, 2011, are - * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are + * libpng versions 1.2.6, August 15, 2004, through 1.5.10, March 29, 2012, are + * Copyright (c) 2004, 2006-2012 Glenn Randers-Pehrson, and are * distributed according to the same disclaimer and license as libpng-1.2.5 * with the following individual added to the list of Contributing Authors: * @@ -205,7 +232,7 @@ * * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are - * distributed according to the same disclaimer and license as libpng-0.96, + * distributed according to the same disclaimer and license as libpng-0.96, * with the following individuals added to the list of Contributing Authors: * * Tom Lane @@ -214,7 +241,7 @@ * * libpng versions 0.89, June 1996, through 0.96, May 1997, are * Copyright (c) 1996, 1997 Andreas Dilger - * Distributed according to the same disclaimer and license as libpng-0.88, + * Distributed according to the same disclaimer and license as libpng-0.88, * with the following individuals added to the list of Contributing Authors: * * John Bowler @@ -237,10 +264,10 @@ * Tim Wegner * * The PNG Reference Library is supplied "AS IS". The Contributing Authors - * and Group 42, Inc. disclaim all warranties, expressed or implied, + * and Group 42, Inc. disclaim all warranties, expressed or implied, * including, without limitation, the warranties of merchantability and of * fitness for any purpose. The Contributing Authors and Group 42, Inc. - * assume no liability for direct, indirect, incidental, special, exemplary, + * assume no liability for direct, indirect, incidental, special, exemplary, * or consequential damages, which may result from the use of the PNG * Reference Library, even if advised of the possibility of such damage. * @@ -290,25 +317,24 @@ * Y2K compliance in libpng: * ========================= * - * February 3, 2011 + * March 29, 2012 * * Since the PNG Development group is an ad-hoc body, we can't make * an official declaration. * * This is your unofficial assurance that libpng from version 0.71 and - * upward through 1.5.1 are Y2K compliant. It is my belief that + * upward through 1.5.10 are Y2K compliant. It is my belief that * earlier versions were also Y2K compliant. * - * Libpng only has three year fields. One is a 2-byte unsigned integer - * that will hold years up to 65535. The other two hold the date in text + * Libpng only has two year fields. One is a 2-byte unsigned integer + * that will hold years up to 65535. The other holds the date in text * format, and will hold years up to 9999. * * The integer is * "png_uint_16 year" in png_time_struct. * - * The strings are - * "png_charp time_buffer" in png_struct and - * "near_time_buffer", which is a local character string in png.c. + * The string is + * "png_char time_buffer" in png_struct * * There are seven time-related functions: * png.c: png_convert_to_rfc_1123() in png.c @@ -326,7 +352,7 @@ * the full 4-digit year. There is a possibility that applications using * libpng are not passing 4-digit years into the png_convert_to_rfc_1123() * function, or that they are incorrectly passing only a 2-digit year - * instead of "year - 1900" into the png_convert_from_struct_tm() function, + * instead of "year - 1900" into the png_convert_from_struct_tm() function, * but this is not under our control. The libpng documentation has always * stated that it works with 4-digit years, and the APIs have been * documented as such. @@ -349,12 +375,15 @@ * describes how to use libpng, and the file example.c summarizes it * with some code on which to build. This file is useful for looking * at the actual function definitions and structure components. + * + * If you just need to read a PNG file and don't want to read the documentation + * skip to the end of this file and read the section entitled 'simplified API'. */ /* Version information for png.h - this should match the version in png.c */ -#define PNG_LIBPNG_VER_STRING "1.5.1" +#define PNG_LIBPNG_VER_STRING "1.5.10" #define PNG_HEADER_VERSION_STRING \ - " libpng version 1.5.1 - February 3, 2011\n" + " libpng version 1.5.10 - March 29, 2012\n" #define PNG_LIBPNG_VER_SONUM 15 #define PNG_LIBPNG_VER_DLLNUM 15 @@ -362,7 +391,8 @@ /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ #define PNG_LIBPNG_VER_MAJOR 1 #define PNG_LIBPNG_VER_MINOR 5 -#define PNG_LIBPNG_VER_RELEASE 1 +#define PNG_LIBPNG_VER_RELEASE 10 + /* This should match the numeric part of the final component of * PNG_LIBPNG_VER_STRING, omitting any leading zero: */ @@ -384,7 +414,7 @@ #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with PNG_LIBPNG_BUILD_PRIVATE */ -#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA +#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE /* Careful here. At one time, Guy wanted to use 082, but that would be octal. * We must not include leading zeros. @@ -392,7 +422,7 @@ * version 1.0.0 was mis-numbered 100 instead of 10000). From * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */ -#define PNG_LIBPNG_VER 10501 /* 1.5.1 */ +#define PNG_LIBPNG_VER 10510 /* 1.5.10 */ /* Library configuration: these options cannot be changed after * the library has been built. @@ -405,19 +435,24 @@ #endif #ifndef PNG_VERSION_INFO_ONLY -/* Standard header files (not needed for the version info) */ -# ifdef PNG_SETJMP_SUPPORTED -# include <setjmp.h> +# ifndef PNG_BUILDING_SYMBOL_TABLE + /* + * Standard header files (not needed for the version info or while + * building symbol table -- see scripts/pnglibconf.dfa) + */ +# ifdef PNG_SETJMP_SUPPORTED +# include <setjmp.h> +# endif + + /* Need the time information for converting tIME chunks, it + * defines struct tm: + */ +# ifdef PNG_CONVERT_tIME_SUPPORTED + /* "time.h" functions are not supported on all operating systems */ +# include <time.h> +# endif # endif -/* Need the time information for converting tIME chunks, it - * defines struct tm: - */ -#ifdef PNG_CONVERT_tIME_SUPPORTED - /* "time.h" functions are not supported on all operating systems */ -# include <time.h> -#endif - /* Machine specific configuration. */ # include "pngconf.h" #endif @@ -509,7 +544,7 @@ extern "C" { /* This triggers a compiler error in png.c, if png.c and png.h * do not agree upon the version number. */ -typedef char* png_libpng_version_1_5_1; +typedef char* png_libpng_version_1_5_10; /* Three color definitions. The order of the red, green, and blue, (and the * exact size) is not important, although the size of the fields need to @@ -582,13 +617,22 @@ typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp; typedef png_sPLT_t FAR * FAR * png_sPLT_tpp; #ifdef PNG_TEXT_SUPPORTED -/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, +/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, * and whether that contents is compressed or not. The "key" field - * points to a regular zero-terminated C string. The "text", "lang", and - * "lang_key" fields can be regular C strings, empty strings, or NULL pointers. - * However, the * structure returned by png_get_text() will always contain - * regular zero-terminated C strings (possibly empty), never NULL pointers, - * so they can be safely used in printf() and other string-handling functions. + * points to a regular zero-terminated C string. The "text" fields can be a + * regular C string, an empty string, or a NULL pointer. + * However, the structure returned by png_get_text() will always contain + * the "text" field as a regular zero-terminated C string (possibly + * empty), never a NULL pointer, so it can be safely used in printf() and + * other string-handling functions. Note that the "itxt_length", "lang", and + * "lang_key" members of the structure only exist when the library is built + * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by + * default without iTXt support. Also note that when iTXt *is* supported, + * the "lang" and "lang_key" fields contain NULL pointers when the + * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or + * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the + * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" + * which is always 0 or 1, or its "compression method" which is always 0. */ typedef struct png_text_struct { @@ -657,12 +701,24 @@ typedef struct png_unknown_chunk_t /* libpng-using applications should NOT directly modify this byte. */ png_byte location; /* mode of operation at read time */ } + + png_unknown_chunk; typedef png_unknown_chunk FAR * png_unknown_chunkp; typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp; typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp; #endif +/* Values for the unknown chunk location byte */ + +#define PNG_HAVE_IHDR 0x01 +#define PNG_HAVE_PLTE 0x02 +#define PNG_AFTER_IDAT 0x08 + +/* The complete definition of png_info has, as of libpng-1.5.0, + * been moved into a separate header file that is not accessible to + * applications. Read libpng-manual.txt or libpng.3 for more info. + */ typedef struct png_info_def png_info; typedef png_info FAR * png_infop; typedef PNG_CONST png_info FAR * png_const_infop; @@ -678,6 +734,8 @@ typedef png_info FAR * FAR * png_infopp; */ #define PNG_FP_1 100000 #define PNG_FP_HALF 50000 +#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) +#define PNG_FP_MIN (-PNG_FP_MAX) /* These describe the color_type field in png_info. */ /* color type masks */ @@ -765,7 +823,7 @@ typedef png_info FAR * FAR * png_infopp; #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ -#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */ +#define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */ /* This is used for the transformation routines, as some of them * change these values for the row. It also should enable using @@ -784,6 +842,14 @@ typedef struct png_row_info_struct typedef png_row_info FAR * png_row_infop; typedef png_row_info FAR * FAR * png_row_infopp; +/* The complete definition of png_struct has, as of libpng-1.5.0, + * been moved into a separate header file that is not accessible to + * applications. Read libpng-manual.txt or libpng.3 for more info. + */ +typedef struct png_struct_def png_struct; +typedef PNG_CONST png_struct FAR * png_const_structp; +typedef png_struct FAR * png_structp; + /* These are the function types for the I/O functions and for the functions * that allow the user to override the default I/O functions with his or her * own. The png_error_ptr type should match that of user-supplied warning @@ -792,61 +858,59 @@ typedef png_row_info FAR * FAR * png_row_infopp; * modify the buffer it is passed. The 'read' function, on the other hand, is * expected to return the read data in the buffer. */ -typedef struct png_struct_def png_struct; -typedef PNG_CONST png_struct FAR * png_const_structp; -typedef png_struct FAR * png_structp; - -typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp), ); -typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t), ); -typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp), ); -typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, - int), ); -typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, - int), ); +typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); +typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); +typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); +typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, + int)); +typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, + int)); #ifdef PNG_PROGRESSIVE_READ_SUPPORTED -typedef PNG_CALLBACK(void, *png_progressive_info_ptr, - (png_structp, png_infop), ); -typedef PNG_CALLBACK(void, *png_progressive_end_ptr, - (png_structp, png_infop), ); -typedef PNG_CALLBACK(void, *png_progressive_row_ptr, - (png_structp, png_bytep, png_uint_32, int), ); +typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); +typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); + +/* The following callback receives png_uint_32 row_number, int pass for the + * png_bytep data of the row. When transforming an interlaced image the + * row number is the row number within the sub-image of the interlace pass, so + * the value will increase to the height of the sub-image (not the full image) + * then reset to 0 for the next pass. + * + * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to + * find the output pixel (x,y) given an interlaced sub-image pixel + * (row,col,pass). (See below for these macros.) + */ +typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, + png_uint_32, int)); #endif #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) -typedef PNG_CALLBACK(void, *png_user_transform_ptr, - (png_structp, png_row_infop, png_bytep), ); +typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, + png_bytep)); #endif #ifdef PNG_USER_CHUNKS_SUPPORTED -typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, - png_unknown_chunkp), ); +typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, + png_unknown_chunkp)); #endif #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED -typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp), ); +typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); #endif #ifdef PNG_SETJMP_SUPPORTED -/* This must match the function definition in <setjmp.h>, and the - * application must include this before png.h to obtain the definition - * of jmp_buf. The function is required to be PNG_NORETURN. (Note that - * PNG_PTR_NORETURN is used here because current versions of the Microsoft - * C compiler do not support the PNG_NORETURN attribute on a pointer.) - * - * If you get a type warning from the compiler when linking against this line - * then your compiler has 'longjmp' that does not match the requirements of the - * compiler that built libpng. You will have to write a wrapper function for - * your compiler's longjmp and call png_set_longjmp_fn directly (not via the - * png_jmpbuf macro.) - * - * If you get a warning here while building the library you will need to make +/* This must match the function definition in <setjmp.h>, and the application + * must include this before png.h to obtain the definition of jmp_buf. The + * function is required to be PNG_NORETURN, but this is not checked. If the + * function does return the application will crash via an abort() or similar + * system level call. + * + * If you get a warning here while building the library you may need to make * changes to ensure that pnglibconf.h records the calling convention used by * your compiler. This may be very difficult - try using a different compiler * to build the library! */ -typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), - PNG_PTR_NORETURN); +PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); #endif /* Transform masks for the high-level interface */ @@ -868,21 +932,24 @@ typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ /* Added to libpng-1.4.0 */ #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ +/* Added to libpng-1.5.4 */ +#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ +#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ /* Flags for MNG supported features */ #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 #define PNG_FLAG_MNG_FILTER_64 0x04 #define PNG_ALL_MNG_FEATURES 0x05 -/* NOTE: prior to 1.5 these functions had no 'API' style declaration, +/* NOTE: prior to 1.5 these functions had no 'API' style declaration, * this allowed the zlib default functions to be used on Windows * platforms. In 1.5 the zlib default malloc (which just calls malloc and * ignores the first argument) should be completely compatible with the * following. */ -typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, - png_alloc_size_t), ); -typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp), ); +typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, + png_alloc_size_t)); +typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); typedef png_struct FAR * FAR * png_structpp; @@ -928,7 +995,7 @@ PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes)); * signature, and non-zero otherwise. Having num_to_check == 0 or * start > 7 will always fail (ie return non-zero). */ -PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, +PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, png_size_t num_to_check)); /* Simple signature checking function. This is the same as calling @@ -939,19 +1006,19 @@ PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, /* Allocate and initialize png_ptr struct for reading, and any other memory. */ PNG_EXPORTA(4, png_structp, png_create_read_struct, (png_const_charp user_png_ver, png_voidp error_ptr, - png_error_ptr error_fn, png_error_ptr warn_fn), + png_error_ptr error_fn, png_error_ptr warn_fn), PNG_ALLOCATED); /* Allocate and initialize png_ptr struct for writing, and any other memory */ PNG_EXPORTA(5, png_structp, png_create_write_struct, (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warn_fn), + png_error_ptr warn_fn), PNG_ALLOCATED); PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, (png_const_structp png_ptr)); -PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr, +PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr, png_size_t size)); /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp @@ -965,7 +1032,7 @@ PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr, * allocated by the library - the call will return NULL on a mismatch * indicating an ABI mismatch. */ -PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr, +PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr, png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); # define png_jmpbuf(png_ptr) \ (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf))) @@ -990,13 +1057,13 @@ PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr)); #ifdef PNG_USER_MEM_SUPPORTED PNG_EXPORTA(11, png_structp, png_create_read_struct_2, (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warn_fn, - png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), PNG_ALLOCATED); PNG_EXPORTA(12, png_structp, png_create_write_struct_2, (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warn_fn, - png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), PNG_ALLOCATED); #endif @@ -1008,7 +1075,7 @@ PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep chunk_name, png_const_bytep data, png_size_t length)); /* Write the start of a PNG chunk - length and chunk name. */ -PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr, +PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr, png_const_bytep chunk_name, png_uint_32 length)); /* Write the data of a PNG chunk started with png_write_chunk_start(). */ @@ -1019,10 +1086,10 @@ PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr, PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr)); /* Allocate and initialize the info structure */ -PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr), +PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr), PNG_ALLOCATED); -PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr, +PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr, png_size_t png_info_struct_size)); /* Writes all the PNG information before the image. */ @@ -1039,13 +1106,13 @@ PNG_EXPORT(22, void, png_read_info, #ifdef PNG_TIME_RFC1123_SUPPORTED PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123, - (png_structp png_ptr, + (png_structp png_ptr, png_const_timep ptime)); #endif #ifdef PNG_CONVERT_tIME_SUPPORTED /* Convert from a struct tm to png_time */ -PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, +PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, PNG_CONST struct tm FAR * ttime)); /* Convert from time_t to png_time. Uses gmtime() */ @@ -1061,6 +1128,13 @@ PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr)); PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr)); #endif +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion + * of a tRNS chunk if present. + */ +PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr)); +#endif + #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) /* Use blue, green, red order for pixels. */ PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr)); @@ -1073,17 +1147,233 @@ PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr)); #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED /* Reduce RGB to grayscale. */ +#define PNG_ERROR_ACTION_NONE 1 +#define PNG_ERROR_ACTION_WARN 2 +#define PNG_ERROR_ACTION_ERROR 3 +#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ + PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr, int error_action, double red, double green)); -PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr, +PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr, int error_action, png_fixed_point red, png_fixed_point green)); PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp png_ptr)); #endif -PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, +#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED +PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, png_colorp palette)); +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +/* How the alpha channel is interpreted - this affects how the color channels of + * a PNG file are returned when an alpha channel, or tRNS chunk in a palette + * file, is present. + * + * This has no effect on the way pixels are written into a PNG output + * datastream. The color samples in a PNG datastream are never premultiplied + * with the alpha samples. + * + * The default is to return data according to the PNG specification: the alpha + * channel is a linear measure of the contribution of the pixel to the + * corresponding composited pixel. The gamma encoded color channels must be + * scaled according to the contribution and to do this it is necessary to undo + * the encoding, scale the color values, perform the composition and reencode + * the values. This is the 'PNG' mode. + * + * The alternative is to 'associate' the alpha with the color information by + * storing color channel values that have been scaled by the alpha. The + * advantage is that the color channels can be resampled (the image can be + * scaled) in this form. The disadvantage is that normal practice is to store + * linear, not (gamma) encoded, values and this requires 16-bit channels for + * still images rather than the 8-bit channels that are just about sufficient if + * gamma encoding is used. In addition all non-transparent pixel values, + * including completely opaque ones, must be gamma encoded to produce the final + * image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the + * latter being the two common names for associated alpha color channels.) + * + * Since it is not necessary to perform arithmetic on opaque color values so + * long as they are not to be resampled and are in the final color space it is + * possible to optimize the handling of alpha by storing the opaque pixels in + * the PNG format (adjusted for the output color space) while storing partially + * opaque pixels in the standard, linear, format. The accuracy required for + * standard alpha composition is relatively low, because the pixels are + * isolated, therefore typically the accuracy loss in storing 8-bit linear + * values is acceptable. (This is not true if the alpha channel is used to + * simulate transparency over large areas - use 16 bits or the PNG mode in + * this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is + * treated as opaque only if the alpha value is equal to the maximum value. + * + * The final choice is to gamma encode the alpha channel as well. This is + * broken because, in practice, no implementation that uses this choice + * correctly undoes the encoding before handling alpha composition. Use this + * choice only if other serious errors in the software or hardware you use + * mandate it; the typical serious error is for dark halos to appear around + * opaque areas of the composited PNG image because of arithmetic overflow. + * + * The API function png_set_alpha_mode specifies which of these choices to use + * with an enumerated 'mode' value and the gamma of the required output: + */ +#define PNG_ALPHA_PNG 0 /* according to the PNG standard */ +#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ +#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ +#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ +#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ +#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ + +PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode, + double output_gamma)); +PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr, + int mode, png_fixed_point output_gamma)); +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) +/* The output_gamma value is a screen gamma in libpng terminology: it expresses + * how to decode the output values, not how they are encoded. The values used + * correspond to the normal numbers used to describe the overall gamma of a + * computer display system; for example 2.2 for an sRGB conformant system. The + * values are scaled by 100000 in the _fixed version of the API (so 220000 for + * sRGB.) + * + * The inverse of the value is always used to provide a default for the PNG file + * encoding if it has no gAMA chunk and if png_set_gamma() has not been called + * to override the PNG gamma information. + * + * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode + * opaque pixels however pixels with lower alpha values are not encoded, + * regardless of the output gamma setting. + * + * When the standard Porter Duff handling is requested with mode 1 the output + * encoding is set to be linear and the output_gamma value is only relevant + * as a default for input data that has no gamma information. The linear output + * encoding will be overridden if png_set_gamma() is called - the results may be + * highly unexpected! + * + * The following numbers are derived from the sRGB standard and the research + * behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of + * 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing + * correction required to take account of any differences in the color + * environment of the original scene and the intended display environment; the + * value expresses how to *decode* the image for display, not how the original + * data was *encoded*. + * + * sRGB provides a peg for the PNG standard by defining a viewing environment. + * sRGB itself, and earlier TV standards, actually use a more complex transform + * (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is + * limited to simple power laws.) By saying that an image for direct display on + * an sRGB conformant system should be stored with a gAMA chunk value of 45455 + * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification + * makes it possible to derive values for other display systems and + * environments. + * + * The Mac value is deduced from the sRGB based on an assumption that the actual + * extra viewing correction used in early Mac display systems was implemented as + * a power 1.45 lookup table. + * + * Any system where a programmable lookup table is used or where the behavior of + * the final display device characteristics can be changed requires system + * specific code to obtain the current characteristic. However this can be + * difficult and most PNG gamma correction only requires an approximate value. + * + * By default, if png_set_alpha_mode() is not called, libpng assumes that all + * values are unencoded, linear, values and that the output device also has a + * linear characteristic. This is only very rarely correct - it is invariably + * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the + * default if you don't know what the right answer is! + * + * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS + * 10.6) which used a correction table to implement a somewhat lower gamma on an + * otherwise sRGB system. + * + * Both these values are reserved (not simple gamma values) in order to allow + * more precise correction internally in the future. + * + * NOTE: the following values can be passed to either the fixed or floating + * point APIs, but the floating point API will also accept floating point + * values. + */ +#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ +#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ +#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ +#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ +#endif + +/* The following are examples of calls to png_set_alpha_mode to achieve the + * required overall gamma correction and, where necessary, alpha + * premultiplication. + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + * This is the default libpng handling of the alpha channel - it is not + * pre-multiplied into the color components. In addition the call states + * that the output is for a sRGB system and causes all PNG files without gAMA + * chunks to be assumed to be encoded using sRGB. + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + * In this case the output is assumed to be something like an sRGB conformant + * display preceeded by a power-law lookup table of power 1.45. This is how + * early Mac systems behaved. + * + * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); + * This is the classic Jim Blinn approach and will work in academic + * environments where everything is done by the book. It has the shortcoming + * of assuming that input PNG data with no gamma information is linear - this + * is unlikely to be correct unless the PNG files where generated locally. + * Most of the time the output precision will be so low as to show + * significant banding in dark areas of the image. + * + * png_set_expand_16(pp); + * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); + * This is a somewhat more realistic Jim Blinn inspired approach. PNG files + * are assumed to have the sRGB encoding if not marked with a gamma value and + * the output is always 16 bits per component. This permits accurate scaling + * and processing of the data. If you know that your input PNG files were + * generated locally you might need to replace PNG_DEFAULT_sRGB with the + * correct value for your system. + * + * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); + * If you just need to composite the PNG image onto an existing background + * and if you control the code that does this you can use the optimization + * setting. In this case you just copy completely opaque pixels to the + * output. For pixels that are not completely transparent (you just skip + * those) you do the composition math using png_composite or png_composite_16 + * below then encode the resultant 8-bit or 16-bit values to match the output + * encoding. + * + * Other cases + * If neither the PNG nor the standard linear encoding work for you because + * of the software or hardware you use then you have a big problem. The PNG + * case will probably result in halos around the image. The linear encoding + * will probably result in a washed out, too bright, image (it's actually too + * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably + * substantially reduce the halos. Alternatively try: + * + * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); + * This option will also reduce the halos, but there will be slight dark + * halos round the opaque parts of the image where the background is light. + * In the OPTIMIZED mode the halos will be light halos where the background + * is dark. Take your pick - the halos are unavoidable unless you can get + * your hardware/software fixed! (The OPTIMIZED approach is slightly + * faster.) + * + * When the default gamma of PNG files doesn't match the output gamma. + * If you have PNG files with no gamma information png_set_alpha_mode allows + * you to provide a default gamma, but it also sets the ouput gamma to the + * matching value. If you know your PNG files have a gamma that doesn't + * match the output you can take advantage of the fact that + * png_set_alpha_mode always sets the output gamma but only sets the PNG + * default if it is not already set: + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + * The first call sets both the default and the output gamma values, the + * second call overrides the output gamma without changing the default. This + * is easier than achieving the same effect with png_set_gamma. You must use + * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will + * fire if more than one call to png_set_alpha_mode and png_set_background is + * made in the same read operation, however multiple calls with PNG_ALPHA_PNG + * are ignored. + */ #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr)); @@ -1101,14 +1391,14 @@ PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr)); #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */ -PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler, +PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); /* The values of the PNG_FILLER_ defines should NOT be changed */ # define PNG_FILLER_BEFORE 0 # define PNG_FILLER_AFTER 1 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ PNG_EXPORT(40, void, png_set_add_alpha, - (png_structp png_ptr, png_uint_32 filler, + (png_structp png_ptr, png_uint_32 filler, int flags)); #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ @@ -1151,12 +1441,16 @@ PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr)); #endif #ifdef PNG_READ_BACKGROUND_SUPPORTED -/* Handle alpha and tRNS by replacing with a background color. */ -PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr, - png_const_color_16p background_color, int background_gamma_code, +/* Handle alpha and tRNS by replacing with a background color. Prior to + * libpng-1.5.4 this API must not be called before the PNG file header has been + * read. Doing so will result in unexpected behavior and possible warnings or + * errors if the PNG file contains a bKGD chunk. + */ +PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr, + png_const_color_16p background_color, int background_gamma_code, int need_expand, double background_gamma)); PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr, - png_const_color_16p background_color, int background_gamma_code, + png_const_color_16p background_color, int background_gamma_code, int need_expand, png_fixed_point background_gamma)); #endif #ifdef PNG_READ_BACKGROUND_SUPPORTED @@ -1166,7 +1460,13 @@ PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr, # define PNG_BACKGROUND_GAMMA_UNIQUE 3 #endif -#ifdef PNG_READ_16_TO_8_SUPPORTED +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +/* Scale a 16-bit depth file down to 8-bit, accurately. */ +PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr)); +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +#define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */ /* Strip the second byte of information from a 16-bit depth file. */ PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr)); #endif @@ -1176,8 +1476,8 @@ PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr)); * available. */ PNG_EXPORT(49, void, png_set_quantize, - (png_structp png_ptr, png_colorp palette, - int num_palette, int maximum_colors, png_const_uint_16p histogram, + (png_structp png_ptr, png_colorp palette, + int num_palette, int maximum_colors, png_const_uint_16p histogram, int full_quantize)); #endif @@ -1187,12 +1487,22 @@ PNG_EXPORT(49, void, png_set_quantize, */ #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) -/* Handle gamma correction. Screen_gamma=(display_exponent) */ +/* Handle gamma correction. Screen_gamma=(display_exponent). + * NOTE: this API simply sets the screen and file gamma values. It will + * therefore override the value for gamma in a PNG file if it is called after + * the file header has been read - use with care - call before reading the PNG + * file for best results! + * + * These routines accept the same gamma values as png_set_alpha_mode (described + * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either + * API (floating point or fixed.) Notice, however, that the 'file_gamma' value + * is the inverse of a 'screen gamma' value. + */ PNG_FP_EXPORT(50, void, png_set_gamma, - (png_structp png_ptr, double screen_gamma, - double default_file_gamma)); -PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr, - png_fixed_point screen_gamma, png_fixed_point default_file_gamma)); + (png_structp png_ptr, double screen_gamma, + double override_file_gamma)); +PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr, + png_fixed_point screen_gamma, png_fixed_point override_file_gamma)); #endif #ifdef PNG_WRITE_FLUSH_SUPPORTED @@ -1211,13 +1521,13 @@ PNG_EXPORT(54, void, png_read_update_info, #ifdef PNG_SEQUENTIAL_READ_SUPPORTED /* Read one or more rows of image data. */ -PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row, +PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row, png_bytepp display_row, png_uint_32 num_rows)); #endif #ifdef PNG_SEQUENTIAL_READ_SUPPORTED /* Read a row of data. */ -PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row, +PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row, png_bytep display_row)); #endif @@ -1235,7 +1545,7 @@ PNG_EXPORT(58, void, png_write_row, * of libpng and to allow the 'display_row' array from read_rows to be passed * unchanged to write_rows. */ -PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row, +PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row, png_uint_32 num_rows)); /* Write the image data */ @@ -1252,15 +1562,15 @@ PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr)); #endif /* Free any memory associated with the png_info_struct */ -PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr, +PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr, png_infopp info_ptr_ptr)); /* Free any memory associated with the png_struct and the png_info_structs */ -PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, +PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); /* Free any memory associated with the png_struct and the png_info_structs */ -PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, +PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)); /* Set the libpng method of handling chunk CRC errors */ @@ -1270,7 +1580,7 @@ PNG_EXPORT(66, void, png_set_crc_action, /* Values for png_set_crc_action() say how to handle CRC errors in * ancillary and critical chunks, and whether to use the data contained * therein. Note that it is impossible to "discard" data in a critical - * chunk. For versions prior to 0.90, the action was always error/quit, + * chunk. For versions prior to 0.90, the action was always error/quit, * whereas in version 0.90 and later, the action for CRC errors in ancillary * chunks is warn/discard. These values should NOT be changed. * @@ -1350,11 +1660,11 @@ PNG_EXPORT(67, void, png_set_filter, * the weights and costs are set to 1.0, this degenerates the WEIGHTED method * to the UNWEIGHTED method, but with added encoding time/computation. */ -PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr, - int heuristic_method, int num_weights, png_const_doublep filter_weights, +PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr, + int heuristic_method, int num_weights, png_const_doublep filter_weights, png_const_doublep filter_costs)); PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, - (png_structp png_ptr, + (png_structp png_ptr, int heuristic_method, int num_weights, png_const_fixed_point_p filter_weights, png_const_fixed_point_p filter_costs)); #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ @@ -1367,30 +1677,56 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ +#ifdef PNG_WRITE_SUPPORTED /* Set the library compression level. Currently, valid values range from * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 * (0 - no compression, 9 - "maximal" compression). Note that tests have * shown that zlib compression levels 3-6 usually perform as well as level 9 - * for PNG images, and do considerably fewer caclulations. In the future, + * for PNG images, and do considerably fewer caclulations. In the future, * these values may not correspond directly to the zlib compression levels. */ PNG_EXPORT(69, void, png_set_compression_level, (png_structp png_ptr, int level)); -PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr, +PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr, int mem_level)); -PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr, +PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr, int strategy)); -PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr, +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr, int window_bits)); PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr, int method)); +#endif + +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +/* Also set zlib parameters for compressing non-IDAT chunks */ +PNG_EXPORT(222, void, png_set_text_compression_level, + (png_structp png_ptr, int level)); + +PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr, + int mem_level)); + +PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr, + int strategy)); + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp + png_ptr, int window_bits)); + +PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr, + int method)); +#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ /* These next functions are called for input/output, memory, and error - * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, + * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, * and call standard C I/O routines such as fread(), fwrite(), and * fprintf(). These functions can be made to use other I/O routines * at run time for those applications that need to handle I/O in a @@ -1412,7 +1748,7 @@ PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp)); */ PNG_EXPORT(75, void, png_set_error_fn, - (png_structp png_ptr, png_voidp error_ptr, + (png_structp png_ptr, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); /* Return the user pointer associated with the error functions */ @@ -1428,43 +1764,43 @@ PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr)); * default flush function, which uses the standard *FILE structure, will * be used. */ -PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr, +PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); /* Replace the default data input function with a user supplied one. */ -PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr, +PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr, png_rw_ptr read_data_fn)); /* Return the user pointer associated with the I/O functions */ PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr)); -PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr, +PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr, png_read_status_ptr read_row_fn)); -PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr, +PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr, png_write_status_ptr write_row_fn)); #ifdef PNG_USER_MEM_SUPPORTED /* Replace the default memory allocation functions with user supplied one(s). */ -PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr, +PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn)); /* Return the user pointer associated with the memory functions */ PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr)); #endif #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED -PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr, +PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr, png_user_transform_ptr read_user_transform_fn)); #endif #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED -PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr, +PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr, png_user_transform_ptr write_user_transform_fn)); #endif #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED -PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr, - png_voidp user_transform_ptr, int user_transform_depth, +PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr, + png_voidp user_transform_ptr, int user_transform_depth, int user_transform_channels)); /* Return the user pointer associated with the user transform functions */ PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, @@ -1475,16 +1811,20 @@ PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, /* Return information about the row currently being processed. Note that these * APIs do not fail but will return unexpected results if called outside a user * transform callback. Also note that when transforming an interlaced image the - * row number is still the row in the final, de-interlaced, image but the row - * only contains the data of the current pass - consult png_row_info for the - * actual width of the row! + * row number is the row number within the sub-image of the interlace pass, so + * the value will increase to the height of the sub-image (not the full image) + * then reset to 0 for the next pass. + * + * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to + * find the output pixel (x,y) given an interlaced sub-image pixel + * (row,col,pass). (See below for these macros.) */ PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp)); PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp)); #endif #ifdef PNG_USER_CHUNKS_SUPPORTED -PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr, +PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr, png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr)); #endif @@ -1493,8 +1833,8 @@ PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr)); /* Sets the function callbacks for the push reader, and a pointer to a * user-defined structure available to the callback functions. */ -PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr, - png_voidp progressive_ptr, png_progressive_info_ptr info_fn, +PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr, + png_voidp progressive_ptr, png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); /* Returns the user pointer associated with the push read functions */ @@ -1502,7 +1842,7 @@ PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr)); /* Function to be called when data becomes available */ PNG_EXPORT(92, void, png_process_data, - (png_structp png_ptr, png_infop info_ptr, + (png_structp png_ptr, png_infop info_ptr, png_bytep buffer, png_size_t buffer_size)); /* A function which may be called *only* within png_process_data to stop the @@ -1522,25 +1862,27 @@ PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save)); */ PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp)); +#ifdef PNG_READ_INTERLACING_SUPPORTED /* Function that combines rows. 'new_row' is a flag that should come from * the callback and be non-NULL if anything needs to be done; the library * stores its own version of the new data internally and ignores the passed * in value. */ -PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr, +PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr, png_bytep old_row, png_const_bytep new_row)); +#endif /* PNG_READ_INTERLACING_SUPPORTED */ #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ PNG_EXPORTA(94, png_voidp, png_malloc, - (png_structp png_ptr, png_alloc_size_t size), + (png_structp png_ptr, png_alloc_size_t size), PNG_ALLOCATED); /* Added at libpng version 1.4.0 */ PNG_EXPORTA(95, png_voidp, png_calloc, - (png_structp png_ptr, png_alloc_size_t size), + (png_structp png_ptr, png_alloc_size_t size), PNG_ALLOCATED); /* Added at libpng version 1.2.4 */ -PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr, +PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr, png_alloc_size_t size), PNG_ALLOCATED); /* Frees a pointer allocated by png_malloc() */ @@ -1575,7 +1917,7 @@ PNG_EXPORT(99, void, png_data_freer, #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ #ifdef PNG_USER_MEM_SUPPORTED -PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr, +PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr, png_alloc_size_t size), PNG_ALLOCATED); PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr)); #endif @@ -1583,11 +1925,11 @@ PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr)); #ifdef PNG_ERROR_TEXT_SUPPORTED /* Fatal error in PNG image of libpng - can't continue */ PNG_EXPORTA(102, void, png_error, - (png_structp png_ptr, png_const_charp error_message), + (png_structp png_ptr, png_const_charp error_message), PNG_NORETURN); /* The same, but the chunk name is prepended to the error string. */ -PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr, +PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr, png_const_charp error_message), PNG_NORETURN); #else @@ -1595,24 +1937,26 @@ PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr, PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN); #endif +#ifdef PNG_WARNINGS_SUPPORTED /* Non-fatal error in libpng. Can continue, but may have a problem. */ -PNG_EXPORT(105, void, png_warning, (png_structp png_ptr, +PNG_EXPORT(105, void, png_warning, (png_structp png_ptr, png_const_charp warning_message)); /* Non-fatal error in libpng, chunk name is prepended to message. */ -PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr, +PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr, png_const_charp warning_message)); +#endif #ifdef PNG_BENIGN_ERRORS_SUPPORTED /* Benign error in libpng. Can continue, but may have a problem. * User can choose whether to handle as a fatal error or as a warning. */ # undef png_benign_error -PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr, +PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr, png_const_charp warning_message)); /* Same, chunk name is prepended to message. */ # undef png_chunk_benign_error -PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr, +PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr, png_const_charp warning_message)); PNG_EXPORT(109, void, png_set_benign_errors, @@ -1641,11 +1985,11 @@ PNG_EXPORT(109, void, png_set_benign_errors, */ /* Returns "flag" if chunk data is valid in info_ptr. */ PNG_EXPORT(110, png_uint_32, png_get_valid, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, png_uint_32 flag)); /* Returns number of bytes needed to hold a transformed row. */ -PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr, +PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr, png_const_infop info_ptr)); #ifdef PNG_INFO_IMAGE_SUPPORTED @@ -1667,11 +2011,11 @@ PNG_EXPORT(114, png_byte, png_get_channels, #ifdef PNG_EASY_ACCESS_SUPPORTED /* Returns image width in pixels. */ -PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr, +PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image height in pixels. */ -PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr, +PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image bit_depth. */ @@ -1679,19 +2023,19 @@ PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image color_type. */ -PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr, +PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image filter_type. */ -PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr, +PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image interlace_type. */ -PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr, +PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image compression_type. */ -PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr, +PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image resolution in pixels per meter, from pHYs chunk data. */ @@ -1705,7 +2049,7 @@ PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, /* Returns pixel aspect ratio, computed from pHYs chunk data. */ PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, (png_const_structp png_ptr, png_const_infop info_ptr)); -PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, +PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ @@ -1726,47 +2070,68 @@ PNG_EXPORT(130, png_const_bytep, png_get_signature, #ifdef PNG_bKGD_SUPPORTED PNG_EXPORT(131, png_uint_32, png_get_bKGD, - (png_const_structp png_ptr, png_infop info_ptr, + (png_const_structp png_ptr, png_infop info_ptr, png_color_16p *background)); #endif #ifdef PNG_bKGD_SUPPORTED -PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr, +PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr, png_const_color_16p background)); #endif #ifdef PNG_cHRM_SUPPORTED -PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr, - png_const_infop info_ptr, double *white_x, double *white_y, double *red_x, - double *red_y, double *green_x, double *green_y, double *blue_x, +PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr, + png_const_infop info_ptr, double *white_x, double *white_y, double *red_x, + double *red_y, double *green_x, double *green_y, double *blue_x, double *blue_y)); +PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_structp png_ptr, + png_const_infop info_ptr, double *red_X, double *red_Y, double *red_Z, + double *green_X, double *green_Y, double *green_Z, double *blue_X, + double *blue_Y, double *blue_Z)); #ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */ PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, - (png_const_structp png_ptr, - png_const_infop info_ptr, png_fixed_point *int_white_x, - png_fixed_point *int_white_y, png_fixed_point *int_red_x, - png_fixed_point *int_red_y, png_fixed_point *int_green_x, - png_fixed_point *int_green_y, png_fixed_point *int_blue_x, + (png_const_structp png_ptr, + png_const_infop info_ptr, png_fixed_point *int_white_x, + png_fixed_point *int_white_y, png_fixed_point *int_red_x, + png_fixed_point *int_red_y, png_fixed_point *int_green_x, + png_fixed_point *int_green_y, png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)); #endif +PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, + (png_structp png_ptr, png_const_infop info_ptr, + png_fixed_point *int_red_X, png_fixed_point *int_red_Y, + png_fixed_point *int_red_Z, png_fixed_point *int_green_X, + png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, + png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, + png_fixed_point *int_blue_Z)); #endif #ifdef PNG_cHRM_SUPPORTED PNG_FP_EXPORT(135, void, png_set_cHRM, - (png_structp png_ptr, png_infop info_ptr, - double white_x, double white_y, double red_x, double red_y, double green_x, + (png_structp png_ptr, png_infop info_ptr, + double white_x, double white_y, double red_x, double red_y, double green_x, double green_y, double blue_x, double blue_y)); -PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr, - png_infop info_ptr, png_fixed_point int_white_x, - png_fixed_point int_white_y, png_fixed_point int_red_x, - png_fixed_point int_red_y, png_fixed_point int_green_x, - png_fixed_point int_green_y, png_fixed_point int_blue_x, +PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_structp png_ptr, + png_infop info_ptr, double red_X, double red_Y, double red_Z, + double green_X, double green_Y, double green_Z, double blue_X, + double blue_Y, double blue_Z)); +PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr, + png_infop info_ptr, png_fixed_point int_white_x, + png_fixed_point int_white_y, png_fixed_point int_red_x, + png_fixed_point int_red_y, png_fixed_point int_green_x, + png_fixed_point int_green_y, png_fixed_point int_blue_x, png_fixed_point int_blue_y)); +PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_structp png_ptr, + png_infop info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, + png_fixed_point int_red_Z, png_fixed_point int_green_X, + png_fixed_point int_green_Y, png_fixed_point int_green_Z, + png_fixed_point int_blue_X, png_fixed_point int_blue_Y, + png_fixed_point int_blue_Z)); #endif #ifdef PNG_gAMA_SUPPORTED PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, double *file_gamma)); PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, (png_const_structp png_ptr, png_const_infop info_ptr, @@ -1776,13 +2141,13 @@ PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, #ifdef PNG_gAMA_SUPPORTED PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr, png_infop info_ptr, double file_gamma)); -PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr, +PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr, png_infop info_ptr, png_fixed_point int_file_gamma)); #endif #ifdef PNG_hIST_SUPPORTED PNG_EXPORT(141, png_uint_32, png_get_hIST, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, png_uint_16p *hist)); #endif @@ -1792,65 +2157,65 @@ PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr, #endif PNG_EXPORT(143, png_uint_32, png_get_IHDR, - (png_structp png_ptr, png_infop info_ptr, - png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type, + (png_structp png_ptr, png_infop info_ptr, + png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type, int *interlace_method, int *compression_method, int *filter_method)); PNG_EXPORT(144, void, png_set_IHDR, - (png_structp png_ptr, png_infop info_ptr, - png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, + (png_structp png_ptr, png_infop info_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int interlace_method, int compression_method, int filter_method)); #ifdef PNG_oFFs_SUPPORTED PNG_EXPORT(145, png_uint_32, png_get_oFFs, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)); #endif #ifdef PNG_oFFs_SUPPORTED PNG_EXPORT(146, void, png_set_oFFs, - (png_structp png_ptr, png_infop info_ptr, + (png_structp png_ptr, png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y, int unit_type)); #endif #ifdef PNG_pCAL_SUPPORTED PNG_EXPORT(147, png_uint_32, png_get_pCAL, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, - int *nparams, + int *nparams, png_charp *units, png_charpp *params)); #endif #ifdef PNG_pCAL_SUPPORTED PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr, - png_infop info_ptr, - png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, + png_infop info_ptr, + png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, png_const_charp units, png_charpp params)); #endif #ifdef PNG_pHYs_SUPPORTED PNG_EXPORT(149, png_uint_32, png_get_pHYs, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)); #endif #ifdef PNG_pHYs_SUPPORTED PNG_EXPORT(150, void, png_set_pHYs, - (png_structp png_ptr, png_infop info_ptr, + (png_structp png_ptr, png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); #endif PNG_EXPORT(151, png_uint_32, png_get_PLTE, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, png_colorp *palette, int *num_palette)); PNG_EXPORT(152, void, png_set_PLTE, - (png_structp png_ptr, png_infop info_ptr, + (png_structp png_ptr, png_infop info_ptr, png_const_colorp palette, int num_palette)); #ifdef PNG_sBIT_SUPPORTED PNG_EXPORT(153, png_uint_32, png_get_sBIT, - (png_const_structp png_ptr, png_infop info_ptr, + (png_const_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)); #endif @@ -1867,44 +2232,44 @@ PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr, #ifdef PNG_sRGB_SUPPORTED PNG_EXPORT(156, void, png_set_sRGB, (png_structp png_ptr, png_infop info_ptr, int srgb_intent)); -PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr, +PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr, png_infop info_ptr, int srgb_intent)); #endif #ifdef PNG_iCCP_SUPPORTED PNG_EXPORT(158, png_uint_32, png_get_iCCP, - (png_const_structp png_ptr, png_const_infop info_ptr, - png_charpp name, int *compression_type, png_bytepp profile, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_charpp name, int *compression_type, png_bytepp profile, png_uint_32 *proflen)); #endif #ifdef PNG_iCCP_SUPPORTED PNG_EXPORT(159, void, png_set_iCCP, - (png_structp png_ptr, png_infop info_ptr, - png_const_charp name, int compression_type, png_const_bytep profile, + (png_structp png_ptr, png_infop info_ptr, + png_const_charp name, int compression_type, png_const_bytep profile, png_uint_32 proflen)); #endif #ifdef PNG_sPLT_SUPPORTED PNG_EXPORT(160, png_uint_32, png_get_sPLT, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, png_sPLT_tpp entries)); #endif #ifdef PNG_sPLT_SUPPORTED PNG_EXPORT(161, void, png_set_sPLT, - (png_structp png_ptr, png_infop info_ptr, + (png_structp png_ptr, png_infop info_ptr, png_const_sPLT_tp entries, int nentries)); #endif #ifdef PNG_TEXT_SUPPORTED /* png_get_text also returns the number of text chunks in *num_text */ PNG_EXPORT(162, png_uint_32, png_get_text, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, png_textp *text_ptr, int *num_text)); #endif -/* Note while png_set_text() will accept a structure whose text, +/* Note while png_set_text() will accept a structure whose text, * language, and translated keywords are NULL pointers, the structure * returned by png_get_text will always contain regular * zero-terminated C strings. They might be empty strings but @@ -1913,7 +2278,7 @@ PNG_EXPORT(162, png_uint_32, png_get_text, #ifdef PNG_TEXT_SUPPORTED PNG_EXPORT(163, void, png_set_text, - (png_structp png_ptr, png_infop info_ptr, + (png_structp png_ptr, png_infop info_ptr, png_const_textp text_ptr, int num_text)); #endif @@ -1929,30 +2294,30 @@ PNG_EXPORT(165, void, png_set_tIME, #ifdef PNG_tRNS_SUPPORTED PNG_EXPORT(166, png_uint_32, png_get_tRNS, - (png_const_structp png_ptr, png_infop info_ptr, + (png_const_structp png_ptr, png_infop info_ptr, png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)); #endif #ifdef PNG_tRNS_SUPPORTED PNG_EXPORT(167, void, png_set_tRNS, - (png_structp png_ptr, png_infop info_ptr, - png_const_bytep trans_alpha, int num_trans, + (png_structp png_ptr, png_infop info_ptr, + png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)); #endif #ifdef PNG_sCAL_SUPPORTED PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, - (png_const_structp png_ptr, png_const_infop info_ptr, + (png_const_structp png_ptr, png_const_infop info_ptr, int *unit, double *width, double *height)); #ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED -/* NOTE: this API is currently implemented using floating point arithmetic, +/* NOTE: this API is currently implemented using floating point arithmetic, * consequently it can only be used on systems with floating point support. * In any case the range of values supported by png_fixed_point is small and it * is highly recommended that png_get_sCAL_s be used instead. */ PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, (png_structp png_ptr, png_const_infop info_ptr, int *unit, - png_fixed_point *width, + png_fixed_point *width, png_fixed_point *height)); #endif PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, @@ -1960,13 +2325,13 @@ PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, int *unit, png_charpp swidth, png_charpp sheight)); PNG_FP_EXPORT(170, void, png_set_sCAL, - (png_structp png_ptr, png_infop info_ptr, + (png_structp png_ptr, png_infop info_ptr, int unit, double width, double height)); -PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr, - png_infop info_ptr, int unit, png_fixed_point width, +PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr, + png_infop info_ptr, int unit, png_fixed_point width, png_fixed_point height)); PNG_EXPORT(171, void, png_set_sCAL_s, - (png_structp png_ptr, png_infop info_ptr, + (png_structp png_ptr, png_infop info_ptr, int unit, png_const_charp swidth, png_const_charp sheight)); #endif /* PNG_sCAL_SUPPORTED */ @@ -1974,30 +2339,36 @@ PNG_EXPORT(171, void, png_set_sCAL_s, /* Provide a list of chunks and how they are to be handled, if the built-in handling or default unknown chunk handling is not desired. Any chunks not listed will be handled in the default manner. The IHDR and IEND chunks - must not be listed. - keep = 0: follow default behaviour - = 1: do not keep - = 2: keep only if safe-to-copy - = 3: keep even if unsafe-to-copy + must not be listed. Because this turns off the default handling for chunks + that would otherwise be recognized the behavior of libpng transformations may + well become incorrect! + keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior + = 1: PNG_HANDLE_CHUNK_NEVER: do not keep + = 2: PNG_HANDLE_CHUNK_IF_SAFE: keep only if safe-to-copy + = 3: PNG_HANDLE_CHUNK_ALWAYS: keep even if unsafe-to-copy */ PNG_EXPORT(172, void, png_set_keep_unknown_chunks, - (png_structp png_ptr, int keep, + (png_structp png_ptr, int keep, png_const_bytep chunk_list, int num_chunks)); -PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr, + +/* The handling code is returned; the result is therefore true (non-zero) if + * special handling is required, false for the default handling. + */ +PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr, png_const_bytep chunk_name)); #endif #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED -PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr, +PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr, png_infop info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)); PNG_EXPORT(175, void, png_set_unknown_chunk_location, (png_structp png_ptr, png_infop info_ptr, int chunk, int location)); -PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr, +PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr, png_const_infop info_ptr, png_unknown_chunkpp entries)); #endif /* Png_free_data() will turn off the "valid" flag for anything it frees. - * If you need to turn it off for a chunk that your application has freed, + * If you need to turn it off for a chunk that your application has freed, * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */ PNG_EXPORT(177, void, png_set_invalid, @@ -2005,9 +2376,9 @@ PNG_EXPORT(177, void, png_set_invalid, #ifdef PNG_INFO_IMAGE_SUPPORTED /* The "params" pointer is currently not used and is for future expansion. */ -PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr, +PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr, int transforms, png_voidp params)); -PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr, +PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr, int transforms, png_voidp params)); #endif @@ -2021,7 +2392,7 @@ PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, (png_const_structp png_ptr)); #ifdef PNG_MNG_FEATURES_SUPPORTED -PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr, +PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr, png_uint_32 mng_features_permitted)); #endif @@ -2036,25 +2407,25 @@ PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr, */ #ifdef PNG_ERROR_NUMBERS_SUPPORTED PNG_EXPORT(185, void, png_set_strip_error_numbers, - (png_structp png_ptr, + (png_structp png_ptr, png_uint_32 strip_mode)); #endif /* Added in libpng-1.2.6 */ #ifdef PNG_SET_USER_LIMITS_SUPPORTED -PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr, +PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max)); PNG_EXPORT(187, png_uint_32, png_get_user_width_max, (png_const_structp png_ptr)); PNG_EXPORT(188, png_uint_32, png_get_user_height_max, (png_const_structp png_ptr)); /* Added in libpng-1.4.0 */ -PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr, +PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr, png_uint_32 user_chunk_cache_max)); PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, (png_const_structp png_ptr)); /* Added in libpng-1.4.1 */ -PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr, +PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr, png_alloc_size_t user_chunk_cache_max)); PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, (png_const_structp png_ptr)); @@ -2073,19 +2444,19 @@ PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, PNG_FP_EXPORT(196, float, png_get_x_offset_inches, (png_const_structp png_ptr, png_const_infop info_ptr)); #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ -PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, +PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, (png_structp png_ptr, png_const_infop info_ptr)); #endif -PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr, +PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr, png_const_infop info_ptr)); #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ -PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, +PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, (png_structp png_ptr, png_const_infop info_ptr)); #endif # ifdef PNG_pHYs_SUPPORTED -PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr, +PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr, png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)); # endif /* PNG_pHYs_SUPPORTED */ @@ -2122,8 +2493,16 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, * full, image which appears in a given pass. 'pass' is in the range 0 * to 6 and the result is in the range 0 to 7. */ -#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) -#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) +#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) + +/* A macro to return the offset between pixels in the output row for a pair of + * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that + * follows. Note that ROW_OFFSET is the offset from one row to the next whereas + * COL_OFFSET is from one column to the next, within a row. + */ +#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) +#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) /* Two macros to help evaluate the number of rows or columns in each * pass. This is expressed as a shift - effectively log2 of the number or @@ -2142,8 +2521,9 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) -/* For the progressive reader it is necessary to find the row in the output - * image given a row in an interlaced image, so two more macros: +/* For the reader row callbacks (both progressive and sequential) it is + * necessary to find the row in the output image given a row in an interlaced + * image, so two more macros: */ #define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) @@ -2157,8 +2537,8 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, * the tile. */ #define PNG_PASS_MASK(pass,off) ( \ - ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \ - ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) + ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ + ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) @@ -2184,14 +2564,14 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ * (png_uint_16)(alpha) \ + (png_uint_16)(bg)*(png_uint_16)(255 \ - - (png_uint_16)(alpha)) + (png_uint_16)128); \ + - (png_uint_16)(alpha)) + 128); \ (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } # define png_composite_16(composite, fg, alpha, bg) \ { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ * (png_uint_32)(alpha) \ - + (png_uint_32)(bg)*(png_uint_32)(65535L \ - - (png_uint_32)(alpha)) + (png_uint_32)32768L); \ + + (png_uint_32)(bg)*(65535 \ + - (png_uint_32)(alpha)) + 32768); \ (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } #else /* Standard method using integer division */ @@ -2199,12 +2579,12 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, # define png_composite(composite, fg, alpha, bg) \ (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ - (png_uint_16)127) / 255) + 127) / 255) # define png_composite_16(composite, fg, alpha, bg) \ (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ - (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \ - (png_uint_32)32767) / (png_uint_32)65535L) + (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ + 32767) / 65535) #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */ #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED @@ -2213,7 +2593,7 @@ PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); #endif -PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr, +PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr, png_const_bytep buf)); /* No png_get_int_16 -- may be added if there's a real need for it. */ @@ -2226,7 +2606,7 @@ PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); #endif /* Place a 16-bit number into a buffer in PNG byte order. - * The parameter is declared unsigned int, not png_uint_16, + * The parameter is declared unsigned int, not png_uint_16, * just to avoid potential problems on pre-ANSI C compilers. */ #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED @@ -2259,6 +2639,12 @@ PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); : (png_int_32)png_get_uint_32(buf))) #endif +#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ + defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) +PNG_EXPORT(234, void, png_set_check_for_invalid_index, (png_structp png_ptr, + int allowed)); +#endif + /* Maintainer: Put new public prototypes here ^, in libpng.3, and project * defs */ @@ -2268,7 +2654,7 @@ PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); * scripts/symbols.def as well. */ #ifdef PNG_EXPORT_LAST_ORDINAL - PNG_EXPORT_LAST_ORDINAL(220); + PNG_EXPORT_LAST_ORDINAL(234); #endif #ifdef __cplusplus diff --git a/png/pngconf.h b/png/pngconf.h index 2633bf890..bbb547f8e 100644 --- a/png/pngconf.h +++ b/png/pngconf.h @@ -1,9 +1,9 @@ /* pngconf.h - machine configurable file for libpng * - * libpng version 1.5.1 - February 3, 2011 + * libpng version 1.5.10 - March 29, 2012 * - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -22,35 +22,37 @@ #ifndef PNGCONF_H #define PNGCONF_H +#ifndef PNG_BUILDING_SYMBOL_TABLE /* PNG_NO_LIMITS_H may be used to turn off the use of the standard C * definition file for machine specific limits, this may impact the * correctness of the definitons below (see uses of INT_MAX). */ -#ifndef PNG_NO_LIMITS_H -# include <limits.h> -#endif +# ifndef PNG_NO_LIMITS_H +# include <limits.h> +# endif /* For the memory copy APIs (i.e. the standard definitions of these), * because this file defines png_memcpy and so on the base APIs must * be defined here. */ -#ifdef BSD -# include <strings.h> -#else -# include <string.h> -#endif +# ifdef BSD +# include <strings.h> +# else +# include <string.h> +# endif /* For png_FILE_p - this provides the standard definition of a * FILE */ -#ifdef PNG_STDIO_SUPPORTED -# include <stdio.h> +# ifdef PNG_STDIO_SUPPORTED +# include <stdio.h> +# endif #endif /* This controls optimization of the reading of 16 and 32 bit values * from PNG files. It can be set on a per-app-file basis - it - * just changes whether a macro is used to the function is called. - * The library builder sets the default, if read functions are not + * just changes whether a macro is used when the function is called. + * The library builder sets the default; if read functions are not * built into the library the macro implementation is forced on. */ #ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED @@ -162,7 +164,9 @@ * 'type', compiler specific. * * PNG_DLL_EXPORT Set to the magic to use during a libpng build to - * make a symbol exported from the DLL. + * make a symbol exported from the DLL. Not used in the + * public header files; see pngpriv.h for how it is used + * in the libpng build. * * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come * from a DLL - used to define PNG_IMPEXP when @@ -256,25 +260,14 @@ # define PNGAPI PNGCAPI #endif -/* The default for PNG_IMPEXP depends on whether the library is - * being built or used. +/* PNG_IMPEXP may be set on the compilation system command line or (if not set) + * then in an internal header file when building the library, otherwise (when + * using the library) it is set here. */ #ifndef PNG_IMPEXP -# ifdef PNGLIB_BUILD - /* Building the library */ -# if (defined(DLL_EXPORT)/*from libtool*/ ||\ - defined(_WINDLL) || defined(_DLL) || defined(__DLL__) ||\ - defined(_USRDLL) ||\ - defined(PNG_BUILD_DLL)) && defined(PNG_DLL_EXPORT) - /* Building a DLL. */ -# define PNG_IMPEXP PNG_DLL_EXPORT -# endif /* DLL */ -# else - /* Using the library */ -# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT) - /* This forces use of a DLL, disallowing static linking */ -# define PNG_IMPEXP PNG_DLL_IMPORT -# endif +# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT) + /* This forces use of a DLL, disallowing static linking */ +# define PNG_IMPEXP PNG_DLL_IMPORT # endif # ifndef PNG_IMPEXP @@ -282,23 +275,15 @@ # endif #endif -/* THe following complexity is concerned with getting the 'attributes' of the - * declared function in the correct place. This potentially requires a separate - * PNG_EXPORT function for every compiler. +/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat + * 'attributes' as a storage class - the attributes go at the start of the + * function definition, and attributes are always appended regardless of the + * compiler. This considerably simplifies these macros but may cause problems + * if any compilers both need function attributes and fail to handle them as + * a storage class (this is unlikely.) */ #ifndef PNG_FUNCTION -# ifdef __GNUC__ -# define PNG_FUNCTION(type, name, args, attributes)\ - attributes type name args -# else /* !GNUC */ -# ifdef _MSC_VER -# define PNG_FUNCTION(type, name, args, attributes)\ - attributes type name args -# else /* !MSC */ -# define PNG_FUNCTION(type, name, args, attributes)\ - type name args -# endif -# endif +# define PNG_FUNCTION(type, name, args, attributes) attributes type name args #endif #ifndef PNG_EXPORT_TYPE @@ -310,13 +295,19 @@ * scripts directory. */ #ifndef PNG_EXPORTA + # define PNG_EXPORTA(ordinal, type, name, args, attributes)\ - extern PNG_FUNCTION(PNG_EXPORT_TYPE(type),(PNGAPI name),PNGARG(args),\ - attributes) + PNG_FUNCTION(PNG_EXPORT_TYPE(type),(PNGAPI name),PNGARG(args), \ + extern attributes) #endif +/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument, + * so make something non-empty to satisfy the requirement: + */ +#define PNG_EMPTY /*empty list*/ + #define PNG_EXPORT(ordinal, type, name, args)\ - PNG_EXPORTA(ordinal, type, name, args, ) + PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY) /* Use PNG_REMOVED to comment out a removed interface. */ #ifndef PNG_REMOVED @@ -324,8 +315,7 @@ #endif #ifndef PNG_CALLBACK -# define PNG_CALLBACK(type, name, args, attributes)\ - type (PNGCBAPI name) PNGARG(args) attributes +# define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args) #endif /* Support for compiler specific function attributes. These are used @@ -347,72 +337,49 @@ * functions in png.h will generate compiler warnings. Added at libpng * version 1.2.41. */ -# ifdef __GNUC__ +# if defined(__GNUC__) # ifndef PNG_USE_RESULT # define PNG_USE_RESULT __attribute__((__warn_unused_result__)) # endif # ifndef PNG_NORETURN # define PNG_NORETURN __attribute__((__noreturn__)) # endif -# ifndef PNG_PTR_NORETURN -# define PNG_PTR_NORETURN __attribute__((__noreturn__)) -# endif # ifndef PNG_ALLOCATED # define PNG_ALLOCATED __attribute__((__malloc__)) # endif - - /* This specifically protects structure members that should only be - * accessed from within the library, therefore should be empty during - * a library build. - */ -# ifndef PNGLIB_BUILD -# ifndef PNG_DEPRECATED -# define PNG_DEPRECATED __attribute__((__deprecated__)) -# endif -# ifndef PNG_DEPSTRUCT -# define PNG_DEPSTRUCT __attribute__((__deprecated__)) +# ifndef PNG_DEPRECATED +# define PNG_DEPRECATED __attribute__((__deprecated__)) +# endif +# ifndef PNG_PRIVATE +# if 0 /* Doesn't work so we use deprecated instead*/ +# define PNG_PRIVATE \ + __attribute__((warning("This function is not exported by libpng."))) +# else +# define PNG_PRIVATE \ + __attribute__((__deprecated__)) # endif -# ifndef PNG_PRIVATE -# if 0 /* Doesn't work so we use deprecated instead*/ -# define PNG_PRIVATE \ - __attribute__((warning("This function is not exported by libpng."))) -# else -# define PNG_PRIVATE \ - __attribute__((__deprecated__)) -# endif -# endif /* PNG_PRIVATE */ -# endif /* PNGLIB_BUILD */ +# endif # endif /* __GNUC__ */ -# ifdef _MSC_VER /* may need to check value */ + +# if defined(_MSC_VER) && (_MSC_VER >= 1300) # ifndef PNG_USE_RESULT -# define PNG_USE_RESULT /*not supported*/ +# define PNG_USE_RESULT /* not supported */ # endif # ifndef PNG_NORETURN -# define PNG_NORETURN __declspec(noreturn) -# endif -# ifndef PNG_PTR_NORETURN -# define PNG_PTR_NORETURN /*not supported*/ +# define PNG_NORETURN __declspec(noreturn) # endif # ifndef PNG_ALLOCATED -# define PNG_ALLOCATED __declspec(restrict) -# endif - - /* This specifically protects structure members that should only be - * accessed from within the library, therefore should be empty during - * a library build. - */ -# ifndef PNGLIB_BUILD -# ifndef PNG_DEPRECATED -# define PNG_DEPRECATED __declspec(deprecated) -# endif -# ifndef PNG_DEPSTRUCT -# define PNG_DEPSTRUCT __declspec(deprecated) +# if (_MSC_VER >= 1400) +# define PNG_ALLOCATED __declspec(restrict) # endif -# ifndef PNG_PRIVATE -# define PNG_PRIVATE __declspec(deprecated) -# endif /* PNG_PRIVATE */ -# endif /* PNGLIB_BUILD */ -# endif /* __GNUC__ */ +# endif +# ifndef PNG_DEPRECATED +# define PNG_DEPRECATED __declspec(deprecated) +# endif +# ifndef PNG_PRIVATE +# define PNG_PRIVATE __declspec(deprecated) +# endif +# endif /* _MSC_VER */ #endif /* PNG_PEDANTIC_WARNINGS */ #ifndef PNG_DEPRECATED @@ -427,9 +394,6 @@ #ifndef PNG_ALLOCATED # define PNG_ALLOCATED /* The result of the function is new memory */ #endif -#ifndef PNG_DEPSTRUCT -# define PNG_DEPSTRUCT /* Access to this struct member is deprecated */ -#endif #ifndef PNG_PRIVATE # define PNG_PRIVATE /* This is a private libpng function */ #endif diff --git a/png/pngerror.c b/png/pngerror.c index 8290bb410..95002f84f 100644 --- a/png/pngerror.c +++ b/png/pngerror.c @@ -1,8 +1,8 @@ /* pngerror.c - stub functions for i/o and memory allocation * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.8 [February 1, 2011] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -89,15 +89,121 @@ png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN) PNG_FUNCTION(void,PNGAPI png_err,(png_structp png_ptr),PNG_NORETURN) { + /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed + * erroneously as '\0', instead of the empty string "". This was + * apparently an error, introduced in libpng-1.2.20, and png_default_error + * will crash in this case. + */ if (png_ptr != NULL && png_ptr->error_fn != NULL) - (*(png_ptr->error_fn))(png_ptr, '\0'); + (*(png_ptr->error_fn))(png_ptr, ""); /* If the custom handler doesn't exist, or if it returns, use the default handler, which will not return. */ - png_default_error(png_ptr, '\0'); + png_default_error(png_ptr, ""); } #endif /* PNG_ERROR_TEXT_SUPPORTED */ +/* Utility to safely appends strings to a buffer. This never errors out so + * error checking is not required in the caller. + */ +size_t +png_safecat(png_charp buffer, size_t bufsize, size_t pos, + png_const_charp string) +{ + if (buffer != NULL && pos < bufsize) + { + if (string != NULL) + while (*string != '\0' && pos < bufsize-1) + buffer[pos++] = *string++; + + buffer[pos] = '\0'; + } + + return pos; +} + +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) +/* Utility to dump an unsigned value into a buffer, given a start pointer and + * and end pointer (which should point just *beyond* the end of the buffer!) + * Returns the pointer to the start of the formatted string. + */ +png_charp +png_format_number(png_const_charp start, png_charp end, int format, + png_alloc_size_t number) +{ + int count = 0; /* number of digits output */ + int mincount = 1; /* minimum number required */ + int output = 0; /* digit output (for the fixed point format) */ + + *--end = '\0'; + + /* This is written so that the loop always runs at least once, even with + * number zero. + */ + while (end > start && (number != 0 || count < mincount)) + { + + static const char digits[] = "0123456789ABCDEF"; + + switch (format) + { + case PNG_NUMBER_FORMAT_fixed: + /* Needs five digits (the fraction) */ + mincount = 5; + if (output || number % 10 != 0) + { + *--end = digits[number % 10]; + output = 1; + } + number /= 10; + break; + + case PNG_NUMBER_FORMAT_02u: + /* Expects at least 2 digits. */ + mincount = 2; + /* fall through */ + + case PNG_NUMBER_FORMAT_u: + *--end = digits[number % 10]; + number /= 10; + break; + + case PNG_NUMBER_FORMAT_02x: + /* This format expects at least two digits */ + mincount = 2; + /* fall through */ + + case PNG_NUMBER_FORMAT_x: + *--end = digits[number & 0xf]; + number >>= 4; + break; + + default: /* an error */ + number = 0; + break; + } + + /* Keep track of the number of digits added */ + ++count; + + /* Float a fixed number here: */ + if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start) + { + /* End of the fraction, but maybe nothing was output? In that case + * drop the decimal point. If the number is a true zero handle that + * here. + */ + if (output) + *--end = '.'; + else if (number == 0) /* and !output */ + *--end = '0'; + } + } + + return end; +} +#endif + #ifdef PNG_WARNINGS_SUPPORTED /* This function is called whenever there is a non-fatal error. This function * should not be changed. If there is a need to handle warnings differently, @@ -128,6 +234,124 @@ png_warning(png_structp png_ptr, png_const_charp warning_message) else png_default_warning(png_ptr, warning_message + offset); } + +/* These functions support 'formatted' warning messages with up to + * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter + * is introduced by @<number>, where 'number' starts at 1. This follows the + * standard established by X/Open for internationalizable error messages. + */ +void +png_warning_parameter(png_warning_parameters p, int number, + png_const_charp string) +{ + if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT) + (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string); +} + +void +png_warning_parameter_unsigned(png_warning_parameters p, int number, int format, + png_alloc_size_t value) +{ + char buffer[PNG_NUMBER_BUFFER_SIZE]; + png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value)); +} + +void +png_warning_parameter_signed(png_warning_parameters p, int number, int format, + png_int_32 value) +{ + png_alloc_size_t u; + png_charp str; + char buffer[PNG_NUMBER_BUFFER_SIZE]; + + /* Avoid overflow by doing the negate in a png_alloc_size_t: */ + u = (png_alloc_size_t)value; + if (value < 0) + u = ~u + 1; + + str = PNG_FORMAT_NUMBER(buffer, format, u); + + if (value < 0 && str > buffer) + *--str = '-'; + + png_warning_parameter(p, number, str); +} + +void +png_formatted_warning(png_structp png_ptr, png_warning_parameters p, + png_const_charp message) +{ + /* The internal buffer is just 192 bytes - enough for all our messages, + * overflow doesn't happen because this code checks! If someone figures + * out how to send us a message longer than 192 bytes, all that will + * happen is that the message will be truncated appropriately. + */ + size_t i = 0; /* Index in the msg[] buffer: */ + char msg[192]; + + /* Each iteration through the following loop writes at most one character + * to msg[i++] then returns here to validate that there is still space for + * the trailing '\0'. It may (in the case of a parameter) read more than + * one character from message[]; it must check for '\0' and continue to the + * test if it finds the end of string. + */ + while (i<(sizeof msg)-1 && *message != '\0') + { + /* '@' at end of string is now just printed (previously it was skipped); + * it is an error in the calling code to terminate the string with @. + */ + if (p != NULL && *message == '@' && message[1] != '\0') + { + int parameter_char = *++message; /* Consume the '@' */ + static const char valid_parameters[] = "123456789"; + int parameter = 0; + + /* Search for the parameter digit, the index in the string is the + * parameter to use. + */ + while (valid_parameters[parameter] != parameter_char && + valid_parameters[parameter] != '\0') + ++parameter; + + /* If the parameter digit is out of range it will just get printed. */ + if (parameter < PNG_WARNING_PARAMETER_COUNT) + { + /* Append this parameter */ + png_const_charp parm = p[parameter]; + png_const_charp pend = p[parameter] + (sizeof p[parameter]); + + /* No need to copy the trailing '\0' here, but there is no guarantee + * that parm[] has been initialized, so there is no guarantee of a + * trailing '\0': + */ + while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend) + msg[i++] = *parm++; + + /* Consume the parameter digit too: */ + ++message; + continue; + } + + /* else not a parameter and there is a character after the @ sign; just + * copy that. This is known not to be '\0' because of the test above. + */ + } + + /* At this point *message can't be '\0', even in the bad parameter case + * above where there is a lone '@' at the end of the message string. + */ + msg[i++] = *message++; + } + + /* i is always less than (sizeof msg), so: */ + msg[i] = '\0'; + + /* And this is the formatted message, it may be larger than + * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these are + * not (currently) formatted. + */ + png_warning(png_ptr, msg); +} #endif /* PNG_WARNINGS_SUPPORTED */ #ifdef PNG_BENIGN_ERRORS_SUPPORTED @@ -159,11 +383,14 @@ static void /* PRIVATE */ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp error_message) { - int iout = 0, iin = 0; + png_uint_32 chunk_name = png_ptr->chunk_name; + int iout = 0, ishift = 24; - while (iin < 4) + while (ishift >= 0) { - int c = png_ptr->chunk_name[iin++]; + int c = (int)(chunk_name >> ishift) & 0xff; + + ishift -= 8; if (isnonalpha(c)) { buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET; @@ -174,7 +401,7 @@ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp else { - buffer[iout++] = (png_byte)c; + buffer[iout++] = (char)c; } } @@ -183,10 +410,16 @@ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp else { + int iin = 0; + buffer[iout++] = ':'; buffer[iout++] = ' '; - png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT); - buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0'; + + while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0') + buffer[iout++] = error_message[iin++]; + + /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */ + buffer[iout] = '\0'; } } #endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */ @@ -272,7 +505,7 @@ png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn, return NULL; png_ptr->longjmp_fn = longjmp_fn; - return &png_ptr->png_jmpbuf; + return &png_ptr->longjmp_buffer; } #endif @@ -287,7 +520,8 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message), { #ifdef PNG_CONSOLE_IO_SUPPORTED #ifdef PNG_ERROR_NUMBERS_SUPPORTED - if (*error_message == PNG_LITERAL_SHARP) + /* Check on NULL only added in 1.5.4 */ + if (error_message != NULL && *error_message == PNG_LITERAL_SHARP) { /* Strip "#nnnn " from beginning of error message. */ int offset; @@ -317,11 +551,11 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message), else #endif { - fprintf(stderr, "libpng error: %s", error_message); + fprintf(stderr, "libpng error: %s", error_message ? error_message : + "undefined"); fprintf(stderr, PNG_STRING_NEWLINE); } -#endif -#ifndef PNG_CONSOLE_IO_SUPPORTED +#else PNG_UNUSED(error_message) /* Make compiler happy */ #endif png_longjmp(png_ptr, 1); @@ -335,13 +569,13 @@ png_longjmp,(png_structp png_ptr, int val),PNG_NORETURN) { # ifdef USE_FAR_KEYWORD { - jmp_buf png_jmpbuf; - png_memcpy(png_jmpbuf, png_ptr->png_jmpbuf, png_sizeof(jmp_buf)); - png_ptr->longjmp_fn(png_jmpbuf, val); + jmp_buf tmp_jmpbuf; + png_memcpy(tmp_jmpbuf, png_ptr->longjmp_buffer, png_sizeof(jmp_buf)); + png_ptr->longjmp_fn(tmp_jmpbuf, val); } # else - png_ptr->longjmp_fn(png_ptr->png_jmpbuf, val); + png_ptr->longjmp_fn(png_ptr->longjmp_buffer, val); # endif } #endif @@ -403,7 +637,7 @@ png_default_warning(png_structp png_ptr, png_const_charp warning_message) /* This function is called when the application wants to use another method * of handling errors and warnings. Note that the error function MUST NOT * return to the calling routine or serious problems will occur. The return - * method used in the default routine calls longjmp(png_ptr->png_jmpbuf, 1) + * method used in the default routine calls longjmp(png_ptr->longjmp_buffer, 1) */ void PNGAPI png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, @@ -414,7 +648,11 @@ png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, png_ptr->error_ptr = error_ptr; png_ptr->error_fn = error_fn; +#ifdef PNG_WARNINGS_SUPPORTED png_ptr->warning_fn = warning_fn; +#else + PNG_UNUSED(warning_fn) +#endif } diff --git a/png/pngget.c b/png/pngget.c index b5e5798c0..43400cda7 100644 --- a/png/pngget.c +++ b/png/pngget.c @@ -1,7 +1,7 @@ /* pngget.c - retrieval of values from info struct * - * Last changed in libpng 1.5.1 [February 3, 2011] + * Last changed in libpng 1.5.7 [December 15, 2011] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) @@ -459,6 +459,65 @@ png_get_bKGD(png_const_structp png_ptr, png_infop info_ptr, #endif #ifdef PNG_cHRM_SUPPORTED +/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the + * same time to correct the rgb grayscale coefficient defaults obtained from the + * cHRM chunk in 1.5.4 + */ +png_uint_32 PNGFAPI +png_get_cHRM_XYZ_fixed(png_structp png_ptr, png_const_infop info_ptr, + png_fixed_point *int_red_X, png_fixed_point *int_red_Y, + png_fixed_point *int_red_Z, png_fixed_point *int_green_X, + png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, + png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, + png_fixed_point *int_blue_Z) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) + { + png_xy xy; + png_XYZ XYZ; + + png_debug1(1, "in %s retrieval function", "cHRM_XYZ"); + + xy.whitex = info_ptr->x_white; + xy.whitey = info_ptr->y_white; + xy.redx = info_ptr->x_red; + xy.redy = info_ptr->y_red; + xy.greenx = info_ptr->x_green; + xy.greeny = info_ptr->y_green; + xy.bluex = info_ptr->x_blue; + xy.bluey = info_ptr->y_blue; + + /* The *_checked function handles error reporting, so just return 0 if + * there is a failure here. + */ + if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy)) + { + if (int_red_X != NULL) + *int_red_X = XYZ.redX; + if (int_red_Y != NULL) + *int_red_Y = XYZ.redY; + if (int_red_Z != NULL) + *int_red_Z = XYZ.redZ; + if (int_green_X != NULL) + *int_green_X = XYZ.greenX; + if (int_green_Y != NULL) + *int_green_Y = XYZ.greenY; + if (int_green_Z != NULL) + *int_green_Z = XYZ.greenZ; + if (int_blue_X != NULL) + *int_blue_X = XYZ.blueX; + if (int_blue_Y != NULL) + *int_blue_Y = XYZ.blueY; + if (int_blue_Z != NULL) + *int_blue_Z = XYZ.blueZ; + + return (PNG_INFO_cHRM); + } + } + + return (0); +} + # ifdef PNG_FLOATING_POINT_SUPPORTED png_uint_32 PNGAPI png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr, @@ -490,6 +549,42 @@ png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr, return (0); } + +png_uint_32 PNGAPI +png_get_cHRM_XYZ(png_structp png_ptr, png_const_infop info_ptr, + double *red_X, double *red_Y, double *red_Z, double *green_X, + double *green_Y, double *green_Z, double *blue_X, double *blue_Y, + double *blue_Z) +{ + png_XYZ XYZ; + + if (png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, + &XYZ.redX, &XYZ.redY, &XYZ.redZ, &XYZ.greenX, &XYZ.greenY, &XYZ.greenZ, + &XYZ.blueX, &XYZ.blueY, &XYZ.blueZ) & PNG_INFO_cHRM) + { + if (red_X != NULL) + *red_X = png_float(png_ptr, XYZ.redX, "cHRM red X"); + if (red_Y != NULL) + *red_Y = png_float(png_ptr, XYZ.redY, "cHRM red Y"); + if (red_Z != NULL) + *red_Z = png_float(png_ptr, XYZ.redZ, "cHRM red Z"); + if (green_X != NULL) + *green_X = png_float(png_ptr, XYZ.greenX, "cHRM green X"); + if (green_Y != NULL) + *green_Y = png_float(png_ptr, XYZ.greenY, "cHRM green Y"); + if (green_Z != NULL) + *green_Z = png_float(png_ptr, XYZ.greenZ, "cHRM green Z"); + if (blue_X != NULL) + *blue_X = png_float(png_ptr, XYZ.blueX, "cHRM blue X"); + if (blue_Y != NULL) + *blue_Y = png_float(png_ptr, XYZ.blueY, "cHRM blue Y"); + if (blue_Z != NULL) + *blue_Z = png_float(png_ptr, XYZ.blueZ, "cHRM blue Z"); + return (PNG_INFO_cHRM); + } + + return (0); +} # endif # ifdef PNG_FIXED_POINT_SUPPORTED @@ -587,15 +682,16 @@ png_get_iCCP(png_const_structp png_ptr, png_const_infop info_ptr, png_debug1(1, "in %s retrieval function", "iCCP"); if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP) - && name != NULL && profile != NULL && proflen != NULL) + && name != NULL && compression_type != NULL && profile != NULL && + proflen != NULL) { *name = info_ptr->iccp_name; *profile = info_ptr->iccp_profile; /* Compression_type is a dummy so the API won't have to change * if we introduce multiple compression types later. */ - *proflen = (int)info_ptr->iccp_proflen; - *compression_type = (int)info_ptr->iccp_compression; + *proflen = info_ptr->iccp_proflen; + *compression_type = info_ptr->iccp_compression; return (PNG_INFO_iCCP); } @@ -855,9 +951,8 @@ png_get_text(png_const_structp png_ptr, png_const_infop info_ptr, { if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0) { - png_debug1(1, "in %s retrieval function", - (png_ptr->chunk_name[0] == '\0' ? "text" : - (png_const_charp)png_ptr->chunk_name)); + png_debug1(1, "in 0x%lx retrieval function", + (unsigned long)png_ptr->chunk_name); if (text_ptr != NULL) *text_ptr = info_ptr->text; @@ -971,10 +1066,9 @@ png_get_user_chunk_ptr(png_const_structp png_ptr) png_size_t PNGAPI png_get_compression_buffer_size(png_const_structp png_ptr) { - return (png_ptr ? png_ptr->zbuf_size : 0L); + return (png_ptr ? png_ptr->zbuf_size : 0); } - #ifdef PNG_SET_USER_LIMITS_SUPPORTED /* These functions were added to libpng 1.2.6 and were enabled * by default in libpng-1.4.0 */ @@ -1016,16 +1110,14 @@ png_get_io_state (png_structp png_ptr) png_uint_32 PNGAPI png_get_io_chunk_type (png_const_structp png_ptr) { - return ((png_ptr->chunk_name[0] << 24) + - (png_ptr->chunk_name[1] << 16) + - (png_ptr->chunk_name[2] << 8) + - (png_ptr->chunk_name[3])); + return png_ptr->chunk_name; } png_const_bytep PNGAPI png_get_io_chunk_name (png_structp png_ptr) { - return png_ptr->chunk_name; + PNG_CSTRING_FROM_CHUNK(png_ptr->io_chunk_string, png_ptr->chunk_name); + return png_ptr->io_chunk_string; } #endif /* ?PNG_IO_STATE_SUPPORTED */ diff --git a/png/pnginfo.h b/png/pnginfo.h index fa19f85e7..a33bfab06 100644 --- a/png/pnginfo.h +++ b/png/pnginfo.h @@ -138,7 +138,6 @@ defined(PNG_READ_BACKGROUND_SUPPORTED) * single color specified that should be treated as fully transparent. * Data is valid if (valid & PNG_INFO_tRNS) is non-zero. */ - png_bytep trans; /* alpha values for paletted image */ png_bytep trans_alpha; /* alpha values for paletted image */ png_color_16 trans_color; /* transparent color for non-palette image */ #endif diff --git a/png/pnglibconf.h b/png/pnglibconf.h index 52a158bf3..6facf39aa 100644 --- a/png/pnglibconf.h +++ b/png/pnglibconf.h @@ -1,173 +1,186 @@ + +/* libpng STANDARD API DEFINITION */ + /* pnglibconf.h - library build configuration */ -/* libpng version 1.5.0 - January 6, 2011 */ +/* Libpng 1.5.10 - March 29, 2012 */ -/* Copyright (c) 1998-2011 Glenn Randers-Pehrson */ +/* Copyright (c) 1998-2012 Glenn Randers-Pehrson */ /* This code is released under the libpng license. */ /* For conditions of distribution and use, see the disclaimer */ /* and license in png.h */ /* pnglibconf.h */ -/* Machine generated file: DO NOT EDIT */ /* Derived from: scripts/pnglibconf.dfa */ +/* If you edit this file by hand you must obey the rules expressed in */ +/* pnglibconf.dfa with respect to the dependencies between the following */ +/* symbols. It is much better to generate a new file using */ +/* scripts/libpngconf.mak */ + #ifndef PNGLCONF_H #define PNGLCONF_H /* settings */ -#define PNG_MAX_GAMMA_8 11 -#define PNG_CALLOC_SUPPORTED -#define PNG_QUANTIZE_RED_BITS 5 -#define PNG_USER_WIDTH_MAX 1000000L -#define PNG_QUANTIZE_GREEN_BITS 5 #define PNG_API_RULE 0 +#define PNG_CALLOC_SUPPORTED +#define PNG_COST_SHIFT 3 +#define PNG_DEFAULT_READ_MACROS 1 +#define PNG_GAMMA_THRESHOLD_FIXED 5000 +#define PNG_MAX_GAMMA_8 11 #define PNG_QUANTIZE_BLUE_BITS 5 -#define PNG_USER_CHUNK_CACHE_MAX 0 -#define PNG_USER_HEIGHT_MAX 1000000L +#define PNG_QUANTIZE_GREEN_BITS 5 +#define PNG_QUANTIZE_RED_BITS 5 #define PNG_sCAL_PRECISION 5 -#define PNG_COST_SHIFT 3 #define PNG_WEIGHT_SHIFT 8 -#define PNG_USER_CHUNK_MALLOC_MAX 0 -#define PNG_DEFAULT_READ_MACROS 1 #define PNG_ZBUF_SIZE 8192 -#define PNG_GAMMA_THRESHOLD_FIXED 5000 /* end of settings */ /* options */ -#define PNG_INFO_IMAGE_SUPPORTED -#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED -#define PNG_POINTER_INDEXING_SUPPORTED -#define PNG_WARNINGS_SUPPORTED -#define PNG_FLOATING_ARITHMETIC_SUPPORTED -#define PNG_WRITE_SUPPORTED -#define PNG_WRITE_INTERLACING_SUPPORTED -#define PNG_WRITE_16BIT_SUPPORTED -#define PNG_EASY_ACCESS_SUPPORTED +#define PNG_16BIT_SUPPORTED #define PNG_ALIGN_MEMORY_SUPPORTED -#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED -#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED -#define PNG_USER_LIMITS_SUPPORTED -#define PNG_FIXED_POINT_SUPPORTED +#define PNG_BENIGN_ERRORS_SUPPORTED +#define PNG_bKGD_SUPPORTED +#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED +#define PNG_CHECK_cHRM_SUPPORTED +#define PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED +#define PNG_cHRM_SUPPORTED +#define PNG_CONSOLE_IO_SUPPORTED +#define PNG_CONVERT_tIME_SUPPORTED +#define PNG_EASY_ACCESS_SUPPORTED /*#undef PNG_ERROR_NUMBERS_SUPPORTED*/ #define PNG_ERROR_TEXT_SUPPORTED -#define PNG_READ_SUPPORTED -/*#undef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED*/ -#define PNG_BENIGN_ERRORS_SUPPORTED -#define PNG_SETJMP_SUPPORTED -#define PNG_WRITE_FLUSH_SUPPORTED -#define PNG_MNG_FEATURES_SUPPORTED +#define PNG_FIXED_POINT_SUPPORTED +#define PNG_FLOATING_ARITHMETIC_SUPPORTED #define PNG_FLOATING_POINT_SUPPORTED +#define PNG_gAMA_SUPPORTED +#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED +#define PNG_hIST_SUPPORTED +#define PNG_iCCP_SUPPORTED #define PNG_INCH_CONVERSIONS_SUPPORTED -#define PNG_STDIO_SUPPORTED -#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED -#define PNG_USER_MEM_SUPPORTED +#define PNG_INFO_IMAGE_SUPPORTED #define PNG_IO_STATE_SUPPORTED -#define PNG_SET_USER_LIMITS_SUPPORTED +#define PNG_iTXt_SUPPORTED +#define PNG_MNG_FEATURES_SUPPORTED +#define PNG_oFFs_SUPPORTED +#define PNG_pCAL_SUPPORTED +#define PNG_pHYs_SUPPORTED +#define PNG_POINTER_INDEXING_SUPPORTED +#define PNG_PROGRESSIVE_READ_SUPPORTED +#define PNG_READ_16BIT_SUPPORTED +#define PNG_READ_ALPHA_MODE_SUPPORTED #define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED -#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED -#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED -#define PNG_WRITE_FILTER_SUPPORTED -#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED -#define PNG_WRITE_iCCP_SUPPORTED -#define PNG_READ_TRANSFORMS_SUPPORTED -#define PNG_READ_GAMMA_SUPPORTED +#define PNG_READ_BACKGROUND_SUPPORTED +#define PNG_READ_BGR_SUPPORTED #define PNG_READ_bKGD_SUPPORTED -#define PNG_UNKNOWN_CHUNKS_SUPPORTED -#define PNG_READ_sCAL_SUPPORTED -#define PNG_WRITE_hIST_SUPPORTED -#define PNG_READ_OPT_PLTE_SUPPORTED -#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED -#define PNG_WRITE_gAMA_SUPPORTED +#define PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED +#define PNG_READ_cHRM_SUPPORTED +#define PNG_READ_COMPOSITE_NODIV_SUPPORTED +#define PNG_READ_COMPRESSED_TEXT_SUPPORTED +#define PNG_READ_EXPAND_16_SUPPORTED +#define PNG_READ_EXPAND_SUPPORTED +#define PNG_READ_FILLER_SUPPORTED +#define PNG_READ_gAMA_SUPPORTED +#define PNG_READ_GAMMA_SUPPORTED #define PNG_READ_GRAY_TO_RGB_SUPPORTED -#define PNG_WRITE_pCAL_SUPPORTED +#define PNG_READ_hIST_SUPPORTED +#define PNG_READ_iCCP_SUPPORTED +#define PNG_READ_INTERLACING_SUPPORTED +#define PNG_READ_INT_FUNCTIONS_SUPPORTED #define PNG_READ_INVERT_ALPHA_SUPPORTED -#define PNG_WRITE_TRANSFORMS_SUPPORTED -#define PNG_READ_sBIT_SUPPORTED +#define PNG_READ_INVERT_SUPPORTED +#define PNG_READ_iTXt_SUPPORTED +#define PNG_READ_oFFs_SUPPORTED +#define PNG_READ_OPT_PLTE_SUPPORTED #define PNG_READ_PACK_SUPPORTED -#define PNG_WRITE_SWAP_SUPPORTED -#define PNG_READ_cHRM_SUPPORTED -#define PNG_WRITE_tIME_SUPPORTED -#define PNG_READ_INTERLACING_SUPPORTED -#define PNG_READ_tRNS_SUPPORTED -#define PNG_WRITE_pHYs_SUPPORTED -#define PNG_WRITE_INVERT_SUPPORTED +#define PNG_READ_PACKSWAP_SUPPORTED +#define PNG_READ_pCAL_SUPPORTED +#define PNG_READ_pHYs_SUPPORTED +#define PNG_READ_QUANTIZE_SUPPORTED #define PNG_READ_RGB_TO_GRAY_SUPPORTED -#define PNG_WRITE_sRGB_SUPPORTED -#define PNG_READ_oFFs_SUPPORTED -#define PNG_WRITE_FILLER_SUPPORTED -#define PNG_WRITE_TEXT_SUPPORTED -#define PNG_WRITE_SHIFT_SUPPORTED -#define PNG_PROGRESSIVE_READ_SUPPORTED +#define PNG_READ_sBIT_SUPPORTED +#define PNG_READ_SCALE_16_TO_8_SUPPORTED +#define PNG_READ_sCAL_SUPPORTED #define PNG_READ_SHIFT_SUPPORTED -#define PNG_CONVERT_tIME_SUPPORTED -#define PNG_READ_USER_TRANSFORM_SUPPORTED -#define PNG_READ_INT_FUNCTIONS_SUPPORTED -#define PNG_READ_USER_CHUNKS_SUPPORTED -#define PNG_READ_hIST_SUPPORTED -#define PNG_READ_16BIT_SUPPORTED -#define PNG_READ_SWAP_ALPHA_SUPPORTED -#define PNG_READ_COMPOSITE_NODIV_SUPPORTED -#define PNG_SEQUENTIAL_READ_SUPPORTED -#define PNG_READ_BACKGROUND_SUPPORTED -#define PNG_READ_QUANTIZE_SUPPORTED -#define PNG_READ_iCCP_SUPPORTED -#define PNG_READ_STRIP_ALPHA_SUPPORTED -#define PNG_READ_PACKSWAP_SUPPORTED +#define PNG_READ_sPLT_SUPPORTED #define PNG_READ_sRGB_SUPPORTED -#define PNG_WRITE_tEXt_SUPPORTED -#define PNG_READ_gAMA_SUPPORTED -#define PNG_READ_pCAL_SUPPORTED -#define PNG_READ_EXPAND_SUPPORTED -#define PNG_WRITE_sPLT_SUPPORTED +#define PNG_READ_STRIP_16_TO_8_SUPPORTED +#define PNG_READ_STRIP_ALPHA_SUPPORTED +#define PNG_READ_SUPPORTED +#define PNG_READ_SWAP_ALPHA_SUPPORTED #define PNG_READ_SWAP_SUPPORTED +#define PNG_READ_tEXt_SUPPORTED +#define PNG_READ_TEXT_SUPPORTED #define PNG_READ_tIME_SUPPORTED -#define PNG_READ_pHYs_SUPPORTED -#define PNG_WRITE_SWAP_ALPHA_SUPPORTED +#define PNG_READ_TRANSFORMS_SUPPORTED +#define PNG_READ_tRNS_SUPPORTED +#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_READ_USER_CHUNKS_SUPPORTED +#define PNG_READ_USER_TRANSFORM_SUPPORTED +#define PNG_READ_zTXt_SUPPORTED +#define PNG_SAVE_INT_32_SUPPORTED +#define PNG_sBIT_SUPPORTED +#define PNG_sCAL_SUPPORTED +#define PNG_SEQUENTIAL_READ_SUPPORTED +#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED +#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED +#define PNG_SETJMP_SUPPORTED +#define PNG_SET_USER_LIMITS_SUPPORTED +#define PNG_sPLT_SUPPORTED +#define PNG_sRGB_SUPPORTED +#define PNG_STDIO_SUPPORTED +#define PNG_tEXt_SUPPORTED +#define PNG_TEXT_SUPPORTED #define PNG_TIME_RFC1123_SUPPORTED -#define PNG_READ_TEXT_SUPPORTED -#define PNG_WRITE_BGR_SUPPORTED +#define PNG_tIME_SUPPORTED +#define PNG_tRNS_SUPPORTED +#define PNG_UNKNOWN_CHUNKS_SUPPORTED #define PNG_USER_CHUNKS_SUPPORTED -#define PNG_CONSOLE_IO_SUPPORTED -#define PNG_WRITE_PACK_SUPPORTED -#define PNG_READ_FILLER_SUPPORTED +#define PNG_USER_LIMITS_SUPPORTED +#define PNG_USER_MEM_SUPPORTED +#define PNG_USER_TRANSFORM_INFO_SUPPORTED +#define PNG_USER_TRANSFORM_PTR_SUPPORTED +#define PNG_WARNINGS_SUPPORTED +#define PNG_WRITE_16BIT_SUPPORTED +#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_WRITE_BGR_SUPPORTED #define PNG_WRITE_bKGD_SUPPORTED -#define PNG_WRITE_tRNS_SUPPORTED -#define PNG_READ_sPLT_SUPPORTED -#define PNG_WRITE_sCAL_SUPPORTED +#define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED +#define PNG_WRITE_cHRM_SUPPORTED +#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED +#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +#define PNG_WRITE_FILLER_SUPPORTED +#define PNG_WRITE_FILTER_SUPPORTED +#define PNG_WRITE_FLUSH_SUPPORTED +#define PNG_WRITE_gAMA_SUPPORTED +#define PNG_WRITE_hIST_SUPPORTED +#define PNG_WRITE_iCCP_SUPPORTED +#define PNG_WRITE_INTERLACING_SUPPORTED +#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED +#define PNG_WRITE_INVERT_ALPHA_SUPPORTED +#define PNG_WRITE_INVERT_SUPPORTED +#define PNG_WRITE_iTXt_SUPPORTED #define PNG_WRITE_oFFs_SUPPORTED -#define PNG_READ_tEXt_SUPPORTED +#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED +#define PNG_WRITE_PACK_SUPPORTED +#define PNG_WRITE_PACKSWAP_SUPPORTED +#define PNG_WRITE_pCAL_SUPPORTED +#define PNG_WRITE_pHYs_SUPPORTED #define PNG_WRITE_sBIT_SUPPORTED -#define PNG_READ_INVERT_SUPPORTED -#define PNG_READ_16_TO_8_SUPPORTED -#define PNG_WRITE_cHRM_SUPPORTED -#define PNG_16BIT_SUPPORTED +#define PNG_WRITE_sCAL_SUPPORTED +#define PNG_WRITE_SHIFT_SUPPORTED +#define PNG_WRITE_sPLT_SUPPORTED +#define PNG_WRITE_sRGB_SUPPORTED +#define PNG_WRITE_SUPPORTED +#define PNG_WRITE_SWAP_ALPHA_SUPPORTED +#define PNG_WRITE_SWAP_SUPPORTED +#define PNG_WRITE_tEXt_SUPPORTED +#define PNG_WRITE_TEXT_SUPPORTED +#define PNG_WRITE_tIME_SUPPORTED +#define PNG_WRITE_TRANSFORMS_SUPPORTED +#define PNG_WRITE_tRNS_SUPPORTED +#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED #define PNG_WRITE_USER_TRANSFORM_SUPPORTED -#define PNG_READ_BGR_SUPPORTED -#define PNG_WRITE_PACKSWAP_SUPPORTED -#define PNG_WRITE_INVERT_ALPHA_SUPPORTED -#define PNG_sCAL_SUPPORTED +#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED #define PNG_WRITE_zTXt_SUPPORTED -#define PNG_USER_TRANSFORM_INFO_SUPPORTED -#define PNG_sBIT_SUPPORTED -#define PNG_cHRM_SUPPORTED -#define PNG_bKGD_SUPPORTED -#define PNG_tRNS_SUPPORTED -#define PNG_WRITE_iTXt_SUPPORTED -#define PNG_oFFs_SUPPORTED -#define PNG_USER_TRANSFORM_PTR_SUPPORTED -#define PNG_hIST_SUPPORTED -#define PNG_iCCP_SUPPORTED -#define PNG_sRGB_SUPPORTED -#define PNG_READ_zTXt_SUPPORTED -#define PNG_gAMA_SUPPORTED -#define PNG_pCAL_SUPPORTED -#define PNG_CHECK_cHRM_SUPPORTED -#define PNG_tIME_SUPPORTED -#define PNG_pHYs_SUPPORTED -#define PNG_READ_iTXt_SUPPORTED -#define PNG_TEXT_SUPPORTED -#define PNG_SAVE_INT_32_SUPPORTED -#define PNG_sPLT_SUPPORTED -#define PNG_tEXt_SUPPORTED #define PNG_zTXt_SUPPORTED -#define PNG_iTXt_SUPPORTED /* end of options */ #endif /* PNGLCONF_H */ diff --git a/png/pngmem.c b/png/pngmem.c index a15d8b085..bf5ff037d 100644 --- a/png/pngmem.c +++ b/png/pngmem.c @@ -1,7 +1,7 @@ /* pngmem.c - stub functions for memory allocation * - * Last changed in libpng 1.5.1 [February 3, 2011] + * Last changed in libpng 1.5.7 [December 15, 2011] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) @@ -56,9 +56,9 @@ png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr), if (malloc_fn != NULL) { png_struct dummy_struct; - png_structp png_ptr = &dummy_struct; - png_ptr->mem_ptr=mem_ptr; - struct_ptr = (*(malloc_fn))(png_ptr, (png_uint_32)size); + memset(&dummy_struct, 0, sizeof dummy_struct); + dummy_struct.mem_ptr=mem_ptr; + struct_ptr = (*(malloc_fn))(&dummy_struct, (png_alloc_size_t)size); } else @@ -90,9 +90,9 @@ png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn, if (free_fn != NULL) { png_struct dummy_struct; - png_structp png_ptr = &dummy_struct; - png_ptr->mem_ptr=mem_ptr; - (*(free_fn))(png_ptr, struct_ptr); + memset(&dummy_struct, 0, sizeof dummy_struct); + dummy_struct.mem_ptr=mem_ptr; + (*(free_fn))(&dummy_struct, struct_ptr); return; } @@ -143,7 +143,7 @@ png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) # ifdef PNG_USER_MEM_SUPPORTED if (png_ptr->malloc_fn != NULL) - ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size)); + ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size)); else ret = (png_malloc_default(png_ptr, size)); @@ -187,8 +187,9 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) int num_blocks; png_uint_32 total_size; png_bytep table; - int i; + int i, mem_level, window_bits; png_byte huge * hptr; + int window_bits if (ret != NULL) { @@ -196,14 +197,22 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) ret = NULL; } - if (png_ptr->zlib_window_bits > 14) - num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14)); + window_bits = + png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ? + png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits; + + if (window_bits > 14) + num_blocks = (int)(1 << (window_bits - 14)); else num_blocks = 1; - if (png_ptr->zlib_mem_level >= 7) - num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7)); + mem_level = + png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ? + png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level; + + if (mem_level >= 7) + num_blocks += (int)(1 << (mem_level - 7)); else num_blocks++; @@ -277,7 +286,7 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { # ifndef PNG_USER_MEM_SUPPORTED if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) - png_error(png_ptr, "Out of Memory"); /* Note "o" and "M" */ + png_error(png_ptr, "Out of Memory"); /* Note "O" and "M" */ else png_warning(png_ptr, "Out of Memory"); diff --git a/png/pngpread.c b/png/pngpread.c index 7b1149bab..8a5aa29ec 100644 --- a/png/pngpread.c +++ b/png/pngpread.c @@ -1,8 +1,8 @@ /* pngpread.c - read a png file in push mode * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.9 [February 18, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -128,30 +128,6 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr) break; } -#ifdef PNG_READ_tEXt_SUPPORTED - case PNG_READ_tEXt_MODE: - { - png_push_read_tEXt(png_ptr, info_ptr); - break; - } - -#endif -#ifdef PNG_READ_zTXt_SUPPORTED - case PNG_READ_zTXt_MODE: - { - png_push_read_zTXt(png_ptr, info_ptr); - break; - } - -#endif -#ifdef PNG_READ_iTXt_SUPPORTED - case PNG_READ_iTXt_MODE: - { - png_push_read_iTXt(png_ptr, info_ptr); - break; - } - -#endif case PNG_SKIP_MODE: { png_push_crc_finish(png_ptr); @@ -176,7 +152,7 @@ void /* PRIVATE */ png_push_read_sig(png_structp png_ptr, png_infop info_ptr) { png_size_t num_checked = png_ptr->sig_bytes, - num_to_check = 8 - num_checked; + num_to_check = 8 - num_checked; if (png_ptr->buffer_size < num_to_check) { @@ -196,6 +172,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr) else png_error(png_ptr, "PNG file corrupted by ASCII conversion"); } + else { if (png_ptr->sig_bytes >= 8) @@ -208,61 +185,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr) void /* PRIVATE */ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) { - PNG_IHDR; - PNG_IDAT; - PNG_IEND; - PNG_PLTE; -#ifdef PNG_READ_bKGD_SUPPORTED - PNG_bKGD; -#endif -#ifdef PNG_READ_cHRM_SUPPORTED - PNG_cHRM; -#endif -#ifdef PNG_READ_gAMA_SUPPORTED - PNG_gAMA; -#endif -#ifdef PNG_READ_hIST_SUPPORTED - PNG_hIST; -#endif -#ifdef PNG_READ_iCCP_SUPPORTED - PNG_iCCP; -#endif -#ifdef PNG_READ_iTXt_SUPPORTED - PNG_iTXt; -#endif -#ifdef PNG_READ_oFFs_SUPPORTED - PNG_oFFs; -#endif -#ifdef PNG_READ_pCAL_SUPPORTED - PNG_pCAL; -#endif -#ifdef PNG_READ_pHYs_SUPPORTED - PNG_pHYs; -#endif -#ifdef PNG_READ_sBIT_SUPPORTED - PNG_sBIT; -#endif -#ifdef PNG_READ_sCAL_SUPPORTED - PNG_sCAL; -#endif -#ifdef PNG_READ_sRGB_SUPPORTED - PNG_sRGB; -#endif -#ifdef PNG_READ_sPLT_SUPPORTED - PNG_sPLT; -#endif -#ifdef PNG_READ_tEXt_SUPPORTED - PNG_tEXt; -#endif -#ifdef PNG_READ_tIME_SUPPORTED - PNG_tIME; -#endif -#ifdef PNG_READ_tRNS_SUPPORTED - PNG_tRNS; -#endif -#ifdef PNG_READ_zTXt_SUPPORTED - PNG_zTXt; -#endif + png_uint_32 chunk_name; /* First we make sure we have enough data for the 4 byte chunk name * and the 4 byte chunk length before proceeding with decoding the @@ -273,6 +196,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) { png_byte chunk_length[4]; + png_byte chunk_tag[4]; if (png_ptr->buffer_size < 8) { @@ -283,16 +207,27 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_push_fill_buffer(png_ptr, chunk_length, 4); png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); png_reset_crc(png_ptr); - png_crc_read(png_ptr, png_ptr->chunk_name, 4); + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); png_check_chunk_name(png_ptr, png_ptr->chunk_name); png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; } - if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + chunk_name = png_ptr->chunk_name; + + if (chunk_name == png_IDAT) + { + /* This is here above the if/else case statement below because if the + * unknown handling marks 'IDAT' as unknown then the IDAT handling case is + * completely skipped. + * + * TODO: there must be a better way of doing this. + */ if (png_ptr->mode & PNG_AFTER_IDAT) png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + } - if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + if (chunk_name == png_IHDR) { if (png_ptr->push_length != 13) png_error(png_ptr, "Invalid IHDR length"); @@ -306,7 +241,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); } - else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + else if (chunk_name == png_IEND) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -321,7 +256,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) } #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) + else if (png_chunk_unknown_handling(png_ptr, chunk_name)) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -329,15 +264,15 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + if (chunk_name == png_IDAT) png_ptr->mode |= PNG_HAVE_IDAT; png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); - if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + if (chunk_name == png_PLTE) png_ptr->mode |= PNG_HAVE_PLTE; - else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + else if (chunk_name == png_IDAT) { if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before IDAT"); @@ -349,7 +284,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) } #endif - else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + else if (chunk_name == png_PLTE) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -359,7 +294,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); } - else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + else if (chunk_name == png_IDAT) { /* If we reach an IDAT chunk, this means we have read all of the * header chunks, and we can start reading the image (or if this @@ -395,7 +330,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) } #ifdef PNG_READ_gAMA_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + else if (png_ptr->chunk_name == png_gAMA) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -408,7 +343,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_sBIT_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) + else if (png_ptr->chunk_name == png_sBIT) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -421,7 +356,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_cHRM_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) + else if (png_ptr->chunk_name == png_cHRM) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -434,7 +369,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_sRGB_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + else if (chunk_name == png_sRGB) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -447,7 +382,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_iCCP_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) + else if (png_ptr->chunk_name == png_iCCP) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -460,7 +395,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_sPLT_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) + else if (chunk_name == png_sPLT) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -473,7 +408,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_tRNS_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) + else if (chunk_name == png_tRNS) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -486,7 +421,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_bKGD_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) + else if (chunk_name == png_bKGD) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -499,7 +434,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_hIST_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) + else if (chunk_name == png_hIST) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -512,7 +447,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_pHYs_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) + else if (chunk_name == png_pHYs) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -525,7 +460,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_oFFs_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) + else if (chunk_name == png_oFFs) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -538,7 +473,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_pCAL_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + else if (chunk_name == png_pCAL) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -551,7 +486,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_sCAL_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) + else if (chunk_name == png_sCAL) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -564,7 +499,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_tIME_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) + else if (chunk_name == png_tIME) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -577,7 +512,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) #endif #ifdef PNG_READ_tEXt_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) + else if (chunk_name == png_tEXt) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -585,12 +520,12 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_zTXt_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) + else if (chunk_name == png_zTXt) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -598,12 +533,12 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); + png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_iTXt_SUPPORTED - else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) + else if (chunk_name == png_iTXt) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -611,7 +546,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); + png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif @@ -622,7 +557,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_push_save_buffer(png_ptr); return; } - png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); } png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; @@ -662,6 +597,7 @@ png_push_crc_finish(png_structp png_ptr) png_ptr->save_buffer_size -= save_size; png_ptr->save_buffer_ptr += save_size; } + if (png_ptr->skip_length && png_ptr->current_buffer_size) { png_size_t save_size = png_ptr->current_buffer_size; @@ -683,6 +619,7 @@ png_push_crc_finish(png_structp png_ptr) png_ptr->current_buffer_size -= save_size; png_ptr->current_buffer_ptr += save_size; } + if (!png_ptr->skip_length) { if (png_ptr->buffer_size < 4) @@ -705,6 +642,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) return; ptr = buffer; + if (png_ptr->save_buffer_size) { png_size_t save_size; @@ -722,6 +660,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) png_ptr->save_buffer_size -= save_size; png_ptr->save_buffer_ptr += save_size; } + if (length && png_ptr->current_buffer_size) { png_size_t save_size; @@ -751,6 +690,7 @@ png_push_save_buffer(png_structp png_ptr) png_bytep dp; istop = png_ptr->save_buffer_size; + for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; i < istop; i++, sp++, dp++) { @@ -758,6 +698,7 @@ png_push_save_buffer(png_structp png_ptr) } } } + if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > png_ptr->save_buffer_max) { @@ -772,8 +713,7 @@ png_push_save_buffer(png_structp png_ptr) new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; old_buffer = png_ptr->save_buffer; - png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, - (png_size_t)new_max); + png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, new_max); if (png_ptr->save_buffer == NULL) { @@ -785,6 +725,7 @@ png_push_save_buffer(png_structp png_ptr) png_free(png_ptr, old_buffer); png_ptr->save_buffer_max = new_max; } + if (png_ptr->current_buffer_size) { png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, @@ -792,6 +733,7 @@ png_push_save_buffer(png_structp png_ptr) png_ptr->save_buffer_size += png_ptr->current_buffer_size; png_ptr->current_buffer_size = 0; } + png_ptr->save_buffer_ptr = png_ptr->save_buffer; png_ptr->buffer_size = 0; } @@ -809,11 +751,12 @@ png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, void /* PRIVATE */ png_push_read_IDAT(png_structp png_ptr) { - PNG_IDAT; if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) { png_byte chunk_length[4]; + png_byte chunk_tag[4]; + /* TODO: this code can be commoned up with the same code in push_read */ if (png_ptr->buffer_size < 8) { png_push_save_buffer(png_ptr); @@ -823,10 +766,11 @@ png_push_read_IDAT(png_structp png_ptr) png_push_fill_buffer(png_ptr, chunk_length, 4); png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); png_reset_crc(png_ptr); - png_crc_read(png_ptr, png_ptr->chunk_name, 4); + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; - if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + if (png_ptr->chunk_name != png_IDAT) { png_ptr->process_mode = PNG_READ_CHUNK_MODE; @@ -838,6 +782,7 @@ png_push_read_IDAT(png_structp png_ptr) png_ptr->idat_size = png_ptr->push_length; } + if (png_ptr->idat_size && png_ptr->save_buffer_size) { png_size_t save_size = png_ptr->save_buffer_size; @@ -890,6 +835,7 @@ png_push_read_IDAT(png_structp png_ptr) png_ptr->current_buffer_size -= save_size; png_ptr->current_buffer_ptr += save_size; } + if (!png_ptr->idat_size) { if (png_ptr->buffer_size < 4) @@ -1011,34 +957,56 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, void /* PRIVATE */ png_push_process_row(png_structp png_ptr) { - png_ptr->row_info.color_type = png_ptr->color_type; - png_ptr->row_info.width = png_ptr->iwidth; - png_ptr->row_info.channels = png_ptr->channels; - png_ptr->row_info.bit_depth = png_ptr->bit_depth; - png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; + /* 1.5.6: row_info moved out of png_struct to a local here. */ + png_row_info row_info; - png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, - png_ptr->row_info.width); + row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ + row_info.color_type = png_ptr->color_type; + row_info.bit_depth = png_ptr->bit_depth; + row_info.channels = png_ptr->channels; + row_info.pixel_depth = png_ptr->pixel_depth; + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); - png_read_filter_row(png_ptr, &(png_ptr->row_info), - png_ptr->row_buf + 1, png_ptr->prev_row + 1, - (int)(png_ptr->row_buf[0])); + if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) + { + if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) + png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, + png_ptr->prev_row + 1, png_ptr->row_buf[0]); + else + png_error(png_ptr, "bad adaptive filter value"); + } + + /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before + * 1.5.6, while the buffer really is this big in current versions of libpng + * it may not be in the future, so this was changed just to copy the + * interlaced row count: + */ + png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + if (png_ptr->transformations) + png_do_read_transformations(png_ptr, &row_info); +#endif + + /* The transformed pixel depth should match the depth now in row_info. */ + if (png_ptr->transformed_pixel_depth == 0) + { + png_ptr->transformed_pixel_depth = row_info.pixel_depth; + if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) + png_error(png_ptr, "progressive row overflow"); + } - png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); + else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) + png_error(png_ptr, "internal progressive row size calculation error"); - if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) - png_do_read_transformations(png_ptr); #ifdef PNG_READ_INTERLACING_SUPPORTED /* Blow up interlaced rows to full size */ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) { if (png_ptr->pass < 6) -/* old interface (pre-1.0.9): - png_do_read_interlace(&(png_ptr->row_info), - png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); - */ - png_do_read_interlace(png_ptr); + png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, + png_ptr->transformations); switch (png_ptr->pass) { @@ -1218,24 +1186,26 @@ png_push_process_row(png_structp png_ptr) void /* PRIVATE */ png_read_push_finish_row(png_structp png_ptr) { +#ifdef PNG_READ_INTERLACING_SUPPORTED /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Start of interlace block */ - PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; + static PNG_CONST png_byte FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; /* Offset to next interlace block */ - PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; /* Start of interlace block in the y direction */ - PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; + static PNG_CONST png_byte FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; /* Offset to next interlace block in the y direction */ - PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; + static PNG_CONST png_byte FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; /* Height of interlace block. This is not currently used - if you need * it, uncomment it here and in png.h - PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; */ +#endif png_ptr->row_number++; if (png_ptr->row_number < png_ptr->num_rows) @@ -1279,519 +1249,6 @@ png_read_push_finish_row(png_structp png_ptr) #endif /* PNG_READ_INTERLACING_SUPPORTED */ } -#ifdef PNG_READ_tEXt_SUPPORTED -void /* PRIVATE */ -png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 - length) -{ - if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) - { - PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ - png_error(png_ptr, "Out of place tEXt"); - /*NOT REACHED*/ - } - -#ifdef PNG_MAX_MALLOC_64K - png_ptr->skip_length = 0; /* This may not be necessary */ - - if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ - { - png_warning(png_ptr, "tEXt chunk too large to fit in memory"); - png_ptr->skip_length = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; - } -#endif - - png_ptr->current_text = (png_charp)png_malloc(png_ptr, - (png_size_t)(length + 1)); - png_ptr->current_text[length] = '\0'; - png_ptr->current_text_ptr = png_ptr->current_text; - png_ptr->current_text_size = (png_size_t)length; - png_ptr->current_text_left = (png_size_t)length; - png_ptr->process_mode = PNG_READ_tEXt_MODE; -} - -void /* PRIVATE */ -png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr) -{ - if (png_ptr->buffer_size && png_ptr->current_text_left) - { - png_size_t text_size; - - if (png_ptr->buffer_size < png_ptr->current_text_left) - text_size = png_ptr->buffer_size; - - else - text_size = png_ptr->current_text_left; - - png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); - png_ptr->current_text_left -= text_size; - png_ptr->current_text_ptr += text_size; - } - if (!(png_ptr->current_text_left)) - { - png_textp text_ptr; - png_charp text; - png_charp key; - int ret; - - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_push_crc_finish(png_ptr); - -#ifdef PNG_MAX_MALLOC_64K - if (png_ptr->skip_length) - return; -#endif - - key = png_ptr->current_text; - - for (text = key; *text; text++) - /* Empty loop */ ; - - if (text < key + png_ptr->current_text_size) - text++; - - text_ptr = (png_textp)png_malloc(png_ptr, png_sizeof(png_text)); - text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; - text_ptr->key = key; - text_ptr->itxt_length = 0; - text_ptr->lang = NULL; - text_ptr->lang_key = NULL; - text_ptr->text = text; - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_free(png_ptr, key); - png_free(png_ptr, text_ptr); - png_ptr->current_text = NULL; - - if (ret) - png_warning(png_ptr, "Insufficient memory to store text chunk"); - } -} -#endif - -#ifdef PNG_READ_zTXt_SUPPORTED -void /* PRIVATE */ -png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 - length) -{ - if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) - { - PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ - png_error(png_ptr, "Out of place zTXt"); - /*NOT REACHED*/ - } - -#ifdef PNG_MAX_MALLOC_64K - /* We can't handle zTXt chunks > 64K, since we don't have enough space - * to be able to store the uncompressed data. Actually, the threshold - * is probably around 32K, but it isn't as definite as 64K is. - */ - if (length > (png_uint_32)65535L) - { - png_warning(png_ptr, "zTXt chunk too large to fit in memory"); - png_push_crc_skip(png_ptr, length); - return; - } -#endif - - png_ptr->current_text = (png_charp)png_malloc(png_ptr, - (png_size_t)(length + 1)); - png_ptr->current_text[length] = '\0'; - png_ptr->current_text_ptr = png_ptr->current_text; - png_ptr->current_text_size = (png_size_t)length; - png_ptr->current_text_left = (png_size_t)length; - png_ptr->process_mode = PNG_READ_zTXt_MODE; -} - -void /* PRIVATE */ -png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) -{ - if (png_ptr->buffer_size && png_ptr->current_text_left) - { - png_size_t text_size; - - if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left) - text_size = png_ptr->buffer_size; - - else - text_size = png_ptr->current_text_left; - - png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); - png_ptr->current_text_left -= text_size; - png_ptr->current_text_ptr += text_size; - } - if (!(png_ptr->current_text_left)) - { - png_textp text_ptr; - png_charp text; - png_charp key; - int ret; - png_size_t text_size, key_size; - - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_push_crc_finish(png_ptr); - - key = png_ptr->current_text; - - for (text = key; *text; text++) - /* Empty loop */ ; - - /* zTXt can't have zero text */ - if (text >= key + png_ptr->current_text_size) - { - png_ptr->current_text = NULL; - png_free(png_ptr, key); - return; - } - - text++; - - if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */ - { - png_ptr->current_text = NULL; - png_free(png_ptr, key); - return; - } - - text++; - - png_ptr->zstream.next_in = (png_bytep)text; - png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size - - (text - key)); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - - key_size = text - key; - text_size = 0; - text = NULL; - ret = Z_STREAM_END; - - while (png_ptr->zstream.avail_in) - { - ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); - if (ret != Z_OK && ret != Z_STREAM_END) - { - inflateReset(&png_ptr->zstream); - png_ptr->zstream.avail_in = 0; - png_ptr->current_text = NULL; - png_free(png_ptr, key); - png_free(png_ptr, text); - return; - } - - if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END) - { - if (text == NULL) - { - text = (png_charp)png_malloc(png_ptr, - (png_ptr->zbuf_size - - png_ptr->zstream.avail_out + key_size + 1)); - - png_memcpy(text + key_size, png_ptr->zbuf, - png_ptr->zbuf_size - png_ptr->zstream.avail_out); - - png_memcpy(text, key, key_size); - - text_size = key_size + png_ptr->zbuf_size - - png_ptr->zstream.avail_out; - - *(text + text_size) = '\0'; - } - - else - { - png_charp tmp; - - tmp = text; - text = (png_charp)png_malloc(png_ptr, text_size + - (png_ptr->zbuf_size - - png_ptr->zstream.avail_out + 1)); - - png_memcpy(text, tmp, text_size); - png_free(png_ptr, tmp); - - png_memcpy(text + text_size, png_ptr->zbuf, - png_ptr->zbuf_size - png_ptr->zstream.avail_out); - - text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; - *(text + text_size) = '\0'; - } - - if (ret != Z_STREAM_END) - { - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - } - } - else - { - break; - } - - if (ret == Z_STREAM_END) - break; - } - - inflateReset(&png_ptr->zstream); - png_ptr->zstream.avail_in = 0; - - if (ret != Z_STREAM_END) - { - png_ptr->current_text = NULL; - png_free(png_ptr, key); - png_free(png_ptr, text); - return; - } - - png_ptr->current_text = NULL; - png_free(png_ptr, key); - key = text; - text += key_size; - - text_ptr = (png_textp)png_malloc(png_ptr, - png_sizeof(png_text)); - text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; - text_ptr->key = key; - text_ptr->itxt_length = 0; - text_ptr->lang = NULL; - text_ptr->lang_key = NULL; - text_ptr->text = text; - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_free(png_ptr, key); - png_free(png_ptr, text_ptr); - - if (ret) - png_warning(png_ptr, "Insufficient memory to store text chunk"); - } -} -#endif - -#ifdef PNG_READ_iTXt_SUPPORTED -void /* PRIVATE */ -png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 - length) -{ - if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) - { - PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ - png_error(png_ptr, "Out of place iTXt"); - /*NOT REACHED*/ - } - -#ifdef PNG_MAX_MALLOC_64K - png_ptr->skip_length = 0; /* This may not be necessary */ - - if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ - { - png_warning(png_ptr, "iTXt chunk too large to fit in memory"); - png_ptr->skip_length = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; - } -#endif - - png_ptr->current_text = (png_charp)png_malloc(png_ptr, - (png_size_t)(length + 1)); - png_ptr->current_text[length] = '\0'; - png_ptr->current_text_ptr = png_ptr->current_text; - png_ptr->current_text_size = (png_size_t)length; - png_ptr->current_text_left = (png_size_t)length; - png_ptr->process_mode = PNG_READ_iTXt_MODE; -} - -void /* PRIVATE */ -png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr) -{ - - if (png_ptr->buffer_size && png_ptr->current_text_left) - { - png_size_t text_size; - - if (png_ptr->buffer_size < png_ptr->current_text_left) - text_size = png_ptr->buffer_size; - - else - text_size = png_ptr->current_text_left; - - png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); - png_ptr->current_text_left -= text_size; - png_ptr->current_text_ptr += text_size; - } - - if (!(png_ptr->current_text_left)) - { - png_textp text_ptr; - png_charp key; - int comp_flag; - png_charp lang; - png_charp lang_key; - png_charp text; - int ret; - - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_push_crc_finish(png_ptr); - -#ifdef PNG_MAX_MALLOC_64K - if (png_ptr->skip_length) - return; -#endif - - key = png_ptr->current_text; - - for (lang = key; *lang; lang++) - /* Empty loop */ ; - - if (lang < key + png_ptr->current_text_size - 3) - lang++; - - comp_flag = *lang++; - lang++; /* Skip comp_type, always zero */ - - for (lang_key = lang; *lang_key; lang_key++) - /* Empty loop */ ; - - lang_key++; /* Skip NUL separator */ - - text=lang_key; - - if (lang_key < key + png_ptr->current_text_size - 1) - { - for (; *text; text++) - /* Empty loop */ ; - } - - if (text < key + png_ptr->current_text_size) - text++; - - text_ptr = (png_textp)png_malloc(png_ptr, - png_sizeof(png_text)); - - text_ptr->compression = comp_flag + 2; - text_ptr->key = key; - text_ptr->lang = lang; - text_ptr->lang_key = lang_key; - text_ptr->text = text; - text_ptr->text_length = 0; - text_ptr->itxt_length = png_strlen(text); - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_ptr->current_text = NULL; - - png_free(png_ptr, text_ptr); - if (ret) - png_warning(png_ptr, "Insufficient memory to store iTXt chunk"); - } -} -#endif - -/* This function is called when we haven't found a handler for this - * chunk. If there isn't a problem with the chunk itself (ie a bad chunk - * name or a critical chunk), the chunk is (currently) silently ignored. - */ -void /* PRIVATE */ -png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 - length) -{ - png_uint_32 skip = 0; - - if (!(png_ptr->chunk_name[0] & 0x20)) - { -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != - PNG_HANDLE_CHUNK_ALWAYS -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED - && png_ptr->read_user_chunk_fn == NULL -#endif - ) -#endif - png_chunk_error(png_ptr, "unknown critical chunk"); - - PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ - } - -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) - { -#ifdef PNG_MAX_MALLOC_64K - if (length > (png_uint_32)65535L) - { - png_warning(png_ptr, "unknown chunk too large to fit in memory"); - skip = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; - } -#endif - png_memcpy((png_charp)png_ptr->unknown_chunk.name, - (png_charp)png_ptr->chunk_name, - png_sizeof(png_ptr->unknown_chunk.name)); - png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1] - = '\0'; - - png_ptr->unknown_chunk.size = (png_size_t)length; - - if (length == 0) - png_ptr->unknown_chunk.data = NULL; - - else - { - png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, - (png_size_t)length); - png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); - } - -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED - if (png_ptr->read_user_chunk_fn != NULL) - { - /* Callback to user unknown chunk handler */ - int ret; - ret = (*(png_ptr->read_user_chunk_fn)) - (png_ptr, &png_ptr->unknown_chunk); - - if (ret < 0) - png_chunk_error(png_ptr, "error in user chunk"); - - if (ret == 0) - { - if (!(png_ptr->chunk_name[0] & 0x20)) - if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != - PNG_HANDLE_CHUNK_ALWAYS) - png_chunk_error(png_ptr, "unknown critical chunk"); - png_set_unknown_chunks(png_ptr, info_ptr, - &png_ptr->unknown_chunk, 1); - } - } - - else -#endif - png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1); - png_free(png_ptr, png_ptr->unknown_chunk.data); - png_ptr->unknown_chunk.data = NULL; - } - - else -#endif - skip=length; - png_push_crc_skip(png_ptr, skip); -} - void /* PRIVATE */ png_push_have_info(png_structp png_ptr, png_infop info_ptr) { @@ -1814,19 +1271,22 @@ png_push_have_row(png_structp png_ptr, png_bytep row) (int)png_ptr->pass); } +#ifdef PNG_READ_INTERLACING_SUPPORTED void PNGAPI png_progressive_combine_row (png_structp png_ptr, png_bytep old_row, png_const_bytep new_row) { - PNG_CONST int FARDATA png_pass_dsp_mask[7] = - {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; - if (png_ptr == NULL) return; - if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */ - png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); + /* new_row is a flag here - if it is NULL then the app callback was called + * from an empty row (see the calls to png_struct::row_fn below), otherwise + * it must be png_ptr->row_buf+1 + */ + if (new_row != NULL) + png_combine_row(png_ptr, old_row, 1/*display*/); } +#endif /* PNG_READ_INTERLACING_SUPPORTED */ void PNGAPI png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, diff --git a/png/pngpriv.h b/png/pngpriv.h index 30ac00473..e76a57975 100644 --- a/png/pngpriv.h +++ b/png/pngpriv.h @@ -2,11 +2,11 @@ /* pngpriv.h - private declarations for use inside libpng * * For conditions of distribution and use, see copyright notice in png.h - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * - * Last changed in libpng 1.5.0 [January 6, 2011] + * Last changed in libpng 1.5.10 [March 29, 2012] * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer @@ -25,12 +25,30 @@ #ifndef PNGPRIV_H #define PNGPRIV_H +/* Feature Test Macros. The following are defined here to ensure that correctly + * implemented libraries reveal the APIs libpng needs to build and hide those + * that are not needed and potentially damaging to the compilation. + * + * Feature Test Macros must be defined before any system header is included (see + * POSIX 1003.1 2.8.2 "POSIX Symbols." + * + * These macros only have an effect if the operating system supports either + * POSIX 1003.1 or C99, or both. On other operating systems (particularly + * Windows/Visual Studio) there is no effect; the OS specific tests below are + * still required (as of 2011-05-02.) + */ +#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */ + /* This is required for the definition of abort(), used as a last ditch * error handler when all else fails. */ #include <stdlib.h> -#define PNGLIB_BUILD +/* This is used to find 'offsetof', used below for alignment tests. */ +#include <stddef.h> + +#define PNGLIB_BUILD /*libpng is being built, not used*/ + #ifdef PNG_USER_CONFIG # include "pngusr.h" /* These should have been defined in pngusr.h */ @@ -41,10 +59,120 @@ # define PNG_USER_DLLFNAME_POSTFIX "Cb" # endif #endif + +/* Is this a build of a DLL where compilation of the object modules requires + * different preprocessor settings to those required for a simple library? If + * so PNG_BUILD_DLL must be set. + * + * If libpng is used inside a DLL but that DLL does not export the libpng APIs + * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a + * static library of libpng then link the DLL against that. + */ +#ifndef PNG_BUILD_DLL +# ifdef DLL_EXPORT + /* This is set by libtool when files are compiled for a DLL; libtool + * always compiles twice, even on systems where it isn't necessary. Set + * PNG_BUILD_DLL in case it is necessary: + */ +# define PNG_BUILD_DLL +# else +# ifdef _WINDLL + /* This is set by the Microsoft Visual Studio IDE in projects that + * build a DLL. It can't easily be removed from those projects (it + * isn't visible in the Visual Studio UI) so it is a fairly reliable + * indication that PNG_IMPEXP needs to be set to the DLL export + * attributes. + */ +# define PNG_BUILD_DLL +# else +# ifdef __DLL__ + /* This is set by the Borland C system when compiling for a DLL + * (as above.) + */ +# define PNG_BUILD_DLL +# else + /* Add additional compiler cases here. */ +# endif +# endif +# endif +#endif /* Setting PNG_BUILD_DLL if required */ + +/* See pngconf.h for more details: the builder of the library may set this on + * the command line to the right thing for the specific compilation system or it + * may be automagically set above (at present we know of no system where it does + * need to be set on the command line.) + * + * PNG_IMPEXP must be set here when building the library to prevent pngconf.h + * setting it to the "import" setting for a DLL build. + */ +#ifndef PNG_IMPEXP +# ifdef PNG_BUILD_DLL +# define PNG_IMPEXP PNG_DLL_EXPORT +# else + /* Not building a DLL, or the DLL doesn't require specific export + * definitions. + */ +# define PNG_IMPEXP +# endif +#endif + +/* No warnings for private or deprecated functions in the build: */ +#ifndef PNG_DEPRECATED +# define PNG_DEPRECATED +#endif +#ifndef PNG_PRIVATE +# define PNG_PRIVATE +#endif + #include "png.h" #include "pnginfo.h" #include "pngstruct.h" +/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */ +#ifndef PNG_DLL_EXPORT +# define PNG_DLL_EXPORT +#endif + +/* SECURITY and SAFETY: + * + * By default libpng is built without any internal limits on image size, + * individual heap (png_malloc) allocations or the total amount of memory used. + * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used + * (unless individually overridden). These limits are believed to be fairly + * safe, but builders of secure systems should verify the values against the + * real system capabilities. + */ + +#ifdef PNG_SAFE_LIMITS_SUPPORTED + /* 'safe' limits */ +# ifndef PNG_USER_WIDTH_MAX +# define PNG_USER_WIDTH_MAX 1000000 +# endif +# ifndef PNG_USER_HEIGHT_MAX +# define PNG_USER_HEIGHT_MAX 1000000 +# endif +# ifndef PNG_USER_CHUNK_CACHE_MAX +# define PNG_USER_CHUNK_CACHE_MAX 128 +# endif +# ifndef PNG_USER_CHUNK_MALLOC_MAX +# define PNG_USER_CHUNK_MALLOC_MAX 8000000 +# endif +#else + /* values for no limits */ +# ifndef PNG_USER_WIDTH_MAX +# define PNG_USER_WIDTH_MAX 0x7fffffff +# endif +# ifndef PNG_USER_HEIGHT_MAX +# define PNG_USER_HEIGHT_MAX 0x7fffffff +# endif +# ifndef PNG_USER_CHUNK_CACHE_MAX +# define PNG_USER_CHUNK_CACHE_MAX 0 +# endif +# ifndef PNG_USER_CHUNK_MALLOC_MAX +# define PNG_USER_CHUNK_MALLOC_MAX 0 +# endif +#endif + /* This is used for 16 bit gamma tables - only the top level pointers are const, * this could be changed: */ @@ -83,13 +211,15 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; # define PNG_MAX_MALLOC_64K #endif +#ifndef PNG_UNUSED /* Unused formal parameter warnings are silenced using the following macro * which is expected to have no bad effects on performance (optimizing * compilers will probably remove it entirely). Note that if you replace * it with something other than whitespace, you must include the terminating * semicolon. */ -#define PNG_UNUSED(param) (void)param; +# define PNG_UNUSED(param) (void)param; +#endif /* Just a little check that someone hasn't tried to define something * contradictory. @@ -99,12 +229,44 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; # define PNG_ZBUF_SIZE 65536L #endif -/* If warnings or errors are turned off the code is disabled - * or redirected here. +/* PNG_STATIC is used to mark internal file scope functions if they need to be + * accessed for implementation tests (see the code in tests/?*). */ -#ifndef PNG_WARNINGS_SUPPORTED -# define png_warning(s1,s2) ((void)0) -# define png_chunk_warning(s1,s2) ((void)0) +#ifndef PNG_STATIC +# define PNG_STATIC static +#endif + +/* C99 restrict is used where possible, to do this 'restrict' is defined as + * empty if we can't be sure it is supported. configure builds have already + * done this work. + */ +#ifdef PNG_CONFIGURE_LIBPNG +# define PNG_RESTRICT restrict +#else + /* Modern compilers support restrict, but assume not for anything not + * recognized here: + */ +# if defined __GNUC__ || defined _MSC_VER || defined __WATCOMC__ +# define PNG_RESTRICT restrict +# else +# define PNG_RESTRICT +# endif +#endif + +/* If warnings or errors are turned off the code is disabled or redirected here. + * From 1.5.4 functions have been added to allow very limited formatting of + * error and warning messages - this code will also be disabled here. + */ +#ifdef PNG_WARNINGS_SUPPORTED +# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p; +#else +# define png_warning(s1,s2) ((void)(s1)) +# define png_chunk_warning(s1,s2) ((void)(s1)) +# define png_warning_parameter(p,number,string) ((void)0) +# define png_warning_parameter_unsigned(p,number,format,value) ((void)0) +# define png_warning_parameter_signed(p,number,format,value) ((void)0) +# define png_formatted_warning(pp,p,message) ((void)(pp)) +# define PNG_WARNING_PARAMETERS(p) #endif #ifndef PNG_ERROR_TEXT_SUPPORTED # define png_error(s1,s2) png_err(s1) @@ -112,15 +274,28 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; # define png_fixed_error(s1,s2) png_err(s1) #endif +/* C allows up-casts from (void*) to any pointer and (const void*) to any + * pointer to a const object. C++ regards this as a type error and requires an + * explicit, static, cast and provides the static_cast<> rune to ensure that + * const is not cast away. + */ +#ifdef __cplusplus +# define png_voidcast(type, value) static_cast<type>(value) +#else +# define png_voidcast(type, value) (value) +#endif /* __cplusplus */ + #ifndef PNG_EXTERN /* The functions exported by PNG_EXTERN are internal functions, which * aren't usually used outside the library (as far as I know), so it is * debatable if they should be exported at all. In the future, when it * is possible to have run-time registry of chunk-handling functions, * some of these might be made available again. -# define PNG_EXTERN extern + * + * 1.5.7: turned the use of 'extern' back on, since it is localized to pngpriv.h + * it should be safe now (it is unclear why it was turned off.) */ -# define PNG_EXTERN +# define PNG_EXTERN extern #endif /* Some fixed point APIs are still required even if not exported because @@ -140,7 +315,7 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) /* png.c requires the following ANSI-C constants if the conversion of * floating point to ASCII is implemented therein: - * + * * DBL_DIG Maximum number of decimal digits (can be set to any constant) * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value) * DBL_MAX Maximum floating point number (can be set to an arbitrary value) @@ -198,60 +373,74 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; # define NOCHECK 0 # define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK)) # define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK)) -# define png_strcpy _fstrcpy -# define png_strncpy _fstrncpy /* Added to v 1.2.6 */ # define png_strlen _fstrlen # define png_memcmp _fmemcmp /* SJT: added */ # define png_memcpy _fmemcpy # define png_memset _fmemset -# define png_sprintf sprintf #else # ifdef _WINDOWS_ /* Favor Windows over C runtime fns */ # define CVT_PTR(ptr) (ptr) # define CVT_PTR_NOCHECK(ptr) (ptr) -# define png_strcpy lstrcpyA -# define png_strncpy lstrcpynA # define png_strlen lstrlenA # define png_memcmp memcmp # define png_memcpy CopyMemory # define png_memset memset -# define png_sprintf wsprintfA # else # define CVT_PTR(ptr) (ptr) # define CVT_PTR_NOCHECK(ptr) (ptr) -# define png_strcpy strcpy -# define png_strncpy strncpy /* Added to v 1.2.6 */ # define png_strlen strlen # define png_memcmp memcmp /* SJT: added */ # define png_memcpy memcpy # define png_memset memset -# define png_sprintf sprintf # endif #endif -/* End of memory model/platform independent support */ -#ifndef PNG_NO_SNPRINTF -# ifdef _MSC_VER -# define png_snprintf _snprintf /* Added to v 1.2.19 */ -# define png_snprintf2 _snprintf -# define png_snprintf6 _snprintf +/* These macros may need to be architecture dependent. */ +#define PNG_ALIGN_NONE 0 /* do not use data alignment */ +#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */ +#ifdef offsetof +# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */ +#else +# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */ +#endif +#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */ + +#ifndef PNG_ALIGN_TYPE + /* Default to using aligned access optimizations and requiring alignment to a + * multiple of the data type size. Override in a compiler specific fashion + * if necessary by inserting tests here: + */ +# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE +#endif + +#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE + /* This is used because in some compiler implementations non-aligned + * structure members are supported, so the offsetof approach below fails. + * Set PNG_ALIGN_TO_SIZE=0 for compiler combinations where unaligned access + * is good for performance. Do not do this unless you have tested the result + * and understand it. + */ +# define png_alignof(type) (sizeof (type)) +#else +# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET +# define png_alignof(type) offsetof(struct{char c; type t;}, t) # else -# define png_snprintf snprintf /* Added to v 1.2.19 */ -# define png_snprintf2 snprintf -# define png_snprintf6 snprintf +# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS +# define png_alignof(type) (1) +# endif + /* Else leave png_alignof undefined to prevent use thereof */ # endif +#endif + +/* This implicitly assumes alignment is always to a power of 2. */ +#ifdef png_alignof +# define png_isaligned(ptr, type)\ + ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0) #else - /* You don't have or don't want to use snprintf(). Caution: Using - * sprintf instead of snprintf exposes your application to accidental - * or malevolent buffer overflows. If you don't have snprintf() - * as a general rule you should provide one (you can get one from - * Portable OpenSSH). - */ -# define png_snprintf(s1,n,fmt,x1) png_sprintf(s1,fmt,x1) -# define png_snprintf2(s1,n,fmt,x1,x2) png_sprintf(s1,fmt,x1,x2) -# define png_snprintf6(s1,n,fmt,x1,x2,x3,x4,x5,x6) \ - png_sprintf(s1,fmt,x1,x2,x3,x4,x5,x6) +# define png_isaligned(ptr, type) 0 #endif + +/* End of memory model/platform independent support */ /* End of 1.5.0beta36 move from pngconf.h */ /* CONSTANTS and UTILITY MACROS @@ -259,12 +448,14 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; */ /* Various modes of operation. Note that after an init, mode is set to - * zero automatically when the structure is created. + * zero automatically when the structure is created. Three of these + * are defined in png.h because they need to be visible to applications + * that call png_set_unknown_chunk(). */ -#define PNG_HAVE_IHDR 0x01 -#define PNG_HAVE_PLTE 0x02 +/* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */ +/* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */ #define PNG_HAVE_IDAT 0x04 -#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */ +/* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */ #define PNG_HAVE_IEND 0x10 #define PNG_HAVE_gAMA 0x20 #define PNG_HAVE_cHRM 0x40 @@ -275,6 +466,7 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; #define PNG_BACKGROUND_IS_GRAY 0x800 #define PNG_HAVE_PNG_SIGNATURE 0x1000 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */ +#define PNG_HAVE_iCCP 0x4000 /* Flags for the transformations the PNG library does on the image data */ #define PNG_BGR 0x0001 @@ -284,32 +476,31 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; #define PNG_SWAP_BYTES 0x0010 #define PNG_INVERT_MONO 0x0020 #define PNG_QUANTIZE 0x0040 -#define PNG_BACKGROUND 0x0080 +#define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */ #define PNG_BACKGROUND_EXPAND 0x0100 - /* 0x0200 unused */ -#define PNG_16_TO_8 0x0400 +#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */ +#define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */ #define PNG_RGBA 0x0800 #define PNG_EXPAND 0x1000 #define PNG_GAMMA 0x2000 #define PNG_GRAY_TO_RGB 0x4000 -#define PNG_FILLER 0x8000L -#define PNG_PACKSWAP 0x10000L -#define PNG_SWAP_ALPHA 0x20000L -#define PNG_STRIP_ALPHA 0x40000L -#define PNG_INVERT_ALPHA 0x80000L -#define PNG_USER_TRANSFORM 0x100000L -#define PNG_RGB_TO_GRAY_ERR 0x200000L -#define PNG_RGB_TO_GRAY_WARN 0x400000L -#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */ - /* 0x800000L Unused */ -#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */ -#define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */ - /* 0x4000000L unused */ - /* 0x8000000L unused */ - /* 0x10000000L unused */ - /* 0x20000000L unused */ - /* 0x40000000L unused */ - +#define PNG_FILLER 0x8000 +#define PNG_PACKSWAP 0x10000 +#define PNG_SWAP_ALPHA 0x20000 +#define PNG_STRIP_ALPHA 0x40000 +#define PNG_INVERT_ALPHA 0x80000 +#define PNG_USER_TRANSFORM 0x100000 +#define PNG_RGB_TO_GRAY_ERR 0x200000 +#define PNG_RGB_TO_GRAY_WARN 0x400000 +#define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */ +#define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */ +#define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */ +#define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */ +#define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */ + /* 0x8000000 unused */ + /* 0x10000000 unused */ + /* 0x20000000 unused */ + /* 0x40000000 unused */ /* Flags for png_create_struct */ #define PNG_STRUCT_PNG 0x0001 #define PNG_STRUCT_INFO 0x0002 @@ -331,25 +522,25 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800 - /* 0x1000 unused */ - /* 0x2000 unused */ - /* 0x4000 unused */ -#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L -#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L -#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L -#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L -#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L -#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L -#define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */ -#define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */ -#define PNG_FLAG_BENIGN_ERRORS_WARN 0x800000L /* Added to libpng-1.4.0 */ - /* 0x1000000L unused */ - /* 0x2000000L unused */ - /* 0x4000000L unused */ - /* 0x8000000L unused */ - /* 0x10000000L unused */ - /* 0x20000000L unused */ - /* 0x40000000L unused */ +#define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */ +#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */ +#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */ +#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 +#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 +#define PNG_FLAG_LIBRARY_MISMATCH 0x20000 +#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000 +#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000 +#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000 + /* 0x200000 unused */ + /* 0x400000 unused */ +#define PNG_FLAG_BENIGN_ERRORS_WARN 0x800000 /* Added to libpng-1.4.0 */ +#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY 0x1000000 /* 5 lines added */ +#define PNG_FLAG_ZTXT_CUSTOM_LEVEL 0x2000000 /* to libpng-1.5.4 */ +#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL 0x4000000 +#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000 +#define PNG_FLAG_ZTXT_CUSTOM_METHOD 0x10000000 + /* 0x20000000 unused */ + /* 0x40000000 unused */ #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \ PNG_FLAG_CRC_ANCILLARY_NOWARN) @@ -431,32 +622,75 @@ PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp, #endif #endif -/* Constant strings for known chunk types. If you need to add a chunk, - * define the name here, and add an invocation of the macro wherever it's - * needed. +/* Constants for known chunk types. If you need to add a chunk, define the name + * here. For historical reasons these constants have the form png_<name>; i.e. + * the prefix is lower case. Please use decimal values as the parameters to + * match the ISO PNG specification and to avoid relying on the C locale + * interpretation of character values. + * + * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values + * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string + * to be generated if required. + * + * PNG_32b correctly produces a value shifted by up to 24 bits, even on + * architectures where (int) is only 16 bits. */ -#define PNG_IHDR PNG_CONST png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'} -#define PNG_IDAT PNG_CONST png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'} -#define PNG_IEND PNG_CONST png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'} -#define PNG_PLTE PNG_CONST png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'} -#define PNG_bKGD PNG_CONST png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'} -#define PNG_cHRM PNG_CONST png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'} -#define PNG_gAMA PNG_CONST png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'} -#define PNG_hIST PNG_CONST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'} -#define PNG_iCCP PNG_CONST png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'} -#define PNG_iTXt PNG_CONST png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'} -#define PNG_oFFs PNG_CONST png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'} -#define PNG_pCAL PNG_CONST png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'} -#define PNG_sCAL PNG_CONST png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'} -#define PNG_pHYs PNG_CONST png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'} -#define PNG_sBIT PNG_CONST png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'} -#define PNG_sPLT PNG_CONST png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'} -#define PNG_sRGB PNG_CONST png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'} -#define PNG_sTER PNG_CONST png_byte png_sTER[5] = {115, 84, 69, 82, '\0'} -#define PNG_tEXt PNG_CONST png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'} -#define PNG_tIME PNG_CONST png_byte png_tIME[5] = {116, 73, 77, 69, '\0'} -#define PNG_tRNS PNG_CONST png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'} -#define PNG_zTXt PNG_CONST png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'} +#define PNG_32b(b,s) ((png_uint_32)(b) << (s)) +#define PNG_CHUNK(b1,b2,b3,b4) \ + (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0)) + +#define png_IHDR PNG_CHUNK( 73, 72, 68, 82) +#define png_IDAT PNG_CHUNK( 73, 68, 65, 84) +#define png_IEND PNG_CHUNK( 73, 69, 78, 68) +#define png_PLTE PNG_CHUNK( 80, 76, 84, 69) +#define png_bKGD PNG_CHUNK( 98, 75, 71, 68) +#define png_cHRM PNG_CHUNK( 99, 72, 82, 77) +#define png_gAMA PNG_CHUNK(103, 65, 77, 65) +#define png_hIST PNG_CHUNK(104, 73, 83, 84) +#define png_iCCP PNG_CHUNK(105, 67, 67, 80) +#define png_iTXt PNG_CHUNK(105, 84, 88, 116) +#define png_oFFs PNG_CHUNK(111, 70, 70, 115) +#define png_pCAL PNG_CHUNK(112, 67, 65, 76) +#define png_sCAL PNG_CHUNK(115, 67, 65, 76) +#define png_pHYs PNG_CHUNK(112, 72, 89, 115) +#define png_sBIT PNG_CHUNK(115, 66, 73, 84) +#define png_sPLT PNG_CHUNK(115, 80, 76, 84) +#define png_sRGB PNG_CHUNK(115, 82, 71, 66) +#define png_sTER PNG_CHUNK(115, 84, 69, 82) +#define png_tEXt PNG_CHUNK(116, 69, 88, 116) +#define png_tIME PNG_CHUNK(116, 73, 77, 69) +#define png_tRNS PNG_CHUNK(116, 82, 78, 83) +#define png_zTXt PNG_CHUNK(122, 84, 88, 116) + +/* The following will work on (signed char*) strings, whereas the get_uint_32 + * macro will fail on top-bit-set values because of the sign extension. + */ +#define PNG_CHUNK_FROM_STRING(s)\ + PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3]) + +/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is + * signed and the argument is a (char[]) This macro will fail miserably on + * systems where (char) is more than 8 bits. + */ +#define PNG_STRING_FROM_CHUNK(s,c)\ + (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\ + ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c))) + +/* Do the same but terminate with a null character. */ +#define PNG_CSTRING_FROM_CHUNK(s,c)\ + (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0) + +/* Test on flag values as defined in the spec (section 5.4): */ +#define PNG_CHUNK_ANCILLIARY(c) (1 & ((c) >> 29)) +#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLIARY(c)) +#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21)) +#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13)) +#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5)) + +/* Gamma values (new at libpng-1.5.4): */ +#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */ +#define PNG_GAMMA_MAC_INVERSE 65909 +#define PNG_GAMMA_sRGB_INVERSE 45455 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ @@ -470,6 +704,12 @@ extern "C" { * be found in the files where the functions are located. */ +/* Check the user version string for compatibility, returns false if the version + * numbers aren't compatible. + */ +PNG_EXTERN int png_user_version_check(png_structp png_ptr, + png_const_charp user_png_ver); + /* Allocate memory for an internal libpng struct */ PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)), PNG_ALLOCATED); @@ -538,8 +778,7 @@ PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf, png_size_t length)); /* Decompress data in a chunk that uses compression */ -#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \ - defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) +#if defined(PNG_READ_COMPRESSED_TEXT_SUPPORTED) PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr, int comp_type, png_size_t chunklength, png_size_t prefix_length, png_size_t *data_length)); @@ -642,6 +881,7 @@ PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_const_uint_16p hist, int num_hist)); #endif +/* Chunks that have keywords */ #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr, @@ -702,17 +942,44 @@ PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)); /* Internal use only. Called before first row of data */ PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)); -/* Combine a row of data, dealing with alpha, etc. if requested */ +/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an + * array of png_ptr->width pixels. If the image is not interlaced or this + * is the final pass this just does a png_memcpy, otherwise the "display" flag + * is used to determine whether to copy pixels that are not in the current pass. + * + * Because 'png_do_read_interlace' (below) replicates pixels this allows this + * function to achieve the documented 'blocky' appearance during interlaced read + * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row' + * are not changed if they are not in the current pass, when display is 0. + * + * 'display' must be 0 or 1, otherwise the memcpy will be done regardless. + * + * The API always reads from the png_struct row buffer and always assumes that + * it is full width (png_do_read_interlace has already been called.) + * + * This function is only ever used to write to row buffers provided by the + * caller of the relevant libpng API and the row must have already been + * transformed by the read transformations. + * + * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed + * bitmasks for use within the code, otherwise runtime generated masks are used. + * The default is compile time masks. + */ +#ifndef PNG_USE_COMPILE_TIME_MASKS +# define PNG_USE_COMPILE_TIME_MASKS 1 +#endif PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row, - int mask)); + int display)); #ifdef PNG_READ_INTERLACING_SUPPORTED -/* Expand an interlaced row */ -/* OLD pre-1.0.9 interface: +/* Expand an interlaced row: the 'row_info' describes the pass data that has + * been read in and must correspond to the pixels in 'row', the pixels are + * expanded (moved apart) in 'row' to match the final layout, when doing this + * the pixels are *replicated* to the intervening space. This is essential for + * the correct operation of png_combine_row, above. + */ PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info, png_bytep row, int pass, png_uint_32 transformations)); - */ -PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr)); #endif /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */ @@ -723,26 +990,42 @@ PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info, png_bytep row, int pass)); #endif -/* Unfilter a row */ -PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr, - png_row_infop row_info, png_bytep row, png_const_bytep prev_row, - int filter)); +/* Unfilter a row: check the filter value before calling this, there is no point + * calling it for PNG_FILTER_VALUE_NONE. + */ +PNG_EXTERN void png_read_filter_row PNGARG((png_structp pp, png_row_infop row_info, + png_bytep row, png_const_bytep prev_row, int filter)); + +PNG_EXTERN void png_read_filter_row_up_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_sub3_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_sub4_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_avg3_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_avg4_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_paeth3_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_paeth4_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); /* Choose the best filter to use and filter the row data */ PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr, png_row_infop row_info)); -/* Write out the filtered row. */ -PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr, - png_bytep filtered_row)); /* Finish a row while reading, dealing with interlacing passes, etc. */ PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr)); /* Initialize the row buffers, etc. */ PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)); + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED /* Optional call to update the users info structure */ PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr, png_infop info_ptr)); +#endif /* These are the functions that do the transformations */ #ifdef PNG_READ_FILLER_SUPPORTED @@ -772,8 +1055,8 @@ PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info, #if defined(PNG_WRITE_FILLER_SUPPORTED) || \ defined(PNG_READ_STRIP_ALPHA_SUPPORTED) -PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info, - png_bytep row, png_uint_32 flags)); +PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info, + png_bytep row, int at_start)); #endif #ifdef PNG_16BIT_SUPPORTED @@ -814,7 +1097,12 @@ PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row)); #endif -#ifdef PNG_READ_16_TO_8_SUPPORTED +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row)); #endif @@ -845,26 +1133,20 @@ PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row, png_const_color_8p bit_depth)); #endif -#ifdef PNG_READ_BACKGROUND_SUPPORTED -# ifdef PNG_READ_GAMMA_SUPPORTED -PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, - png_bytep row, png_const_color_16p trans_color, - png_const_color_16p background, png_const_color_16p background_1, - png_const_bytep gamma_table, png_const_bytep gamma_from_1, - png_const_bytep gamma_to_1, png_const_uint_16pp gamma_16, - png_const_uint_16pp gamma_16_from_1, png_const_uint_16pp gamma_16_to_1, - int gamma_shift)); -# else -PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, - png_bytep row, png_const_color_16p trans_color, - png_const_color_16p background)); -# endif +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) +PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info, + png_bytep row, png_structp png_ptr)); #endif #ifdef PNG_READ_GAMMA_SUPPORTED PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, - png_bytep row, png_const_bytep gamma_table, - png_const_uint_16pp gamma_16_table, int gamma_shift)); + png_bytep row, png_structp png_ptr)); +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info, + png_bytep row, png_structp png_ptr)); #endif #ifdef PNG_READ_EXPAND_SUPPORTED @@ -875,6 +1157,11 @@ PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info, png_bytep row, png_const_color_16p trans_color)); #endif +#ifdef PNG_READ_EXPAND_16_SUPPORTED +PNG_EXTERN void png_do_expand_16 PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + /* The following decodes the appropriate chunks, and does error correction, * then calls the appropriate callback for the chunk if it is valid. */ @@ -972,17 +1259,35 @@ PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length)); #endif +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length)); +#endif PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr, - png_const_bytep chunk_name)); + png_uint_32 chunk_name)); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +/* Exactly as png_handle_as_unknown() except that the argument is a 32-bit chunk + * name, not a string. + */ +PNG_EXTERN int png_chunk_unknown_handling PNGARG((png_structp png_ptr, + png_uint_32 chunk_name)); +#endif /* Handle the transformations for reading and writing */ -PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr)); -PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr)); +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr, + png_row_infop row_info)); +#endif +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED +PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr, + png_row_infop row_info)); +#endif +#ifdef PNG_READ_TRANSFORMS_SUPPORTED PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr)); +#endif #ifdef PNG_PROGRESSIVE_READ_SUPPORTED PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr, @@ -1056,12 +1361,48 @@ PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2, unsigned long *hi_product, unsigned long *lo_product)); #endif +#ifdef PNG_cHRM_SUPPORTED +/* Added at libpng version 1.5.5 */ +typedef struct png_xy +{ + png_fixed_point redx, redy; + png_fixed_point greenx, greeny; + png_fixed_point bluex, bluey; + png_fixed_point whitex, whitey; +} png_xy; + +typedef struct png_XYZ +{ + png_fixed_point redX, redY, redZ; + png_fixed_point greenX, greenY, greenZ; + png_fixed_point blueX, blueY, blueZ; +} png_XYZ; + +/* The conversion APIs return 0 on success, non-zero on a parameter error. They + * allow conversion between the above representations of a color encoding. When + * converting from XYZ end points to chromaticities the absolute magnitude of + * the end points is lost, when converting back the sum of the Y values of the + * three end points will be 1.0 + */ +PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ)); +PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy)); +PNG_EXTERN int png_XYZ_from_xy_checked PNGARG((png_structp png_ptr, + png_XYZ *XYZ, png_xy xy)); +#endif + /* Added at libpng version 1.4.0 */ PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int interlace_type, int compression_type, int filter_type)); +/* Added at libpng version 1.5.10 */ +#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ + defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) +PNG_EXTERN void png_do_check_palette_indexes PNGARG((png_structp png_ptr, + png_row_infop row_info)); +#endif + /* Free all memory used by the read (old method - NOT DLL EXPORTED) */ PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)); @@ -1079,6 +1420,76 @@ PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr, png_const_charp name),PNG_NORETURN); #endif +/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite + * the end. Always leaves the buffer nul terminated. Never errors out (and + * there is no error code.) + */ +PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos, + png_const_charp string); + +/* Various internal functions to handle formatted warning messages, currently + * only implemented for warnings. + */ +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) +/* Utility to dump an unsigned value into a buffer, given a start pointer and + * and end pointer (which should point just *beyond* the end of the buffer!) + * Returns the pointer to the start of the formatted string. This utility only + * does unsigned values. + */ +PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end, + int format, png_alloc_size_t number); + +/* Convenience macro that takes an array: */ +#define PNG_FORMAT_NUMBER(buffer,format,number) \ + png_format_number(buffer, buffer + (sizeof buffer), format, number) + +/* Suggested size for a number buffer (enough for 64 bits and a sign!) */ +#define PNG_NUMBER_BUFFER_SIZE 24 + +/* These are the integer formats currently supported, the name is formed from + * the standard printf(3) format string. + */ +#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */ +#define PNG_NUMBER_FORMAT_02u 2 +#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */ +#define PNG_NUMBER_FORMAT_02d 2 +#define PNG_NUMBER_FORMAT_x 3 +#define PNG_NUMBER_FORMAT_02x 4 +#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */ +#endif + +#ifdef PNG_WARNINGS_SUPPORTED +/* New defines and members adding in libpng-1.5.4 */ +# define PNG_WARNING_PARAMETER_SIZE 32 +# define PNG_WARNING_PARAMETER_COUNT 8 + +/* An l-value of this type has to be passed to the APIs below to cache the + * values of the parameters to a formatted warning message. + */ +typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][ + PNG_WARNING_PARAMETER_SIZE]; + +PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number, + png_const_charp string); + /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters, + * including the trailing '\0'. + */ +PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p, + int number, int format, png_alloc_size_t value); + /* Use png_alloc_size_t because it is an unsigned type as big as any we + * need to output. Use the following for a signed value. + */ +PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p, + int number, int format, png_int_32 value); + +PNG_EXTERN void png_formatted_warning(png_structp png_ptr, + png_warning_parameters p, png_const_charp message); + /* 'message' follows the X/Open approach of using @1, @2 to insert + * parameters previously supplied using the above functions. Errors in + * specifying the paramters will simple result in garbage substitutions. + */ +#endif + /* ASCII to FP interfaces, currently only implemented if sCAL * support is required. */ @@ -1141,8 +1552,18 @@ PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr, #define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */ #define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */ #define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */ + +/* These three values don't affect the parser. They are set but not used. + */ #define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */ -#define PNG_FP_INVALID 128 /* Available for callers as a distinct value */ +#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */ +#define PNG_FP_NONZERO 256 /* A non-zero value */ +#define PNG_FP_STICKY 448 /* The above three flags */ + +/* This is available for the caller to store in 'state' if required. Do not + * call the parser after setting it (the parser sometimes clears it.) + */ +#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */ /* Result codes for the parser (boolean - true meants ok, false means * not ok yet.) @@ -1150,6 +1571,20 @@ PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr, #define PNG_FP_MAYBE 0 /* The number may be valid in the future */ #define PNG_FP_OK 1 /* The number is valid */ +/* Tests on the sticky non-zero and negative flags. To pass these checks + * the state must also indicate that the whole number is valid - this is + * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this + * is equivalent to PNG_FP_OK above.) + */ +#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO) + /* NZ_MASK: the string is valid and a non-zero negative value */ +#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO) + /* Z MASK: the string is valid and a non-zero value. */ + /* PNG_FP_SAW_DIGIT: the string is valid. */ +#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT) +#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK) +#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK) + /* The actual parser. This can be called repeatedly, it updates * the index into the string and the state variable (which must * be initialzed to 0). It returns a result code, as above. There @@ -1169,7 +1604,10 @@ PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string, png_size_t size, int *statep, png_size_tp whereami)); /* This is the same but it checks a complete string and returns true - * only if it just contains a floating point number. + * only if it just contains a floating point number. As of 1.5.4 this + * function also returns the state at the end of parsing the number if + * it was valid (otherwise it returns 0.) This can be used for testing + * for negative or zero values using the sticky flag. */ PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string, png_size_t size)); @@ -1184,13 +1622,13 @@ PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string, * holds the result. */ PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a, - png_int_32 times, png_int_32 div)); + png_int_32 multiplied_by, png_int_32 divided_by)); #endif #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) /* Same deal, but issue a warning on overflow and return 0. */ PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr, - png_fixed_point a, png_int_32 times, png_int_32 div)); + png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by)); #endif #ifdef PNG_READ_GAMMA_SUPPORTED @@ -1217,19 +1655,19 @@ PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a, * correct bit value - 0..255 or 0..65535 as required. */ PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr, - unsigned int value, png_fixed_point gamma)); -PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma)); + unsigned int value, png_fixed_point gamma_value)); +PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value)); PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value, - png_fixed_point gamma)); + png_fixed_point gamma_value)); PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value, - png_fixed_point gamma)); + png_fixed_point gamma_value)); +PNG_EXTERN void png_destroy_gamma_table(png_structp png_ptr); PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr, int bit_depth)); #endif /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */ - #include "pngdebug.h" #ifdef __cplusplus diff --git a/png/pngread.c b/png/pngread.c index 2c8f2cd68..1d8c6b334 100644 --- a/png/pngread.c +++ b/png/pngread.c @@ -1,8 +1,8 @@ /* pngread.c - read a PNG file * - * Last changed in libpng 1.5.1 [$RDATE%] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -47,12 +47,10 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, #ifdef PNG_SETJMP_SUPPORTED #ifdef USE_FAR_KEYWORD - jmp_buf png_jmpbuf; + jmp_buf tmp_jmpbuf; #endif #endif - int i; - png_debug(1, "in png_create_read_struct"); #ifdef PNG_USER_MEM_SUPPORTED @@ -69,29 +67,26 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, png_ptr->user_width_max = PNG_USER_WIDTH_MAX; png_ptr->user_height_max = PNG_USER_HEIGHT_MAX; -# ifdef PNG_USER_CHUNK_CACHE_MAX /* Added at libpng-1.2.43 and 1.4.0 */ png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX; -# endif -# ifdef PNG_SET_USER_CHUNK_MALLOC_MAX /* Added at libpng-1.2.43 and 1.4.1 */ png_ptr->user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX; -# endif #endif #ifdef PNG_SETJMP_SUPPORTED /* Applications that neglect to set up their own setjmp() and then - encounter a png_error() will longjmp here. Since the jmpbuf is - then meaningless we abort instead of returning. */ + * encounter a png_error() will longjmp here. Since the jmpbuf is + * then meaningless we abort instead of returning. + */ #ifdef USE_FAR_KEYWORD - if (setjmp(png_jmpbuf)) + if (setjmp(tmp_jmpbuf)) #else if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */ #endif PNG_ABORT(); #ifdef USE_FAR_KEYWORD - png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf)); + png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf)); #endif #endif /* PNG_SETJMP_SUPPORTED */ @@ -101,54 +96,9 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); - if (user_png_ver) - { - i = 0; - - do - { - if (user_png_ver[i] != png_libpng_ver[i]) - png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; - } while (png_libpng_ver[i++]); - } - - else - png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; - - - if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) - { - /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so - * we must recompile any applications that use any older library version. - * For versions after libpng 1.0, we will be compatible, so we need - * only check the first digit. - */ - if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || - (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || - (user_png_ver[0] == '0' && user_png_ver[2] < '9')) - { -#ifdef PNG_CONSOLE_IO_SUPPORTED - char msg[80]; - if (user_png_ver) - { - png_snprintf2(msg, 80, - "Application built with libpng-%.20s" - " but running with %.20s", - user_png_ver, - png_libpng_ver); - png_warning(png_ptr, msg); - } -#else - png_warning(png_ptr, - "Incompatible libpng version in application and library"); -#endif -#ifdef PNG_ERROR_NUMBERS_SUPPORTED - png_ptr->flags = 0; -#endif - - png_cleanup_needed = 1; - } - } + /* Call the general version checker (shared with read and write code): */ + if (!png_user_version_check(png_ptr, user_png_ver)) + png_cleanup_needed = 1; if (!png_cleanup_needed) { @@ -237,89 +187,35 @@ png_read_info(png_structp png_ptr, png_infop info_ptr) for (;;) { - PNG_IHDR; - PNG_IDAT; - PNG_IEND; - PNG_PLTE; -#ifdef PNG_READ_bKGD_SUPPORTED - PNG_bKGD; -#endif -#ifdef PNG_READ_cHRM_SUPPORTED - PNG_cHRM; -#endif -#ifdef PNG_READ_gAMA_SUPPORTED - PNG_gAMA; -#endif -#ifdef PNG_READ_hIST_SUPPORTED - PNG_hIST; -#endif -#ifdef PNG_READ_iCCP_SUPPORTED - PNG_iCCP; -#endif -#ifdef PNG_READ_iTXt_SUPPORTED - PNG_iTXt; -#endif -#ifdef PNG_READ_oFFs_SUPPORTED - PNG_oFFs; -#endif -#ifdef PNG_READ_pCAL_SUPPORTED - PNG_pCAL; -#endif -#ifdef PNG_READ_pHYs_SUPPORTED - PNG_pHYs; -#endif -#ifdef PNG_READ_sBIT_SUPPORTED - PNG_sBIT; -#endif -#ifdef PNG_READ_sCAL_SUPPORTED - PNG_sCAL; -#endif -#ifdef PNG_READ_sPLT_SUPPORTED - PNG_sPLT; -#endif -#ifdef PNG_READ_sRGB_SUPPORTED - PNG_sRGB; -#endif -#ifdef PNG_READ_tEXt_SUPPORTED - PNG_tEXt; -#endif -#ifdef PNG_READ_tIME_SUPPORTED - PNG_tIME; -#endif -#ifdef PNG_READ_tRNS_SUPPORTED - PNG_tRNS; -#endif -#ifdef PNG_READ_zTXt_SUPPORTED - PNG_zTXt; -#endif png_uint_32 length = png_read_chunk_header(png_ptr); - PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; + png_uint_32 chunk_name = png_ptr->chunk_name; /* This should be a binary subdivision search or a hash for * matching the chunk name rather than a linear search. */ - if (!png_memcmp(chunk_name, png_IDAT, 4)) + if (chunk_name == png_IDAT) if (png_ptr->mode & PNG_AFTER_IDAT) png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; - if (!png_memcmp(chunk_name, png_IHDR, 4)) + if (chunk_name == png_IHDR) png_handle_IHDR(png_ptr, info_ptr, length); - else if (!png_memcmp(chunk_name, png_IEND, 4)) + else if (chunk_name == png_IEND) png_handle_IEND(png_ptr, info_ptr, length); #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - else if (png_handle_as_unknown(png_ptr, chunk_name)) + else if (png_chunk_unknown_handling(png_ptr, chunk_name) != + PNG_HANDLE_CHUNK_AS_DEFAULT) { - if (!png_memcmp(chunk_name, png_IDAT, 4)) + if (chunk_name == png_IDAT) png_ptr->mode |= PNG_HAVE_IDAT; png_handle_unknown(png_ptr, info_ptr, length); - if (!png_memcmp(chunk_name, png_PLTE, 4)) + if (chunk_name == png_PLTE) png_ptr->mode |= PNG_HAVE_PLTE; - else if (!png_memcmp(chunk_name, png_IDAT, 4)) + else if (chunk_name == png_IDAT) { if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before IDAT"); @@ -332,10 +228,10 @@ png_read_info(png_structp png_ptr, png_infop info_ptr) } } #endif - else if (!png_memcmp(chunk_name, png_PLTE, 4)) + else if (chunk_name == png_PLTE) png_handle_PLTE(png_ptr, info_ptr, length); - else if (!png_memcmp(chunk_name, png_IDAT, 4)) + else if (chunk_name == png_IDAT) { if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before IDAT"); @@ -350,87 +246,87 @@ png_read_info(png_structp png_ptr, png_infop info_ptr) } #ifdef PNG_READ_bKGD_SUPPORTED - else if (!png_memcmp(chunk_name, png_bKGD, 4)) + else if (chunk_name == png_bKGD) png_handle_bKGD(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_cHRM_SUPPORTED - else if (!png_memcmp(chunk_name, png_cHRM, 4)) + else if (chunk_name == png_cHRM) png_handle_cHRM(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_gAMA_SUPPORTED - else if (!png_memcmp(chunk_name, png_gAMA, 4)) + else if (chunk_name == png_gAMA) png_handle_gAMA(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_hIST_SUPPORTED - else if (!png_memcmp(chunk_name, png_hIST, 4)) + else if (chunk_name == png_hIST) png_handle_hIST(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_oFFs_SUPPORTED - else if (!png_memcmp(chunk_name, png_oFFs, 4)) + else if (chunk_name == png_oFFs) png_handle_oFFs(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_pCAL_SUPPORTED - else if (!png_memcmp(chunk_name, png_pCAL, 4)) + else if (chunk_name == png_pCAL) png_handle_pCAL(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sCAL_SUPPORTED - else if (!png_memcmp(chunk_name, png_sCAL, 4)) + else if (chunk_name == png_sCAL) png_handle_sCAL(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_pHYs_SUPPORTED - else if (!png_memcmp(chunk_name, png_pHYs, 4)) + else if (chunk_name == png_pHYs) png_handle_pHYs(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sBIT_SUPPORTED - else if (!png_memcmp(chunk_name, png_sBIT, 4)) + else if (chunk_name == png_sBIT) png_handle_sBIT(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sRGB_SUPPORTED - else if (!png_memcmp(chunk_name, png_sRGB, 4)) + else if (chunk_name == png_sRGB) png_handle_sRGB(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_iCCP_SUPPORTED - else if (!png_memcmp(chunk_name, png_iCCP, 4)) + else if (chunk_name == png_iCCP) png_handle_iCCP(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sPLT_SUPPORTED - else if (!png_memcmp(chunk_name, png_sPLT, 4)) + else if (chunk_name == png_sPLT) png_handle_sPLT(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tEXt_SUPPORTED - else if (!png_memcmp(chunk_name, png_tEXt, 4)) + else if (chunk_name == png_tEXt) png_handle_tEXt(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tIME_SUPPORTED - else if (!png_memcmp(chunk_name, png_tIME, 4)) + else if (chunk_name == png_tIME) png_handle_tIME(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tRNS_SUPPORTED - else if (!png_memcmp(chunk_name, png_tRNS, 4)) + else if (chunk_name == png_tRNS) png_handle_tRNS(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_zTXt_SUPPORTED - else if (!png_memcmp(chunk_name, png_zTXt, 4)) + else if (chunk_name == png_zTXt) png_handle_zTXt(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_iTXt_SUPPORTED - else if (!png_memcmp(chunk_name, png_iTXt, 4)) + else if (chunk_name == png_iTXt) png_handle_iTXt(png_ptr, info_ptr, length); #endif @@ -449,15 +345,13 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr) if (png_ptr == NULL) return; - if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) - png_read_start_row(png_ptr); - - else - png_warning(png_ptr, - "Ignoring extra png_read_update_info() call;" - " row buffer not reallocated"); + png_read_start_row(png_ptr); +#ifdef PNG_READ_TRANSFORMS_SUPPORTED png_read_transform_info(png_ptr, info_ptr); +#else + PNG_UNUSED(info_ptr) +#endif } #ifdef PNG_SEQUENTIAL_READ_SUPPORTED @@ -471,15 +365,8 @@ png_start_read_image(png_structp png_ptr) { png_debug(1, "in png_start_read_image"); - if (png_ptr == NULL) - return; - - if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) - png_read_start_row(png_ptr); - else - png_warning(png_ptr, - "Ignoring extra png_start_read_image() call;" - " row buffer not reallocated"); + if (png_ptr != NULL) + png_read_start_row(png_ptr); } #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ @@ -487,21 +374,30 @@ png_start_read_image(png_structp png_ptr) void PNGAPI png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) { - PNG_IDAT; - PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, - 0xff}; - PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; int ret; + png_row_info row_info; + if (png_ptr == NULL) return; png_debug2(1, "in png_read_row (row %lu, pass %d)", (unsigned long)png_ptr->row_number, png_ptr->pass); + /* png_read_start_row sets the information (in particular iwidth) for this + * interlace pass. + */ if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) png_read_start_row(png_ptr); + /* 1.5.6: row_info moved out of png_struct to a local here. */ + row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ + row_info.color_type = png_ptr->color_type; + row_info.bit_depth = png_ptr->bit_depth; + row_info.channels = png_ptr->channels; + row_info.pixel_depth = png_ptr->pixel_depth; + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + if (png_ptr->row_number == 0 && png_ptr->pass == 0) { /* Check for transforms that have been set but were defined out */ @@ -543,7 +439,12 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) } #ifdef PNG_READ_INTERLACING_SUPPORTED - /* If interlaced and we do not need a new row, combine row and return */ + /* If interlaced and we do not need a new row, combine row and return. + * Notice that the pixels we have from previous rows have been transformed + * already; we can only combine like with like (transformed or + * untransformed) and, because of the libpng API for interlaced images, this + * means we must transform before de-interlacing. + */ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) { switch (png_ptr->pass) @@ -552,8 +453,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) if (png_ptr->row_number & 0x07) { if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, - png_pass_dsp_mask[png_ptr->pass]); + png_combine_row(png_ptr, dsp_row, 1/*display*/); png_read_finish_row(png_ptr); return; } @@ -563,8 +463,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) { if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, - png_pass_dsp_mask[png_ptr->pass]); + png_combine_row(png_ptr, dsp_row, 1/*display*/); png_read_finish_row(png_ptr); return; @@ -575,8 +474,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) if ((png_ptr->row_number & 0x07) != 4) { if (dsp_row != NULL && (png_ptr->row_number & 4)) - png_combine_row(png_ptr, dsp_row, - png_pass_dsp_mask[png_ptr->pass]); + png_combine_row(png_ptr, dsp_row, 1/*display*/); png_read_finish_row(png_ptr); return; @@ -587,8 +485,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) if ((png_ptr->row_number & 3) || png_ptr->width < 3) { if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, - png_pass_dsp_mask[png_ptr->pass]); + png_combine_row(png_ptr, dsp_row, 1/*display*/); png_read_finish_row(png_ptr); return; @@ -599,8 +496,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) if ((png_ptr->row_number & 3) != 2) { if (dsp_row != NULL && (png_ptr->row_number & 2)) - png_combine_row(png_ptr, dsp_row, - png_pass_dsp_mask[png_ptr->pass]); + png_combine_row(png_ptr, dsp_row, 1/*display*/); png_read_finish_row(png_ptr); return; @@ -610,8 +506,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) if ((png_ptr->row_number & 1) || png_ptr->width < 2) { if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, - png_pass_dsp_mask[png_ptr->pass]); + png_combine_row(png_ptr, dsp_row, 1/*display*/); png_read_finish_row(png_ptr); return; @@ -647,7 +542,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) png_crc_finish(png_ptr, 0); png_ptr->idat_size = png_read_chunk_header(png_ptr); - if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + if (png_ptr->chunk_name != png_IDAT) png_error(png_ptr, "Not enough image data"); } png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; @@ -677,33 +572,47 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) } while (png_ptr->zstream.avail_out); - png_ptr->row_info.color_type = png_ptr->color_type; - png_ptr->row_info.width = png_ptr->iwidth; - png_ptr->row_info.channels = png_ptr->channels; - png_ptr->row_info.bit_depth = png_ptr->bit_depth; - png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; - png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, - png_ptr->row_info.width); - - if (png_ptr->row_buf[0]) - png_read_filter_row(png_ptr, &(png_ptr->row_info), - png_ptr->row_buf + 1, png_ptr->prev_row + 1, - (int)(png_ptr->row_buf[0])); + if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) + { + if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) + png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, + png_ptr->prev_row + 1, png_ptr->row_buf[0]); + else + png_error(png_ptr, "bad adaptive filter value"); + } - png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); + /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before + * 1.5.6, while the buffer really is this big in current versions of libpng + * it may not be in the future, so this was changed just to copy the + * interlaced count: + */ + png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); #ifdef PNG_MNG_FEATURES_SUPPORTED if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) { /* Intrapixel differencing */ - png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1); } #endif - if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) - png_do_read_transformations(png_ptr); +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + if (png_ptr->transformations) + png_do_read_transformations(png_ptr, &row_info); +#endif + + /* The transformed pixel depth should match the depth now in row_info. */ + if (png_ptr->transformed_pixel_depth == 0) + { + png_ptr->transformed_pixel_depth = row_info.pixel_depth; + if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) + png_error(png_ptr, "sequential row overflow"); + } + + else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) + png_error(png_ptr, "internal sequential row size calculation error"); #ifdef PNG_READ_INTERLACING_SUPPORTED /* Blow up interlaced rows to full size */ @@ -711,27 +620,24 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) (png_ptr->transformations & PNG_INTERLACE)) { if (png_ptr->pass < 6) - /* Old interface (pre-1.0.9): - * png_do_read_interlace(&(png_ptr->row_info), - * png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); - */ - png_do_read_interlace(png_ptr); + png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, + png_ptr->transformations); if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); + png_combine_row(png_ptr, dsp_row, 1/*display*/); if (row != NULL) - png_combine_row(png_ptr, row, png_pass_mask[png_ptr->pass]); + png_combine_row(png_ptr, row, 0/*row*/); } else #endif { if (row != NULL) - png_combine_row(png_ptr, row, 0xff); + png_combine_row(png_ptr, row, -1/*ignored*/); if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, 0xff); + png_combine_row(png_ptr, dsp_row, -1/*ignored*/); } png_read_finish_row(png_ptr); @@ -895,87 +801,40 @@ png_read_end(png_structp png_ptr, png_infop info_ptr) png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Report invalid palette index; added at libng-1.5.10 */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + png_ptr->num_palette_max > png_ptr->num_palette) + png_benign_error(png_ptr, "Read palette index exceeding num_palette"); +#endif + do { - PNG_IHDR; - PNG_IDAT; - PNG_IEND; - PNG_PLTE; -#ifdef PNG_READ_bKGD_SUPPORTED - PNG_bKGD; -#endif -#ifdef PNG_READ_cHRM_SUPPORTED - PNG_cHRM; -#endif -#ifdef PNG_READ_gAMA_SUPPORTED - PNG_gAMA; -#endif -#ifdef PNG_READ_hIST_SUPPORTED - PNG_hIST; -#endif -#ifdef PNG_READ_iCCP_SUPPORTED - PNG_iCCP; -#endif -#ifdef PNG_READ_iTXt_SUPPORTED - PNG_iTXt; -#endif -#ifdef PNG_READ_oFFs_SUPPORTED - PNG_oFFs; -#endif -#ifdef PNG_READ_pCAL_SUPPORTED - PNG_pCAL; -#endif -#ifdef PNG_READ_pHYs_SUPPORTED - PNG_pHYs; -#endif -#ifdef PNG_READ_sBIT_SUPPORTED - PNG_sBIT; -#endif -#ifdef PNG_READ_sCAL_SUPPORTED - PNG_sCAL; -#endif -#ifdef PNG_READ_sPLT_SUPPORTED - PNG_sPLT; -#endif -#ifdef PNG_READ_sRGB_SUPPORTED - PNG_sRGB; -#endif -#ifdef PNG_READ_tEXt_SUPPORTED - PNG_tEXt; -#endif -#ifdef PNG_READ_tIME_SUPPORTED - PNG_tIME; -#endif -#ifdef PNG_READ_tRNS_SUPPORTED - PNG_tRNS; -#endif -#ifdef PNG_READ_zTXt_SUPPORTED - PNG_zTXt; -#endif png_uint_32 length = png_read_chunk_header(png_ptr); - PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; + png_uint_32 chunk_name = png_ptr->chunk_name; - if (!png_memcmp(chunk_name, png_IHDR, 4)) + if (chunk_name == png_IHDR) png_handle_IHDR(png_ptr, info_ptr, length); - else if (!png_memcmp(chunk_name, png_IEND, 4)) + else if (chunk_name == png_IEND) png_handle_IEND(png_ptr, info_ptr, length); #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - else if (png_handle_as_unknown(png_ptr, chunk_name)) + else if (png_chunk_unknown_handling(png_ptr, chunk_name) != + PNG_HANDLE_CHUNK_AS_DEFAULT) { - if (!png_memcmp(chunk_name, png_IDAT, 4)) + if (chunk_name == png_IDAT) { if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) png_benign_error(png_ptr, "Too many IDATs found"); } png_handle_unknown(png_ptr, info_ptr, length); - if (!png_memcmp(chunk_name, png_PLTE, 4)) + if (chunk_name == png_PLTE) png_ptr->mode |= PNG_HAVE_PLTE; } #endif - else if (!png_memcmp(chunk_name, png_IDAT, 4)) + else if (chunk_name == png_IDAT) { /* Zero length IDATs are legal after the last IDAT has been * read, but not after other chunks have been read. @@ -985,91 +844,91 @@ png_read_end(png_structp png_ptr, png_infop info_ptr) png_crc_finish(png_ptr, length); } - else if (!png_memcmp(chunk_name, png_PLTE, 4)) + else if (chunk_name == png_PLTE) png_handle_PLTE(png_ptr, info_ptr, length); #ifdef PNG_READ_bKGD_SUPPORTED - else if (!png_memcmp(chunk_name, png_bKGD, 4)) + else if (chunk_name == png_bKGD) png_handle_bKGD(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_cHRM_SUPPORTED - else if (!png_memcmp(chunk_name, png_cHRM, 4)) + else if (chunk_name == png_cHRM) png_handle_cHRM(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_gAMA_SUPPORTED - else if (!png_memcmp(chunk_name, png_gAMA, 4)) + else if (chunk_name == png_gAMA) png_handle_gAMA(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_hIST_SUPPORTED - else if (!png_memcmp(chunk_name, png_hIST, 4)) + else if (chunk_name == png_hIST) png_handle_hIST(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_oFFs_SUPPORTED - else if (!png_memcmp(chunk_name, png_oFFs, 4)) + else if (chunk_name == png_oFFs) png_handle_oFFs(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_pCAL_SUPPORTED - else if (!png_memcmp(chunk_name, png_pCAL, 4)) + else if (chunk_name == png_pCAL) png_handle_pCAL(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sCAL_SUPPORTED - else if (!png_memcmp(chunk_name, png_sCAL, 4)) + else if (chunk_name == png_sCAL) png_handle_sCAL(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_pHYs_SUPPORTED - else if (!png_memcmp(chunk_name, png_pHYs, 4)) + else if (chunk_name == png_pHYs) png_handle_pHYs(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sBIT_SUPPORTED - else if (!png_memcmp(chunk_name, png_sBIT, 4)) + else if (chunk_name == png_sBIT) png_handle_sBIT(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sRGB_SUPPORTED - else if (!png_memcmp(chunk_name, png_sRGB, 4)) + else if (chunk_name == png_sRGB) png_handle_sRGB(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_iCCP_SUPPORTED - else if (!png_memcmp(chunk_name, png_iCCP, 4)) + else if (chunk_name == png_iCCP) png_handle_iCCP(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sPLT_SUPPORTED - else if (!png_memcmp(chunk_name, png_sPLT, 4)) + else if (chunk_name == png_sPLT) png_handle_sPLT(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tEXt_SUPPORTED - else if (!png_memcmp(chunk_name, png_tEXt, 4)) + else if (chunk_name == png_tEXt) png_handle_tEXt(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tIME_SUPPORTED - else if (!png_memcmp(chunk_name, png_tIME, 4)) + else if (chunk_name == png_tIME) png_handle_tIME(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tRNS_SUPPORTED - else if (!png_memcmp(chunk_name, png_tRNS, 4)) + else if (chunk_name == png_tRNS) png_handle_tRNS(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_zTXt_SUPPORTED - else if (!png_memcmp(chunk_name, png_zTXt, 4)) + else if (chunk_name == png_zTXt) png_handle_zTXt(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_iTXt_SUPPORTED - else if (!png_memcmp(chunk_name, png_iTXt, 4)) + else if (chunk_name == png_iTXt) png_handle_iTXt(png_ptr, info_ptr, length); #endif @@ -1161,7 +1020,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, jmp_buf tmp_jmp; #endif png_error_ptr error_fn; +#ifdef PNG_WARNINGS_SUPPORTED png_error_ptr warning_fn; +#endif png_voidp error_ptr; #ifdef PNG_USER_MEM_SUPPORTED png_free_ptr free_fn; @@ -1175,9 +1036,13 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, if (end_info_ptr != NULL) png_info_destroy(png_ptr, end_info_ptr); +#ifdef PNG_READ_GAMMA_SUPPORTED + png_destroy_gamma_table(png_ptr); +#endif + png_free(png_ptr, png_ptr->zbuf); png_free(png_ptr, png_ptr->big_row_buf); - png_free(png_ptr, png_ptr->prev_row); + png_free(png_ptr, png_ptr->big_prev_row); png_free(png_ptr, png_ptr->chunkdata); #ifdef PNG_READ_QUANTIZE_SUPPORTED @@ -1185,15 +1050,6 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_free(png_ptr, png_ptr->quantize_index); #endif -#ifdef PNG_READ_GAMMA_SUPPORTED - png_free(png_ptr, png_ptr->gamma_table); -#endif - -#ifdef PNG_READ_BACKGROUND_SUPPORTED - png_free(png_ptr, png_ptr->gamma_from_1); - png_free(png_ptr, png_ptr->gamma_to_1); -#endif - if (png_ptr->free_me & PNG_FREE_PLTE) png_zfree(png_ptr, png_ptr->palette); png_ptr->free_me &= ~PNG_FREE_PLTE; @@ -1211,67 +1067,23 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_ptr->free_me &= ~PNG_FREE_HIST; #endif -#ifdef PNG_READ_GAMMA_SUPPORTED - if (png_ptr->gamma_16_table != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_table[i]); - } - png_free(png_ptr, png_ptr->gamma_16_table); - } - -#ifdef PNG_READ_BACKGROUND_SUPPORTED - if (png_ptr->gamma_16_from_1 != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_from_1[i]); - } - png_free(png_ptr, png_ptr->gamma_16_from_1); - } - if (png_ptr->gamma_16_to_1 != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_to_1[i]); - } - png_free(png_ptr, png_ptr->gamma_16_to_1); - } -#endif -#endif - -#ifdef PNG_TIME_RFC1123_SUPPORTED - png_free(png_ptr, png_ptr->time_buffer); -#endif - inflateEnd(&png_ptr->zstream); #ifdef PNG_PROGRESSIVE_READ_SUPPORTED png_free(png_ptr, png_ptr->save_buffer); #endif -#ifdef PNG_PROGRESSIVE_READ_SUPPORTED -#ifdef PNG_TEXT_SUPPORTED - png_free(png_ptr, png_ptr->current_text); -#endif /* PNG_TEXT_SUPPORTED */ -#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ - /* Save the important info out of the png_struct, in case it is * being used again. */ #ifdef PNG_SETJMP_SUPPORTED - png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf)); + png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf)); #endif error_fn = png_ptr->error_fn; +#ifdef PNG_WARNINGS_SUPPORTED warning_fn = png_ptr->warning_fn; +#endif error_ptr = png_ptr->error_ptr; #ifdef PNG_USER_MEM_SUPPORTED free_fn = png_ptr->free_fn; @@ -1280,14 +1092,16 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_memset(png_ptr, 0, png_sizeof(png_struct)); png_ptr->error_fn = error_fn; +#ifdef PNG_WARNINGS_SUPPORTED png_ptr->warning_fn = warning_fn; +#endif png_ptr->error_ptr = error_ptr; #ifdef PNG_USER_MEM_SUPPORTED png_ptr->free_fn = free_fn; #endif #ifdef PNG_SETJMP_SUPPORTED - png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf)); + png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf)); #endif } @@ -1311,7 +1125,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr, { int row; - if (png_ptr == NULL) + if (png_ptr == NULL || info_ptr == NULL) return; /* png_read_info() gives us all of the information from the @@ -1323,8 +1137,22 @@ png_read_png(png_structp png_ptr, png_infop info_ptr, /* -------------- image transformations start here ------------------- */ -#ifdef PNG_READ_16_TO_8_SUPPORTED - /* Tell libpng to strip 16 bit/color files down to 8 bits per color. +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + /* Tell libpng to strip 16-bit/color files down to 8 bits per color. + */ + if (transforms & PNG_TRANSFORM_SCALE_16) + { + /* Added at libpng-1.5.4. "strip_16" produces the same result that it + * did in earlier versions, while "scale_16" is now more accurate. + */ + png_set_scale_16(png_ptr); + } +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + /* If both SCALE and STRIP are required pngrtran will effectively cancel the + * latter by doing SCALE first. This is ok and allows apps not to check for + * which is supported to get the right answer. */ if (transforms & PNG_TRANSFORM_STRIP_16) png_set_strip_16(png_ptr); @@ -1405,7 +1233,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr, #endif #ifdef PNG_READ_SWAP_SUPPORTED - /* Swap bytes of 16 bit files to least significant byte first */ + /* Swap bytes of 16-bit files to least significant byte first */ if (transforms & PNG_TRANSFORM_SWAP_ENDIAN) png_set_swap(png_ptr); #endif @@ -1424,8 +1252,19 @@ png_read_png(png_structp png_ptr, png_infop info_ptr, png_set_gray_to_rgb(png_ptr); #endif +/* Added at libpng-1.5.4 */ +#ifdef PNG_READ_EXPAND_16_SUPPORTED + if (transforms & PNG_TRANSFORM_EXPAND_16) + png_set_expand_16(png_ptr); +#endif + /* We don't handle adding filler bytes */ + /* We use png_read_image and rely on that for interlace handling, but we also + * call png_read_update_info therefore must turn on interlace handling now: + */ + (void)png_set_interlace_handling(png_ptr); + /* Optional call to gamma correct and add the background to the palette * and update info structure. REQUIRED if you are expecting libpng to * update the palette for you (i.e., you selected such a transform above). diff --git a/png/pngrtran.c b/png/pngrtran.c index e6e0c46b4..556185286 100644 --- a/png/pngrtran.c +++ b/png/pngrtran.c @@ -1,8 +1,8 @@ /* pngrtran.c - transforms the data in a row for PNG readers * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -106,12 +106,18 @@ png_set_background_fixed(png_structp png_ptr, return; } - png_ptr->transformations |= PNG_BACKGROUND; + png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + png_memcpy(&(png_ptr->background), background_color, png_sizeof(png_color_16)); png_ptr->background_gamma = background_gamma; png_ptr->background_gamma_type = (png_byte)(background_gamma_code); - png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); + if (need_expand) + png_ptr->transformations |= PNG_BACKGROUND_EXPAND; + else + png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; } # ifdef PNG_FLOATING_POINT_SUPPORTED @@ -126,8 +132,25 @@ png_set_background(png_structp png_ptr, # endif /* FLOATING_POINT */ #endif /* READ_BACKGROUND */ -#ifdef PNG_READ_16_TO_8_SUPPORTED -/* Strip 16 bit depth files to 8 bit depth */ +/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the + * one that pngrtran does first (scale) happens. This is necessary to allow the + * TRANSFORM and API behavior to be somewhat consistent, and it's simpler. + */ +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +void PNGAPI +png_set_scale_16(png_structp png_ptr) +{ + png_debug(1, "in png_set_scale_16"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_SCALE_16_TO_8; +} +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +/* Chop 16-bit depth files to 8-bit depth */ void PNGAPI png_set_strip_16(png_structp png_ptr) { @@ -149,12 +172,194 @@ png_set_strip_alpha(png_structp png_ptr) if (png_ptr == NULL) return; - png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; + png_ptr->transformations |= PNG_STRIP_ALPHA; } #endif +#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED) +static png_fixed_point +translate_gamma_flags(png_structp png_ptr, png_fixed_point output_gamma, + int is_screen) +{ + /* Check for flag values. The main reason for having the old Mac value as a + * flag is that it is pretty near impossible to work out what the correct + * value is from Apple documentation - a working Mac system is needed to + * discover the value! + */ + if (output_gamma == PNG_DEFAULT_sRGB || + output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB) + { + /* If there is no sRGB support this just sets the gamma to the standard + * sRGB value. (This is a side effect of using this function!) + */ +# ifdef PNG_READ_sRGB_SUPPORTED + png_ptr->flags |= PNG_FLAG_ASSUME_sRGB; +# endif + if (is_screen) + output_gamma = PNG_GAMMA_sRGB; + else + output_gamma = PNG_GAMMA_sRGB_INVERSE; + } + + else if (output_gamma == PNG_GAMMA_MAC_18 || + output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18) + { + if (is_screen) + output_gamma = PNG_GAMMA_MAC_OLD; + else + output_gamma = PNG_GAMMA_MAC_INVERSE; + } + + return output_gamma; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +static png_fixed_point +convert_gamma_value(png_structp png_ptr, double output_gamma) +{ + /* The following silently ignores cases where fixed point (times 100,000) + * gamma values are passed to the floating point API. This is safe and it + * means the fixed point constants work just fine with the floating point + * API. The alternative would just lead to undetected errors and spurious + * bug reports. Negative values fail inside the _fixed API unless they + * correspond to the flag values. + */ + if (output_gamma > 0 && output_gamma < 128) + output_gamma *= PNG_FP_1; + + /* This preserves -1 and -2 exactly: */ + output_gamma = floor(output_gamma + .5); + + if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN) + png_fixed_error(png_ptr, "gamma value"); + + return (png_fixed_point)output_gamma; +} +# endif +#endif /* READ_ALPHA_MODE || READ_GAMMA */ + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +void PNGFAPI +png_set_alpha_mode_fixed(png_structp png_ptr, int mode, + png_fixed_point output_gamma) +{ + int compose = 0; + png_fixed_point file_gamma; + + png_debug(1, "in png_set_alpha_mode"); + + if (png_ptr == NULL) + return; + + output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/); + + /* Validate the value to ensure it is in a reasonable range. The value + * is expected to be 1 or greater, but this range test allows for some + * viewing correction values. The intent is to weed out users of this API + * who use the inverse of the gamma value accidentally! Since some of these + * values are reasonable this may have to be changed. + */ + if (output_gamma < 70000 || output_gamma > 300000) + png_error(png_ptr, "output gamma out of expected range"); + + /* The default file gamma is the inverse of the output gamma; the output + * gamma may be changed below so get the file value first: + */ + file_gamma = png_reciprocal(output_gamma); + + /* There are really 8 possibilities here, composed of any combination + * of: + * + * premultiply the color channels + * do not encode non-opaque pixels + * encode the alpha as well as the color channels + * + * The differences disappear if the input/output ('screen') gamma is 1.0, + * because then the encoding is a no-op and there is only the choice of + * premultiplying the color channels or not. + * + * png_set_alpha_mode and png_set_background interact because both use + * png_compose to do the work. Calling both is only useful when + * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along + * with a default gamma value. Otherwise PNG_COMPOSE must not be set. + */ + switch (mode) + { + case PNG_ALPHA_PNG: /* default: png standard */ + /* No compose, but it may be set by png_set_background! */ + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + break; + + case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */ + compose = 1; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + /* The output is linear: */ + output_gamma = PNG_FP_1; + break; + + case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */ + compose = 1; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA; + /* output_gamma records the encoding of opaque pixels! */ + break; + + case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */ + compose = 1; + png_ptr->transformations |= PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + break; + + default: + png_error(png_ptr, "invalid alpha mode"); + } + + /* Only set the default gamma if the file gamma has not been set (this has + * the side effect that the gamma in a second call to png_set_alpha_mode will + * be ignored.) + */ + if (png_ptr->gamma == 0) + png_ptr->gamma = file_gamma; + + /* But always set the output gamma: */ + png_ptr->screen_gamma = output_gamma; + + /* Finally, if pre-multiplying, set the background fields to achieve the + * desired result. + */ + if (compose) + { + /* And obtain alpha pre-multiplication by composing on black: */ + png_memset(&png_ptr->background, 0, sizeof png_ptr->background); + png_ptr->background_gamma = png_ptr->gamma; /* just in case */ + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE; + png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; + + if (png_ptr->transformations & PNG_COMPOSE) + png_error(png_ptr, + "conflicting calls to set alpha mode and background"); + + png_ptr->transformations |= PNG_COMPOSE; + } + + /* New API, make sure apps call the correct initializers: */ + png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_alpha_mode(png_structp png_ptr, int mode, double output_gamma) +{ + png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr, + output_gamma)); +} +# endif +#endif + #ifdef PNG_READ_QUANTIZE_SUPPORTED -/* Dither file to 8 bit. Supply a palette, the current number +/* Dither file to 8-bit. Supply a palette, the current number * of elements in the palette, the maximum number of elements * allowed, and a histogram if possible. If the current number * of colors is greater then the maximum number, the palette will be @@ -560,30 +765,6 @@ png_set_quantize(png_structp png_ptr, png_colorp palette, #endif /* PNG_READ_QUANTIZE_SUPPORTED */ #ifdef PNG_READ_GAMMA_SUPPORTED -/* Transform the image from the file_gamma to the screen_gamma. We - * only do transformations on images where the file_gamma and screen_gamma - * are not close reciprocals, otherwise it slows things down slightly, and - * also needlessly introduces small errors. - * - * We will turn off gamma transformation later if no semitransparent entries - * are present in the tRNS array for palette images. We can't do it here - * because we don't necessarily have the tRNS chunk yet. - */ -static int /* PRIVATE */ -png_gamma_threshold(png_fixed_point scrn_gamma, png_fixed_point file_gamma) -{ - /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma - * correction as a difference of the overall transform from 1.0 - * - * We want to compare the threshold with s*f - 1, if we get - * overflow here it is because of wacky gamma values so we - * turn on processing anyway. - */ - png_fixed_point gtest; - return !png_muldiv(>est, scrn_gamma, file_gamma, PNG_FP_1) || - png_gamma_significant(gtest); -} - void PNGFAPI png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma, png_fixed_point file_gamma) @@ -593,10 +774,32 @@ png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma, if (png_ptr == NULL) return; - if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) || - (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) || - png_gamma_threshold(scrn_gamma, file_gamma)) - png_ptr->transformations |= PNG_GAMMA; + /* New in libpng-1.5.4 - reserve particular negative values as flags. */ + scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/); + file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/); + +#if PNG_LIBPNG_VER >= 10600 + /* Checking the gamma values for being >0 was added in 1.5.4 along with the + * premultiplied alpha support; this actually hides an undocumented feature + * of the previous implementation which allowed gamma processing to be + * disabled in background handling. There is no evidence (so far) that this + * was being used; however, png_set_background itself accepted and must still + * accept '0' for the gamma value it takes, because it isn't always used. + * + * Since this is an API change (albeit a very minor one that removes an + * undocumented API feature) it will not be made until libpng-1.6.0. + */ + if (file_gamma <= 0) + png_error(png_ptr, "invalid file gamma in png_set_gamma"); + + if (scrn_gamma <= 0) + png_error(png_ptr, "invalid screen gamma in png_set_gamma"); +#endif + + /* Set the gamma values unconditionally - this overrides the value in the PNG + * file if a gAMA chunk was present. png_set_alpha_mode provides a + * different, easier, way to default the file gamma. + */ png_ptr->gamma = file_gamma; png_ptr->screen_gamma = scrn_gamma; } @@ -605,9 +808,8 @@ png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma, void PNGAPI png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) { - png_set_gamma_fixed(png_ptr, - png_fixed(png_ptr, scrn_gamma, "png_set_gamma screen gamma"), - png_fixed(png_ptr, file_gamma, "png_set_gamma file gamma")); + png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma), + convert_gamma_value(png_ptr, file_gamma)); } # endif /* FLOATING_POINT_SUPPORTED */ #endif /* READ_GAMMA */ @@ -686,6 +888,26 @@ png_set_tRNS_to_alpha(png_structp png_ptr) } #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise + * it may not work correctly.) + */ +void PNGAPI +png_set_expand_16(png_structp png_ptr) +{ + png_debug(1, "in png_set_expand_16"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS); + png_ptr->flags &= ~PNG_FLAG_ROW_INIT; + + /* New API, make sure apps call the correct initializers: */ + png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; +} +#endif + #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED void PNGAPI png_set_gray_to_rgb(png_structp png_ptr) @@ -714,15 +936,15 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, switch(error_action) { - case 1: + case PNG_ERROR_ACTION_NONE: png_ptr->transformations |= PNG_RGB_TO_GRAY; break; - case 2: + case PNG_ERROR_ACTION_WARN: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; break; - case 3: + case PNG_ERROR_ACTION_ERROR: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; break; @@ -742,30 +964,43 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, } #endif { - png_uint_16 red_int, green_int; - if (red < 0 || green < 0) + if (red >= 0 && green >= 0 && red + green <= PNG_FP_1) { - red_int = 6968; /* .212671 * 32768 + .5 */ - green_int = 23434; /* .715160 * 32768 + .5 */ - } + png_uint_16 red_int, green_int; - else if (red + green < 100000L) - { - red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); - green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); + /* NOTE: this calculation does not round, but this behavior is retained + * for consistency, the inaccuracy is very small. The code here always + * overwrites the coefficients, regardless of whether they have been + * defaulted or set already. + */ + red_int = (png_uint_16)(((png_uint_32)red*32768)/100000); + green_int = (png_uint_16)(((png_uint_32)green*32768)/100000); + + png_ptr->rgb_to_gray_red_coeff = red_int; + png_ptr->rgb_to_gray_green_coeff = green_int; + png_ptr->rgb_to_gray_coefficients_set = 1; } else { - png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); - red_int = 6968; - green_int = 23434; + if (red >= 0 && green >= 0) + png_warning(png_ptr, + "ignoring out of range rgb_to_gray coefficients"); + + /* Use the defaults, from the cHRM chunk if set, else the historical + * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See + * png_do_rgb_to_gray for more discussion of the values. In this case + * the coefficients are not marked as 'set' and are not overwritten if + * something has already provided a default. + */ + if (png_ptr->rgb_to_gray_red_coeff == 0 && + png_ptr->rgb_to_gray_green_coeff == 0) + { + png_ptr->rgb_to_gray_red_coeff = 6968; + png_ptr->rgb_to_gray_green_coeff = 23434; + /* png_ptr->rgb_to_gray_blue_coeff = 2366; */ + } } - - png_ptr->rgb_to_gray_red_coeff = red_int; - png_ptr->rgb_to_gray_green_coeff = green_int; - png_ptr->rgb_to_gray_blue_coeff = - (png_uint_16)(32768 - red_int - green_int); } } @@ -807,167 +1042,513 @@ png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr } #endif +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +#ifdef PNG_READ_GAMMA_SUPPORTED +/* In the case of gamma transformations only do transformations on images where + * the [file] gamma and screen_gamma are not close reciprocals, otherwise it + * slows things down slightly, and also needlessly introduces small errors. + */ +static int /* PRIVATE */ +png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma) +{ + /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma + * correction as a difference of the overall transform from 1.0 + * + * We want to compare the threshold with s*f - 1, if we get + * overflow here it is because of wacky gamma values so we + * turn on processing anyway. + */ + png_fixed_point gtest; + return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) || + png_gamma_significant(gtest); +} +#endif + /* Initialize everything needed for the read. This includes modifying * the palette. */ -void /* PRIVATE */ -png_init_read_transformations(png_structp png_ptr) + +/*For the moment 'png_init_palette_transformations' and + * 'png_init_rgb_transformations' only do some flag canceling optimizations. + * The intent is that these two routines should have palette or rgb operations + * extracted from 'png_init_read_transformations'. + */ +static void /* PRIVATE */ +png_init_palette_transformations(png_structp png_ptr) { - png_debug(1, "in png_init_read_transformations"); + /* Called to handle the (input) palette case. In png_do_read_transformations + * the first step is to expand the palette if requested, so this code must + * take care to only make changes that are invariant with respect to the + * palette expansion, or only do them if there is no expansion. + * + * STRIP_ALPHA has already been handled in the caller (by setting num_trans + * to 0.) + */ + int input_has_alpha = 0; + int input_has_transparency = 0; - { -#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ - defined(PNG_READ_SHIFT_SUPPORTED) || \ - defined(PNG_READ_GAMMA_SUPPORTED) - int color_type = png_ptr->color_type; -#endif + if (png_ptr->num_trans > 0) + { + int i; + + /* Ignore if all the entries are opaque (unlikely!) */ + for (i=0; i<png_ptr->num_trans; ++i) + if (png_ptr->trans_alpha[i] == 255) + continue; + else if (png_ptr->trans_alpha[i] == 0) + input_has_transparency = 1; + else + input_has_alpha = 1; + } + + /* If no alpha we can optimize. */ + if (!input_has_alpha) + { + /* Any alpha means background and associative alpha processing is + * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA + * and ENCODE_ALPHA are irrelevant. + */ + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + + if (!input_has_transparency) + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); + } #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + /* png_set_background handling - deals with the complexity of whether the + * background color is in the file format or the screen format in the case + * where an 'expand' will happen. + */ -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED - /* Detect gray background and attempt to enable optimization - * for gray --> RGB case - * - * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or - * RGB_ALPHA (in which case need_expand is superfluous anyway), the - * background color might actually be gray yet not be flagged as such. - * This is not a problem for the current code, which uses - * PNG_BACKGROUND_IS_GRAY only to decide when to do the - * png_do_gray_to_rgb() transformation. + /* The following code cannot be entered in the alpha pre-multiplication case + * because PNG_BACKGROUND_EXPAND is cancelled below. */ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && - !(color_type & PNG_COLOR_MASK_COLOR)) + (png_ptr->transformations & PNG_EXPAND)) { - png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; - } + { + png_ptr->background.red = + png_ptr->palette[png_ptr->background.index].red; + png_ptr->background.green = + png_ptr->palette[png_ptr->background.index].green; + png_ptr->background.blue = + png_ptr->palette[png_ptr->background.index].blue; + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + if (png_ptr->transformations & PNG_INVERT_ALPHA) + { + if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) + { + /* Invert the alpha channel (in tRNS) unless the pixels are + * going to be expanded, in which case leave it for later + */ + int i, istop = png_ptr->num_trans; + + for (i=0; i<istop; i++) + png_ptr->trans_alpha[i] = (png_byte)(255 - + png_ptr->trans_alpha[i]); + } + } +#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */ + } + } /* background expand and (therefore) no alpha association. */ +#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ +} - else if ((png_ptr->transformations & PNG_BACKGROUND) && - !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && - (png_ptr->transformations & PNG_GRAY_TO_RGB) && - png_ptr->background.red == png_ptr->background.green && - png_ptr->background.red == png_ptr->background.blue) +static void /* PRIVATE */ +png_init_rgb_transformations(png_structp png_ptr) +{ + /* Added to libpng-1.5.4: check the color type to determine whether there + * is any alpha or transparency in the image and simply cancel the + * background and alpha mode stuff if there isn't. + */ + int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0; + int input_has_transparency = png_ptr->num_trans > 0; + + /* If no alpha we can optimize. */ + if (!input_has_alpha) { - png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; - png_ptr->background.gray = png_ptr->background.red; + /* Any alpha means background and associative alpha processing is + * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA + * and ENCODE_ALPHA are irrelevant. + */ +# ifdef PNG_READ_ALPHA_MODE_SUPPORTED + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; +# endif + + if (!input_has_transparency) + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); } -#endif +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + /* png_set_background handling - deals with the complexity of whether the + * background color is in the file format or the screen format in the case + * where an 'expand' will happen. + */ + + /* The following code cannot be entered in the alpha pre-multiplication case + * because PNG_BACKGROUND_EXPAND is cancelled below. + */ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && - (png_ptr->transformations & PNG_EXPAND)) + (png_ptr->transformations & PNG_EXPAND) && + !(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) + /* i.e., GRAY or GRAY_ALPHA */ { - if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */ { /* Expand background and tRNS chunks */ + int gray = png_ptr->background.gray; + int trans_gray = png_ptr->trans_color.gray; + switch (png_ptr->bit_depth) { case 1: - png_ptr->background.gray *= (png_uint_16)0xff; - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) - { - png_ptr->trans_color.gray *= (png_uint_16)0xff; - png_ptr->trans_color.red = png_ptr->trans_color.green - = png_ptr->trans_color.blue = png_ptr->trans_color.gray; - } + gray *= 0xff; + trans_gray *= 0xff; break; case 2: - png_ptr->background.gray *= (png_uint_16)0x55; - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) - { - png_ptr->trans_color.gray *= (png_uint_16)0x55; - png_ptr->trans_color.red = png_ptr->trans_color.green - = png_ptr->trans_color.blue = png_ptr->trans_color.gray; - } + gray *= 0x55; + trans_gray *= 0x55; break; case 4: - png_ptr->background.gray *= (png_uint_16)0x11; - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) - { - png_ptr->trans_color.gray *= (png_uint_16)0x11; - png_ptr->trans_color.red = png_ptr->trans_color.green - = png_ptr->trans_color.blue = png_ptr->trans_color.gray; - } + gray *= 0x11; + trans_gray *= 0x11; break; default: case 8: + /* Already 8 bits, fall through */ case 16: - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; + /* Already a full 16 bits */ break; } + + png_ptr->background.red = png_ptr->background.green = + png_ptr->background.blue = (png_uint_16)gray; + + if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) + { + png_ptr->trans_color.red = png_ptr->trans_color.green = + png_ptr->trans_color.blue = (png_uint_16)trans_gray; + } } - else if (color_type == PNG_COLOR_TYPE_PALETTE) - { - png_ptr->background.red = - png_ptr->palette[png_ptr->background.index].red; - png_ptr->background.green = - png_ptr->palette[png_ptr->background.index].green; - png_ptr->background.blue = - png_ptr->palette[png_ptr->background.index].blue; + } /* background expand and (therefore) no alpha association. */ +#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ +} -#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED - if (png_ptr->transformations & PNG_INVERT_ALPHA) - { -#ifdef PNG_READ_EXPAND_SUPPORTED - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) -#endif - { - /* Invert the alpha channel (in tRNS) unless the pixels are - * going to be expanded, in which case leave it for later - */ - int i, istop; - istop=(int)png_ptr->num_trans; - for (i=0; i<istop; i++) - png_ptr->trans_alpha[i] = (png_byte)(255 - - png_ptr->trans_alpha[i]); - } - } -#endif +void /* PRIVATE */ +png_init_read_transformations(png_structp png_ptr) +{ + png_debug(1, "in png_init_read_transformations"); + + /* This internal function is called from png_read_start_row in pngrutil.c + * and it is called before the 'rowbytes' calculation is done, so the code + * in here can change or update the transformations flags. + * + * First do updates that do not depend on the details of the PNG image data + * being processed. + */ +#ifdef PNG_READ_GAMMA_SUPPORTED + /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds + * png_set_alpha_mode and this is another source for a default file gamma so + * the test needs to be performed later - here. In addition prior to 1.5.4 + * the tests were repeated for the PALETTE color type here - this is no + * longer necessary (and doesn't seem to have been necessary before.) + */ + { + /* The following temporary indicates if overall gamma correction is + * required. + */ + int gamma_correction = 0; + + if (png_ptr->gamma != 0) /* has been set */ + { + if (png_ptr->screen_gamma != 0) /* screen set too */ + gamma_correction = png_gamma_threshold(png_ptr->gamma, + png_ptr->screen_gamma); + + else + /* Assume the output matches the input; a long time default behavior + * of libpng, although the standard has nothing to say about this. + */ + png_ptr->screen_gamma = png_reciprocal(png_ptr->gamma); } + + else if (png_ptr->screen_gamma != 0) + /* The converse - assume the file matches the screen, note that this + * perhaps undesireable default can (from 1.5.4) be changed by calling + * png_set_alpha_mode (even if the alpha handling mode isn't required + * or isn't changed from the default.) + */ + png_ptr->gamma = png_reciprocal(png_ptr->screen_gamma); + + else /* neither are set */ + /* Just in case the following prevents any processing - file and screen + * are both assumed to be linear and there is no way to introduce a + * third gamma value other than png_set_background with 'UNIQUE', and, + * prior to 1.5.4 + */ + png_ptr->screen_gamma = png_ptr->gamma = PNG_FP_1; + + /* Now turn the gamma transformation on or off as appropriate. Notice + * that PNG_GAMMA just refers to the file->screen correction. Alpha + * composition may independently cause gamma correction because it needs + * linear data (e.g. if the file has a gAMA chunk but the screen gamma + * hasn't been specified.) In any case this flag may get turned off in + * the code immediately below if the transform can be handled outside the + * row loop. + */ + if (gamma_correction) + png_ptr->transformations |= PNG_GAMMA; + + else + png_ptr->transformations &= ~PNG_GAMMA; } #endif -#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) - png_ptr->background_1 = png_ptr->background; + /* Certain transformations have the effect of preventing other + * transformations that happen afterward in png_do_read_transformations, + * resolve the interdependencies here. From the code of + * png_do_read_transformations the order is: + * + * 1) PNG_EXPAND (including PNG_EXPAND_tRNS) + * 2) PNG_STRIP_ALPHA (if no compose) + * 3) PNG_RGB_TO_GRAY + * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY + * 5) PNG_COMPOSE + * 6) PNG_GAMMA + * 7) PNG_STRIP_ALPHA (if compose) + * 8) PNG_ENCODE_ALPHA + * 9) PNG_SCALE_16_TO_8 + * 10) PNG_16_TO_8 + * 11) PNG_QUANTIZE (converts to palette) + * 12) PNG_EXPAND_16 + * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY + * 14) PNG_INVERT_MONO + * 15) PNG_SHIFT + * 16) PNG_PACK + * 17) PNG_BGR + * 18) PNG_PACKSWAP + * 19) PNG_FILLER (includes PNG_ADD_ALPHA) + * 20) PNG_INVERT_ALPHA + * 21) PNG_SWAP_ALPHA + * 22) PNG_SWAP_BYTES + * 23) PNG_USER_TRANSFORM [must be last] + */ +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) && + !(png_ptr->transformations & PNG_COMPOSE)) + { + /* Stripping the alpha channel happens immediately after the 'expand' + * transformations, before all other transformation, so it cancels out + * the alpha handling. It has the side effect negating the effect of + * PNG_EXPAND_tRNS too: + */ + png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA | + PNG_EXPAND_tRNS); + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + + /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen + * so transparency information would remain just so long as it wasn't + * expanded. This produces unexpected API changes if the set of things + * that do PNG_EXPAND_tRNS changes (perfectly possible given the + * documentation - which says ask for what you want, accept what you + * get.) This makes the behavior consistent from 1.5.4: + */ + png_ptr->num_trans = 0; + } +#endif /* STRIP_ALPHA supported, no COMPOSE */ + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA + * settings will have no effect. + */ + if (!png_gamma_significant(png_ptr->screen_gamma)) + { + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + } #endif -#ifdef PNG_READ_GAMMA_SUPPORTED - if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0) - && png_gamma_threshold(png_ptr->screen_gamma, png_ptr->gamma)) +#if defined(PNG_READ_EXPAND_SUPPORTED) && \ + defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) + /* Detect gray background and attempt to enable optimization for + * gray --> RGB case. + * + * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or + * RGB_ALPHA (in which case need_expand is superfluous anyway), the + * background color might actually be gray yet not be flagged as such. + * This is not a problem for the current code, which uses + * PNG_BACKGROUND_IS_GRAY only to decide when to do the + * png_do_gray_to_rgb() transformation. + * + * TODO: this code needs to be revised to avoid the complexity and + * interdependencies. The color type of the background should be recorded in + * png_set_background, along with the bit depth, then the code has a record + * of exactly what color space the background is currently in. + */ + if (png_ptr->transformations & PNG_BACKGROUND_EXPAND) + { + /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if + * the file was grayscale the background value is gray. + */ + if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; + } + + else if (png_ptr->transformations & PNG_COMPOSE) { - int i, k; - k=0; - for (i=0; i<png_ptr->num_trans; i++) + /* PNG_COMPOSE: png_set_background was called with need_expand false, + * so the color is in the color space of the output or png_set_alpha_mode + * was called and the color is black. Ignore RGB_TO_GRAY because that + * happens before GRAY_TO_RGB. + */ + if (png_ptr->transformations & PNG_GRAY_TO_RGB) { - if (png_ptr->trans_alpha[i] != 0 && png_ptr->trans_alpha[i] != 0xff) - k=1; /* Partial transparency is present */ + if (png_ptr->background.red == png_ptr->background.green && + png_ptr->background.red == png_ptr->background.blue) + { + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; + png_ptr->background.gray = png_ptr->background.red; + } } - if (k == 0) - png_ptr->transformations &= ~PNG_GAMMA; } +#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED (etc) */ + + /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations + * can be performed directly on the palette, and some (such as rgb to gray) + * can be optimized inside the palette. This is particularly true of the + * composite (background and alpha) stuff, which can be pretty much all done + * in the palette even if the result is expanded to RGB or gray afterward. + * + * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and + * earlier and the palette stuff is actually handled on the first row. This + * leads to the reported bug that the palette returned by png_get_PLTE is not + * updated. + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_init_palette_transformations(png_ptr); - if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) && - png_ptr->gamma != 0) + else + png_init_rgb_transformations(png_ptr); + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + defined(PNG_READ_EXPAND_16_SUPPORTED) + if ((png_ptr->transformations & PNG_EXPAND_16) && + (png_ptr->transformations & PNG_COMPOSE) && + !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && + png_ptr->bit_depth != 16) + { + /* TODO: fix this. Because the expand_16 operation is after the compose + * handling the background color must be 8, not 16, bits deep, but the + * application will supply a 16-bit value so reduce it here. + * + * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at + * present, so that case is ok (until do_expand_16 is moved.) + * + * NOTE: this discards the low 16 bits of the user supplied background + * color, but until expand_16 works properly there is no choice! + */ +# define CHOP(x) (x)=((png_uint_16)(((png_uint_32)(x)*255+32895) >> 16)) + CHOP(png_ptr->background.red); + CHOP(png_ptr->background.green); + CHOP(png_ptr->background.blue); + CHOP(png_ptr->background.gray); +# undef CHOP + } +#endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */ + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \ + defined(PNG_READ_STRIP_16_TO_8_SUPPORTED)) + if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) && + (png_ptr->transformations & PNG_COMPOSE) && + !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && + png_ptr->bit_depth == 16) + { + /* On the other hand, if a 16-bit file is to be reduced to 8-bits per + * component this will also happen after PNG_COMPOSE and so the background + * color must be pre-expanded here. + * + * TODO: fix this too. + */ + png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257); + png_ptr->background.green = + (png_uint_16)(png_ptr->background.green * 257); + png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257); + png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257); + } +#endif + + /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the + * background support (see the comments in scripts/pnglibconf.dfa), this + * allows pre-multiplication of the alpha channel to be implemented as + * compositing on black. This is probably sub-optimal and has been done in + * 1.5.4 betas simply to enable external critique and testing (i.e. to + * implement the new API quickly, without lots of internal changes.) + */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +# ifdef PNG_READ_BACKGROUND_SUPPORTED + /* Includes ALPHA_MODE */ + png_ptr->background_1 = png_ptr->background; +# endif + + /* This needs to change - in the palette image case a whole set of tables are + * built when it would be quicker to just calculate the correct value for + * each palette entry directly. Also, the test is too tricky - why check + * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that + * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the + * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction + * the gamma tables will not be built even if composition is required on a + * gamma encoded value. + * + * In 1.5.4 this is addressed below by an additional check on the individual + * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the + * tables. + */ + if ((png_ptr->transformations & PNG_GAMMA) + || ((png_ptr->transformations & PNG_RGB_TO_GRAY) + && (png_gamma_significant(png_ptr->gamma) || + png_gamma_significant(png_ptr->screen_gamma))) + || ((png_ptr->transformations & PNG_COMPOSE) + && (png_gamma_significant(png_ptr->gamma) + || png_gamma_significant(png_ptr->screen_gamma) +# ifdef PNG_READ_BACKGROUND_SUPPORTED + || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE + && png_gamma_significant(png_ptr->background_gamma)) +# endif + )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) + && png_gamma_significant(png_ptr->screen_gamma)) + ) { png_build_gamma_table(png_ptr, png_ptr->bit_depth); #ifdef PNG_READ_BACKGROUND_SUPPORTED - if (png_ptr->transformations & PNG_BACKGROUND) + if (png_ptr->transformations & PNG_COMPOSE) { - if (color_type == PNG_COLOR_TYPE_PALETTE) + /* Issue a warning about this combination: because RGB_TO_GRAY is + * optimized to do the gamma transform if present yet do_background has + * to do the same thing if both options are set a + * double-gamma-correction happens. This is true in all versions of + * libpng to date. + */ + if (png_ptr->transformations & PNG_RGB_TO_GRAY) + png_warning(png_ptr, + "libpng does not support gamma+background+rgb_to_gray"); + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - /* Could skip if no transparency */ + /* We don't get to here unless there is a tRNS chunk with non-opaque + * entries - see the checking code at the start of this function. + */ png_color back, back_1; png_colorp palette = png_ptr->palette; int num_palette = png_ptr->num_palette; @@ -1013,26 +1594,39 @@ png_init_read_transformations(png_structp png_ptr) if (png_gamma_significant(gs)) { + back.red = png_gamma_8bit_correct(png_ptr->background.red, + gs); + back.green = png_gamma_8bit_correct(png_ptr->background.green, + gs); + back.blue = png_gamma_8bit_correct(png_ptr->background.blue, + gs); + } + + else + { back.red = (png_byte)png_ptr->background.red; back.green = (png_byte)png_ptr->background.green; back.blue = (png_byte)png_ptr->background.blue; } + if (png_gamma_significant(g)) + { + back_1.red = png_gamma_8bit_correct(png_ptr->background.red, + g); + back_1.green = png_gamma_8bit_correct( + png_ptr->background.green, g); + back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, + g); + } + else { - back.red = png_gamma_8bit_correct(png_ptr->background.red, - gs); - back.green = png_gamma_8bit_correct(png_ptr->background.green, - gs); - back.blue = png_gamma_8bit_correct(png_ptr->background.blue, - gs); + back_1.red = (png_byte)png_ptr->background.red; + back_1.green = (png_byte)png_ptr->background.green; + back_1.blue = (png_byte)png_ptr->background.blue; } - back_1.red = png_gamma_8bit_correct(png_ptr->background.red, g); - back_1.green = png_gamma_8bit_correct(png_ptr->background.green, - g); - back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, - g); } + for (i = 0; i < num_palette; i++) { if (i < (int)png_ptr->num_trans && @@ -1066,22 +1660,22 @@ png_init_read_transformations(png_structp png_ptr) palette[i].blue = png_ptr->gamma_table[palette[i].blue]; } } - /* Prevent the transformations being done again, and make sure - * that the now spurious alpha channel is stripped - the code - * has just reduced background composition and gamma correction - * to a simple alpha channel strip. + + /* Prevent the transformations being done again. + * + * NOTE: this is highly dubious; it removes the transformations in + * place. This seems inconsistent with the general treatment of the + * transformations elsewhere. */ - png_ptr->transformations &= ~PNG_BACKGROUND; - png_ptr->transformations &= ~PNG_GAMMA; - png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; - } + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA); + } /* color_type == PNG_COLOR_TYPE_PALETTE */ /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ - else - /* color_type != PNG_COLOR_TYPE_PALETTE */ + else /* color_type != PNG_COLOR_TYPE_PALETTE */ { - png_fixed_point g = PNG_FP_1; - png_fixed_point gs = PNG_FP_1; + int gs_sig, g_sig; + png_fixed_point g = PNG_FP_1; /* Correction to linear */ + png_fixed_point gs = PNG_FP_1; /* Correction to screen */ switch (png_ptr->background_gamma_type) { @@ -1105,34 +1699,45 @@ png_init_read_transformations(png_structp png_ptr) png_error(png_ptr, "invalid background gamma type"); } - png_ptr->background_1.gray = png_gamma_correct(png_ptr, - png_ptr->background.gray, g); + g_sig = png_gamma_significant(g); + gs_sig = png_gamma_significant(gs); + + if (g_sig) + png_ptr->background_1.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, g); - png_ptr->background.gray = png_gamma_correct(png_ptr, - png_ptr->background.gray, gs); + if (gs_sig) + png_ptr->background.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, gs); if ((png_ptr->background.red != png_ptr->background.green) || (png_ptr->background.red != png_ptr->background.blue) || (png_ptr->background.red != png_ptr->background.gray)) { /* RGB or RGBA with color background */ - png_ptr->background_1.red = png_gamma_correct(png_ptr, - png_ptr->background.red, g); + if (g_sig) + { + png_ptr->background_1.red = png_gamma_correct(png_ptr, + png_ptr->background.red, g); - png_ptr->background_1.green = png_gamma_correct(png_ptr, - png_ptr->background.green, g); + png_ptr->background_1.green = png_gamma_correct(png_ptr, + png_ptr->background.green, g); - png_ptr->background_1.blue = png_gamma_correct(png_ptr, - png_ptr->background.blue, g); + png_ptr->background_1.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, g); + } - png_ptr->background.red = png_gamma_correct(png_ptr, - png_ptr->background.red, gs); + if (gs_sig) + { + png_ptr->background.red = png_gamma_correct(png_ptr, + png_ptr->background.red, gs); - png_ptr->background.green = png_gamma_correct(png_ptr, - png_ptr->background.green, gs); + png_ptr->background.green = png_gamma_correct(png_ptr, + png_ptr->background.green, gs); - png_ptr->background.blue = png_gamma_correct(png_ptr, - png_ptr->background.blue, gs); + png_ptr->background.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, gs); + } } else @@ -1144,17 +1749,30 @@ png_init_read_transformations(png_structp png_ptr) png_ptr->background.red = png_ptr->background.green = png_ptr->background.blue = png_ptr->background.gray; } - } - } + + /* The background is now in screen gamma: */ + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN; + } /* color_type != PNG_COLOR_TYPE_PALETTE */ + }/* png_ptr->transformations & PNG_BACKGROUND */ + else /* Transformation does not include PNG_BACKGROUND */ #endif /* PNG_READ_BACKGROUND_SUPPORTED */ - if (color_type == PNG_COLOR_TYPE_PALETTE) + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* RGB_TO_GRAY needs to have non-gamma-corrected values! */ + && ((png_ptr->transformations & PNG_EXPAND) == 0 || + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) +#endif + ) { png_colorp palette = png_ptr->palette; int num_palette = png_ptr->num_palette; int i; + /*NOTE: there are other transformations that should probably be in here + * too. + */ for (i = 0; i < num_palette; i++) { palette[i].red = png_ptr->gamma_table[palette[i].red]; @@ -1164,16 +1782,17 @@ png_init_read_transformations(png_structp png_ptr) /* Done the gamma correction. */ png_ptr->transformations &= ~PNG_GAMMA; - } + } /* color_type == PALETTE && !PNG_BACKGROUND transformation */ } #ifdef PNG_READ_BACKGROUND_SUPPORTED else #endif #endif /* PNG_READ_GAMMA_SUPPORTED */ + #ifdef PNG_READ_BACKGROUND_SUPPORTED - /* No GAMMA transformation */ - if ((png_ptr->transformations & PNG_BACKGROUND) && - (color_type == PNG_COLOR_TYPE_PALETTE)) + /* No GAMMA transformation (see the hanging else 4 lines above) */ + if ((png_ptr->transformations & PNG_COMPOSE) && + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) { int i; int istop = (int)png_ptr->num_trans; @@ -1205,45 +1824,52 @@ png_init_read_transformations(png_structp png_ptr) } } - /* Handled alpha, still need to strip the channel. */ - png_ptr->transformations &= ~PNG_BACKGROUND; - png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; + png_ptr->transformations &= ~PNG_COMPOSE; } #endif /* PNG_READ_BACKGROUND_SUPPORTED */ #ifdef PNG_READ_SHIFT_SUPPORTED if ((png_ptr->transformations & PNG_SHIFT) && - (color_type == PNG_COLOR_TYPE_PALETTE)) + !(png_ptr->transformations & PNG_EXPAND) && + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) { - png_uint_16 i; - png_uint_16 istop = png_ptr->num_palette; - int sr = 8 - png_ptr->sig_bit.red; - int sg = 8 - png_ptr->sig_bit.green; - int sb = 8 - png_ptr->sig_bit.blue; + int i; + int istop = png_ptr->num_palette; + int shift = 8 - png_ptr->sig_bit.red; - if (sr < 0 || sr > 8) - sr = 0; + png_ptr->transformations &= ~PNG_SHIFT; - if (sg < 0 || sg > 8) - sg = 0; + /* significant bits can be in the range 1 to 7 for a meaninful result, if + * the number of significant bits is 0 then no shift is done (this is an + * error condition which is silently ignored.) + */ + if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].red; - if (sb < 0 || sb > 8) - sb = 0; + component >>= shift; + png_ptr->palette[i].red = (png_byte)component; + } - for (i = 0; i < istop; i++) + shift = 8 - png_ptr->sig_bit.green; + if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) { - png_ptr->palette[i].red >>= sr; - png_ptr->palette[i].green >>= sg; - png_ptr->palette[i].blue >>= sb; + int component = png_ptr->palette[i].green; + + component >>= shift; + png_ptr->palette[i].green = (png_byte)component; + } + + shift = 8 - png_ptr->sig_bit.blue; + if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].blue; + + component >>= shift; + png_ptr->palette[i].blue = (png_byte)component; } } #endif /* PNG_READ_SHIFT_SUPPORTED */ - } -#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \ - && !defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr) - return; -#endif } /* Modify the info structure to reflect the transformations. The @@ -1260,8 +1886,11 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) { if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - if (png_ptr->num_trans && - (png_ptr->transformations & PNG_EXPAND_tRNS)) + /* This check must match what actually happens in + * png_do_expand_palette; if it ever checks the tRNS chunk to see if + * it is all opaque we must do the same (at present it does not.) + */ + if (png_ptr->num_trans > 0) info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; else @@ -1285,45 +1914,72 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) } #endif -#ifdef PNG_READ_BACKGROUND_SUPPORTED - if (png_ptr->transformations & PNG_BACKGROUND) - { - info_ptr->color_type = (png_byte)(info_ptr->color_type & - ~PNG_COLOR_MASK_ALPHA); - info_ptr->num_trans = 0; +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + /* The following is almost certainly wrong unless the background value is in + * the screen space! + */ + if (png_ptr->transformations & PNG_COMPOSE) info_ptr->background = png_ptr->background; - } #endif #ifdef PNG_READ_GAMMA_SUPPORTED - if (png_ptr->transformations & PNG_GAMMA) - { - info_ptr->gamma = png_ptr->gamma; - } + /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4), + * however it seems that the code in png_init_read_transformations, which has + * been called before this from png_read_update_info->png_read_start_row + * sometimes does the gamma transform and cancels the flag. + */ + info_ptr->gamma = png_ptr->gamma; #endif -#ifdef PNG_READ_16_TO_8_SUPPORTED -#ifdef PNG_READ_16BIT_SUPPORTED - if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16)) - info_ptr->bit_depth = 8; -#else - /* Force chopping 16-bit input down to 8 */ if (info_ptr->bit_depth == 16) { - png_ptr->transformations |=PNG_16_TO_8; - info_ptr->bit_depth = 8; +# ifdef PNG_READ_16BIT_SUPPORTED +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + if (png_ptr->transformations & PNG_SCALE_16_TO_8) + info_ptr->bit_depth = 8; +# endif + +# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + if (png_ptr->transformations & PNG_16_TO_8) + info_ptr->bit_depth = 8; +# endif + +# else + /* No 16 bit support: force chopping 16-bit input down to 8, in this case + * the app program can chose if both APIs are available by setting the + * correct scaling to use. + */ +# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + /* For compatibility with previous versions use the strip method by + * default. This code works because if PNG_SCALE_16_TO_8 is already + * set the code below will do that in preference to the chop. + */ + png_ptr->transformations |= PNG_16_TO_8; + info_ptr->bit_depth = 8; +# else + +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + png_ptr->transformations |= PNG_SCALE_16_TO_8; + info_ptr->bit_depth = 8; +# else + + CONFIGURATION ERROR: you must enable at least one 16 to 8 method +# endif +# endif +#endif /* !READ_16BIT_SUPPORTED */ } -#endif -#endif #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED if (png_ptr->transformations & PNG_GRAY_TO_RGB) - info_ptr->color_type |= PNG_COLOR_MASK_COLOR; + info_ptr->color_type = (png_byte)(info_ptr->color_type | + PNG_COLOR_MASK_COLOR); #endif #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED if (png_ptr->transformations & PNG_RGB_TO_GRAY) - info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_COLOR); #endif #ifdef PNG_READ_QUANTIZE_SUPPORTED @@ -1338,6 +1994,14 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) } #endif +#ifdef PNG_READ_EXPAND_16_SUPPORTED + if (png_ptr->transformations & PNG_EXPAND_16 && info_ptr->bit_depth == 8 && + info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + info_ptr->bit_depth = 16; + } +#endif + #ifdef PNG_READ_PACK_SUPPORTED if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8)) info_ptr->bit_depth = 8; @@ -1353,8 +2017,12 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) info_ptr->channels = 1; #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) - info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; + if (png_ptr->transformations & PNG_STRIP_ALPHA) + { + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_ALPHA); + info_ptr->num_trans = 0; + } #endif if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) @@ -1390,6 +2058,14 @@ defined(PNG_READ_USER_TRANSFORM_SUPPORTED) info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); + /* Adding in 1.5.4: cache the above value in png_struct so that we can later + * check in png_rowbytes that the user buffer won't get overwritten. Note + * that the field is not always set - if png_read_update_info isn't called + * the application has to either not do any transforms or get the calculation + * right itself. + */ + png_ptr->info_rowbytes = info_ptr->rowbytes; + #ifndef PNG_READ_EXPAND_SUPPORTED if (png_ptr) return; @@ -1401,69 +2077,71 @@ defined(PNG_READ_USER_TRANSFORM_SUPPORTED) * decide how it fits in with the other transformations here. */ void /* PRIVATE */ -png_do_read_transformations(png_structp png_ptr) +png_do_read_transformations(png_structp png_ptr, png_row_infop row_info) { png_debug(1, "in png_do_read_transformations"); if (png_ptr->row_buf == NULL) { -#ifdef PNG_CONSOLE_IO_SUPPORTED - char msg[50]; - - png_snprintf2(msg, 50, - "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number, - png_ptr->pass); - png_error(png_ptr, msg); -#else + /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this + * error is incredibly rare and incredibly easy to debug without this + * information. + */ png_error(png_ptr, "NULL row buffer"); -#endif } -#ifdef PNG_WARN_UNINITIALIZED_ROW - if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) - /* Application has failed to call either png_read_start_image() - * or png_read_update_info() after setting transforms that expand - * pixels. This check added to libpng-1.2.19 + + /* The following is debugging; prior to 1.5.4 the code was never compiled in; + * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro + * PNG_WARN_UNINITIALIZED_ROW removed. In 1.5 the new flag is set only for + * selected new APIs to ensure that there is no API change. + */ + if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 && + !(png_ptr->flags & PNG_FLAG_ROW_INIT)) + { + /* Application has failed to call either png_read_start_image() or + * png_read_update_info() after setting transforms that expand pixels. + * This check added to libpng-1.2.19 (but not enabled until 1.5.4). */ -#if (PNG_WARN_UNINITIALIZED_ROW==1) png_error(png_ptr, "Uninitialized row"); -#else - png_warning(png_ptr, "Uninitialized row"); -#endif -#endif + } #ifdef PNG_READ_EXPAND_SUPPORTED if (png_ptr->transformations & PNG_EXPAND) { - if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) { - png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_expand_palette(row_info, png_ptr->row_buf + 1, png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); } + else { if (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND_tRNS)) - png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_expand(row_info, png_ptr->row_buf + 1, &(png_ptr->trans_color)); - else - png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, + else + png_do_expand(row_info, png_ptr->row_buf + 1, NULL); } } #endif #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) - png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, - PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)); + if ((png_ptr->transformations & PNG_STRIP_ALPHA) && + !(png_ptr->transformations & PNG_COMPOSE) && + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + 0 /* at_start == false, because SWAP_ALPHA happens later */); #endif #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED if (png_ptr->transformations & PNG_RGB_TO_GRAY) { int rgb_error = - png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), + png_do_rgb_to_gray(png_ptr, row_info, png_ptr->row_buf + 1); if (rgb_error) @@ -1517,107 +2195,146 @@ png_do_read_transformations(png_structp png_ptr) */ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) - png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); #endif -#ifdef PNG_READ_BACKGROUND_SUPPORTED - if ((png_ptr->transformations & PNG_BACKGROUND) && - ((png_ptr->num_trans != 0) || - (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) - png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, - &(png_ptr->trans_color), &(png_ptr->background) -#ifdef PNG_READ_GAMMA_SUPPORTED - , &(png_ptr->background_1), - png_ptr->gamma_table, png_ptr->gamma_from_1, - png_ptr->gamma_to_1, png_ptr->gamma_16_table, - png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, - png_ptr->gamma_shift -#endif - ); +#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ + (defined PNG_READ_ALPHA_MODE_SUPPORTED) + if (png_ptr->transformations & PNG_COMPOSE) + png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr); #endif #ifdef PNG_READ_GAMMA_SUPPORTED if ((png_ptr->transformations & PNG_GAMMA) && -#ifdef PNG_READ_BACKGROUND_SUPPORTED - !((png_ptr->transformations & PNG_BACKGROUND) && +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Because RGB_TO_GRAY does the gamma transform. */ + !(png_ptr->transformations & PNG_RGB_TO_GRAY) && +#endif +#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ + (defined PNG_READ_ALPHA_MODE_SUPPORTED) + /* Because PNG_COMPOSE does the gamma transform if there is something to + * do (if there is an alpha channel or transparency.) + */ + !((png_ptr->transformations & PNG_COMPOSE) && ((png_ptr->num_trans != 0) || (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && #endif + /* Because png_init_read_transformations transforms the palette, unless + * RGB_TO_GRAY will do the transform. + */ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) - png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, - png_ptr->gamma_table, png_ptr->gamma_16_table, - png_ptr->gamma_shift); + png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr); +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) && + (png_ptr->transformations & PNG_COMPOSE) && + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + 0 /* at_start == false, because SWAP_ALPHA happens later */); +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + if ((png_ptr->transformations & PNG_ENCODE_ALPHA) && + (row_info->color_type & PNG_COLOR_MASK_ALPHA)) + png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr); +#endif + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + if (png_ptr->transformations & PNG_SCALE_16_TO_8) + png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1); #endif -#ifdef PNG_READ_16_TO_8_SUPPORTED +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + /* There is no harm in doing both of these because only one has any effect, + * by putting the 'scale' option first if the app asks for scale (either by + * calling the API or in a TRANSFORM flag) this is what happens. + */ if (png_ptr->transformations & PNG_16_TO_8) - png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_chop(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_QUANTIZE_SUPPORTED if (png_ptr->transformations & PNG_QUANTIZE) { - png_do_quantize(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_quantize(row_info, png_ptr->row_buf + 1, png_ptr->palette_lookup, png_ptr->quantize_index); - if (png_ptr->row_info.rowbytes == 0) + if (row_info->rowbytes == 0) png_error(png_ptr, "png_do_quantize returned rowbytes=0"); } #endif /* PNG_READ_QUANTIZE_SUPPORTED */ +#ifdef PNG_READ_EXPAND_16_SUPPORTED + /* Do the expansion now, after all the arithmetic has been done. Notice + * that previous transformations can handle the PNG_EXPAND_16 flag if this + * is efficient (particularly true in the case of gamma correction, where + * better accuracy results faster!) + */ + if (png_ptr->transformations & PNG_EXPAND_16) + png_do_expand_16(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /*NOTE: moved here in 1.5.4 (from much later in this list.) */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && + (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); +#endif + #ifdef PNG_READ_INVERT_SUPPORTED if (png_ptr->transformations & PNG_INVERT_MONO) - png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_invert(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_SHIFT_SUPPORTED if (png_ptr->transformations & PNG_SHIFT) - png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_unshift(row_info, png_ptr->row_buf + 1, &(png_ptr->shift)); #endif #ifdef PNG_READ_PACK_SUPPORTED if (png_ptr->transformations & PNG_PACK) - png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_unpack(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Added at libpng-1.5.10 */ + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) + png_do_check_palette_indexes(png_ptr, row_info); #endif #ifdef PNG_READ_BGR_SUPPORTED if (png_ptr->transformations & PNG_BGR) - png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_bgr(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_PACKSWAP_SUPPORTED if (png_ptr->transformations & PNG_PACKSWAP) - png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED - /* If gray -> RGB, do so now only if we did not do so above */ - if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && - (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) - png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_packswap(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_FILLER_SUPPORTED if (png_ptr->transformations & PNG_FILLER) - png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_read_filler(row_info, png_ptr->row_buf + 1, (png_uint_32)png_ptr->filler, png_ptr->flags); #endif #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED if (png_ptr->transformations & PNG_INVERT_ALPHA) - png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED if (png_ptr->transformations & PNG_SWAP_ALPHA) - png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_16BIT_SUPPORTED #ifdef PNG_READ_SWAP_SUPPORTED if (png_ptr->transformations & PNG_SWAP_BYTES) - png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_swap(row_info, png_ptr->row_buf + 1); #endif #endif @@ -1626,8 +2343,8 @@ png_do_read_transformations(png_structp png_ptr) { if (png_ptr->read_user_transform_fn != NULL) (*(png_ptr->read_user_transform_fn)) /* User read transform function */ - (png_ptr, /* png_ptr */ - &(png_ptr->row_info), /* row_info: */ + (png_ptr, /* png_ptr */ + row_info, /* row_info: */ /* png_uint_32 width; width of row */ /* png_size_t rowbytes; number of bytes in row */ /* png_byte color_type; color type of pixels */ @@ -1637,19 +2354,17 @@ png_do_read_transformations(png_structp png_ptr) png_ptr->row_buf + 1); /* start of pixel data for row */ #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED if (png_ptr->user_transform_depth) - png_ptr->row_info.bit_depth = png_ptr->user_transform_depth; + row_info->bit_depth = png_ptr->user_transform_depth; if (png_ptr->user_transform_channels) - png_ptr->row_info.channels = png_ptr->user_transform_channels; + row_info->channels = png_ptr->user_transform_channels; #endif - png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * - png_ptr->row_info.channels); + row_info->pixel_depth = (png_byte)(row_info->bit_depth * + row_info->channels); - png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, - png_ptr->row_info.width); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width); } #endif - } #ifdef PNG_READ_PACK_SUPPORTED @@ -1761,105 +2476,128 @@ void /* PRIVATE */ png_do_unshift(png_row_infop row_info, png_bytep row, png_const_color_8p sig_bits) { + int color_type; + png_debug(1, "in png_do_unshift"); - if ( - row_info->color_type != PNG_COLOR_TYPE_PALETTE) + /* The palette case has already been handled in the _init routine. */ + color_type = row_info->color_type; + + if (color_type != PNG_COLOR_TYPE_PALETTE) { int shift[4]; int channels = 0; - int c; - png_uint_16 value = 0; - png_uint_32 row_width = row_info->width; + int bit_depth = row_info->bit_depth; - if (row_info->color_type & PNG_COLOR_MASK_COLOR) + if (color_type & PNG_COLOR_MASK_COLOR) { - shift[channels++] = row_info->bit_depth - sig_bits->red; - shift[channels++] = row_info->bit_depth - sig_bits->green; - shift[channels++] = row_info->bit_depth - sig_bits->blue; + shift[channels++] = bit_depth - sig_bits->red; + shift[channels++] = bit_depth - sig_bits->green; + shift[channels++] = bit_depth - sig_bits->blue; } else { - shift[channels++] = row_info->bit_depth - sig_bits->gray; + shift[channels++] = bit_depth - sig_bits->gray; } - if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + if (color_type & PNG_COLOR_MASK_ALPHA) { - shift[channels++] = row_info->bit_depth - sig_bits->alpha; + shift[channels++] = bit_depth - sig_bits->alpha; } - for (c = 0; c < channels; c++) { - if (shift[c] <= 0) - shift[c] = 0; + int c, have_shift; - else - value = 1; - } + for (c = have_shift = 0; c < channels; ++c) + { + /* A shift of more than the bit depth is an error condition but it + * gets ignored here. + */ + if (shift[c] <= 0 || shift[c] >= bit_depth) + shift[c] = 0; - if (!value) - return; + else + have_shift = 1; + } - switch (row_info->bit_depth) + if (!have_shift) + return; + } + + switch (bit_depth) { default: - break; + /* Must be 1bpp gray: should not be here! */ + /* NOTREACHED */ + break; case 2: + /* Must be 2bpp gray */ + /* assert(channels == 1 && shift[0] == 1) */ { - png_bytep bp; - png_size_t i; - png_size_t istop = row_info->rowbytes; + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; - for (bp = row, i = 0; i < istop; i++) + while (bp < bp_end) { - *bp >>= 1; - *bp++ &= 0x55; + int b = (*bp >> 1) & 0x55; + *bp++ = (png_byte)b; } break; } case 4: + /* Must be 4bpp gray */ + /* assert(channels == 1) */ { png_bytep bp = row; - png_size_t i; - png_size_t istop = row_info->rowbytes; - png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) | - (png_byte)((int)0xf >> shift[0])); + png_bytep bp_end = bp + row_info->rowbytes; + int gray_shift = shift[0]; + int mask = 0xf >> gray_shift; + + mask |= mask << 4; - for (i = 0; i < istop; i++) + while (bp < bp_end) { - *bp >>= shift[0]; - *bp++ &= mask; + int b = (*bp >> gray_shift) & mask; + *bp++ = (png_byte)b; } break; } case 8: + /* Single byte components, G, GA, RGB, RGBA */ { png_bytep bp = row; - png_uint_32 i; - png_uint_32 istop = row_width * channels; + png_bytep bp_end = bp + row_info->rowbytes; + int channel = 0; - for (i = 0; i < istop; i++) + while (bp < bp_end) { - *bp++ >>= shift[i%channels]; + int b = *bp >> shift[channel]; + if (++channel >= channels) + channel = 0; + *bp++ = (png_byte)b; } break; } #ifdef PNG_READ_16BIT_SUPPORTED case 16: + /* Double byte components, G, GA, RGB, RGBA */ { png_bytep bp = row; - png_uint_32 i; - png_uint_32 istop = channels * row_width; + png_bytep bp_end = bp + row_info->rowbytes; + int channel = 0; - for (i = 0; i < istop; i++) + while (bp < bp_end) { - value = (png_uint_16)((*bp << 8) + *(bp + 1)); - value >>= shift[i%channels]; + int value = (bp[0] << 8) + bp[1]; + + value >>= shift[channel]; + if (++channel >= channels) + channel = 0; *bp++ = (png_byte)(value >> 8); *bp++ = (png_byte)(value & 0xff); } @@ -1871,54 +2609,86 @@ png_do_unshift(png_row_infop row_info, png_bytep row, } #endif -#ifdef PNG_READ_16_TO_8_SUPPORTED -/* Chop rows of bit depth 16 down to 8 */ +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +/* Scale rows of bit depth 16 down to 8 accurately */ void /* PRIVATE */ -png_do_chop(png_row_infop row_info, png_bytep row) +png_do_scale_16_to_8(png_row_infop row_info, png_bytep row) { - png_debug(1, "in png_do_chop"); + png_debug(1, "in png_do_scale_16_to_8"); if (row_info->bit_depth == 16) { - png_bytep sp = row; - png_bytep dp = row; - png_uint_32 i; - png_uint_32 istop = row_info->width * row_info->channels; + png_bytep sp = row; /* source */ + png_bytep dp = row; /* destination */ + png_bytep ep = sp + row_info->rowbytes; /* end+1 */ - for (i = 0; i<istop; i++, sp += 2, dp++) + while (sp < ep) { -#ifdef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED - /* This does a more accurate scaling of the 16-bit color - * value, rather than a simple low-byte truncation. - * - * What the ideal calculation should be: - * *dp = (((((png_uint_32)(*sp) << 8) | - * (png_uint_32)(*(sp + 1))) * 255 + 127) - * / (png_uint_32)65535L; - * - * GRR: no, I think this is what it really should be: - * *dp = (((((png_uint_32)(*sp) << 8) | - * (png_uint_32)(*(sp + 1))) + 128L) - * / (png_uint_32)257L; - * - * GRR: here's the exact calculation with shifts: - * temp = (((png_uint_32)(*sp) << 8) | - * (png_uint_32)(*(sp + 1))) + 128L; - * *dp = (temp - (temp >> 8)) >> 8; - * - * Approximate calculation with shift/add instead of multiply/divide: - * *dp = ((((png_uint_32)(*sp) << 8) | - * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8; - * - * What we actually do to avoid extra shifting and conversion: - */ + /* The input is an array of 16 bit components, these must be scaled to + * 8 bits each. For a 16 bit value V the required value (from the PNG + * specification) is: + * + * (V * 255) / 65535 + * + * This reduces to round(V / 257), or floor((V + 128.5)/257) + * + * Represent V as the two byte value vhi.vlo. Make a guess that the + * result is the top byte of V, vhi, then the correction to this value + * is: + * + * error = floor(((V-vhi.vhi) + 128.5) / 257) + * = floor(((vlo-vhi) + 128.5) / 257) + * + * This can be approximated using integer arithmetic (and a signed + * shift): + * + * error = (vlo-vhi+128) >> 8; + * + * The approximate differs from the exact answer only when (vlo-vhi) is + * 128; it then gives a correction of +1 when the exact correction is + * 0. This gives 128 errors. The exact answer (correct for all 16 bit + * input values) is: + * + * error = (vlo-vhi+128)*65535 >> 24; + * + * An alternative arithmetic calculation which also gives no errors is: + * + * (V * 255 + 32895) >> 16 + */ - *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0); -#else - /* Simply discard the low order byte */ - *dp = *sp; + png_int_32 tmp = *sp++; /* must be signed! */ + tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24; + *dp++ = (png_byte)tmp; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_info->width * row_info->channels; + } +} #endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +void /* PRIVATE */ +/* Simply discard the low byte. This was the default behavior prior + * to libpng-1.5.4. + */ +png_do_chop(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_chop"); + + if (row_info->bit_depth == 16) + { + png_bytep sp = row; /* source */ + png_bytep dp = row; /* destination */ + png_bytep ep = sp + row_info->rowbytes; /* end+1 */ + + while (sp < ep) + { + *dp++ = *sp; + sp += 2; /* skip low byte */ } + row_info->bit_depth = 8; row_info->pixel_depth = (png_byte)(8 * row_info->channels); row_info->rowbytes = row_info->width * row_info->channels; @@ -2390,7 +3160,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) } } } - row_info->channels += (png_byte)2; + row_info->channels = (png_byte)(row_info->channels + 2); row_info->color_type |= PNG_COLOR_MASK_COLOR; row_info->pixel_depth = (png_byte)(row_info->channels * row_info->bit_depth); @@ -2401,33 +3171,61 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED /* Reduce RGB files to grayscale, with or without alpha - * using the equation given in Poynton's ColorFAQ at - * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008) - * New link: - * <http://www.poynton.com/notes/colour_and_gamma/> + * using the equation given in Poynton's ColorFAQ of 1998-01-04 at + * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but + * versions dated 1998 through November 2002 have been archived at + * http://web.archive.org/web/20000816232553/http://www.inforamp.net/ + * ~poynton/notes/colour_and_gamma/ColorFAQ.txt ) * Charles Poynton poynton at poynton.com * * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B * - * We approximate this with + * which can be expressed with integers as + * + * Y = (6969 * R + 23434 * G + 2365 * B)/32768 * - * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B + * Poynton's current link (as of January 2003 through July 2011): + * <http://www.poynton.com/notes/colour_and_gamma/> + * has changed the numbers slightly: + * + * Y = 0.2126*R + 0.7152*G + 0.0722*B * * which can be expressed with integers as * - * Y = (6969 * R + 23434 * G + 2365 * B)/32768 + * Y = (6966 * R + 23436 * G + 2366 * B)/32768 + * + * Historically, however, libpng uses numbers derived from the ITU-R Rec 709 + * end point chromaticities and the D65 white point. Depending on the + * precision used for the D65 white point this produces a variety of different + * numbers, however if the four decimal place value used in ITU-R Rec 709 is + * used (0.3127,0.3290) the Y calculation would be: + * + * Y = (6968 * R + 23435 * G + 2366 * B)/32768 + * + * While this is correct the rounding results in an overflow for white, because + * the sum of the rounded coefficients is 32769, not 32768. Consequently + * libpng uses, instead, the closest non-overflowing approximation: + * + * Y = (6968 * R + 23434 * G + 2366 * B)/32768 * - * The calculation is to be done in a linear colorspace. + * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk + * (including an sRGB chunk) then the chromaticities are used to calculate the + * coefficients. See the chunk handling in pngrutil.c for more information. * - * Other integer coefficents can be used via png_set_rgb_to_gray(). + * In all cases the calculation is to be done in a linear colorspace. If no + * gamma information is available to correct the encoding of the original RGB + * values this results in an implicit assumption that the original PNG RGB + * values were linear. + * + * Other integer coefficents can be used via png_set_rgb_to_gray(). Because + * the API takes just red and green coefficients the blue coefficient is + * calculated to make the sum 32768. This will result in different rounding + * to that used above. */ int /* PRIVATE */ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) { - png_uint_32 i; - - png_uint_32 row_width = row_info->width; int rgb_error = 0; png_debug(1, "in png_do_rgb_to_gray"); @@ -2435,235 +3233,180 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) if (!(row_info->color_type & PNG_COLOR_MASK_PALETTE) && (row_info->color_type & PNG_COLOR_MASK_COLOR)) { - png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; - png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; - png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; + PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; + PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; + PNG_CONST png_uint_32 bc = 32768 - rc - gc; + PNG_CONST png_uint_32 row_width = row_info->width; + PNG_CONST int have_alpha = + (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0; - if (row_info->color_type == PNG_COLOR_TYPE_RGB) + if (row_info->bit_depth == 8) { - if (row_info->bit_depth == 8) - { #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + /* Notice that gamma to/from 1 are not necessarily inverses (if + * there is an overall gamma correction). Prior to 1.5.5 this code + * checked the linearized values for equality; this doesn't match + * the documentation, the original values must be checked. + */ + if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) { - png_bytep sp = row; - png_bytep dp = row; + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); - for (i = 0; i < row_width; i++) + if (red != green || red != blue) { - png_byte red = png_ptr->gamma_to_1[*(sp++)]; - png_byte green = png_ptr->gamma_to_1[*(sp++)]; - png_byte blue = png_ptr->gamma_to_1[*(sp++)]; - - if (red != green || red != blue) - { - rgb_error |= 1; - *(dp++) = png_ptr->gamma_from_1[ - (rc*red + gc*green + bc*blue)>>15]; - } + red = png_ptr->gamma_to_1[red]; + green = png_ptr->gamma_to_1[green]; + blue = png_ptr->gamma_to_1[blue]; - else - *(dp++) = *(sp - 1); + rgb_error |= 1; + *(dp++) = png_ptr->gamma_from_1[ + (rc*red + gc*green + bc*blue + 16384)>>15]; } - } - else -#endif - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_byte red = *(sp++); - png_byte green = *(sp++); - png_byte blue = *(sp++); - if (red != green || red != blue) - { - rgb_error |= 1; - *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); - } + else + { + /* If there is no overall correction the table will not be + * set. + */ + if (png_ptr->gamma_table != NULL) + red = png_ptr->gamma_table[red]; - else - *(dp++) = *(sp - 1); + *(dp++) = red; } + + if (have_alpha) + *(dp++) = *(sp++); } } - - else /* RGB bit_depth == 16 */ + else +#endif { -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->gamma_16_to_1 != NULL && - png_ptr->gamma_16_from_1 != NULL) - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 red, green, blue, w; - - red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - - if (red == green && red == blue) - w = red; - - else - { - png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) - >> png_ptr->gamma_shift][red>>8]; - png_uint_16 green_1 = - png_ptr->gamma_16_to_1[(green&0xff) >> - png_ptr->gamma_shift][green>>8]; - png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) - >> png_ptr->gamma_shift][blue>>8]; - png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 - + bc*blue_1)>>15); - w = png_ptr->gamma_16_from_1[(gray16&0xff) >> - png_ptr->gamma_shift][gray16 >> 8]; - rgb_error |= 1; - } + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; - *(dp++) = (png_byte)((w>>8) & 0xff); - *(dp++) = (png_byte)(w & 0xff); - } - } - else -#endif + for (i = 0; i < row_width; i++) { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 red, green, blue, gray16; + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); - red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + if (red != green || red != blue) + { + rgb_error |= 1; + /*NOTE: this is the historical approach which simply + * truncates the results. + */ + *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); + } - if (red != green || red != blue) - rgb_error |= 1; + else + *(dp++) = red; - gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); - *(dp++) = (png_byte)((gray16>>8) & 0xff); - *(dp++) = (png_byte)(gray16 & 0xff); - } + if (have_alpha) + *(dp++) = *(sp++); } } } - if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + + else /* RGB bit_depth == 16 */ { - if (row_info->bit_depth == 8) - { #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_byte red = png_ptr->gamma_to_1[*(sp++)]; - png_byte green = png_ptr->gamma_to_1[*(sp++)]; - png_byte blue = png_ptr->gamma_to_1[*(sp++)]; + png_uint_16 red, green, blue, w; - if (red != green || red != blue) - rgb_error |= 1; + red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - *(dp++) = png_ptr->gamma_from_1 - [(rc*red + gc*green + bc*blue)>>15]; + if (red == green && red == blue) + { + if (png_ptr->gamma_16_table != NULL) + w = png_ptr->gamma_16_table[(red&0xff) + >> png_ptr->gamma_shift][red>>8]; - *(dp++) = *(sp++); /* alpha */ + else + w = red; } - } - else -#endif - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) + + else + { + png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) + >> png_ptr->gamma_shift][red>>8]; + png_uint_16 green_1 = + png_ptr->gamma_16_to_1[(green&0xff) >> + png_ptr->gamma_shift][green>>8]; + png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) + >> png_ptr->gamma_shift][blue>>8]; + png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 + + bc*blue_1 + 16384)>>15); + w = png_ptr->gamma_16_from_1[(gray16&0xff) >> + png_ptr->gamma_shift][gray16 >> 8]; + rgb_error |= 1; + } + + *(dp++) = (png_byte)((w>>8) & 0xff); + *(dp++) = (png_byte)(w & 0xff); + + if (have_alpha) { - png_byte red = *(sp++); - png_byte green = *(sp++); - png_byte blue = *(sp++); - if (red != green || red != blue) - rgb_error |= 1; - - *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); - *(dp++) = *(sp++); /* alpha */ + *(dp++) = *(sp++); + *(dp++) = *(sp++); } } } - else /* RGBA bit_depth == 16 */ + else +#endif { -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->gamma_16_to_1 != NULL && - png_ptr->gamma_16_from_1 != NULL) - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 red, green, blue, w; - - red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - - if (red == green && red == blue) - w = red; - - else - { - png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> - png_ptr->gamma_shift][red>>8]; - - png_uint_16 green_1 = - png_ptr->gamma_16_to_1[(green&0xff) >> - png_ptr->gamma_shift][green>>8]; + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; - png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> - png_ptr->gamma_shift][blue>>8]; + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, gray16; - png_uint_16 gray16 = (png_uint_16)((rc * red_1 - + gc * green_1 + bc * blue_1)>>15); + red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - w = png_ptr->gamma_16_from_1[(gray16&0xff) >> - png_ptr->gamma_shift][gray16 >> 8]; + if (red != green || red != blue) + rgb_error |= 1; - rgb_error |= 1; - } + /* From 1.5.5 in the 16 bit case do the accurate conversion even + * in the 'fast' case - this is because this is where the code + * ends up when handling linear 16 bit data. + */ + gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >> + 15); + *(dp++) = (png_byte)((gray16>>8) & 0xff); + *(dp++) = (png_byte)(gray16 & 0xff); - *(dp++) = (png_byte)((w>>8) & 0xff); - *(dp++) = (png_byte)(w & 0xff); - *(dp++) = *(sp++); /* alpha */ - *(dp++) = *(sp++); - } - } - else -#endif - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) + if (have_alpha) { - png_uint_16 red, green, blue, gray16; - red = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; - green = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; - blue = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; - - if (red != green || red != blue) - rgb_error |= 1; - - gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); - *(dp++) = (png_byte)((gray16>>8) & 0xff); - *(dp++) = (png_byte)(gray16 & 0xff); - *(dp++) = *(sp++); /* alpha */ + *(dp++) = *(sp++); *(dp++) = *(sp++); } } } } - row_info->channels -= 2; + + row_info->channels = (png_byte)(row_info->channels - 2); row_info->color_type = (png_byte)(row_info->color_type & ~PNG_COLOR_MASK_COLOR); row_info->pixel_depth = (png_byte)(row_info->channels * @@ -2673,11 +3416,13 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) return rgb_error; } #endif +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ +#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth * large of png_color. This lets grayscale images be treated as * paletted. Most useful for gamma correction and simplification - * of code. + * of code. This API is not used internally. */ void PNGAPI png_build_grayscale_palette(int bit_depth, png_colorp palette) @@ -2727,34 +3472,37 @@ png_build_grayscale_palette(int bit_depth, png_colorp palette) palette[i].blue = (png_byte)v; } } +#endif -#ifdef PNG_READ_BACKGROUND_SUPPORTED +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ + (defined PNG_READ_ALPHA_MODE_SUPPORTED) /* Replace any alpha or transparency with the supplied background color. * "background" is already in the screen gamma, while "background_1" is * at a gamma of 1.0. Paletted files have already been taken care of. */ void /* PRIVATE */ -png_do_background(png_row_infop row_info, png_bytep row, - png_const_color_16p trans_color, png_const_color_16p background +png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr) +{ #ifdef PNG_READ_GAMMA_SUPPORTED - , png_const_color_16p background_1, png_const_bytep gamma_table, - png_const_bytep gamma_from_1, png_const_bytep gamma_to_1, - png_const_uint_16pp gamma_16, png_const_uint_16pp gamma_16_from_1, - png_const_uint_16pp gamma_16_to_1, int gamma_shift + png_const_bytep gamma_table = png_ptr->gamma_table; + png_const_bytep gamma_from_1 = png_ptr->gamma_from_1; + png_const_bytep gamma_to_1 = png_ptr->gamma_to_1; + png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table; + png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1; + png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1; + int gamma_shift = png_ptr->gamma_shift; #endif - ) -{ - png_bytep sp, dp; + + png_bytep sp; png_uint_32 i; png_uint_32 row_width = row_info->width; + int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; int shift; - png_debug(1, "in png_do_background"); + png_debug(1, "in png_do_compose"); - if (background != NULL && - (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) || - (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_color))) { switch (row_info->color_type) { @@ -2769,10 +3517,10 @@ png_do_background(png_row_infop row_info, png_bytep row, for (i = 0; i < row_width; i++) { if ((png_uint_16)((*sp >> shift) & 0x01) - == trans_color->gray) + == png_ptr->trans_color.gray) { *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); - *sp |= (png_byte)(background->gray << shift); + *sp |= (png_byte)(png_ptr->background.gray << shift); } if (!shift) @@ -2797,10 +3545,10 @@ png_do_background(png_row_infop row_info, png_bytep row, for (i = 0; i < row_width; i++) { if ((png_uint_16)((*sp >> shift) & 0x03) - == trans_color->gray) + == png_ptr->trans_color.gray) { *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); - *sp |= (png_byte)(background->gray << shift); + *sp |= (png_byte)(png_ptr->background.gray << shift); } else @@ -2831,10 +3579,10 @@ png_do_background(png_row_infop row_info, png_bytep row, for (i = 0; i < row_width; i++) { if ((png_uint_16)((*sp >> shift) & 0x03) - == trans_color->gray) + == png_ptr->trans_color.gray) { *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); - *sp |= (png_byte)(background->gray << shift); + *sp |= (png_byte)(png_ptr->background.gray << shift); } if (!shift) @@ -2860,10 +3608,10 @@ png_do_background(png_row_infop row_info, png_bytep row, for (i = 0; i < row_width; i++) { if ((png_uint_16)((*sp >> shift) & 0x0f) - == trans_color->gray) + == png_ptr->trans_color.gray) { *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); - *sp |= (png_byte)(background->gray << shift); + *sp |= (png_byte)(png_ptr->background.gray << shift); } else @@ -2894,10 +3642,10 @@ png_do_background(png_row_infop row_info, png_bytep row, for (i = 0; i < row_width; i++) { if ((png_uint_16)((*sp >> shift) & 0x0f) - == trans_color->gray) + == png_ptr->trans_color.gray) { *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); - *sp |= (png_byte)(background->gray << shift); + *sp |= (png_byte)(png_ptr->background.gray << shift); } if (!shift) @@ -2921,8 +3669,8 @@ png_do_background(png_row_infop row_info, png_bytep row, sp = row; for (i = 0; i < row_width; i++, sp++) { - if (*sp == trans_color->gray) - *sp = (png_byte)background->gray; + if (*sp == png_ptr->trans_color.gray) + *sp = (png_byte)png_ptr->background.gray; else *sp = gamma_table[*sp]; @@ -2934,8 +3682,8 @@ png_do_background(png_row_infop row_info, png_bytep row, sp = row; for (i = 0; i < row_width; i++, sp++) { - if (*sp == trans_color->gray) - *sp = (png_byte)background->gray; + if (*sp == png_ptr->trans_color.gray) + *sp = (png_byte)png_ptr->background.gray; } } break; @@ -2953,11 +3701,11 @@ png_do_background(png_row_infop row_info, png_bytep row, v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - if (v == trans_color->gray) + if (v == png_ptr->trans_color.gray) { /* Background is already in screen gamma */ - *sp = (png_byte)((background->gray >> 8) & 0xff); - *(sp + 1) = (png_byte)(background->gray & 0xff); + *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); } else @@ -2978,10 +3726,10 @@ png_do_background(png_row_infop row_info, png_bytep row, v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - if (v == trans_color->gray) + if (v == png_ptr->trans_color.gray) { - *sp = (png_byte)((background->gray >> 8) & 0xff); - *(sp + 1) = (png_byte)(background->gray & 0xff); + *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); } } } @@ -3004,13 +3752,13 @@ png_do_background(png_row_infop row_info, png_bytep row, sp = row; for (i = 0; i < row_width; i++, sp += 3) { - if (*sp == trans_color->red && - *(sp + 1) == trans_color->green && - *(sp + 2) == trans_color->blue) + if (*sp == png_ptr->trans_color.red && + *(sp + 1) == png_ptr->trans_color.green && + *(sp + 2) == png_ptr->trans_color.blue) { - *sp = (png_byte)background->red; - *(sp + 1) = (png_byte)background->green; - *(sp + 2) = (png_byte)background->blue; + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; } else @@ -3027,13 +3775,13 @@ png_do_background(png_row_infop row_info, png_bytep row, sp = row; for (i = 0; i < row_width; i++, sp += 3) { - if (*sp == trans_color->red && - *(sp + 1) == trans_color->green && - *(sp + 2) == trans_color->blue) + if (*sp == png_ptr->trans_color.red && + *(sp + 1) == png_ptr->trans_color.green && + *(sp + 2) == png_ptr->trans_color.blue) { - *sp = (png_byte)background->red; - *(sp + 1) = (png_byte)background->green; - *(sp + 2) = (png_byte)background->blue; + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; } } } @@ -3054,16 +3802,17 @@ png_do_background(png_row_infop row_info, png_bytep row, png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + *(sp + 5)); - if (r == trans_color->red && g == trans_color->green && - b == trans_color->blue) + if (r == png_ptr->trans_color.red && + g == png_ptr->trans_color.green && + b == png_ptr->trans_color.blue) { /* Background is already in screen gamma */ - *sp = (png_byte)((background->red >> 8) & 0xff); - *(sp + 1) = (png_byte)(background->red & 0xff); - *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); - *(sp + 3) = (png_byte)(background->green & 0xff); - *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); - *(sp + 5) = (png_byte)(background->blue & 0xff); + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); } else @@ -3097,15 +3846,16 @@ png_do_background(png_row_infop row_info, png_bytep row, png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + *(sp + 5)); - if (r == trans_color->red && g == trans_color->green && - b == trans_color->blue) + if (r == png_ptr->trans_color.red && + g == png_ptr->trans_color.green && + b == png_ptr->trans_color.blue) { - *sp = (png_byte)((background->red >> 8) & 0xff); - *(sp + 1) = (png_byte)(background->red & 0xff); - *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); - *(sp + 3) = (png_byte)(background->green & 0xff); - *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); - *(sp + 5) = (png_byte)(background->blue & 0xff); + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); } } } @@ -3122,18 +3872,17 @@ png_do_background(png_row_infop row_info, png_bytep row, gamma_table != NULL) { sp = row; - dp = row; - for (i = 0; i < row_width; i++, sp += 2, dp++) + for (i = 0; i < row_width; i++, sp += 2) { png_uint_16 a = *(sp + 1); if (a == 0xff) - *dp = gamma_table[*sp]; + *sp = gamma_table[*sp]; else if (a == 0) { /* Background is already in screen gamma */ - *dp = (png_byte)background->gray; + *sp = (png_byte)png_ptr->background.gray; } else @@ -3141,8 +3890,10 @@ png_do_background(png_row_infop row_info, png_bytep row, png_byte v, w; v = gamma_to_1[*sp]; - png_composite(w, v, a, background_1->gray); - *dp = gamma_from_1[w]; + png_composite(w, v, a, png_ptr->background_1.gray); + if (!optimize) + w = gamma_from_1[w]; + *sp = w; } } } @@ -3150,24 +3901,15 @@ png_do_background(png_row_infop row_info, png_bytep row, #endif { sp = row; - dp = row; - for (i = 0; i < row_width; i++, sp += 2, dp++) + for (i = 0; i < row_width; i++, sp += 2) { png_byte a = *(sp + 1); - if (a == 0xff) - *dp = *sp; - -#ifdef PNG_READ_GAMMA_SUPPORTED - else if (a == 0) - *dp = (png_byte)background->gray; - - else - png_composite(*dp, *sp, a, background_1->gray); + if (a == 0) + *sp = (png_byte)png_ptr->background.gray; -#else - *dp = (png_byte)background->gray; -#endif + else if (a < 0xff) + png_composite(*sp, *sp, a, png_ptr->background_1.gray); } } } @@ -3178,8 +3920,7 @@ png_do_background(png_row_infop row_info, png_bytep row, gamma_16_to_1 != NULL) { sp = row; - dp = row; - for (i = 0; i < row_width; i++, sp += 4, dp += 2) + for (i = 0; i < row_width; i++, sp += 4) { png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) + *(sp + 3)); @@ -3189,69 +3930,56 @@ png_do_background(png_row_infop row_info, png_bytep row, png_uint_16 v; v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; - *dp = (png_byte)((v >> 8) & 0xff); - *(dp + 1) = (png_byte)(v & 0xff); + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); } -#ifdef PNG_READ_GAMMA_SUPPORTED else if (a == 0) -#else - else -#endif { /* Background is already in screen gamma */ - *dp = (png_byte)((background->gray >> 8) & 0xff); - *(dp + 1) = (png_byte)(background->gray & 0xff); + *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); } -#ifdef PNG_READ_GAMMA_SUPPORTED else { png_uint_16 g, v, w; g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; - png_composite_16(v, g, a, background_1->gray); - w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; - *dp = (png_byte)((w >> 8) & 0xff); - *(dp + 1) = (png_byte)(w & 0xff); + png_composite_16(v, g, a, png_ptr->background_1.gray); + if (optimize) + w = v; + else + w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; + *sp = (png_byte)((w >> 8) & 0xff); + *(sp + 1) = (png_byte)(w & 0xff); } -#endif } } else #endif { sp = row; - dp = row; - for (i = 0; i < row_width; i++, sp += 4, dp += 2) + for (i = 0; i < row_width; i++, sp += 4) { png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) + *(sp + 3)); - if (a == (png_uint_16)0xffff) - png_memcpy(dp, sp, 2); - -#ifdef PNG_READ_GAMMA_SUPPORTED - else if (a == 0) -#else - else -#endif + if (a == 0) { - *dp = (png_byte)((background->gray >> 8) & 0xff); - *(dp + 1) = (png_byte)(background->gray & 0xff); + *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); } -#ifdef PNG_READ_GAMMA_SUPPORTED - else + else if (a < 0xffff) { png_uint_16 g, v; g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - png_composite_16(v, g, a, background_1->gray); - *dp = (png_byte)((v >> 8) & 0xff); - *(dp + 1) = (png_byte)(v & 0xff); + png_composite_16(v, g, a, png_ptr->background_1.gray); + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); } -#endif } } } @@ -3267,24 +3995,23 @@ png_do_background(png_row_infop row_info, png_bytep row, gamma_table != NULL) { sp = row; - dp = row; - for (i = 0; i < row_width; i++, sp += 4, dp += 3) + for (i = 0; i < row_width; i++, sp += 4) { png_byte a = *(sp + 3); if (a == 0xff) { - *dp = gamma_table[*sp]; - *(dp + 1) = gamma_table[*(sp + 1)]; - *(dp + 2) = gamma_table[*(sp + 2)]; + *sp = gamma_table[*sp]; + *(sp + 1) = gamma_table[*(sp + 1)]; + *(sp + 2) = gamma_table[*(sp + 2)]; } else if (a == 0) { /* Background is already in screen gamma */ - *dp = (png_byte)background->red; - *(dp + 1) = (png_byte)background->green; - *(dp + 2) = (png_byte)background->blue; + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; } else @@ -3292,16 +4019,19 @@ png_do_background(png_row_infop row_info, png_bytep row, png_byte v, w; v = gamma_to_1[*sp]; - png_composite(w, v, a, background_1->red); - *dp = gamma_from_1[w]; + png_composite(w, v, a, png_ptr->background_1.red); + if (!optimize) w = gamma_from_1[w]; + *sp = w; v = gamma_to_1[*(sp + 1)]; - png_composite(w, v, a, background_1->green); - *(dp + 1) = gamma_from_1[w]; + png_composite(w, v, a, png_ptr->background_1.green); + if (!optimize) w = gamma_from_1[w]; + *(sp + 1) = w; v = gamma_to_1[*(sp + 2)]; - png_composite(w, v, a, background_1->blue); - *(dp + 2) = gamma_from_1[w]; + png_composite(w, v, a, png_ptr->background_1.blue); + if (!optimize) w = gamma_from_1[w]; + *(sp + 2) = w; } } } @@ -3309,34 +4039,26 @@ png_do_background(png_row_infop row_info, png_bytep row, #endif { sp = row; - dp = row; - for (i = 0; i < row_width; i++, sp += 4, dp += 3) + for (i = 0; i < row_width; i++, sp += 4) { png_byte a = *(sp + 3); - if (a == 0xff) - { - *dp = *sp; - *(dp + 1) = *(sp + 1); - *(dp + 2) = *(sp + 2); - } - - else if (a == 0) + if (a == 0) { - *dp = (png_byte)background->red; - *(dp + 1) = (png_byte)background->green; - *(dp + 2) = (png_byte)background->blue; + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; } - else + else if (a < 0xff) { - png_composite(*dp, *sp, a, background->red); + png_composite(*sp, *sp, a, png_ptr->background.red); - png_composite(*(dp + 1), *(sp + 1), a, - background->green); + png_composite(*(sp + 1), *(sp + 1), a, + png_ptr->background.green); - png_composite(*(dp + 2), *(sp + 2), a, - background->blue); + png_composite(*(sp + 2), *(sp + 2), a, + png_ptr->background.blue); } } } @@ -3348,8 +4070,7 @@ png_do_background(png_row_infop row_info, png_bytep row, gamma_16_to_1 != NULL) { sp = row; - dp = row; - for (i = 0; i < row_width; i++, sp += 8, dp += 6) + for (i = 0; i < row_width; i++, sp += 8) { png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) << 8) + (png_uint_16)(*(sp + 7))); @@ -3359,53 +4080,55 @@ png_do_background(png_row_infop row_info, png_bytep row, png_uint_16 v; v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; - *dp = (png_byte)((v >> 8) & 0xff); - *(dp + 1) = (png_byte)(v & 0xff); + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; - *(dp + 2) = (png_byte)((v >> 8) & 0xff); - *(dp + 3) = (png_byte)(v & 0xff); + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; - *(dp + 4) = (png_byte)((v >> 8) & 0xff); - *(dp + 5) = (png_byte)(v & 0xff); + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); } else if (a == 0) { /* Background is already in screen gamma */ - *dp = (png_byte)((background->red >> 8) & 0xff); - *(dp + 1) = (png_byte)(background->red & 0xff); - *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); - *(dp + 3) = (png_byte)(background->green & 0xff); - *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); - *(dp + 5) = (png_byte)(background->blue & 0xff); + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); } else { - png_uint_16 v, w, x; + png_uint_16 v, w; v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; - png_composite_16(w, v, a, background_1->red); - - x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; - *dp = (png_byte)((x >> 8) & 0xff); - *(dp + 1) = (png_byte)(x & 0xff); + png_composite_16(w, v, a, png_ptr->background_1.red); + if (!optimize) + w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; + *sp = (png_byte)((w >> 8) & 0xff); + *(sp + 1) = (png_byte)(w & 0xff); v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; - png_composite_16(w, v, a, background_1->green); + png_composite_16(w, v, a, png_ptr->background_1.green); + if (!optimize) + w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; - x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; - *(dp + 2) = (png_byte)((x >> 8) & 0xff); - *(dp + 3) = (png_byte)(x & 0xff); + *(sp + 2) = (png_byte)((w >> 8) & 0xff); + *(sp + 3) = (png_byte)(w & 0xff); v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; - png_composite_16(w, v, a, background_1->blue); + png_composite_16(w, v, a, png_ptr->background_1.blue); + if (!optimize) + w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; - x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8]; - *(dp + 4) = (png_byte)((x >> 8) & 0xff); - *(dp + 5) = (png_byte)(x & 0xff); + *(sp + 4) = (png_byte)((w >> 8) & 0xff); + *(sp + 5) = (png_byte)(w & 0xff); } } } @@ -3414,28 +4137,22 @@ png_do_background(png_row_infop row_info, png_bytep row, #endif { sp = row; - dp = row; - for (i = 0; i < row_width; i++, sp += 8, dp += 6) + for (i = 0; i < row_width; i++, sp += 8) { png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) << 8) + (png_uint_16)(*(sp + 7))); - if (a == (png_uint_16)0xffff) - { - png_memcpy(dp, sp, 6); - } - - else if (a == 0) + if (a == 0) { - *dp = (png_byte)((background->red >> 8) & 0xff); - *(dp + 1) = (png_byte)(background->red & 0xff); - *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); - *(dp + 3) = (png_byte)(background->green & 0xff); - *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); - *(dp + 5) = (png_byte)(background->blue & 0xff); + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); } - else + else if (a < 0xffff) { png_uint_16 v; @@ -3445,17 +4162,17 @@ png_do_background(png_row_infop row_info, png_bytep row, png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + *(sp + 5)); - png_composite_16(v, r, a, background->red); - *dp = (png_byte)((v >> 8) & 0xff); - *(dp + 1) = (png_byte)(v & 0xff); + png_composite_16(v, r, a, png_ptr->background.red); + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); - png_composite_16(v, g, a, background->green); - *(dp + 2) = (png_byte)((v >> 8) & 0xff); - *(dp + 3) = (png_byte)(v & 0xff); + png_composite_16(v, g, a, png_ptr->background.green); + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); - png_composite_16(v, b, a, background->blue); - *(dp + 4) = (png_byte)((v >> 8) & 0xff); - *(dp + 5) = (png_byte)(v & 0xff); + png_composite_16(v, b, a, png_ptr->background.blue); + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); } } } @@ -3466,19 +4183,9 @@ png_do_background(png_row_infop row_info, png_bytep row, default: break; } - - if (row_info->color_type & PNG_COLOR_MASK_ALPHA) - { - row_info->color_type = (png_byte)(row_info->color_type & - ~PNG_COLOR_MASK_ALPHA); - row_info->channels--; - row_info->pixel_depth = (png_byte)(row_info->channels * - row_info->bit_depth); - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); - } } } -#endif +#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_READ_ALPHA_MODE_SUPPORTED */ #ifdef PNG_READ_GAMMA_SUPPORTED /* Gamma correct the image, avoiding the alpha channel. Make sure @@ -3488,10 +4195,12 @@ png_do_background(png_row_infop row_info, png_bytep row, * build_gamma_table(). */ void /* PRIVATE */ -png_do_gamma(png_row_infop row_info, png_bytep row, - png_const_bytep gamma_table, png_const_uint_16pp gamma_16_table, - int gamma_shift) +png_do_gamma(png_row_infop row_info, png_bytep row, png_structp png_ptr) { + png_const_bytep gamma_table = png_ptr->gamma_table; + png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table; + int gamma_shift = png_ptr->gamma_shift; + png_bytep sp; png_uint_32 i; png_uint_32 row_width=row_info->width; @@ -3681,6 +4390,73 @@ png_do_gamma(png_row_infop row_info, png_bytep row, } #endif +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +/* Encode the alpha channel to the output gamma (the input channel is always + * linear.) Called only with color types that have an alpha channel. Needs the + * from_1 tables. + */ +void /* PRIVATE */ +png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structp png_ptr) +{ + png_uint_32 row_width = row_info->width; + + png_debug(1, "in png_do_encode_alpha"); + + if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + { + if (row_info->bit_depth == 8) + { + PNG_CONST png_bytep table = png_ptr->gamma_from_1; + + if (table != NULL) + { + PNG_CONST int step = + (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2; + + /* The alpha channel is the last component: */ + row += step - 1; + + for (; row_width > 0; --row_width, row += step) + *row = table[*row]; + + return; + } + } + + else if (row_info->bit_depth == 16) + { + PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1; + PNG_CONST int gamma_shift = png_ptr->gamma_shift; + + if (table != NULL) + { + PNG_CONST int step = + (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4; + + /* The alpha channel is the last component: */ + row += step - 2; + + for (; row_width > 0; --row_width, row += step) + { + png_uint_16 v; + + v = table[*(row + 1) >> gamma_shift][*row]; + *row = (png_byte)((v >> 8) & 0xff); + *(row + 1) = (png_byte)(v & 0xff); + } + + return; + } + } + } + + /* Only get to here if called with a weird row_info; no harm has been done, + * so just issue a warning. + */ + png_warning(png_ptr, "png_do_encode_alpha: unexpected call"); +} +#endif + #ifdef PNG_READ_EXPAND_SUPPORTED /* Expands a palette row to an RGB or RGBA row depending * upon whether you supply trans and num_trans. @@ -3786,7 +4562,7 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row, if (row_info->bit_depth == 8) { { - if (trans_alpha != NULL) + if (num_trans > 0) { sp = row + (png_size_t)row_width - 1; dp = row + (png_size_t)(row_width << 2) - 1; @@ -3840,7 +4616,7 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row, */ void /* PRIVATE */ png_do_expand(png_row_infop row_info, png_bytep row, - png_const_color_16p trans_value) + png_const_color_16p trans_color) { int shift, value; png_bytep sp, dp; @@ -3852,7 +4628,7 @@ png_do_expand(png_row_infop row_info, png_bytep row, { if (row_info->color_type == PNG_COLOR_TYPE_GRAY) { - png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0); + png_uint_16 gray = (png_uint_16)(trans_color ? trans_color->gray : 0); if (row_info->bit_depth < 8) { @@ -3944,7 +4720,7 @@ png_do_expand(png_row_infop row_info, png_bytep row, row_info->rowbytes = row_width; } - if (trans_value != NULL) + if (trans_color != NULL) { if (row_info->bit_depth == 8) { @@ -3996,13 +4772,13 @@ png_do_expand(png_row_infop row_info, png_bytep row, row_width); } } - else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value) + else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_color) { if (row_info->bit_depth == 8) { - png_byte red = (png_byte)(trans_value->red & 0xff); - png_byte green = (png_byte)(trans_value->green & 0xff); - png_byte blue = (png_byte)(trans_value->blue & 0xff); + png_byte red = (png_byte)(trans_color->red & 0xff); + png_byte green = (png_byte)(trans_color->green & 0xff); + png_byte blue = (png_byte)(trans_color->blue & 0xff); sp = row + (png_size_t)row_info->rowbytes - 1; dp = row + (png_size_t)(row_width << 2) - 1; for (i = 0; i < row_width; i++) @@ -4020,12 +4796,12 @@ png_do_expand(png_row_infop row_info, png_bytep row, } else if (row_info->bit_depth == 16) { - png_byte red_high = (png_byte)((trans_value->red >> 8) & 0xff); - png_byte green_high = (png_byte)((trans_value->green >> 8) & 0xff); - png_byte blue_high = (png_byte)((trans_value->blue >> 8) & 0xff); - png_byte red_low = (png_byte)(trans_value->red & 0xff); - png_byte green_low = (png_byte)(trans_value->green & 0xff); - png_byte blue_low = (png_byte)(trans_value->blue & 0xff); + png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff); + png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff); + png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff); + png_byte red_low = (png_byte)(trans_color->red & 0xff); + png_byte green_low = (png_byte)(trans_color->green & 0xff); + png_byte blue_low = (png_byte)(trans_color->blue & 0xff); sp = row + row_info->rowbytes - 1; dp = row + (png_size_t)(row_width << 3) - 1; for (i = 0; i < row_width; i++) @@ -4064,6 +4840,37 @@ png_do_expand(png_row_infop row_info, png_bytep row, } #endif +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* If the bit depth is 8 and the color type is not a palette type expand the + * whole row to 16 bits. Has no effect otherwise. + */ +void /* PRIVATE */ +png_do_expand_16(png_row_infop row_info, png_bytep row) +{ + if (row_info->bit_depth == 8 && + row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + /* The row have a sequence of bytes containing [0..255] and we need + * to turn it into another row containing [0..65535], to do this we + * calculate: + * + * (input / 255) * 65535 + * + * Which happens to be exactly input * 257 and this can be achieved + * simply by byte replication in place (copying backwards). + */ + png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */ + png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */ + while (dp > sp) + dp[-2] = dp[-1] = *--sp, dp -= 2; + + row_info->rowbytes *= 2; + row_info->bit_depth = 16; + row_info->pixel_depth = (png_byte)(row_info->channels * 16); + } +} +#endif + #ifdef PNG_READ_QUANTIZE_SUPPORTED void /* PRIVATE */ png_do_quantize(png_row_infop row_info, png_bytep row, @@ -4157,6 +4964,7 @@ png_do_quantize(png_row_infop row_info, png_bytep row, } } #endif /* PNG_READ_QUANTIZE_SUPPORTED */ +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ #ifdef PNG_MNG_FEATURES_SUPPORTED /* Undoes intrapixel differencing */ @@ -4210,8 +5018,8 @@ png_do_read_intrapixel(png_row_infop row_info, png_bytep row) png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); - png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL); - png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL); + png_uint_32 red = (s0 + s1 + 65536) & 0xffff; + png_uint_32 blue = (s2 + s1 + 65536) & 0xffff; *(rp ) = (png_byte)((red >> 8) & 0xff); *(rp + 1) = (png_byte)(red & 0xff); *(rp + 4) = (png_byte)((blue >> 8) & 0xff); diff --git a/png/pngrutil.c b/png/pngrutil.c index 4c3cd5381..aa592ccfb 100644 --- a/png/pngrutil.c +++ b/png/pngrutil.c @@ -1,8 +1,8 @@ /* pngrutil.c - utilities to read a PNG file * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -87,10 +87,10 @@ png_int_32 (PNGAPI png_get_int_32)(png_const_bytep buf) { png_uint_32 uval = png_get_uint_32(buf); - if ((uval & 0x80000000L) == 0) /* non-negative */ + if ((uval & 0x80000000) == 0) /* non-negative */ return uval; - uval = (uval ^ 0xffffffffL) + 1; /* 2's complement: -x = ~x+1 */ + uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ return -(png_int_32)uval; } @@ -165,14 +165,14 @@ png_read_chunk_header(png_structp png_ptr) length = png_get_uint_31(png_ptr, buf); /* Put the chunk name into png_ptr->chunk_name. */ - png_memcpy(png_ptr->chunk_name, buf + 4, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); - png_debug2(0, "Reading %s chunk, length = %u", - png_ptr->chunk_name, length); + png_debug2(0, "Reading %lx chunk, length = %lu", + (unsigned long)png_ptr->chunk_name, (unsigned long)length); /* Reset the crc and run it over the chunk name. */ png_reset_crc(png_ptr); - png_calculate_crc(png_ptr, png_ptr->chunk_name, 4); + png_calculate_crc(png_ptr, buf + 4, 4); /* Check to see if chunk name is valid. */ png_check_chunk_name(png_ptr, png_ptr->chunk_name); @@ -218,10 +218,9 @@ png_crc_finish(png_structp png_ptr, png_uint_32 skip) if (png_crc_error(png_ptr)) { - if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */ - !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) || - (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */ - (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))) + if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name) ? + !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) : + (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)) { png_chunk_warning(png_ptr, "CRC error"); } @@ -248,14 +247,14 @@ png_crc_error(png_structp png_ptr) png_uint_32 crc; int need_crc = 1; - if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name)) { if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) need_crc = 0; } - else /* critical */ + else /* critical */ { if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) need_crc = 0; @@ -278,8 +277,7 @@ png_crc_error(png_structp png_ptr) return (0); } -#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \ - defined(PNG_READ_iCCP_SUPPORTED) +#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED static png_size_t png_inflate(png_structp png_ptr, png_bytep data, png_size_t size, png_bytep output, png_size_t output_size) @@ -303,7 +301,7 @@ png_inflate(png_structp png_ptr, png_bytep data, png_size_t size, { int ret, avail; - /* The setting of 'avail_in' used to be outside the loop, by setting it + /* The setting of 'avail_in' used to be outside the loop; by setting it * inside it is possible to chunk the input to zlib and simply rely on * zlib to advance the 'next_in' pointer. This allows arbitrary amounts o * data to be passed through zlib at the unavoidable cost of requiring a @@ -370,41 +368,31 @@ png_inflate(png_structp png_ptr, png_bytep data, png_size_t size, * and the error message is dumped into the uncompressed * buffer if available. */ +# ifdef PNG_WARNINGS_SUPPORTED { - PNG_CONST char *msg; -#ifdef PNG_CONSOLE_IO_SUPPORTED - char umsg[52]; -#endif + png_const_charp msg; + if (png_ptr->zstream.msg != 0) msg = png_ptr->zstream.msg; - else + else switch (ret) { -#ifdef PNG_CONSOLE_IO_SUPPORTED - switch (ret) - { - case Z_BUF_ERROR: - msg = "Buffer error in compressed datastream in %s chunk"; - break; - - case Z_DATA_ERROR: - msg = "Data error in compressed datastream in %s chunk"; - break; + case Z_BUF_ERROR: + msg = "Buffer error in compressed datastream"; + break; - default: - msg = "Incomplete compressed datastream in %s chunk"; - break; - } + case Z_DATA_ERROR: + msg = "Data error in compressed datastream"; + break; - png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name); - msg = umsg; -#else - msg = "Damaged compressed datastream in chunk other than IDAT"; -#endif + default: + msg = "Incomplete compressed datastream"; + break; } - png_warning(png_ptr, msg); + png_chunk_warning(png_ptr, msg); } +# endif /* 0 means an error - notice that this code simply ignores * zero length compressed chunks as a result. @@ -438,21 +426,22 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, png_size_t expanded_size = png_inflate(png_ptr, (png_bytep)(png_ptr->chunkdata + prefix_size), chunklength - prefix_size, - 0, /*output*/ - 0); /*output size*/ + 0, /* output */ + 0); /* output size */ /* Now check the limits on this chunk - if the limit fails the * compressed data will be removed, the prefix will remain. */ -#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED - if (png_ptr->user_chunk_malloc_max && + if (prefix_size >= (~(png_size_t)0) - 1 || + expanded_size >= (~(png_size_t)0) - 1 - prefix_size +#ifdef PNG_USER_LIMITS_SUPPORTED + || (png_ptr->user_chunk_malloc_max && (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1)) #else -# ifdef PNG_USER_CHUNK_MALLOC_MAX - if ((PNG_USER_CHUNK_MALLOC_MAX > 0) && + || ((PNG_USER_CHUNK_MALLOC_MAX > 0) && prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1) -# endif #endif + ) png_warning(png_ptr, "Exceeded size limit while expanding chunk"); /* If the size is zero either there was an error and a message @@ -460,16 +449,11 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, * and we have nothing to do - the code will exit through the * error case below. */ -#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \ - defined(PNG_USER_CHUNK_MALLOC_MAX) else if (expanded_size > 0) -#else - if (expanded_size > 0) -#endif { /* Success (maybe) - really uncompress the chunk. */ png_size_t new_size = 0; - png_charp text = png_malloc_warn(png_ptr, + png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + expanded_size + 1); if (text != NULL) @@ -500,15 +484,9 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ { -#ifdef PNG_STDIO_SUPPORTED - char umsg[50]; - - png_snprintf(umsg, sizeof umsg, - "Unknown zTXt compression type %d", comp_type); - png_warning(png_ptr, umsg); -#else - png_warning(png_ptr, "Unknown zTXt compression type"); -#endif + PNG_WARNING_PARAMETERS(p) + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type); + png_formatted_warning(png_ptr, p, "Unknown compression type @1"); /* The recovery is to simply drop the data. */ } @@ -518,7 +496,7 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, * amount of compressed data. */ { - png_charp text = png_malloc_warn(png_ptr, prefix_size + 1); + png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1); if (text != NULL) { @@ -536,7 +514,7 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, *newlength = prefix_size; } -#endif +#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */ /* Read and check the IDHR chunk */ void /* PRIVATE */ @@ -844,14 +822,12 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) # ifdef PNG_READ_sRGB_SUPPORTED if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) { - if (PNG_OUT_OF_RANGE(igamma, 45500L, 500)) + if (PNG_OUT_OF_RANGE(igamma, 45500, 500)) { - png_warning(png_ptr, - "Ignoring incorrect gAMA value when sRGB is also present"); - -# ifdef PNG_CONSOLE_IO_SUPPORTED - fprintf(stderr, "gamma = (%d/100000)", (int)igamma); -# endif + PNG_WARNING_PARAMETERS(p) + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma); + png_formatted_warning(png_ptr, p, + "Ignoring incorrect gAMA value @1 when sRGB is also present"); return; } } @@ -961,7 +937,7 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) else if (png_ptr->mode & PNG_HAVE_PLTE) /* Should be an error, but we can cope with it */ - png_warning(png_ptr, "Missing PLTE before cHRM"); + png_warning(png_ptr, "Out of place cHRM chunk"); if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM) # ifdef PNG_READ_sRGB_SUPPORTED @@ -1013,28 +989,112 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) || PNG_OUT_OF_RANGE(y_white, 32900, 1000) || - PNG_OUT_OF_RANGE(x_red, 64000L, 1000) || + PNG_OUT_OF_RANGE(x_red, 64000, 1000) || PNG_OUT_OF_RANGE(y_red, 33000, 1000) || PNG_OUT_OF_RANGE(x_green, 30000, 1000) || - PNG_OUT_OF_RANGE(y_green, 60000L, 1000) || + PNG_OUT_OF_RANGE(y_green, 60000, 1000) || PNG_OUT_OF_RANGE(x_blue, 15000, 1000) || PNG_OUT_OF_RANGE(y_blue, 6000, 1000)) { - png_warning(png_ptr, - "Ignoring incorrect cHRM value when sRGB is also present"); - -#ifdef PNG_CONSOLE_IO_SUPPORTED - fprintf(stderr, "wx=%d, wy=%d, rx=%d, ry=%d\n", - x_white, y_white, x_red, y_red); - - fprintf(stderr, "gx=%d, gy=%d, bx=%d, by=%d\n", - x_green, y_green, x_blue, y_blue); -#endif /* PNG_CONSOLE_IO_SUPPORTED */ + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white); + png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white); + png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red); + png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red); + png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green); + png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green); + png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue); + png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue); + + png_formatted_warning(png_ptr, p, + "Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) " + "when sRGB is also present"); } return; } #endif /* PNG_READ_sRGB_SUPPORTED */ +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Store the _white values as default coefficients for the rgb to gray + * operation if it is supported. Check if the transform is already set to + * avoid destroying the transform values. + */ + if (!png_ptr->rgb_to_gray_coefficients_set) + { + /* png_set_background has not been called and we haven't seen an sRGB + * chunk yet. Find the XYZ of the three end points. + */ + png_XYZ XYZ; + png_xy xy; + + xy.redx = x_red; + xy.redy = y_red; + xy.greenx = x_green; + xy.greeny = y_green; + xy.bluex = x_blue; + xy.bluey = y_blue; + xy.whitex = x_white; + xy.whitey = y_white; + + if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy)) + { + /* The success case, because XYZ_from_xy normalises to a reference + * white Y of 1.0 we just need to scale the numbers. This should + * always work just fine. It is an internal error if this overflows. + */ + { + png_fixed_point r, g, b; + if (png_muldiv(&r, XYZ.redY, 32768, PNG_FP_1) && + r >= 0 && r <= 32768 && + png_muldiv(&g, XYZ.greenY, 32768, PNG_FP_1) && + g >= 0 && g <= 32768 && + png_muldiv(&b, XYZ.blueY, 32768, PNG_FP_1) && + b >= 0 && b <= 32768 && + r+g+b <= 32769) + { + /* We allow 0 coefficients here. r+g+b may be 32769 if two or + * all of the coefficients were rounded up. Handle this by + * reducing the *largest* coefficient by 1; this matches the + * approach used for the default coefficients in pngrtran.c + */ + int add = 0; + + if (r+g+b > 32768) + add = -1; + else if (r+g+b < 32768) + add = 1; + + if (add != 0) + { + if (g >= r && g >= b) + g += add; + else if (r >= g && r >= b) + r += add; + else + b += add; + } + + /* Check for an internal error. */ + if (r+g+b != 32768) + png_error(png_ptr, + "internal error handling cHRM coefficients"); + + png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r; + png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g; + } + + /* This is a png_error at present even though it could be ignored - + * it should never happen, but it is important that if it does, the + * bug is fixed. + */ + else + png_error(png_ptr, "internal error handling cHRM->XYZ"); + } + } + } +#endif + png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red, x_green, y_green, x_blue, y_blue); } @@ -1094,13 +1154,15 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)) { - if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500L, 500)) + if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500)) { - png_warning(png_ptr, - "Ignoring incorrect gAMA value when sRGB is also present"); -#ifdef PNG_CONSOLE_IO_SUPPORTED - fprintf(stderr, "incorrect gamma=(%d/100000)\n", info_ptr->gamma); -#endif + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, + info_ptr->gamma); + + png_formatted_warning(png_ptr, p, + "Ignoring incorrect gAMA value @1 when sRGB is also present"); } } #endif /* PNG_READ_gAMA_SUPPORTED */ @@ -1109,10 +1171,10 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270, 1000) || PNG_OUT_OF_RANGE(info_ptr->y_white, 32900, 1000) || - PNG_OUT_OF_RANGE(info_ptr->x_red, 64000L, 1000) || + PNG_OUT_OF_RANGE(info_ptr->x_red, 64000, 1000) || PNG_OUT_OF_RANGE(info_ptr->y_red, 33000, 1000) || PNG_OUT_OF_RANGE(info_ptr->x_green, 30000, 1000) || - PNG_OUT_OF_RANGE(info_ptr->y_green, 60000L, 1000) || + PNG_OUT_OF_RANGE(info_ptr->y_green, 60000, 1000) || PNG_OUT_OF_RANGE(info_ptr->x_blue, 15000, 1000) || PNG_OUT_OF_RANGE(info_ptr->y_blue, 6000, 1000)) { @@ -1121,6 +1183,47 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif /* PNG_READ_cHRM_SUPPORTED */ + /* This is recorded for use when handling the cHRM chunk above. An sRGB + * chunk unconditionally overwrites the coefficients for grayscale conversion + * too. + */ + png_ptr->is_sRGB = 1; + +# ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Don't overwrite user supplied values: */ + if (!png_ptr->rgb_to_gray_coefficients_set) + { + /* These numbers come from the sRGB specification (or, since one has to + * pay much money to get a copy, the wikipedia sRGB page) the + * chromaticity values quoted have been inverted to get the reverse + * transformation from RGB to XYZ and the 'Y' coefficients scaled by + * 32768 (then rounded). + * + * sRGB and ITU Rec-709 both truncate the values for the D65 white + * point to four digits and, even though it actually stores five + * digits, the PNG spec gives the truncated value. + * + * This means that when the chromaticities are converted back to XYZ + * end points we end up with (6968,23435,2366), which, as described in + * pngrtran.c, would overflow. If the five digit precision and up is + * used we get, instead: + * + * 6968*R + 23435*G + 2365*B + * + * (Notice that this rounds the blue coefficient down, rather than the + * choice used in pngrtran.c which is to round the green one down.) + */ + png_ptr->rgb_to_gray_red_coeff = 6968; /* 0.212639005871510 */ + png_ptr->rgb_to_gray_green_coeff = 23434; /* 0.715168678767756 */ + /* png_ptr->rgb_to_gray_blue_coeff = 2366; 0.072192315360734 */ + + /* The following keeps the cHRM chunk from destroying the + * coefficients again in the event that it follows the sRGB chunk. + */ + png_ptr->rgb_to_gray_coefficients_set = 1; + } +# endif + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); } #endif /* PNG_READ_sRGB_SUPPORTED */ @@ -1154,13 +1257,16 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Out of place iCCP chunk"); - if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)) + if ((png_ptr->mode & PNG_HAVE_iCCP) || (info_ptr != NULL && + (info_ptr->valid & (PNG_INFO_iCCP|PNG_INFO_sRGB)))) { png_warning(png_ptr, "Duplicate iCCP chunk"); png_crc_finish(png_ptr, length); return; } + png_ptr->mode |= PNG_HAVE_iCCP; + #ifdef PNG_MAX_MALLOC_64K if (length > (png_uint_32)65535L) { @@ -1172,7 +1278,7 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_free(png_ptr, png_ptr->chunkdata); png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1); - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) @@ -1240,23 +1346,15 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* And the following guarantees that profile_size == profile_length. */ if (profile_size > profile_length) { + PNG_WARNING_PARAMETERS(p) + png_free(png_ptr, png_ptr->chunkdata); png_ptr->chunkdata = NULL; -#ifdef PNG_STDIO_SUPPORTED - { - char umsg[80]; - - png_snprintf2(umsg, 80, - "Ignoring iCCP chunk with declared size = %u " - "and actual length = %u", - (unsigned int) profile_size, - (unsigned int) profile_length); - png_warning(png_ptr, umsg); - } -#else - png_warning(png_ptr, - "Ignoring iCCP chunk with uncompressed size mismatch"); -#endif + + png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size); + png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length); + png_formatted_warning(png_ptr, p, + "Ignoring iCCP chunk with declared size = @1 and actual length = @2"); return; } @@ -1275,9 +1373,7 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_bytep entry_start; png_sPLT_t new_palette; -#ifdef PNG_POINTER_INDEXING_SUPPORTED png_sPLT_entryp pp; -#endif png_uint_32 data_length; int entry_size, i; png_uint_32 skip = 0; @@ -1332,7 +1428,7 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a * potential breakage point if the types in pngconf.h aren't exactly right. */ - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) @@ -1442,7 +1538,7 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; } - pp->frequency = png_get_uint_16(entry_start); entry_start += 2; + pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2; } #endif @@ -1567,6 +1663,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_size_t truelen; png_byte buf[6]; + png_color_16 background; png_debug(1, "in png_handle_bKGD"); @@ -1623,7 +1720,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) */ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - png_ptr->background.index = buf[0]; + background.index = buf[0]; if (info_ptr && info_ptr->num_palette) { @@ -1633,33 +1730,36 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - png_ptr->background.red = - (png_uint_16)png_ptr->palette[buf[0]].red; + background.red = (png_uint_16)png_ptr->palette[buf[0]].red; + background.green = (png_uint_16)png_ptr->palette[buf[0]].green; + background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; + } - png_ptr->background.green = - (png_uint_16)png_ptr->palette[buf[0]].green; + else + background.red = background.green = background.blue = 0; - png_ptr->background.blue = - (png_uint_16)png_ptr->palette[buf[0]].blue; - } + background.gray = 0; } else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */ { - png_ptr->background.red = - png_ptr->background.green = - png_ptr->background.blue = - png_ptr->background.gray = png_get_uint_16(buf); + background.index = 0; + background.red = + background.green = + background.blue = + background.gray = png_get_uint_16(buf); } else { - png_ptr->background.red = png_get_uint_16(buf); - png_ptr->background.green = png_get_uint_16(buf + 2); - png_ptr->background.blue = png_get_uint_16(buf + 4); + background.index = 0; + background.red = png_get_uint_16(buf); + background.green = png_get_uint_16(buf + 2); + background.blue = png_get_uint_16(buf + 4); + background.gray = 0; } - png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background)); + png_set_bKGD(png_ptr, info_ptr, &background); } #endif @@ -1696,16 +1796,16 @@ png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - num = length / 2 ; - - if (num != (unsigned int)png_ptr->num_palette || num > - (unsigned int)PNG_MAX_PALETTE_LENGTH) + if (length > 2*PNG_MAX_PALETTE_LENGTH || + length != (unsigned int) (2*png_ptr->num_palette)) { png_warning(png_ptr, "Incorrect hIST chunk length"); png_crc_finish(png_ptr, length); return; } + num = length / 2 ; + for (i = 0; i < num; i++) { png_byte buf[2]; @@ -1855,7 +1955,7 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, 0)) @@ -1984,6 +2084,14 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } + /* Need unit type, width, \0, height: minimum 4 bytes */ + else if (length < 4) + { + png_warning(png_ptr, "sCAL chunk too short"); + png_crc_finish(png_ptr, length); + return; + } + png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)", length + 1); @@ -1996,7 +2104,7 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ @@ -2019,23 +2127,29 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* Validate the ASCII numbers, need two ASCII numbers separated by * a '\0' and they need to fit exactly in the chunk data. */ - i = 0; + i = 1; state = 0; - if (png_ptr->chunkdata[1] == 45 /* negative width */ || - !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || + if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || i >= slength || png_ptr->chunkdata[i++] != 0) png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format"); + else if (!PNG_FP_IS_POSITIVE(state)) + png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width"); + else { png_size_t heighti = i; - if (png_ptr->chunkdata[i] == 45 /* negative height */ || - !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || + state = 0; + if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || i != slength) png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format"); + else if (!PNG_FP_IS_POSITIVE(state)) + png_warning(png_ptr, + "Invalid sCAL chunk ignored: non-positive height"); + else /* This is the (only) success case. */ png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], @@ -2150,7 +2264,7 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) @@ -2258,7 +2372,7 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, 0)) @@ -2389,7 +2503,7 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, 0)) @@ -2425,6 +2539,14 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) comp_type = *lang++; } + if (comp_type || (comp_flag && comp_flag != PNG_TEXT_COMPRESSION_zTXt)) + { + png_warning(png_ptr, "Unknown iTXt compression type or method"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + for (lang_key = lang; *lang_key; lang_key++) /* Empty loop */ ; @@ -2525,16 +2647,14 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (png_ptr->mode & PNG_HAVE_IDAT) { - PNG_IDAT; - - if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */ + if (png_ptr->chunk_name != png_IDAT) png_ptr->mode |= PNG_AFTER_IDAT; } - if (!(png_ptr->chunk_name[0] & 0x20)) + if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) { #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) != PNG_HANDLE_CHUNK_ALWAYS #ifdef PNG_READ_USER_CHUNKS_SUPPORTED && png_ptr->read_user_chunk_fn == NULL @@ -2552,21 +2672,20 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) ) { #ifdef PNG_MAX_MALLOC_64K - if (length > (png_uint_32)65535L) + if (length > 65535) { png_warning(png_ptr, "unknown chunk too large to fit in memory"); - skip = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; + skip = length - 65535; + length = 65535; } #endif - png_memcpy((png_charp)png_ptr->unknown_chunk.name, - (png_charp)png_ptr->chunk_name, - png_sizeof(png_ptr->unknown_chunk.name)); - - png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1] - = '\0'; - + /* TODO: this code is very close to the unknown handling in pngpread.c, + * maybe it can be put into a common utility routine? + * png_struct::unknown_chunk is just used as a temporary variable, along + * with the data into which the chunk is read. These can be eliminated. + */ + PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name); png_ptr->unknown_chunk.size = (png_size_t)length; if (length == 0) @@ -2575,7 +2694,7 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) else { png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length); - png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); + png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length); } #ifdef PNG_READ_USER_CHUNKS_SUPPORTED @@ -2592,10 +2711,10 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (ret == 0) { - if (!(png_ptr->chunk_name[0] & 0x20)) + if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) { #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) != PNG_HANDLE_CHUNK_ALWAYS) #endif png_chunk_error(png_ptr, "unknown critical chunk"); @@ -2632,259 +2751,523 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) * the chunk name itself is valid. */ -#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) +/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is: + * + * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) + */ void /* PRIVATE */ -png_check_chunk_name(png_structp png_ptr, png_const_bytep chunk_name) +png_check_chunk_name(png_structp png_ptr, png_uint_32 chunk_name) { + int i; + png_debug(1, "in png_check_chunk_name"); - if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || - isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) + + for (i=1; i<=4; ++i) { - png_chunk_error(png_ptr, "invalid chunk type"); + int c = chunk_name & 0xff; + + if (c < 65 || c > 122 || (c > 90 && c < 97)) + png_chunk_error(png_ptr, "invalid chunk type"); + + chunk_name >>= 8; } } -/* Combines the row recently read in with the existing pixels in the - * row. This routine takes care of alpha and transparency if requested. - * This routine also handles the two methods of progressive display - * of interlaced images, depending on the mask value. - * The mask value describes which pixels are to be combined with - * the row. The pattern always repeats every 8 pixels, so just 8 - * bits are needed. A one indicates the pixel is to be combined, - * a zero indicates the pixel is to be skipped. This is in addition - * to any alpha or transparency value associated with the pixel. If - * you want all pixels to be combined, pass 0xff (255) in mask. +/* Combines the row recently read in with the existing pixels in the row. This + * routine takes care of alpha and transparency if requested. This routine also + * handles the two methods of progressive display of interlaced images, + * depending on the 'display' value; if 'display' is true then the whole row + * (dp) is filled from the start by replicating the available pixels. If + * 'display' is false only those pixels present in the pass are filled in. */ - void /* PRIVATE */ -png_combine_row(png_structp png_ptr, png_bytep row, int mask) +png_combine_row(png_structp png_ptr, png_bytep dp, int display) { + unsigned int pixel_depth = png_ptr->transformed_pixel_depth; + png_const_bytep sp = png_ptr->row_buf + 1; + png_uint_32 row_width = png_ptr->width; + unsigned int pass = png_ptr->pass; + png_bytep end_ptr = 0; + png_byte end_byte = 0; + unsigned int end_mask; + png_debug(1, "in png_combine_row"); - if (mask == 0xff) - { - png_memcpy(row, png_ptr->row_buf + 1, - PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width)); - } + /* Added in 1.5.6: it should not be possible to enter this routine until at + * least one row has been read from the PNG data and transformed. + */ + if (pixel_depth == 0) + png_error(png_ptr, "internal row logic error"); - else + /* Added in 1.5.4: the pixel depth should match the information returned by + * any call to png_read_update_info at this point. Do not continue if we got + * this wrong. + */ + if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes != + PNG_ROWBYTES(pixel_depth, row_width)) + png_error(png_ptr, "internal row size calculation error"); + + /* Don't expect this to ever happen: */ + if (row_width == 0) + png_error(png_ptr, "internal row width error"); + + /* Preserve the last byte in cases where only part of it will be overwritten, + * the multiply below may overflow, we don't care because ANSI-C guarantees + * we get the low bits. + */ + end_mask = (pixel_depth * row_width) & 7; + if (end_mask != 0) + { + /* end_ptr == NULL is a flag to say do nothing */ + end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1; + end_byte = *end_ptr; +# ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */ + end_mask = 0xff << end_mask; + + else /* big-endian byte */ +# endif + end_mask = 0xff >> end_mask; + /* end_mask is now the bits to *keep* from the destination row */ + } + + /* For non-interlaced images this reduces to a png_memcpy(). A png_memcpy() + * will also happen if interlacing isn't supported or if the application + * does not call png_set_interlace_handling(). In the latter cases the + * caller just gets a sequence of the unexpanded rows from each interlace + * pass. + */ +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) && + pass < 6 && (display == 0 || + /* The following copies everything for 'display' on passes 0, 2 and 4. */ + (display == 1 && (pass & 1) != 0))) { - switch (png_ptr->row_info.pixel_depth) + /* Narrow images may have no bits in a pass; the caller should handle + * this, but this test is cheap: + */ + if (row_width <= PNG_PASS_START_COL(pass)) + return; + + if (pixel_depth < 8) { - case 1: + /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit + * into 32 bits, then a single loop over the bytes using the four byte + * values in the 32-bit mask can be used. For the 'display' option the + * expanded mask may also not require any masking within a byte. To + * make this work the PACKSWAP option must be taken into account - it + * simply requires the pixels to be reversed in each byte. + * + * The 'regular' case requires a mask for each of the first 6 passes, + * the 'display' case does a copy for the even passes in the range + * 0..6. This has already been handled in the test above. + * + * The masks are arranged as four bytes with the first byte to use in + * the lowest bits (little-endian) regardless of the order (PACKSWAP or + * not) of the pixels in each byte. + * + * NOTE: the whole of this logic depends on the caller of this function + * only calling it on rows appropriate to the pass. This function only + * understands the 'x' logic; the 'y' logic is handled by the caller. + * + * The following defines allow generation of compile time constant bit + * masks for each pixel depth and each possibility of swapped or not + * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index, + * is in the range 0..7; and the result is 1 if the pixel is to be + * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B' + * for the block method. + * + * With some compilers a compile time expression of the general form: + * + * (shift >= 32) ? (a >> (shift-32)) : (b >> shift) + * + * Produces warnings with values of 'shift' in the range 33 to 63 + * because the right hand side of the ?: expression is evaluated by + * the compiler even though it isn't used. Microsoft Visual C (various + * versions) and the Intel C compiler are known to do this. To avoid + * this the following macros are used in 1.5.6. This is a temporary + * solution to avoid destabilizing the code during the release process. + */ +# if PNG_USE_COMPILE_TIME_MASKS +# define PNG_LSR(x,s) ((x)>>((s) & 0x1f)) +# define PNG_LSL(x,s) ((x)<<((s) & 0x1f)) +# else +# define PNG_LSR(x,s) ((x)>>(s)) +# define PNG_LSL(x,s) ((x)<<(s)) +# endif +# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1) +# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1) + + /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is + * little endian - the first pixel is at bit 0 - however the extra + * parameter 's' can be set to cause the mask position to be swapped + * within each byte, to match the PNG format. This is done by XOR of + * the shift with 7, 6 or 4 for bit depths 1, 2 and 4. + */ +# define PIXEL_MASK(p,x,d,s) \ + (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0)))) + + /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask. + */ +# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) +# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) + + /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp + * cases the result needs replicating, for the 4-bpp case the above + * generates a full 32 bits. + */ +# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1))) + +# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\ + S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\ + S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d) + +# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\ + B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\ + B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d) + +#if PNG_USE_COMPILE_TIME_MASKS + /* Utility macros to construct all the masks for a depth/swap + * combination. The 's' parameter says whether the format is PNG + * (big endian bytes) or not. Only the three odd-numbered passes are + * required for the display/block algorithm. + */ +# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\ + S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) } + +# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) } + +# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2)) + + /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and + * then pass: + */ + static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = { - png_bytep sp = png_ptr->row_buf + 1; - png_bytep dp = row; - int s_inc, s_start, s_end; - int m = 0x80; - int shift; - png_uint_32 i; - png_uint_32 row_width = png_ptr->width; - -#ifdef PNG_READ_PACKSWAP_SUPPORTED + /* Little-endian byte masks for PACKSWAP */ + { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) } + }; + + /* display_mask has only three entries for the odd passes, so index by + * pass>>1. + */ + static PNG_CONST png_uint_32 display_mask[2][3][3] = + { + /* Little-endian byte masks for PACKSWAP */ + { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) } + }; + +# define MASK(pass,depth,display,png)\ + ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\ + row_mask[png][DEPTH_INDEX(depth)][pass]) + +#else /* !PNG_USE_COMPILE_TIME_MASKS */ + /* This is the runtime alternative: it seems unlikely that this will + * ever be either smaller or faster than the compile time approach. + */ +# define MASK(pass,depth,display,png)\ + ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png)) +#endif /* !PNG_USE_COMPILE_TIME_MASKS */ + + /* Use the appropriate mask to copy the required bits. In some cases + * the byte mask will be 0 or 0xff, optimize these cases. row_width is + * the number of pixels, but the code copies bytes, so it is necessary + * to special case the end. + */ + png_uint_32 pixels_per_byte = 8 / pixel_depth; + png_uint_32 mask; + +# ifdef PNG_READ_PACKSWAP_SUPPORTED if (png_ptr->transformations & PNG_PACKSWAP) - { - s_start = 0; - s_end = 7; - s_inc = 1; - } + mask = MASK(pass, pixel_depth, display, 0); else -#endif +# endif + mask = MASK(pass, pixel_depth, display, 1); + + for (;;) + { + png_uint_32 m; + + /* It doesn't matter in the following if png_uint_32 has more than + * 32 bits because the high bits always match those in m<<24; it is, + * however, essential to use OR here, not +, because of this. + */ + m = mask; + mask = (m >> 8) | (m << 24); /* rotate right to good compilers */ + m &= 0xff; + + if (m != 0) /* something to copy */ { - s_start = 7; - s_end = 0; - s_inc = -1; + if (m != 0xff) + *dp = (png_byte)((*dp & ~m) | (*sp & m)); + else + *dp = *sp; } - shift = s_start; + /* NOTE: this may overwrite the last byte with garbage if the image + * is not an exact number of bytes wide; libpng has always done + * this. + */ + if (row_width <= pixels_per_byte) + break; /* May need to restore part of the last byte */ - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - int value; + row_width -= pixels_per_byte; + ++dp; + ++sp; + } + } - value = (*sp >> shift) & 0x01; - *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); - } + else /* pixel_depth >= 8 */ + { + unsigned int bytes_to_copy, bytes_to_jump; - if (shift == s_end) - { - shift = s_start; - sp++; - dp++; - } + /* Validate the depth - it must be a multiple of 8 */ + if (pixel_depth & 7) + png_error(png_ptr, "invalid user transform pixel depth"); - else - shift += s_inc; + pixel_depth >>= 3; /* now in bytes */ + row_width *= pixel_depth; - if (m == 1) - m = 0x80; + /* Regardless of pass number the Adam 7 interlace always results in a + * fixed number of pixels to copy then to skip. There may be a + * different number of pixels to skip at the start though. + */ + { + unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth; - else - m >>= 1; - } - break; + row_width -= offset; + dp += offset; + sp += offset; } - case 2: + /* Work out the bytes to copy. */ + if (display) { - png_bytep sp = png_ptr->row_buf + 1; - png_bytep dp = row; - int s_start, s_end, s_inc; - int m = 0x80; - int shift; - png_uint_32 i; - png_uint_32 row_width = png_ptr->width; - int value; + /* When doing the 'block' algorithm the pixel in the pass gets + * replicated to adjacent pixels. This is why the even (0,2,4,6) + * passes are skipped above - the entire expanded row is copied. + */ + bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth; -#ifdef PNG_READ_PACKSWAP_SUPPORTED - if (png_ptr->transformations & PNG_PACKSWAP) - { - s_start = 0; - s_end = 6; - s_inc = 2; - } + /* But don't allow this number to exceed the actual row width. */ + if (bytes_to_copy > row_width) + bytes_to_copy = row_width; + } - else -#endif - { - s_start = 6; - s_end = 0; - s_inc = -2; - } + else /* normal row; Adam7 only ever gives us one pixel to copy. */ + bytes_to_copy = pixel_depth; + + /* In Adam7 there is a constant offset between where the pixels go. */ + bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth; + + /* And simply copy these bytes. Some optimization is possible here, + * depending on the value of 'bytes_to_copy'. Special case the low + * byte counts, which we know to be frequent. + * + * Notice that these cases all 'return' rather than 'break' - this + * avoids an unnecessary test on whether to restore the last byte + * below. + */ + switch (bytes_to_copy) + { + case 1: + for (;;) + { + *dp = *sp; - shift = s_start; + if (row_width <= bytes_to_jump) + return; - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - value = (*sp >> shift) & 0x03; - *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); + dp += bytes_to_jump; + sp += bytes_to_jump; + row_width -= bytes_to_jump; } - if (shift == s_end) + case 2: + /* There is a possibility of a partial copy at the end here; this + * slows the code down somewhat. + */ + do { - shift = s_start; - sp++; - dp++; - } + dp[0] = sp[0], dp[1] = sp[1]; - else - shift += s_inc; + if (row_width <= bytes_to_jump) + return; - if (m == 1) - m = 0x80; + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + } + while (row_width > 1); - else - m >>= 1; - } - break; - } + /* And there can only be one byte left at this point: */ + *dp = *sp; + return; - case 4: - { - png_bytep sp = png_ptr->row_buf + 1; - png_bytep dp = row; - int s_start, s_end, s_inc; - int m = 0x80; - int shift; - png_uint_32 i; - png_uint_32 row_width = png_ptr->width; - int value; - -#ifdef PNG_READ_PACKSWAP_SUPPORTED - if (png_ptr->transformations & PNG_PACKSWAP) - { - s_start = 0; - s_end = 4; - s_inc = 4; - } + case 3: + /* This can only be the RGB case, so each copy is exactly one + * pixel and it is not necessary to check for a partial copy. + */ + for(;;) + { + dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2]; - else -#endif - { - s_start = 4; - s_end = 0; - s_inc = -4; - } - shift = s_start; + if (row_width <= bytes_to_jump) + return; - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - value = (*sp >> shift) & 0xf; - *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; } - if (shift == s_end) + default: +#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE + /* Check for double byte alignment and, if possible, use a + * 16-bit copy. Don't attempt this for narrow images - ones that + * are less than an interlace panel wide. Don't attempt it for + * wide bytes_to_copy either - use the png_memcpy there. + */ + if (bytes_to_copy < 16 /*else use png_memcpy*/ && + png_isaligned(dp, png_uint_16) && + png_isaligned(sp, png_uint_16) && + bytes_to_copy % sizeof (png_uint_16) == 0 && + bytes_to_jump % sizeof (png_uint_16) == 0) { - shift = s_start; - sp++; - dp++; + /* Everything is aligned for png_uint_16 copies, but try for + * png_uint_32 first. + */ + if (png_isaligned(dp, png_uint_32) && + png_isaligned(sp, png_uint_32) && + bytes_to_copy % sizeof (png_uint_32) == 0 && + bytes_to_jump % sizeof (png_uint_32) == 0) + { + png_uint_32p dp32 = (png_uint_32p)dp; + png_const_uint_32p sp32 = (png_const_uint_32p)sp; + unsigned int skip = (bytes_to_jump-bytes_to_copy) / + sizeof (png_uint_32); + + do + { + size_t c = bytes_to_copy; + do + { + *dp32++ = *sp32++; + c -= sizeof (png_uint_32); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp32 += skip; + sp32 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* Get to here when the row_width truncates the final copy. + * There will be 1-3 bytes left to copy, so don't try the + * 16-bit loop below. + */ + dp = (png_bytep)dp32; + sp = (png_const_bytep)sp32; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } + + /* Else do it in 16-bit quantities, but only if the size is + * not too large. + */ + else + { + png_uint_16p dp16 = (png_uint_16p)dp; + png_const_uint_16p sp16 = (png_const_uint_16p)sp; + unsigned int skip = (bytes_to_jump-bytes_to_copy) / + sizeof (png_uint_16); + + do + { + size_t c = bytes_to_copy; + do + { + *dp16++ = *sp16++; + c -= sizeof (png_uint_16); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp16 += skip; + sp16 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* End of row - 1 byte left, bytes_to_copy > row_width: */ + dp = (png_bytep)dp16; + sp = (png_const_bytep)sp16; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } } +#endif /* PNG_ALIGN_ code */ - else - shift += s_inc; + /* The true default - use a png_memcpy: */ + for (;;) + { + png_memcpy(dp, sp, bytes_to_copy); - if (m == 1) - m = 0x80; + if (row_width <= bytes_to_jump) + return; - else - m >>= 1; - } - break; + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + if (bytes_to_copy > row_width) + bytes_to_copy = row_width; + } } - default: - { - png_bytep sp = png_ptr->row_buf + 1; - png_bytep dp = row; - png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3); - png_uint_32 i; - png_uint_32 row_width = png_ptr->width; - png_byte m = 0x80; - - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - png_memcpy(dp, sp, pixel_bytes); - } + /* NOT REACHED*/ + } /* pixel_depth >= 8 */ - sp += pixel_bytes; - dp += pixel_bytes; + /* Here if pixel_depth < 8 to check 'end_ptr' below. */ + } + else +#endif - if (m == 1) - m = 0x80; + /* If here then the switch above wasn't used so just png_memcpy the whole row + * from the temporary row buffer (notice that this overwrites the end of the + * destination row if it is a partial byte.) + */ + png_memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width)); - else - m >>= 1; - } - break; - } - } - } + /* Restore the overwritten bits from the last byte if necessary. */ + if (end_ptr != NULL) + *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask)); } #ifdef PNG_READ_INTERLACING_SUPPORTED void /* PRIVATE */ -png_do_read_interlace(png_structp png_ptr) +png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, + png_uint_32 transformations /* Because these may affect the byte layout */) { - png_row_infop row_info = &(png_ptr->row_info); - png_bytep row = png_ptr->row_buf + 1; - int pass = png_ptr->pass; - png_uint_32 transformations = png_ptr->transformations; /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Offset to next interlace block */ - PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; png_debug(1, "in png_do_read_interlace"); if (row != NULL && row_info != NULL) @@ -3049,7 +3432,7 @@ png_do_read_interlace(png_structp png_ptr) for (i = 0; i < row_info->width; i++) { - png_byte v = (png_byte)((*sp >> sshift) & 0xf); + png_byte v = (png_byte)((*sp >> sshift) & 0x0f); int j; for (j = 0; j < jstop; j++) @@ -3078,6 +3461,7 @@ png_do_read_interlace(png_structp png_ptr) } break; } + default: { png_size_t pixel_bytes = (row_info->pixel_depth >> 3); @@ -3108,6 +3492,7 @@ png_do_read_interlace(png_structp png_ptr) break; } } + row_info->width = final_width; row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); } @@ -3117,132 +3502,252 @@ png_do_read_interlace(png_structp png_ptr) } #endif /* PNG_READ_INTERLACING_SUPPORTED */ -void /* PRIVATE */ -png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row, - png_const_bytep prev_row, int filter) +static void +png_read_filter_row_sub(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) { - png_debug(1, "in png_read_filter_row"); - png_debug2(2, "row = %u, filter = %d", png_ptr->row_number, filter); - switch (filter) + png_size_t i; + png_size_t istop = row_info->rowbytes; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp = row + bpp; + + PNG_UNUSED(prev_row) + + for (i = bpp; i < istop; i++) { - case PNG_FILTER_VALUE_NONE: - break; + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } +} - case PNG_FILTER_VALUE_SUB: - { - png_size_t i; - png_size_t istop = row_info->rowbytes; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_bytep rp = row + bpp; - png_bytep lp = row; +static void +png_read_filter_row_up(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_size_t istop = row_info->rowbytes; + png_bytep rp = row; + png_const_bytep pp = prev_row; - for (i = bpp; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff); - rp++; - } - break; - } - case PNG_FILTER_VALUE_UP: - { - png_size_t i; - png_size_t istop = row_info->rowbytes; - png_bytep rp = row; - png_const_bytep pp = prev_row; + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); + rp++; + } +} - for (i = 0; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; - } - break; - } - case PNG_FILTER_VALUE_AVG: - { - png_size_t i; - png_bytep rp = row; - png_const_bytep pp = prev_row; - png_bytep lp = row; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_size_t istop = row_info->rowbytes - bpp; - - for (i = 0; i < bpp; i++) - { - *rp = (png_byte)(((int)(*rp) + - ((int)(*pp++) / 2 )) & 0xff); +static void +png_read_filter_row_avg(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_bytep rp = row; + png_const_bytep pp = prev_row; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_size_t istop = row_info->rowbytes - bpp; - rp++; - } + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp++) / 2 )) & 0xff); - for (i = 0; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + - (int)(*pp++ + *lp++) / 2 ) & 0xff); + rp++; + } - rp++; - } - break; - } - case PNG_FILTER_VALUE_PAETH: - { - png_size_t i; - png_bytep rp = row; - png_const_bytep pp = prev_row; - png_bytep lp = row; - png_const_bytep cp = prev_row; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_size_t istop=row_info->rowbytes - bpp; - - for (i = 0; i < bpp; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; - } + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); - for (i = 0; i < istop; i++) /* Use leftover rp,pp */ - { - int a, b, c, pa, pb, pc, p; + rp++; + } +} - a = *lp++; - b = *pp++; - c = *cp++; +static void +png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp_end = row + row_info->rowbytes; + int a, c; - p = b - c; - pc = a - c; + /* First pixel/byte */ + c = *prev_row++; + a = *row + c; + *row++ = (png_byte)a; -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif + /* Remainder */ + while (row < rp_end) + { + int b, pa, pb, pc, p; - /* - if (pa <= pb && pa <= pc) - p = a; + a &= 0xff; /* From previous iteration or start */ + b = *prev_row++; - else if (pb <= pc) - p = b; + p = b - c; + pc = a - c; - else - p = c; - */ +# ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +# else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +# endif - p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c; + /* Find the best predictor, the least of pa, pb, pc favoring the earlier + * ones in the case of a tie. + */ + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; - *rp = (png_byte)(((int)(*rp) + p) & 0xff); - rp++; - } + /* Calculate the current pixel in a, and move the previous row pixel to c + * for the next time round the loop + */ + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +static void +png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp_end = row + bpp; + + /* Process the first pixel in the row completely (this is the same as 'up' + * because there is only one candidate predictor for the first row). + */ + while (row < rp_end) + { + int a = *row + *prev_row++; + *row++ = (png_byte)a; + } + + /* Remainder */ + rp_end += row_info->rowbytes - bpp; + + while (row < rp_end) + { + int a, b, c, pa, pb, pc, p; + + c = *(prev_row - bpp); + a = *(row - bpp); + b = *prev_row++; + + p = b - c; + pc = a - c; + +# ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +# else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +# endif + + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; + + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +#ifdef PNG_ARM_NEON + +#ifdef __linux__ +#include <stdio.h> +#include <elf.h> +#include <asm/hwcap.h> + +static int png_have_hwcap(unsigned cap) +{ + FILE *f = fopen("/proc/self/auxv", "r"); + Elf32_auxv_t aux; + int have_cap = 0; + + if (!f) + return 0; + + while (fread(&aux, sizeof(aux), 1, f) > 0) + { + if (aux.a_type == AT_HWCAP && + aux.a_un.a_val & cap) + { + have_cap = 1; break; } - default: - png_error(png_ptr, "Ignoring bad adaptive filter type"); - /*NOT REACHED */ - break; } + + fclose(f); + + return have_cap; +} +#endif /* __linux__ */ + +static void +png_init_filter_functions_neon(png_structp pp, unsigned int bpp) +{ +#ifdef __linux__ + if (!png_have_hwcap(HWCAP_NEON)) + return; +#endif + + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_neon; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_neon; + } +} +#endif /* PNG_ARM_NEON */ + +static void +png_init_filter_functions(png_structp pp) +{ + unsigned int bpp = (pp->pixel_depth + 7) >> 3; + + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; + if (bpp == 1) + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_1byte_pixel; + else + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_multibyte_pixel; + +#ifdef PNG_ARM_NEON + png_init_filter_functions_neon(pp, bpp); +#endif +} + +void /* PRIVATE */ +png_read_filter_row(png_structp pp, png_row_infop row_info, png_bytep row, + png_const_bytep prev_row, int filter) +{ + if (pp->read_filter[0] == NULL) + png_init_filter_functions(pp); + if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) + pp->read_filter[filter-1](row_info, row, prev_row); } #ifdef PNG_SEQUENTIAL_READ_SUPPORTED @@ -3253,16 +3758,16 @@ png_read_finish_row(png_structp png_ptr) /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Start of interlace block */ - PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* Offset to next interlace block */ - PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; /* Start of interlace block in the y direction */ - PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; /* Offset to next interlace block in the y direction */ - PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif /* PNG_READ_INTERLACING_SUPPORTED */ png_debug(1, "in png_read_finish_row"); @@ -3275,6 +3780,9 @@ png_read_finish_row(png_structp png_ptr) { png_ptr->row_number = 0; + /* TO DO: don't do this if prev_row isn't needed (requires + * read-ahead of the next row's filter byte. + */ png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); do @@ -3309,7 +3817,6 @@ png_read_finish_row(png_structp png_ptr) if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) { - PNG_IDAT; char extra; int ret; @@ -3324,7 +3831,7 @@ png_read_finish_row(png_structp png_ptr) { png_crc_finish(png_ptr, 0); png_ptr->idat_size = png_read_chunk_header(png_ptr); - if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + if (png_ptr->chunk_name != png_IDAT) png_error(png_ptr, "Not enough image data"); } @@ -3383,16 +3890,16 @@ png_read_start_row(png_structp png_ptr) /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Start of interlace block */ - PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* Offset to next interlace block */ - PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; /* Start of interlace block in the y direction */ - PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; /* Offset to next interlace block in the y direction */ - PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif int max_pixel_depth; @@ -3400,7 +3907,9 @@ png_read_start_row(png_structp png_ptr) png_debug(1, "in png_read_start_row"); png_ptr->zstream.avail_in = 0; +#ifdef PNG_READ_TRANSFORMS_SUPPORTED png_init_read_transformations(png_ptr); +#endif #ifdef PNG_READ_INTERLACING_SUPPORTED if (png_ptr->interlaced) { @@ -3426,6 +3935,16 @@ png_read_start_row(png_structp png_ptr) max_pixel_depth = png_ptr->pixel_depth; + /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of + * calculations to calculate the final pixel depth, then + * png_do_read_transforms actually does the transforms. This means that the + * code which effectively calculates this value is actually repeated in three + * separate places. They must all match. Innocent changes to the order of + * transformations can and will break libpng in a way that causes memory + * overwrites. + * + * TODO: fix this. + */ #ifdef PNG_READ_PACK_SUPPORTED if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) max_pixel_depth = 8; @@ -3463,13 +3982,28 @@ png_read_start_row(png_structp png_ptr) } #endif +#ifdef PNG_READ_EXPAND_16_SUPPORTED + if (png_ptr->transformations & PNG_EXPAND_16) + { +# ifdef PNG_READ_EXPAND_SUPPORTED + /* In fact it is an error if it isn't supported, but checking is + * the safe way. + */ + if (png_ptr->transformations & PNG_EXPAND) + { + if (png_ptr->bit_depth < 16) + max_pixel_depth *= 2; + } + else +# endif + png_ptr->transformations &= ~PNG_EXPAND_16; + } +#endif + #ifdef PNG_READ_FILLER_SUPPORTED if (png_ptr->transformations & (PNG_FILLER)) { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - max_pixel_depth = 32; - - else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) { if (max_pixel_depth <= 8) max_pixel_depth = 16; @@ -3478,7 +4012,8 @@ png_read_start_row(png_structp png_ptr) max_pixel_depth = 32; } - else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB || + png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { if (max_pixel_depth <= 32) max_pixel_depth = 32; @@ -3532,14 +4067,20 @@ png_read_start_row(png_structp png_ptr) defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) if (png_ptr->transformations & PNG_USER_TRANSFORM) { - int user_pixel_depth = png_ptr->user_transform_depth* + int user_pixel_depth = png_ptr->user_transform_depth * png_ptr->user_transform_channels; if (user_pixel_depth > max_pixel_depth) - max_pixel_depth=user_pixel_depth; + max_pixel_depth = user_pixel_depth; } #endif + /* This value is stored in png_struct and double checked in the row read + * code. + */ + png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth; + png_ptr->transformed_pixel_depth = 0; /* calculated on demand */ + /* Align the width on the next larger 8 pixels. Mainly used * for interlacing */ @@ -3558,28 +4099,39 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) if (row_bytes + 48 > png_ptr->old_big_row_buf_size) { png_free(png_ptr, png_ptr->big_row_buf); + png_free(png_ptr, png_ptr->big_prev_row); if (png_ptr->interlaced) png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, row_bytes + 48); else - png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, - row_bytes + 48); + png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48); - png_ptr->old_big_row_buf_size = row_bytes + 48; + png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48); #ifdef PNG_ALIGNED_MEMORY_SUPPORTED /* Use 16-byte aligned memory for row_buf with at least 16 bytes - * of padding before and after row_buf. + * of padding before and after row_buf; treat prev_row similarly. + * NOTE: the alignment is to the start of the pixels, one beyond the start + * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this + * was incorrect; the filter byte was aligned, which had the exact + * opposite effect of that intended. */ - png_ptr->row_buf = png_ptr->big_row_buf + 32 - - (((png_alloc_size_t)png_ptr->big_row_buf + 15) & 0x0F); + { + png_bytep temp = png_ptr->big_row_buf + 32; + int extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->row_buf = temp - extra - 1/*filter byte*/; + + temp = png_ptr->big_prev_row + 32; + extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->prev_row = temp - extra - 1/*filter byte*/; + } - png_ptr->old_big_row_buf_size = row_bytes + 48; #else - /* Use 32 bytes of padding before and 16 bytes after row_buf. */ - png_ptr->row_buf = png_ptr->big_row_buf + 32; + /* Use 31 bytes of padding before and 17 bytes after row_buf. */ + png_ptr->row_buf = png_ptr->big_row_buf + 31; + png_ptr->prev_row = png_ptr->big_prev_row + 31; #endif png_ptr->old_big_row_buf_size = row_bytes + 48; } @@ -3592,15 +4144,6 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) png_error(png_ptr, "Row has too many bytes to allocate in memory"); - if (png_ptr->rowbytes + 1 > png_ptr->old_prev_row_size) - { - png_free(png_ptr, png_ptr->prev_row); - - png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); - - png_ptr->old_prev_row_size = png_ptr->rowbytes + 1; - } - png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); png_debug1(3, "width = %u,", png_ptr->width); diff --git a/png/pngset.c b/png/pngset.c index 2cfcf33bd..e0118fa8c 100644 --- a/png/pngset.c +++ b/png/pngset.c @@ -1,8 +1,8 @@ /* pngset.c - storage of image information into info struct * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [(PENDING RELEASE)] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -64,6 +64,39 @@ png_set_cHRM_fixed(png_structp png_ptr, png_infop info_ptr, } } +void PNGFAPI +png_set_cHRM_XYZ_fixed(png_structp png_ptr, png_infop info_ptr, + png_fixed_point int_red_X, png_fixed_point int_red_Y, + png_fixed_point int_red_Z, png_fixed_point int_green_X, + png_fixed_point int_green_Y, png_fixed_point int_green_Z, + png_fixed_point int_blue_X, png_fixed_point int_blue_Y, + png_fixed_point int_blue_Z) +{ + png_XYZ XYZ; + png_xy xy; + + png_debug1(1, "in %s storage function", "cHRM XYZ fixed"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + XYZ.redX = int_red_X; + XYZ.redY = int_red_Y; + XYZ.redZ = int_red_Z; + XYZ.greenX = int_green_X; + XYZ.greenY = int_green_Y; + XYZ.greenZ = int_green_Z; + XYZ.blueX = int_blue_X; + XYZ.blueY = int_blue_Y; + XYZ.blueZ = int_blue_Z; + + if (png_xy_from_XYZ(&xy, XYZ)) + png_error(png_ptr, "XYZ values out of representable range"); + + png_set_cHRM_fixed(png_ptr, info_ptr, xy.whitex, xy.whitey, xy.redx, xy.redy, + xy.greenx, xy.greeny, xy.bluex, xy.bluey); +} + # ifdef PNG_FLOATING_POINT_SUPPORTED void PNGAPI png_set_cHRM(png_structp png_ptr, png_infop info_ptr, @@ -80,6 +113,23 @@ png_set_cHRM(png_structp png_ptr, png_infop info_ptr, png_fixed(png_ptr, blue_x, "cHRM Blue X"), png_fixed(png_ptr, blue_y, "cHRM Blue Y")); } + +void PNGAPI +png_set_cHRM_XYZ(png_structp png_ptr, png_infop info_ptr, double red_X, + double red_Y, double red_Z, double green_X, double green_Y, double green_Z, + double blue_X, double blue_Y, double blue_Z) +{ + png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, + png_fixed(png_ptr, red_X, "cHRM Red X"), + png_fixed(png_ptr, red_Y, "cHRM Red Y"), + png_fixed(png_ptr, red_Z, "cHRM Red Z"), + png_fixed(png_ptr, green_X, "cHRM Red X"), + png_fixed(png_ptr, green_Y, "cHRM Red Y"), + png_fixed(png_ptr, green_Z, "cHRM Red Z"), + png_fixed(png_ptr, blue_X, "cHRM Red X"), + png_fixed(png_ptr, blue_Y, "cHRM Red Y"), + png_fixed(png_ptr, blue_Z, "cHRM Red Z")); +} # endif /* PNG_FLOATING_POINT_SUPPORTED */ #endif /* PNG_cHRM_SUPPORTED */ @@ -94,15 +144,16 @@ png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point if (png_ptr == NULL || info_ptr == NULL) return; - /* Previously these values were limited, however they must be - * wrong, therefore storing them (and setting PNG_INFO_gAMA) - * must be wrong too. + /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't + * occur. Since the fixed point representation is assymetrical it is + * possible for 1/gamma to overflow the limit of 21474 and this means the + * gamma value must be at least 5/100000 and hence at most 20000.0. For + * safety the limits here are a little narrower. The values are 0.00016 to + * 6250.0, which are truly ridiculous gammma values (and will produce + * displays that are all black or all white.) */ - if (file_gamma > (png_fixed_point)PNG_UINT_31_MAX) - png_warning(png_ptr, "Gamma too large, ignored"); - - else if (file_gamma <= 0) - png_warning(png_ptr, "Negative or zero gamma ignored"); + if (file_gamma < 16 || file_gamma > 625000000) + png_warning(png_ptr, "Out of range gamma value ignored"); else { @@ -340,12 +391,12 @@ png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr, if (unit != 1 && unit != 2) png_error(png_ptr, "Invalid sCAL unit"); - if (swidth == NULL || (lengthw = png_strlen(swidth)) <= 0 || - swidth[0] == 45 /*'-'*/ || !png_check_fp_string(swidth, lengthw)) + if (swidth == NULL || (lengthw = png_strlen(swidth)) == 0 || + swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw)) png_error(png_ptr, "Invalid sCAL width"); - if (sheight == NULL || (lengthh = png_strlen(sheight)) <= 0 || - sheight[0] == 45 /*'-'*/ || !png_check_fp_string(sheight, lengthh)) + if (sheight == NULL || (lengthh = png_strlen(sheight)) == 0 || + sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh)) png_error(png_ptr, "Invalid sCAL height"); info_ptr->scal_unit = (png_byte)unit; @@ -545,16 +596,16 @@ png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr, png_set_sRGB(png_ptr, info_ptr, srgb_intent); # ifdef PNG_gAMA_SUPPORTED - png_set_gAMA_fixed(png_ptr, info_ptr, 45455L); + png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE); # endif # ifdef PNG_cHRM_SUPPORTED png_set_cHRM_fixed(png_ptr, info_ptr, /* color x y */ - /* white */ 31270L, 32900L, - /* red */ 64000L, 33000L, - /* green */ 30000L, 60000L, - /* blue */ 15000L, 6000L + /* white */ 31270, 32900, + /* red */ 64000, 33000, + /* green */ 30000, 60000, + /* blue */ 15000, 6000 ); # endif /* cHRM */ } @@ -569,7 +620,7 @@ png_set_iCCP(png_structp png_ptr, png_infop info_ptr, { png_charp new_iccp_name; png_bytep new_iccp_profile; - png_uint_32 length; + png_size_t length; png_debug1(1, "in %s storage function", "iCCP"); @@ -630,9 +681,8 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, { int i; - png_debug1(1, "in %s storage function", ((png_ptr == NULL || - png_ptr->chunk_name[0] == '\0') ? - "text" : (png_const_charp)png_ptr->chunk_name)); + png_debug1(1, "in %lx storage function", png_ptr == NULL ? "unexpected" : + (unsigned long)png_ptr->chunk_name); if (png_ptr == NULL || info_ptr == NULL || num_text == 0) return(0); @@ -642,24 +692,28 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, */ if (info_ptr->num_text + num_text > info_ptr->max_text) { + int old_max_text = info_ptr->max_text; + int old_num_text = info_ptr->num_text; + if (info_ptr->text != NULL) { png_textp old_text; - int old_max; - old_max = info_ptr->max_text; info_ptr->max_text = info_ptr->num_text + num_text + 8; old_text = info_ptr->text; + info_ptr->text = (png_textp)png_malloc_warn(png_ptr, (png_size_t)(info_ptr->max_text * png_sizeof(png_text))); if (info_ptr->text == NULL) { - png_free(png_ptr, old_text); + /* Restore to previous condition */ + info_ptr->max_text = old_max_text; + info_ptr->text = old_text; return(1); } - png_memcpy(info_ptr->text, old_text, (png_size_t)(old_max * + png_memcpy(info_ptr->text, old_text, (png_size_t)(old_max_text * png_sizeof(png_text))); png_free(png_ptr, old_text); } @@ -671,7 +725,12 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, info_ptr->text = (png_textp)png_malloc_warn(png_ptr, (png_size_t)(info_ptr->max_text * png_sizeof(png_text))); if (info_ptr->text == NULL) + { + /* Restore to previous condition */ + info_ptr->num_text = old_num_text; + info_ptr->max_text = old_max_text; return(1); + } info_ptr->free_me |= PNG_FREE_TEXT; } @@ -814,6 +873,15 @@ png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time) (png_ptr->mode & PNG_WROTE_tIME)) return; + if (mod_time->month == 0 || mod_time->month > 12 || + mod_time->day == 0 || mod_time->day > 31 || + mod_time->hour > 23 || mod_time->minute > 59 || + mod_time->second > 60) + { + png_warning(png_ptr, "Ignoring invalid time value"); + return; + } + png_memcpy(&(info_ptr->mod_time), mod_time, png_sizeof(png_time)); info_ptr->valid |= PNG_INFO_tIME; } @@ -915,10 +983,10 @@ png_set_sPLT(png_structp png_ptr, { png_sPLT_tp to = np + info_ptr->splt_palettes_num + i; png_const_sPLT_tp from = entries + i; - png_uint_32 length; + png_size_t length; length = png_strlen(from->name) + 1; - to->name = (png_charp)png_malloc_warn(png_ptr, (png_size_t)length); + to->name = (png_charp)png_malloc_warn(png_ptr, length); if (to->name == NULL) { @@ -929,7 +997,7 @@ png_set_sPLT(png_structp png_ptr, png_memcpy(to->name, from->name, length); to->entries = (png_sPLT_entryp)png_malloc_warn(png_ptr, - (png_size_t)(from->nentries * png_sizeof(png_sPLT_entry))); + from->nentries * png_sizeof(png_sPLT_entry)); if (to->entries == NULL) { @@ -1222,4 +1290,20 @@ png_set_benign_errors(png_structp png_ptr, int allowed) png_ptr->flags &= ~PNG_FLAG_BENIGN_ERRORS_WARN; } #endif /* PNG_BENIGN_ERRORS_SUPPORTED */ + +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Do not report invalid palette index; added at libng-1.5.10 */ +void PNGAPI +png_set_check_for_invalid_index(png_structp png_ptr, int allowed) +{ + png_debug(1, "in png_set_check_for_invalid_index"); + + if (allowed) + png_ptr->num_palette_max = 0; + + else + png_ptr->num_palette_max = -1; +} +#endif + #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ diff --git a/png/pngstruct.h b/png/pngstruct.h index 8d781faef..43a45cdec 100644 --- a/png/pngstruct.h +++ b/png/pngstruct.h @@ -5,7 +5,7 @@ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * - * Last changed in libpng 1.5.0 [January 6, 2011] + * Last changed in libpng 1.5.9 [March 29, 2012] * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer @@ -29,11 +29,13 @@ struct png_struct_def { #ifdef PNG_SETJMP_SUPPORTED - jmp_buf png_jmpbuf; /* used in png_error */ + jmp_buf longjmp_buffer; /* used in png_error */ png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ #endif png_error_ptr error_fn; /* function for printing errors and aborting */ +#ifdef PNG_WARNINGS_SUPPORTED png_error_ptr warning_fn; /* function for printing warnings */ +#endif png_voidp error_ptr; /* user supplied struct for error functions */ png_rw_ptr write_data_fn; /* function for writing output data */ png_rw_ptr read_data_fn; /* function for reading input data */ @@ -64,11 +66,36 @@ struct png_struct_def z_stream zstream; /* pointer to decompression structure (below) */ png_bytep zbuf; /* buffer for zlib */ uInt zbuf_size; /* size of zbuf (typically 65536) */ +#ifdef PNG_WRITE_SUPPORTED + +/* Added in 1.5.4: state to keep track of whether the zstream has been + * initialized and if so whether it is for IDAT or some other chunk. + */ +#define PNG_ZLIB_UNINITIALIZED 0 +#define PNG_ZLIB_FOR_IDAT 1 +#define PNG_ZLIB_FOR_TEXT 2 /* anything other than IDAT */ +#define PNG_ZLIB_USE_MASK 3 /* bottom two bits */ +#define PNG_ZLIB_IN_USE 4 /* a flag value */ + + png_uint_32 zlib_state; /* State of zlib initialization */ +/* End of material added at libpng 1.5.4 */ + int zlib_level; /* holds zlib compression level */ int zlib_method; /* holds zlib compression method */ int zlib_window_bits; /* holds zlib compression window bits */ int zlib_mem_level; /* holds zlib compression memory level */ int zlib_strategy; /* holds zlib compression strategy */ +#endif +/* Added at libpng 1.5.4 */ +#if defined(PNG_WRITE_COMPRESSED_TEXT_SUPPORTED) || \ + defined(PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED) + int zlib_text_level; /* holds zlib compression level */ + int zlib_text_method; /* holds zlib compression method */ + int zlib_text_window_bits; /* holds zlib compression window bits */ + int zlib_text_mem_level; /* holds zlib compression memory level */ + int zlib_text_strategy; /* holds zlib compression strategy */ +#endif +/* End of material added at libpng 1.5.4 */ png_uint_32 width; /* width of image in pixels */ png_uint_32 height; /* height of image in pixels */ @@ -77,20 +104,30 @@ struct png_struct_def png_size_t rowbytes; /* size of row in bytes */ png_uint_32 iwidth; /* width of current interlaced row in pixels */ png_uint_32 row_number; /* current row in interlace pass */ - png_bytep prev_row; /* buffer to save previous (unfiltered) row */ - png_bytep row_buf; /* buffer to save current (unfiltered) row */ + png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ + png_bytep prev_row; /* buffer to save previous (unfiltered) row. + * This is a pointer into big_prev_row + */ + png_bytep row_buf; /* buffer to save current (unfiltered) row. + * This is a pointer into big_row_buf + */ png_bytep sub_row; /* buffer to save "sub" row when filtering */ png_bytep up_row; /* buffer to save "up" row when filtering */ png_bytep avg_row; /* buffer to save "avg" row when filtering */ png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */ - png_row_info row_info; /* used for transformation routines */ + png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ png_uint_32 idat_size; /* current IDAT size for read */ png_uint_32 crc; /* current chunk CRC value */ png_colorp palette; /* palette from the input file */ png_uint_16 num_palette; /* number of color entries in palette */ + +/* Added at libpng-1.5.10 */ +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED + int num_palette_max; /* maximum palette index found in IDAT */ +#endif + png_uint_16 num_trans; /* number of transparency values */ - png_byte chunk_name[5]; /* null-terminated name of current chunk */ png_byte compression; /* file compression type (always 0) */ png_byte filter; /* file filter type (always 0) */ png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ @@ -98,17 +135,24 @@ struct png_struct_def png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */ png_byte color_type; /* color type of file */ png_byte bit_depth; /* bit depth of file */ - png_byte usr_bit_depth; /* bit depth of users row */ + png_byte usr_bit_depth; /* bit depth of users row: write only */ png_byte pixel_depth; /* number of bits per pixel */ png_byte channels; /* number of channels in file */ - png_byte usr_channels; /* channels at start of write */ + png_byte usr_channels; /* channels at start of write: write only */ png_byte sig_bytes; /* magic bytes read/written from start of file */ + png_byte maximum_pixel_depth; + /* pixel depth used for the row buffers */ + png_byte transformed_pixel_depth; + /* pixel depth after read/write transforms */ + png_byte io_chunk_string[5]; + /* string name of chunk */ #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) png_uint_16 filler; /* filler bytes for pixel expansion */ #endif -#ifdef PNG_bKGD_SUPPORTED +#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) png_byte background_gamma_type; png_fixed_point background_gamma; png_color_16 background; /* background color in screen gamma space */ @@ -123,19 +167,21 @@ struct png_struct_def png_uint_32 flush_rows; /* number of rows written since last flush */ #endif -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) +#ifdef PNG_READ_GAMMA_SUPPORTED int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ png_fixed_point gamma; /* file gamma value */ png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ -#endif -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) png_bytep gamma_table; /* gamma table for 8-bit depth files */ + png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) png_bytep gamma_from_1; /* converts from 1.0 to screen */ png_bytep gamma_to_1; /* converts from file to 1.0 */ - png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ #endif #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) @@ -171,13 +217,6 @@ struct png_struct_def int process_mode; /* what push library is currently doing */ int cur_palette; /* current push library palette index */ -# ifdef PNG_TEXT_SUPPORTED - png_size_t current_text_size; /* current size of text input data */ - png_size_t current_text_left; /* how much text left to read in input */ - png_charp current_text; /* current text chunk buffer */ - png_charp current_text_ptr; /* current location in current_text */ -# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */ - #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) @@ -209,7 +248,7 @@ struct png_struct_def #endif #ifdef PNG_TIME_RFC1123_SUPPORTED - png_charp time_buffer; /* String to hold RFC 1123 time text */ + char time_buffer[29]; /* String to hold RFC 1123 time text */ #endif /* New members added in libpng-1.0.6 */ @@ -226,19 +265,24 @@ struct png_struct_def png_bytep chunk_list; #endif +#ifdef PNG_READ_sRGB_SUPPORTED + /* Added in 1.5.5 to record an sRGB chunk in the png. */ + png_byte is_sRGB; +#endif + /* New members added in libpng-1.0.3 */ #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED png_byte rgb_to_gray_status; + /* Added in libpng 1.5.5 to record setting of coefficients: */ + png_byte rgb_to_gray_coefficients_set; /* These were changed from png_byte in libpng-1.0.6 */ png_uint_16 rgb_to_gray_red_coeff; png_uint_16 rgb_to_gray_green_coeff; - png_uint_16 rgb_to_gray_blue_coeff; + /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ #endif /* New member added in libpng-1.0.4 (renamed in 1.0.9) */ -#if defined(PNG_MNG_FEATURES_SUPPORTED) || \ - defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \ - defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) +#if defined(PNG_MNG_FEATURES_SUPPORTED) /* Changed from png_byte to png_uint_32 at version 1.2.0 */ png_uint_32 mng_features_permitted; #endif @@ -293,9 +337,8 @@ struct png_struct_def png_unknown_chunk unknown_chunk; #endif -/* New members added in libpng-1.2.26 */ +/* New member added in libpng-1.2.26 */ png_size_t old_big_row_buf_size; - png_size_t old_prev_row_size; /* New member added in libpng-1.2.30 */ png_charp chunkdata; /* buffer for reading chunk data */ @@ -304,5 +347,11 @@ struct png_struct_def /* New member added in libpng-1.4.0 */ png_uint_32 io_state; #endif + +/* New member added in libpng-1.5.6 */ + png_bytep big_prev_row; + + void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row); }; #endif /* PNGSTRUCT_H */ diff --git a/png/pngtrans.c b/png/pngtrans.c index 137f555a6..fef12f185 100644 --- a/png/pngtrans.c +++ b/png/pngtrans.c @@ -1,8 +1,8 @@ /* pngtrans.c - transforms the data in a row (used by both readers and writers) * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -424,170 +424,119 @@ png_do_packswap(png_row_infop row_info, png_bytep row) #if defined(PNG_WRITE_FILLER_SUPPORTED) || \ defined(PNG_READ_STRIP_ALPHA_SUPPORTED) -/* Remove filler or alpha byte(s) */ +/* Remove a channel - this used to be 'png_do_strip_filler' but it used a + * somewhat weird combination of flags to determine what to do. All the calls + * to png_do_strip_filler are changed in 1.5.2 to call this instead with the + * correct arguments. + * + * The routine isn't general - the channel must be the channel at the start or + * end (not in the middle) of each pixel. + */ void /* PRIVATE */ -png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags) +png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start) { - png_debug(1, "in png_do_strip_filler"); - + png_bytep sp = row; /* source pointer */ + png_bytep dp = row; /* destination pointer */ + png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */ + + /* At the start sp will point to the first byte to copy and dp to where + * it is copied to. ep always points just beyond the end of the row, so + * the loop simply copies (channels-1) channels until sp reaches ep. + * + * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc. + * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc. + */ + + /* GA, GX, XG cases */ + if (row_info->channels == 2) { - png_bytep sp = row; - png_bytep dp = row; - png_uint_32 row_width = row_info->width; - png_uint_32 i; - - if ((row_info->color_type == PNG_COLOR_TYPE_RGB || - (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && - (flags & PNG_FLAG_STRIP_ALPHA))) && - row_info->channels == 4) + if (row_info->bit_depth == 8) { - if (row_info->bit_depth == 8) - { - /* This converts from RGBX or RGBA to RGB */ - if (flags & PNG_FLAG_FILLER_AFTER) - { - dp += 3; sp += 4; - for (i = 1; i < row_width; i++) - { - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - sp++; - } - } + if (at_start) /* Skip initial filler */ + ++sp; + else /* Skip initial channel and, for sp, the filler */ + sp += 2, ++dp; - /* This converts from XRGB or ARGB to RGB */ - else - { - for (i = 0; i < row_width; i++) - { - sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - } - } - row_info->pixel_depth = 24; - row_info->rowbytes = row_width * 3; - } + /* For a 1 pixel wide image there is nothing to do */ + while (sp < ep) + *dp++ = *sp, sp += 2; - else /* if (row_info->bit_depth == 16) */ - { - if (flags & PNG_FLAG_FILLER_AFTER) - { - /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */ - sp += 8; dp += 6; - for (i = 1; i < row_width; i++) - { - /* This could be (although png_memcpy is probably slower): - png_memcpy(dp, sp, 6); - sp += 8; - dp += 6; - */ - - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - sp += 2; - } - } + row_info->pixel_depth = 8; + } - else - { - /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */ - for (i = 0; i < row_width; i++) - { - /* This could be (although png_memcpy is probably slower): - png_memcpy(dp, sp, 6); - sp += 8; - dp += 6; - */ - - sp += 2; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - } - } + else if (row_info->bit_depth == 16) + { + if (at_start) /* Skip initial filler */ + sp += 2; + else /* Skip initial channel and, for sp, the filler */ + sp += 4, dp += 2; - row_info->pixel_depth = 48; - row_info->rowbytes = row_width * 6; - } - row_info->channels = 3; + while (sp < ep) + *dp++ = *sp++, *dp++ = *sp, sp += 3; + + row_info->pixel_depth = 16; } - else if ((row_info->color_type == PNG_COLOR_TYPE_GRAY || - (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && - (flags & PNG_FLAG_STRIP_ALPHA))) && - row_info->channels == 2) - { - if (row_info->bit_depth == 8) - { - if (flags & PNG_FLAG_FILLER_AFTER) - { - /* This converts from GX or GA to G */ - for (i = 0; i < row_width; i++) - { - *dp++ = *sp++; - sp++; - } - } + else + return; /* bad bit depth */ - else - { - /* This converts from XG or AG to G */ - for (i = 0; i < row_width; i++) - { - sp++; - *dp++ = *sp++; - } - } + row_info->channels = 1; - row_info->pixel_depth = 8; - row_info->rowbytes = row_width; - } + /* Finally fix the color type if it records an alpha channel */ + if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + row_info->color_type = PNG_COLOR_TYPE_GRAY; + } - else /* if (row_info->bit_depth == 16) */ - { - if (flags & PNG_FLAG_FILLER_AFTER) - { - /* This converts from GGXX or GGAA to GG */ - sp += 4; dp += 2; - for (i = 1; i < row_width; i++) - { - *dp++ = *sp++; - *dp++ = *sp++; - sp += 2; - } - } + /* RGBA, RGBX, XRGB cases */ + else if (row_info->channels == 4) + { + if (row_info->bit_depth == 8) + { + if (at_start) /* Skip initial filler */ + ++sp; + else /* Skip initial channels and, for sp, the filler */ + sp += 4, dp += 3; - else - { - /* This converts from XXGG or AAGG to GG */ - for (i = 0; i < row_width; i++) - { - sp += 2; - *dp++ = *sp++; - *dp++ = *sp++; - } - } + /* Note that the loop adds 3 to dp and 4 to sp each time. */ + while (sp < ep) + *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2; + + row_info->pixel_depth = 24; + } + + else if (row_info->bit_depth == 16) + { + if (at_start) /* Skip initial filler */ + sp += 2; + else /* Skip initial channels and, for sp, the filler */ + sp += 8, dp += 6; - row_info->pixel_depth = 16; - row_info->rowbytes = row_width * 2; + while (sp < ep) + { + /* Copy 6 bytes, skip 2 */ + *dp++ = *sp++, *dp++ = *sp++; + *dp++ = *sp++, *dp++ = *sp++; + *dp++ = *sp++, *dp++ = *sp, sp += 3; } - row_info->channels = 1; + + row_info->pixel_depth = 48; } - if (flags & PNG_FLAG_STRIP_ALPHA) - row_info->color_type = (png_byte)(row_info->color_type & - ~PNG_COLOR_MASK_ALPHA); + else + return; /* bad bit depth */ + + row_info->channels = 3; + + /* Finally fix the color type if it records an alpha channel */ + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + row_info->color_type = PNG_COLOR_TYPE_RGB; } + + else + return; /* The filler channel has gone already */ + + /* Fix the rowbytes value. */ + row_info->rowbytes = dp-row; } #endif @@ -670,6 +619,109 @@ png_do_bgr(png_row_infop row_info, png_bytep row) } #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */ +#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ + defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) +/* Added at libpng-1.5.10 */ +void /* PRIVATE */ +png_do_check_palette_indexes(png_structp png_ptr, png_row_infop row_info) +{ + if (png_ptr->num_palette < (1 << row_info->bit_depth) && + png_ptr->num_palette_max >= 0) + { + /* Calculations moved outside switch in an attempt to stop different + * compiler warnings. 'padding' is in *bits* within the last byte, it is + * an 'int' because pixel_depth becomes an 'int' in the expression below, + * and this calculation is used because it avoids warnings that other + * forms produced on either GCC or MSVC. + */ + int padding = (-row_info->pixel_depth * row_info->width) & 7; + png_bytep rp = png_ptr->row_buf + row_info->rowbytes; + + switch (row_info->bit_depth) + { + case 1: + { + /* in this case, all bytes must be 0 so we don't need + * to unpack the pixels except for the rightmost one. + */ + for (; rp > png_ptr->row_buf; rp--) + { + if (*rp >> padding != 0) + png_ptr->num_palette_max = 1; + padding = 0; + } + + break; + } + + case 2: + { + for (; rp > png_ptr->row_buf; rp--) + { + int i = ((*rp >> padding) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 2) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 4) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 6) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + padding = 0; + } + + break; + } + + case 4: + { + for (; rp > png_ptr->row_buf; rp--) + { + int i = ((*rp >> padding) & 0x0f); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 4) & 0x0f); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + padding = 0; + } + + break; + } + + case 8: + { + for (; rp > png_ptr->row_buf; rp--) + { + if (*rp >= png_ptr->num_palette_max) + png_ptr->num_palette_max = (int) *rp; + } + + break; + } + + default: + break; + } + } +} +#endif /* PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED */ + #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED @@ -703,11 +755,16 @@ png_get_user_transform_ptr(png_const_structp png_ptr) } #endif +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED png_uint_32 PNGAPI png_get_current_row_number(png_const_structp png_ptr) { + /* See the comments in png.h - this is the sub-image row when reading and + * interlaced image. + */ if (png_ptr != NULL) return png_ptr->row_number; + return PNG_UINT_32_MAX; /* help the app not to fail silently */ } @@ -718,6 +775,7 @@ png_get_current_pass_number(png_const_structp png_ptr) return png_ptr->pass; return 8; /* invalid */ } +#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */ #endif /* PNG_READ_USER_TRANSFORM_SUPPORTED || PNG_WRITE_USER_TRANSFORM_SUPPORTED */ #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ diff --git a/png/pngwrite.c b/png/pngwrite.c index d90f449e3..b587f1b99 100644 --- a/png/pngwrite.c +++ b/png/pngwrite.c @@ -1,8 +1,8 @@ /* pngwrite.c - general routines to write a PNG file * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -99,8 +99,10 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr) int keep = png_handle_as_unknown(png_ptr, up->name); if (keep != PNG_HANDLE_CHUNK_NEVER && - up->location && !(up->location & PNG_HAVE_PLTE) && + up->location && + !(up->location & PNG_HAVE_PLTE) && !(up->location & PNG_HAVE_IDAT) && + !(up->location & PNG_AFTER_IDAT) && ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS || (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS))) { @@ -273,8 +275,10 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) { int keep = png_handle_as_unknown(png_ptr, up->name); if (keep != PNG_HANDLE_CHUNK_NEVER && - up->location && (up->location & PNG_HAVE_PLTE) && + up->location && + (up->location & PNG_HAVE_PLTE) && !(up->location & PNG_HAVE_IDAT) && + !(up->location & PNG_AFTER_IDAT) && ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS || (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS))) { @@ -301,6 +305,11 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) if (!(png_ptr->mode & PNG_HAVE_IDAT)) png_error(png_ptr, "No IDATs written into file"); +#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED + if (png_ptr->num_palette_max > png_ptr->num_palette) + png_benign_error(png_ptr, "Wrote palette index exceeding num_palette"); +#endif + /* See if user wants us to write information chunks */ if (info_ptr != NULL) { @@ -380,7 +389,8 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) { int keep = png_handle_as_unknown(png_ptr, up->name); if (keep != PNG_HANDLE_CHUNK_NEVER && - up->location && (up->location & PNG_AFTER_IDAT) && + up->location && + (up->location & PNG_AFTER_IDAT) && ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS || (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS))) { @@ -462,10 +472,9 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, png_structp png_ptr; #ifdef PNG_SETJMP_SUPPORTED #ifdef USE_FAR_KEYWORD - jmp_buf png_jmpbuf; + jmp_buf tmp_jmpbuf; #endif #endif - int i; png_debug(1, "in png_create_write_struct"); @@ -486,15 +495,16 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, #ifdef PNG_SETJMP_SUPPORTED /* Applications that neglect to set up their own setjmp() and then - encounter a png_error() will longjmp here. Since the jmpbuf is - then meaningless we abort instead of returning. */ + * encounter a png_error() will longjmp here. Since the jmpbuf is + * then meaningless we abort instead of returning. + */ #ifdef USE_FAR_KEYWORD - if (setjmp(png_jmpbuf)) + if (setjmp(tmp_jmpbuf)) #else if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */ #endif #ifdef USE_FAR_KEYWORD - png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf)); + png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf)); #endif PNG_ABORT(); #endif @@ -504,49 +514,8 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, #endif /* PNG_USER_MEM_SUPPORTED */ png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); - if (user_png_ver) - { - i = 0; - do - { - if (user_png_ver[i] != png_libpng_ver[i]) - png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; - } while (png_libpng_ver[i++]); - } - - if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) - { - /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so - * we must recompile any applications that use any older library version. - * For versions after libpng 1.0, we will be compatible, so we need - * only check the first digit. - */ - if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || - (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || - (user_png_ver[0] == '0' && user_png_ver[2] < '9')) - { -#ifdef PNG_CONSOLE_IO_SUPPORTED - char msg[80]; - - if (user_png_ver) - { - png_snprintf2(msg, 80, - "Application built with libpng-%.20s" - " but running with %.20s", - user_png_ver, - png_libpng_ver); - png_warning(png_ptr, msg); - } -#else - png_warning(png_ptr, - "Incompatible libpng version in application and library"); -#endif -#ifdef PNG_ERROR_NUMBERS_SUPPORTED - png_ptr->flags = 0; -#endif - png_cleanup_needed = 1; - } - } + if (!png_user_version_check(png_ptr, user_png_ver)) + png_cleanup_needed = 1; /* Initialize zbuf - compression buffer */ png_ptr->zbuf_size = PNG_ZBUF_SIZE; @@ -645,6 +614,9 @@ png_write_image(png_structp png_ptr, png_bytepp image) void PNGAPI png_write_row(png_structp png_ptr, png_const_bytep row) { + /* 1.5.6: moved from png_struct to be a local structure: */ + png_row_info row_info; + if (png_ptr == NULL) return; @@ -768,36 +740,31 @@ png_write_row(png_structp png_ptr, png_const_bytep row) #endif /* Set up row info for transformations */ - png_ptr->row_info.color_type = png_ptr->color_type; - png_ptr->row_info.width = png_ptr->usr_width; - png_ptr->row_info.channels = png_ptr->usr_channels; - png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth; - png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * - png_ptr->row_info.channels); - - png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, - png_ptr->row_info.width); - - png_debug1(3, "row_info->color_type = %d", png_ptr->row_info.color_type); - png_debug1(3, "row_info->width = %u", png_ptr->row_info.width); - png_debug1(3, "row_info->channels = %d", png_ptr->row_info.channels); - png_debug1(3, "row_info->bit_depth = %d", png_ptr->row_info.bit_depth); - png_debug1(3, "row_info->pixel_depth = %d", png_ptr->row_info.pixel_depth); - png_debug1(3, "row_info->rowbytes = %lu", - (unsigned long)png_ptr->row_info.rowbytes); + row_info.color_type = png_ptr->color_type; + row_info.width = png_ptr->usr_width; + row_info.channels = png_ptr->usr_channels; + row_info.bit_depth = png_ptr->usr_bit_depth; + row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels); + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + + png_debug1(3, "row_info->color_type = %d", row_info.color_type); + png_debug1(3, "row_info->width = %u", row_info.width); + png_debug1(3, "row_info->channels = %d", row_info.channels); + png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth); + png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth); + png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes); /* Copy user's row into buffer, leaving room for filter byte. */ - png_memcpy(png_ptr->row_buf + 1, row, png_ptr->row_info.rowbytes); + png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes); #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* Handle interlacing */ if (png_ptr->interlaced && png_ptr->pass < 6 && (png_ptr->transformations & PNG_INTERLACE)) { - png_do_write_interlace(&(png_ptr->row_info), - png_ptr->row_buf + 1, png_ptr->pass); + png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass); /* This should always get caught above, but still ... */ - if (!(png_ptr->row_info.width)) + if (!(row_info.width)) { png_write_finish_row(png_ptr); return; @@ -805,9 +772,18 @@ png_write_row(png_structp png_ptr, png_const_bytep row) } #endif +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED /* Handle other transformations */ if (png_ptr->transformations) - png_do_write_transformations(png_ptr); + png_do_write_transformations(png_ptr, &row_info); +#endif + + /* At this point the row_info pixel depth must match the 'transformed' depth, + * which is also the output depth. + */ + if (row_info.pixel_depth != png_ptr->pixel_depth || + row_info.pixel_depth != png_ptr->transformed_pixel_depth) + png_error(png_ptr, "internal write transform logic error"); #ifdef PNG_MNG_FEATURES_SUPPORTED /* Write filter_method 64 (intrapixel differencing) only if @@ -823,12 +799,19 @@ png_write_row(png_structp png_ptr, png_const_bytep row) (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) { /* Intrapixel differencing */ - png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1); } #endif +/* Added at libpng-1.5.10 */ +#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Check for out-of-range palette index */ + if(row_info.color_type == PNG_COLOR_TYPE_PALETTE) + png_do_check_palette_indexes(png_ptr, &row_info); +#endif + /* Find a filter if necessary, filter the row and write it out. */ - png_write_find_filter(png_ptr, &(png_ptr->row_info)); + png_write_find_filter(png_ptr, &row_info); if (png_ptr->write_row_fn != NULL) (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); @@ -884,8 +867,6 @@ png_write_flush(png_structp png_ptr) { /* Write the IDAT and reset the zlib output buffer */ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; wrote_IDAT = 1; } } while (wrote_IDAT == 1); @@ -896,8 +877,6 @@ png_write_flush(png_structp png_ptr) /* Write the IDAT and reset the zlib output buffer */ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - png_ptr->zstream.avail_out); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; } png_ptr->flush_rows = 0; png_flush(png_ptr); @@ -918,13 +897,7 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) png_debug(1, "in png_destroy_write_struct"); if (png_ptr_ptr != NULL) - { png_ptr = *png_ptr_ptr; -#ifdef PNG_USER_MEM_SUPPORTED - free_fn = png_ptr->free_fn; - mem_ptr = png_ptr->mem_ptr; -#endif - } #ifdef PNG_USER_MEM_SUPPORTED if (png_ptr != NULL) @@ -983,7 +956,9 @@ png_write_destroy(png_structp png_ptr) jmp_buf tmp_jmp; /* Save jump buffer */ #endif png_error_ptr error_fn; +#ifdef PNG_WARNINGS_SUPPORTED png_error_ptr warning_fn; +#endif png_voidp error_ptr; #ifdef PNG_USER_MEM_SUPPORTED png_free_ptr free_fn; @@ -992,7 +967,8 @@ png_write_destroy(png_structp png_ptr) png_debug(1, "in png_write_destroy"); /* Free any memory zlib uses */ - deflateEnd(&png_ptr->zstream); + if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED) + deflateEnd(&png_ptr->zstream); /* Free our memory. png_free checks NULL for us. */ png_free(png_ptr, png_ptr->zbuf); @@ -1005,10 +981,6 @@ png_write_destroy(png_structp png_ptr) png_free(png_ptr, png_ptr->paeth_row); #endif -#ifdef PNG_TIME_RFC1123_SUPPORTED - png_free(png_ptr, png_ptr->time_buffer); -#endif - #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* Use this to save a little code space, it doesn't free the filter_costs */ png_reset_filter_heuristics(png_ptr); @@ -1018,11 +990,13 @@ png_write_destroy(png_structp png_ptr) #ifdef PNG_SETJMP_SUPPORTED /* Reset structure */ - png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf)); + png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf)); #endif error_fn = png_ptr->error_fn; +#ifdef PNG_WARNINGS_SUPPORTED warning_fn = png_ptr->warning_fn; +#endif error_ptr = png_ptr->error_ptr; #ifdef PNG_USER_MEM_SUPPORTED free_fn = png_ptr->free_fn; @@ -1031,14 +1005,16 @@ png_write_destroy(png_structp png_ptr) png_memset(png_ptr, 0, png_sizeof(png_struct)); png_ptr->error_fn = error_fn; +#ifdef PNG_WARNINGS_SUPPORTED png_ptr->warning_fn = warning_fn; +#endif png_ptr->error_ptr = error_ptr; #ifdef PNG_USER_MEM_SUPPORTED png_ptr->free_fn = free_fn; #endif #ifdef PNG_SETJMP_SUPPORTED - png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf)); + png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf)); #endif } @@ -1177,7 +1153,7 @@ png_set_filter(png_structp png_ptr, int method, int filters) * better compression. */ #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */ -/* Conveneince reset API. */ +/* Convenience reset API. */ static void png_reset_filter_heuristics(png_structp png_ptr) { @@ -1451,6 +1427,9 @@ png_set_compression_strategy(png_structp png_ptr, int strategy) png_ptr->zlib_strategy = strategy; } +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ void PNGAPI png_set_compression_window_bits(png_structp png_ptr, int window_bits) { @@ -1491,6 +1470,89 @@ png_set_compression_method(png_structp png_ptr, int method) png_ptr->zlib_method = method; } +/* The following were added to libpng-1.5.4 */ +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +void PNGAPI +png_set_text_compression_level(png_structp png_ptr, int level) +{ + png_debug(1, "in png_set_text_compression_level"); + + if (png_ptr == NULL) + return; + + png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_LEVEL; + png_ptr->zlib_text_level = level; +} + +void PNGAPI +png_set_text_compression_mem_level(png_structp png_ptr, int mem_level) +{ + png_debug(1, "in png_set_text_compression_mem_level"); + + if (png_ptr == NULL) + return; + + png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL; + png_ptr->zlib_text_mem_level = mem_level; +} + +void PNGAPI +png_set_text_compression_strategy(png_structp png_ptr, int strategy) +{ + png_debug(1, "in png_set_text_compression_strategy"); + + if (png_ptr == NULL) + return; + + png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_STRATEGY; + png_ptr->zlib_text_strategy = strategy; +} + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +void PNGAPI +png_set_text_compression_window_bits(png_structp png_ptr, int window_bits) +{ + if (png_ptr == NULL) + return; + + if (window_bits > 15) + png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); + + else if (window_bits < 8) + png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); + +#ifndef WBITS_8_OK + /* Avoid libpng bug with 256-byte windows */ + if (window_bits == 8) + { + png_warning(png_ptr, "Text compression window is being reset to 512"); + window_bits = 9; + } + +#endif + png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS; + png_ptr->zlib_text_window_bits = window_bits; +} + +void PNGAPI +png_set_text_compression_method(png_structp png_ptr, int method) +{ + png_debug(1, "in png_set_text_compression_method"); + + if (png_ptr == NULL) + return; + + if (method != 8) + png_warning(png_ptr, "Only compression method 8 is supported by PNG"); + + png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD; + png_ptr->zlib_text_method = method; +} +#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ +/* end of API added to libpng-1.5.4 */ + void PNGAPI png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn) { @@ -1557,7 +1619,7 @@ png_write_png(png_structp png_ptr, png_infop info_ptr, #endif #ifdef PNG_WRITE_FILLER_SUPPORTED - /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */ + /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */ if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); diff --git a/png/pngwtran.c b/png/pngwtran.c index 115ca3721..96608efcb 100644 --- a/png/pngwtran.c +++ b/png/pngwtran.c @@ -1,7 +1,7 @@ /* pngwtran.c - transforms the data in a row for PNG writers * - * Last changed in libpng 1.5.0 [January 6, 2011] + * Last changed in libpng 1.5.6 [November 3, 2011] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) @@ -15,11 +15,12 @@ #ifdef PNG_WRITE_SUPPORTED +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED /* Transform the data according to the user's wishes. The order of * transformations is significant. */ void /* PRIVATE */ -png_do_write_transformations(png_structp png_ptr) +png_do_write_transformations(png_structp png_ptr, png_row_infop row_info) { png_debug(1, "in png_do_write_transformations"); @@ -31,8 +32,8 @@ png_do_write_transformations(png_structp png_ptr) if (png_ptr->write_user_transform_fn != NULL) (*(png_ptr->write_user_transform_fn)) /* User write transform function */ - (png_ptr, /* png_ptr */ - &(png_ptr->row_info), /* row_info: */ + (png_ptr, /* png_ptr */ + row_info, /* row_info: */ /* png_uint_32 width; width of row */ /* png_size_t rowbytes; number of bytes in row */ /* png_byte color_type; color type of pixels */ @@ -44,50 +45,50 @@ png_do_write_transformations(png_structp png_ptr) #ifdef PNG_WRITE_FILLER_SUPPORTED if (png_ptr->transformations & PNG_FILLER) - png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, - png_ptr->flags); + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + !(png_ptr->flags & PNG_FLAG_FILLER_AFTER)); #endif #ifdef PNG_WRITE_PACKSWAP_SUPPORTED if (png_ptr->transformations & PNG_PACKSWAP) - png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_packswap(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_WRITE_PACK_SUPPORTED if (png_ptr->transformations & PNG_PACK) - png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_pack(row_info, png_ptr->row_buf + 1, (png_uint_32)png_ptr->bit_depth); #endif #ifdef PNG_WRITE_SWAP_SUPPORTED if (png_ptr->transformations & PNG_SWAP_BYTES) - png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_swap(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_WRITE_SHIFT_SUPPORTED if (png_ptr->transformations & PNG_SHIFT) - png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_shift(row_info, png_ptr->row_buf + 1, &(png_ptr->shift)); #endif #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED if (png_ptr->transformations & PNG_SWAP_ALPHA) - png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED if (png_ptr->transformations & PNG_INVERT_ALPHA) - png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_WRITE_BGR_SUPPORTED if (png_ptr->transformations & PNG_BGR) - png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_bgr(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_WRITE_INVERT_SUPPORTED if (png_ptr->transformations & PNG_INVERT_MONO) - png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_invert(row_info, png_ptr->row_buf + 1); #endif } @@ -563,6 +564,7 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) } } #endif +#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */ #ifdef PNG_MNG_FEATURES_SUPPORTED /* Undoes intrapixel differencing */ diff --git a/png/pngwutil.c b/png/pngwutil.c index 2c35785aa..b49704f1a 100644 --- a/png/pngwutil.c +++ b/png/pngwutil.c @@ -1,8 +1,8 @@ /* pngwutil.c - utilities to write a PNG file * - * Last changed in libpng 1.5.0 [January 6, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -82,39 +82,20 @@ png_write_sig(png_structp png_ptr) png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; } -/* Write a PNG chunk all at once. The type is an array of ASCII characters - * representing the chunk name. The array must be at least 4 bytes in - * length, and does not need to be null terminated. To be safe, pass the - * pre-defined chunk names here, and if you need a new one, define it - * where the others are defined. The length is the length of the data. - * All the data must be present. If that is not possible, use the - * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() - * functions instead. - */ -void PNGAPI -png_write_chunk(png_structp png_ptr, png_const_bytep chunk_name, - png_const_bytep data, png_size_t length) -{ - if (png_ptr == NULL) - return; - - png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length); - png_write_chunk_data(png_ptr, data, (png_size_t)length); - png_write_chunk_end(png_ptr); -} - /* Write the start of a PNG chunk. The type is the chunk type. * The total_length is the sum of the lengths of all the data you will be * passing in png_write_chunk_data(). */ -void PNGAPI -png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name, +static void +png_write_chunk_header(png_structp png_ptr, png_uint_32 chunk_name, png_uint_32 length) { png_byte buf[8]; - png_debug2(0, "Writing %s chunk, length = %lu", chunk_name, - (unsigned long)length); +#if defined(PNG_DEBUG) && (PNG_DEBUG > 0) + PNG_CSTRING_FROM_CHUNK(buf, chunk_name); + png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length); +#endif if (png_ptr == NULL) return; @@ -128,16 +109,16 @@ png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name, /* Write the length and the chunk name */ png_save_uint_32(buf, length); - png_memcpy(buf + 4, chunk_name, 4); - png_write_data(png_ptr, buf, (png_size_t)8); + png_save_uint_32(buf + 4, chunk_name); + png_write_data(png_ptr, buf, 8); /* Put the chunk name into png_ptr->chunk_name */ - png_memcpy(png_ptr->chunk_name, chunk_name, 4); + png_ptr->chunk_name = chunk_name; /* Reset the crc and run it over the chunk name */ png_reset_crc(png_ptr); - png_calculate_crc(png_ptr, chunk_name, 4); + png_calculate_crc(png_ptr, buf + 4, 4); #ifdef PNG_IO_STATE_SUPPORTED /* Inform the I/O callback that chunk data will (possibly) be written. @@ -147,10 +128,17 @@ png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name, #endif } -/* Write the data of a PNG chunk started with png_write_chunk_start(). +void PNGAPI +png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_string, + png_uint_32 length) +{ + png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length); +} + +/* Write the data of a PNG chunk started with png_write_chunk_header(). * Note that multiple calls to this function are allowed, and that the * sum of the lengths from these calls *must* add up to the total_length - * given to png_write_chunk_start(). + * given to png_write_chunk_header(). */ void PNGAPI png_write_chunk_data(png_structp png_ptr, png_const_bytep data, @@ -171,7 +159,7 @@ png_write_chunk_data(png_structp png_ptr, png_const_bytep data, } } -/* Finish a chunk started with png_write_chunk_start(). */ +/* Finish a chunk started with png_write_chunk_header(). */ void PNGAPI png_write_chunk_end(png_structp png_ptr) { @@ -192,7 +180,183 @@ png_write_chunk_end(png_structp png_ptr) png_write_data(png_ptr, buf, (png_size_t)4); } -#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED) +/* Write a PNG chunk all at once. The type is an array of ASCII characters + * representing the chunk name. The array must be at least 4 bytes in + * length, and does not need to be null terminated. To be safe, pass the + * pre-defined chunk names here, and if you need a new one, define it + * where the others are defined. The length is the length of the data. + * All the data must be present. If that is not possible, use the + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() + * functions instead. + */ +static void +png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name, + png_const_bytep data, png_size_t length) +{ + if (png_ptr == NULL) + return; + + /* On 64 bit architectures 'length' may not fit in a png_uint_32. */ + if (length > PNG_UINT_32_MAX) + png_error(png_ptr, "length exceeds PNG maxima"); + + png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length); + png_write_chunk_data(png_ptr, data, length); + png_write_chunk_end(png_ptr); +} + +/* This is the API that calls the internal function above. */ +void PNGAPI +png_write_chunk(png_structp png_ptr, png_const_bytep chunk_string, + png_const_bytep data, png_size_t length) +{ + png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data, + length); +} + +/* Initialize the compressor for the appropriate type of compression. */ +static void +png_zlib_claim(png_structp png_ptr, png_uint_32 state) +{ + if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE)) + { + /* If already initialized for 'state' do not re-init. */ + if (png_ptr->zlib_state != state) + { + int ret = Z_OK; + png_const_charp who = "-"; + + /* If actually initialized for another state do a deflateEnd. */ + if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED) + { + ret = deflateEnd(&png_ptr->zstream); + who = "end"; + png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED; + } + + /* zlib itself detects an incomplete state on deflateEnd */ + if (ret == Z_OK) switch (state) + { +# ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED + case PNG_ZLIB_FOR_TEXT: + ret = deflateInit2(&png_ptr->zstream, + png_ptr->zlib_text_level, png_ptr->zlib_text_method, + png_ptr->zlib_text_window_bits, + png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy); + who = "text"; + break; +# endif + + case PNG_ZLIB_FOR_IDAT: + ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, + png_ptr->zlib_method, png_ptr->zlib_window_bits, + png_ptr->zlib_mem_level, png_ptr->zlib_strategy); + who = "IDAT"; + break; + + default: + png_error(png_ptr, "invalid zlib state"); + } + + if (ret == Z_OK) + png_ptr->zlib_state = state; + + else /* an error in deflateEnd or deflateInit2 */ + { + size_t pos = 0; + char msg[64]; + + pos = png_safecat(msg, sizeof msg, pos, + "zlib failed to initialize compressor ("); + pos = png_safecat(msg, sizeof msg, pos, who); + + switch (ret) + { + case Z_VERSION_ERROR: + pos = png_safecat(msg, sizeof msg, pos, ") version error"); + break; + + case Z_STREAM_ERROR: + pos = png_safecat(msg, sizeof msg, pos, ") stream error"); + break; + + case Z_MEM_ERROR: + pos = png_safecat(msg, sizeof msg, pos, ") memory error"); + break; + + default: + pos = png_safecat(msg, sizeof msg, pos, ") unknown error"); + break; + } + + png_error(png_ptr, msg); + } + } + + /* Here on success, claim the zstream: */ + png_ptr->zlib_state |= PNG_ZLIB_IN_USE; + } + + else + png_error(png_ptr, "zstream already in use (internal error)"); +} + +/* The opposite: release the stream. It is also reset, this API will warn on + * error but will not fail. + */ +static void +png_zlib_release(png_structp png_ptr) +{ + if (png_ptr->zlib_state & PNG_ZLIB_IN_USE) + { + int ret = deflateReset(&png_ptr->zstream); + + png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE; + + if (ret != Z_OK) + { + png_const_charp err; + PNG_WARNING_PARAMETERS(p) + + switch (ret) + { + case Z_VERSION_ERROR: + err = "version"; + break; + + case Z_STREAM_ERROR: + err = "stream"; + break; + + case Z_MEM_ERROR: + err = "memory"; + break; + + default: + err = "unknown"; + break; + } + + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret); + png_warning_parameter(p, 2, err); + + if (png_ptr->zstream.msg) + err = png_ptr->zstream.msg; + else + err = "[no zlib message]"; + + png_warning_parameter(p, 3, err); + + png_formatted_warning(png_ptr, p, + "zlib failed to reset compressor: @1(@2): @3"); + } + } + + else + png_warning(png_ptr, "zstream not in use (internal error)"); +} + +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED /* This pair of functions encapsulates the operation of (a) compressing a * text string, and (b) issuing it later as a series of chunk data writes. * The compression_state structure is shared context for these functions @@ -220,25 +384,22 @@ png_text_compress(png_structp png_ptr, comp->max_output_ptr = 0; comp->output_ptr = NULL; comp->input = NULL; - comp->input_len = 0; + comp->input_len = text_len; /* We may just want to pass the text right through */ if (compression == PNG_TEXT_COMPRESSION_NONE) { comp->input = (png_const_bytep)text; - comp->input_len = text_len; return((int)text_len); } if (compression >= PNG_TEXT_COMPRESSION_LAST) { -#ifdef PNG_CONSOLE_IO_SUPPORTED - char msg[50]; - png_snprintf(msg, 50, "Unknown compression type %d", compression); - png_warning(png_ptr, msg); -#else - png_warning(png_ptr, "Unknown compression type"); -#endif + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, + compression); + png_formatted_warning(png_ptr, p, "Unknown compression type @1"); } /* We can't write the chunk until we find out how much data we have, @@ -255,10 +416,12 @@ png_text_compress(png_structp png_ptr, * data, or if the input string is incredibly large (although this * wouldn't cause a failure, just a slowdown due to swapping). */ + png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT); /* Set up the compression buffers */ /* TODO: the following cast hides a potential overflow problem. */ png_ptr->zstream.avail_in = (uInt)text_len; + /* NOTE: assume zlib doesn't overwrite the input */ png_ptr->zstream.next_in = (Bytef *)text; png_ptr->zstream.avail_out = png_ptr->zbuf_size; @@ -406,18 +569,84 @@ png_text_compress(png_structp png_ptr, /* Ship the compressed text out via chunk writes */ static void /* PRIVATE */ -png_write_compressed_data_out(png_structp png_ptr, compression_state *comp) +png_write_compressed_data_out(png_structp png_ptr, compression_state *comp, + png_size_t data_len) { int i; /* Handle the no-compression case */ if (comp->input) { - png_write_chunk_data(png_ptr, comp->input, comp->input_len); + png_write_chunk_data(png_ptr, comp->input, data_len); return; } +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + /* The zbuf_size test is because the code below doesn't work if zbuf_size is + * '1'; simply skip it to avoid memory overwrite. + */ + if (data_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1) + { + unsigned int z_cmf; /* zlib compression method and flags */ + + /* Optimize the CMF field in the zlib stream. This hack of the zlib + * stream is compliant to the stream specification. + */ + + if (comp->num_output_ptr) + z_cmf = comp->output_ptr[0][0]; + else + z_cmf = png_ptr->zbuf[0]; + + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + { + unsigned int z_cinfo; + unsigned int half_z_window_size; + png_size_t uncompressed_text_size = comp->input_len; + + z_cinfo = z_cmf >> 4; + half_z_window_size = 1 << (z_cinfo + 7); + + while (uncompressed_text_size <= half_z_window_size && + half_z_window_size >= 256) + { + z_cinfo--; + half_z_window_size >>= 1; + } + + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + + if (comp->num_output_ptr) + { + + if (comp->output_ptr[0][0] != z_cmf) + { + int tmp; + + comp->output_ptr[0][0] = (png_byte)z_cmf; + tmp = comp->output_ptr[0][1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + comp->output_ptr[0][1] = (png_byte)tmp; + } + } + else + { + int tmp; + + png_ptr->zbuf[0] = (png_byte)z_cmf; + tmp = png_ptr->zbuf[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + png_ptr->zbuf[1] = (png_byte)tmp; + } + } + + else + png_error(png_ptr, + "Invalid zlib compression method or flags in non-IDAT chunk"); + } +#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ + /* Write saved output buffers, if any */ for (i = 0; i < comp->num_output_ptr; i++) { @@ -436,10 +665,9 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp) (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); /* Reset zlib for another zTXt/iTXt or image data */ - deflateReset(&png_ptr->zstream); - png_ptr->zstream.data_type = Z_BINARY; + png_zlib_release(png_ptr); } -#endif +#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ /* Write the IHDR chunk, and update the png_struct with the necessary * information. Note that the rest of this code depends upon this @@ -450,9 +678,6 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int compression_type, int filter_type, int interlace_type) { - PNG_IHDR; - int ret; - png_byte buf[13]; /* Buffer to store the IHDR info */ png_debug(1, "in png_write_IHDR"); @@ -594,7 +819,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, buf[12] = (png_byte)interlace_type; /* Write the chunk */ - png_write_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); + png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); /* Initialize zlib with PNG info */ png_ptr->zstream.zalloc = png_zalloc; @@ -632,35 +857,35 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) png_ptr->zlib_method = 8; - ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, - png_ptr->zlib_method, png_ptr->zlib_window_bits, - png_ptr->zlib_mem_level, png_ptr->zlib_strategy); +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_STRATEGY)) + png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY; - if (ret != Z_OK) - { - if (ret == Z_VERSION_ERROR) - png_error(png_ptr, - "zlib failed to initialize compressor -- version error"); + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_LEVEL)) + png_ptr->zlib_text_level = png_ptr->zlib_level; - if (ret == Z_STREAM_ERROR) - png_error(png_ptr, - "zlib failed to initialize compressor -- stream error"); - - if (ret == Z_MEM_ERROR) - png_error(png_ptr, - "zlib failed to initialize compressor -- mem error"); + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL)) + png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level; - png_error(png_ptr, "zlib failed to initialize compressor"); - } + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS)) + png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits; - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - /* libpng is not interested in zstream.data_type, so set it - * to a predefined value, to avoid its evaluation inside zlib - */ - png_ptr->zstream.data_type = Z_BINARY; - - png_ptr->mode = PNG_HAVE_IHDR; + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_METHOD)) + png_ptr->zlib_text_method = png_ptr->zlib_method; +#else + png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY; + png_ptr->zlib_text_level = png_ptr->zlib_level; + png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level; + png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits; + png_ptr->zlib_text_method = png_ptr->zlib_method; +#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ +#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ + + /* Record that the compressor has not yet been initialized. */ + png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED; + + png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */ } /* Write the palette. We are careful not to trust png_color to be in the @@ -671,7 +896,6 @@ void /* PRIVATE */ png_write_PLTE(png_structp png_ptr, png_const_colorp palette, png_uint_32 num_pal) { - PNG_PLTE; png_uint_32 i; png_const_colorp pal_ptr; png_byte buf[3]; @@ -707,7 +931,7 @@ png_write_PLTE(png_structp png_ptr, png_const_colorp palette, png_ptr->num_palette = (png_uint_16)num_pal; png_debug1(3, "num_palette = %d", png_ptr->num_palette); - png_write_chunk_start(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); + png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); #ifdef PNG_POINTER_INDEXING_SUPPORTED for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) @@ -741,16 +965,17 @@ png_write_PLTE(png_structp png_ptr, png_const_colorp palette, void /* PRIVATE */ png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) { - PNG_IDAT; - png_debug(1, "in png_write_IDAT"); - /* Optimize the CMF field in the zlib stream. */ - /* This hack of the zlib stream is compliant to the stream specification. */ +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED if (!(png_ptr->mode & PNG_HAVE_IDAT) && png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) { + /* Optimize the CMF field in the zlib stream. This hack of the zlib + * stream is compliant to the stream specification. + */ unsigned int z_cmf = data[0]; /* zlib compression method and flags */ + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) { /* Avoid memory underflows and multiplication overflows. @@ -761,11 +986,29 @@ png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) if (length >= 2 && png_ptr->height < 16384 && png_ptr->width < 16384) { + /* Compute the maximum possible length of the datastream */ + + /* Number of pixels, plus for each row a filter byte + * and possibly a padding byte, so increase the maximum + * size to account for these. + */ + unsigned int z_cinfo; + unsigned int half_z_window_size; png_uint_32 uncompressed_idat_size = png_ptr->height * ((png_ptr->width * png_ptr->channels * png_ptr->bit_depth + 15) >> 3); - unsigned int z_cinfo = z_cmf >> 4; - unsigned int half_z_window_size = 1 << (z_cinfo + 7); + + /* If it's interlaced, each block of 8 rows is sent as up to + * 14 rows, i.e., 6 additional rows, each with a filter byte + * and possibly a padding byte + */ + if (png_ptr->interlaced) + uncompressed_idat_size += ((png_ptr->height + 7)/8) * + (png_ptr->bit_depth < 8 ? 12 : 6); + + z_cinfo = z_cmf >> 4; + half_z_window_size = 1 << (z_cinfo + 7); + while (uncompressed_idat_size <= half_z_window_size && half_z_window_size >= 256) { @@ -790,20 +1033,26 @@ png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) png_error(png_ptr, "Invalid zlib compression method or flags in IDAT"); } +#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ - png_write_chunk(png_ptr, png_IDAT, data, length); + png_write_complete_chunk(png_ptr, png_IDAT, data, length); png_ptr->mode |= PNG_HAVE_IDAT; + + /* Prior to 1.5.4 this code was replicated in every caller (except at the + * end, where it isn't technically necessary). Since this function has + * flushed the data we can safely reset the zlib output buffer here. + */ + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; } /* Write an IEND chunk */ void /* PRIVATE */ png_write_IEND(png_structp png_ptr) { - PNG_IEND; - png_debug(1, "in png_write_IEND"); - png_write_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); + png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); png_ptr->mode |= PNG_HAVE_IEND; } @@ -812,14 +1061,13 @@ png_write_IEND(png_structp png_ptr) void /* PRIVATE */ png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) { - PNG_gAMA; png_byte buf[4]; png_debug(1, "in png_write_gAMA"); /* file_gamma is saved in 1/100,000ths */ png_save_uint_32(buf, (png_uint_32)file_gamma); - png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); + png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); } #endif @@ -828,7 +1076,6 @@ png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) void /* PRIVATE */ png_write_sRGB(png_structp png_ptr, int srgb_intent) { - PNG_sRGB; png_byte buf[1]; png_debug(1, "in png_write_sRGB"); @@ -838,7 +1085,7 @@ png_write_sRGB(png_structp png_ptr, int srgb_intent) "Invalid sRGB rendering intent specified"); buf[0]=(png_byte)srgb_intent; - png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); + png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); } #endif @@ -848,7 +1095,6 @@ void /* PRIVATE */ png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, png_const_charp profile, int profile_len) { - PNG_iCCP; png_size_t name_len; png_charp new_name; compression_state comp; @@ -909,7 +1155,7 @@ png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); /* Make sure we include the NULL after the name and the compression type */ - png_write_chunk_start(png_ptr, png_iCCP, + png_write_chunk_header(png_ptr, png_iCCP, (png_uint_32)(name_len + profile_len + 2)); new_name[name_len + 1] = 0x00; @@ -918,7 +1164,9 @@ png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, (png_size_t)(name_len + 2)); if (profile_len) - png_write_compressed_data_out(png_ptr, &comp); + { + png_write_compressed_data_out(png_ptr, &comp, profile_len); + } png_write_chunk_end(png_ptr); png_free(png_ptr, new_name); @@ -930,7 +1178,6 @@ png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, void /* PRIVATE */ png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) { - PNG_sPLT; png_size_t name_len; png_charp new_name; png_byte entrybuf[10]; @@ -947,7 +1194,7 @@ png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) return; /* Make sure we include the NULL after the name */ - png_write_chunk_start(png_ptr, png_sPLT, + png_write_chunk_header(png_ptr, png_sPLT, (png_uint_32)(name_len + 2 + palette_size)); png_write_chunk_data(png_ptr, (png_bytep)new_name, @@ -1015,7 +1262,6 @@ png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) void /* PRIVATE */ png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) { - PNG_sBIT; png_byte buf[4]; png_size_t size; @@ -1066,7 +1312,7 @@ png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) buf[size++] = sbit->alpha; } - png_write_chunk(png_ptr, png_sBIT, buf, size); + png_write_complete_chunk(png_ptr, png_sBIT, buf, size); } #endif @@ -1078,7 +1324,6 @@ png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, png_fixed_point blue_y) { - PNG_cHRM; png_byte buf[32]; png_debug(1, "in png_write_cHRM"); @@ -1101,7 +1346,7 @@ png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, png_save_uint_32(buf + 24, (png_uint_32)blue_x); png_save_uint_32(buf + 28, (png_uint_32)blue_y); - png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); + png_write_complete_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); } } #endif @@ -1112,7 +1357,6 @@ void /* PRIVATE */ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, png_const_color_16p tran, int num_trans, int color_type) { - PNG_tRNS; png_byte buf[6]; png_debug(1, "in png_write_tRNS"); @@ -1126,7 +1370,7 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, } /* Write the chunk out as it is */ - png_write_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans); + png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans); } else if (color_type == PNG_COLOR_TYPE_GRAY) @@ -1141,7 +1385,7 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, } png_save_uint_16(buf, tran->gray); - png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); + png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); } else if (color_type == PNG_COLOR_TYPE_RGB) @@ -1161,7 +1405,7 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, return; } - png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); + png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); } else @@ -1176,7 +1420,6 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, void /* PRIVATE */ png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) { - PNG_bKGD; png_byte buf[6]; png_debug(1, "in png_write_bKGD"); @@ -1195,7 +1438,7 @@ png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) } buf[0] = back->index; - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); } else if (color_type & PNG_COLOR_MASK_COLOR) @@ -1215,7 +1458,7 @@ png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) return; } - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); } else @@ -1229,7 +1472,7 @@ png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) } png_save_uint_16(buf, back->gray); - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); } } #endif @@ -1239,7 +1482,6 @@ png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) void /* PRIVATE */ png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist) { - PNG_hIST; int i; png_byte buf[3]; @@ -1254,7 +1496,7 @@ png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist) return; } - png_write_chunk_start(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); for (i = 0; i < num_hist; i++) { @@ -1313,15 +1555,11 @@ png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key) if ((png_byte)*ikp < 0x20 || ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1)) { -#ifdef PNG_CONSOLE_IO_SUPPORTED - char msg[40]; + PNG_WARNING_PARAMETERS(p) - png_snprintf(msg, 40, - "invalid keyword character 0x%02X", (png_byte)*ikp); - png_warning(png_ptr, msg); -#else - png_warning(png_ptr, "invalid character in keyword"); -#endif + png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_02x, + (png_byte)*ikp); + png_formatted_warning(png_ptr, p, "invalid keyword character 0x@1"); *dp = ' '; } @@ -1408,7 +1646,6 @@ void /* PRIVATE */ png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, png_size_t text_len) { - PNG_tEXt; png_size_t key_len; png_charp new_key; @@ -1424,7 +1661,7 @@ png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, text_len = png_strlen(text); /* Make sure we include the 0 after the key */ - png_write_chunk_start(png_ptr, png_tEXt, + png_write_chunk_header(png_ptr, png_tEXt, (png_uint_32)(key_len + text_len + 1)); /* * We leave it to the application to meet PNG-1.0 requirements on the @@ -1450,7 +1687,6 @@ void /* PRIVATE */ png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, png_size_t text_len, int compression) { - PNG_zTXt; png_size_t key_len; png_byte buf; png_charp new_key; @@ -1484,7 +1720,7 @@ png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, &comp); /* Write start of chunk */ - png_write_chunk_start(png_ptr, png_zTXt, + png_write_chunk_header(png_ptr, png_zTXt, (png_uint_32)(key_len+text_len + 2)); /* Write key */ @@ -1499,7 +1735,7 @@ png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, png_write_chunk_data(png_ptr, &buf, (png_size_t)1); /* Write the compressed data */ - png_write_compressed_data_out(png_ptr, &comp); + png_write_compressed_data_out(png_ptr, &comp, text_len); /* Close the chunk */ png_write_chunk_end(png_ptr); @@ -1512,7 +1748,6 @@ void /* PRIVATE */ png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, png_const_charp lang, png_const_charp lang_key, png_const_charp text) { - PNG_iTXt; png_size_t lang_len, key_len, lang_key_len, text_len; png_charp new_lang; png_charp new_key = NULL; @@ -1557,7 +1792,7 @@ png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, * and the NULs after the key, lang, and lang_key parts */ - png_write_chunk_start(png_ptr, png_iTXt, (png_uint_32)( + png_write_chunk_header(png_ptr, png_iTXt, (png_uint_32)( 5 /* comp byte, comp flag, terminators for key, lang and lang_key */ + key_len + lang_len @@ -1591,7 +1826,7 @@ png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf), (png_size_t)(lang_key_len + 1)); - png_write_compressed_data_out(png_ptr, &comp); + png_write_compressed_data_out(png_ptr, &comp, text_len); png_write_chunk_end(png_ptr); @@ -1606,7 +1841,6 @@ void /* PRIVATE */ png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, int unit_type) { - PNG_oFFs; png_byte buf[9]; png_debug(1, "in png_write_oFFs"); @@ -1618,7 +1852,7 @@ png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, png_save_int_32(buf + 4, y_offset); buf[8] = (png_byte)unit_type; - png_write_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); + png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); } #endif #ifdef PNG_WRITE_pCAL_SUPPORTED @@ -1628,9 +1862,8 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, png_const_charp units, png_charpp params) { - PNG_pCAL; png_size_t purpose_len, units_len, total_len; - png_uint_32p params_len; + png_size_tp params_len; png_byte buf[10]; png_charp new_purpose; int i; @@ -1646,8 +1879,8 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, png_debug1(3, "pCAL units length = %d", (int)units_len); total_len = purpose_len + units_len + 10; - params_len = (png_uint_32p)png_malloc(png_ptr, - (png_alloc_size_t)(nparams * png_sizeof(png_uint_32))); + params_len = (png_size_tp)png_malloc(png_ptr, + (png_alloc_size_t)(nparams * png_sizeof(png_size_t))); /* Find the length of each parameter, making sure we don't count the * null terminator for the last parameter. @@ -1657,13 +1890,12 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); png_debug2(3, "pCAL parameter %d length = %lu", i, (unsigned long)params_len[i]); - total_len += (png_size_t)params_len[i]; + total_len += params_len[i]; } png_debug1(3, "pCAL total length = %d", (int)total_len); - png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len); - png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, - (png_size_t)purpose_len); + png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len); + png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, purpose_len); png_save_int_32(buf, X0); png_save_int_32(buf + 4, X1); buf[8] = (png_byte)type; @@ -1675,8 +1907,7 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, for (i = 0; i < nparams; i++) { - png_write_chunk_data(png_ptr, (png_const_bytep)params[i], - (png_size_t)params_len[i]); + png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]); } png_free(png_ptr, params_len); @@ -1690,7 +1921,6 @@ void /* PRIVATE */ png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, png_const_charp height) { - PNG_sCAL; png_byte buf[64]; png_size_t wlen, hlen, total_len; @@ -1711,7 +1941,7 @@ png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); - png_write_chunk(png_ptr, png_sCAL, buf, total_len); + png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len); } #endif @@ -1722,7 +1952,6 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, int unit_type) { - PNG_pHYs; png_byte buf[9]; png_debug(1, "in png_write_pHYs"); @@ -1734,7 +1963,7 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, png_save_uint_32(buf + 4, y_pixels_per_unit); buf[8] = (png_byte)unit_type; - png_write_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); + png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); } #endif @@ -1745,7 +1974,6 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, void /* PRIVATE */ png_write_tIME(png_structp png_ptr, png_const_timep mod_time) { - PNG_tIME; png_byte buf[7]; png_debug(1, "in png_write_tIME"); @@ -1765,7 +1993,7 @@ png_write_tIME(png_structp png_ptr, png_const_timep mod_time) buf[5] = mod_time->minute; buf[6] = mod_time->second; - png_write_chunk(png_ptr, png_tIME, buf, (png_size_t)7); + png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7); } #endif @@ -1777,28 +2005,32 @@ png_write_start_row(png_structp png_ptr) /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Start of interlace block */ - int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* Offset to next interlace block */ - int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; /* Start of interlace block in the y direction */ - int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; /* Offset to next interlace block in the y direction */ - int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif - png_size_t buf_size; + png_alloc_size_t buf_size; + int usr_pixel_depth; png_debug(1, "in png_write_start_row"); - buf_size = (png_size_t)(PNG_ROWBYTES( - png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1); + usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; + buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1; + + /* 1.5.6: added to allow checking in the row write code. */ + png_ptr->transformed_pixel_depth = png_ptr->pixel_depth; + png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth; /* Set up row buffer */ - png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, - (png_alloc_size_t)buf_size); + png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size); png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; @@ -1815,8 +2047,7 @@ png_write_start_row(png_structp png_ptr) if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) { /* Set up previous row buffer */ - png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, - (png_alloc_size_t)buf_size); + png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size); if (png_ptr->do_filter & PNG_FILTER_UP) { @@ -1871,6 +2102,7 @@ png_write_start_row(png_structp png_ptr) png_ptr->usr_width = png_ptr->width; } + png_zlib_claim(png_ptr, PNG_ZLIB_FOR_IDAT); png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; png_ptr->zstream.next_out = png_ptr->zbuf; } @@ -1883,16 +2115,16 @@ png_write_finish_row(png_structp png_ptr) /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Start of interlace block */ - int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* Offset to next interlace block */ - int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; /* Start of interlace block in the y direction */ - int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; /* Offset to next interlace block in the y direction */ - int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif int ret; @@ -1992,7 +2224,7 @@ png_write_finish_row(png_structp png_ptr) png_ptr->zstream.avail_out); } - deflateReset(&png_ptr->zstream); + png_zlib_release(png_ptr); png_ptr->zstream.data_type = Z_BINARY; } @@ -2010,10 +2242,10 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Start of interlace block */ - int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* Offset to next interlace block */ - int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; png_debug(1, "in png_do_write_interlace"); @@ -2181,6 +2413,9 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) * been specified by the application, and then writes the row out with the * chosen filter. */ +static void png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row, + png_size_t row_bytes); + #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1) #define PNG_HISHIFT 10 #define PNG_LOMASK ((png_uint_32)0xffffL) @@ -2195,7 +2430,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) png_byte filter_to_do = png_ptr->do_filter; png_size_t row_bytes = row_info->rowbytes; #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - int num_p_filters = (int)png_ptr->num_prev_filters; + int num_p_filters = png_ptr->num_prev_filters; #endif png_debug(1, "in png_write_find_filter"); @@ -2832,9 +3067,9 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) } } #endif /* PNG_WRITE_FILTER_SUPPORTED */ - /* Do the actual writing of the filtered row data from the chosen filter. */ - png_write_filtered_row(png_ptr, best_row); + /* Do the actual writing of the filtered row data from the chosen filter. */ + png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1); #ifdef PNG_WRITE_FILTER_SUPPORTED #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED @@ -2856,11 +3091,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) /* Do the actual writing of a previously filtered row. */ -void /* PRIVATE */ -png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) +static void +png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row, + png_size_t avail/*includes filter byte*/) { - png_size_t avail; - png_debug(1, "in png_write_filtered_row"); png_debug1(2, "filter = %d", filtered_row[0]); @@ -2868,7 +3102,6 @@ png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) png_ptr->zstream.next_in = filtered_row; png_ptr->zstream.avail_in = 0; - avail = png_ptr->row_info.rowbytes + 1; /* Repeat until we have compressed all the data */ do { @@ -2916,8 +3149,6 @@ png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) { /* Write the IDAT and reset the zlib output buffer */ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; } /* Repeat until all data has been compressed */ } while (avail > 0 || png_ptr->zstream.avail_in > 0); |