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| author | Michael R Sweet <michael.r.sweet@gmail.com> | 2011-02-15 15:28:27 +0000 |
|---|---|---|
| committer | Michael R Sweet <michael.r.sweet@gmail.com> | 2011-02-15 15:28:27 +0000 |
| commit | f8697125f4ac2e0690ee0e5be408ff35be29252e (patch) | |
| tree | 67d8dc37339502ef09c92971b940f35fa82ce5b0 /jpeg/jcmarker.c | |
| parent | 1216e9530fe541df6b95ffa39d00df9919cee4fa (diff) | |
Merge changes from JPEG 8c (released Jan 16, 2011)
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@8426 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
Diffstat (limited to 'jpeg/jcmarker.c')
| -rw-r--r-- | jpeg/jcmarker.c | 36 |
1 files changed, 19 insertions, 17 deletions
diff --git a/jpeg/jcmarker.c b/jpeg/jcmarker.c index 2e2898342..606c19af3 100644 --- a/jpeg/jcmarker.c +++ b/jpeg/jcmarker.c @@ -2,7 +2,7 @@ * jcmarker.c * * Copyright (C) 1991-1998, Thomas G. Lane. - * Modified 2003-2009 by Guido Vollbeding. + * Modified 2003-2010 by Guido Vollbeding. * This file is part of the Independent JPEG Group's software. * For conditions of distribution and use, see the accompanying README file. * @@ -231,10 +231,10 @@ emit_dac (j_compress_ptr cinfo) char ac_in_use[NUM_ARITH_TBLS]; int length, i; jpeg_component_info *compptr; - + for (i = 0; i < NUM_ARITH_TBLS; i++) dc_in_use[i] = ac_in_use[i] = 0; - + for (i = 0; i < cinfo->comps_in_scan; i++) { compptr = cinfo->cur_comp_info[i]; /* DC needs no table for refinement scan */ @@ -244,23 +244,25 @@ emit_dac (j_compress_ptr cinfo) if (cinfo->Se) ac_in_use[compptr->ac_tbl_no] = 1; } - + length = 0; for (i = 0; i < NUM_ARITH_TBLS; i++) length += dc_in_use[i] + ac_in_use[i]; - - emit_marker(cinfo, M_DAC); - - emit_2bytes(cinfo, length*2 + 2); - - for (i = 0; i < NUM_ARITH_TBLS; i++) { - if (dc_in_use[i]) { - emit_byte(cinfo, i); - emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4)); - } - if (ac_in_use[i]) { - emit_byte(cinfo, i + 0x10); - emit_byte(cinfo, cinfo->arith_ac_K[i]); + + if (length) { + emit_marker(cinfo, M_DAC); + + emit_2bytes(cinfo, length*2 + 2); + + for (i = 0; i < NUM_ARITH_TBLS; i++) { + if (dc_in_use[i]) { + emit_byte(cinfo, i); + emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4)); + } + if (ac_in_use[i]) { + emit_byte(cinfo, i + 0x10); + emit_byte(cinfo, cinfo->arith_ac_K[i]); + } } } #endif /* C_ARITH_CODING_SUPPORTED */ |