diff options
Diffstat (limited to 'chromium/third_party/libjpeg_turbo/jcmarker.c')
| -rw-r--r-- | chromium/third_party/libjpeg_turbo/jcmarker.c | 114 |
1 files changed, 56 insertions, 58 deletions
diff --git a/chromium/third_party/libjpeg_turbo/jcmarker.c b/chromium/third_party/libjpeg_turbo/jcmarker.c index b1c1e4581e5..4fbece4bcd8 100644 --- a/chromium/third_party/libjpeg_turbo/jcmarker.c +++ b/chromium/third_party/libjpeg_turbo/jcmarker.c @@ -1,9 +1,11 @@ /* * jcmarker.c * + * This file was part of the Independent JPEG Group's software: * Copyright (C) 1991-1998, Thomas G. Lane. + * Modified 2003-2010 by Guido Vollbeding. + * libjpeg-turbo Modifications: * Copyright (C) 2010, D. R. Commander. - * This file is part of the Independent JPEG Group's software. * For conditions of distribution and use, see the accompanying README file. * * This file contains routines to write JPEG datastream markers. @@ -20,24 +22,24 @@ typedef enum { /* JPEG marker codes */ M_SOF1 = 0xc1, M_SOF2 = 0xc2, M_SOF3 = 0xc3, - + M_SOF5 = 0xc5, M_SOF6 = 0xc6, M_SOF7 = 0xc7, - + M_JPG = 0xc8, M_SOF9 = 0xc9, M_SOF10 = 0xca, M_SOF11 = 0xcb, - + M_SOF13 = 0xcd, M_SOF14 = 0xce, M_SOF15 = 0xcf, - + M_DHT = 0xc4, - + M_DAC = 0xcc, - + M_RST0 = 0xd0, M_RST1 = 0xd1, M_RST2 = 0xd2, @@ -46,7 +48,7 @@ typedef enum { /* JPEG marker codes */ M_RST5 = 0xd5, M_RST6 = 0xd6, M_RST7 = 0xd7, - + M_SOI = 0xd8, M_EOI = 0xd9, M_SOS = 0xda, @@ -55,7 +57,7 @@ typedef enum { /* JPEG marker codes */ M_DRI = 0xdd, M_DHP = 0xde, M_EXP = 0xdf, - + M_APP0 = 0xe0, M_APP1 = 0xe1, M_APP2 = 0xe2, @@ -72,13 +74,13 @@ typedef enum { /* JPEG marker codes */ M_APP13 = 0xed, M_APP14 = 0xee, M_APP15 = 0xef, - + M_JPG0 = 0xf0, M_JPG13 = 0xfd, M_COM = 0xfe, - + M_TEM = 0x01, - + M_ERROR = 0x100 } JPEG_MARKER; @@ -231,32 +233,38 @@ 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_in_use[compptr->dc_tbl_no] = 1; - ac_in_use[compptr->ac_tbl_no] = 1; + /* DC needs no table for refinement scan */ + if (cinfo->Ss == 0 && cinfo->Ah == 0) + dc_in_use[compptr->dc_tbl_no] = 1; + /* AC needs no table when not present */ + 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 */ @@ -322,22 +330,16 @@ emit_sos (j_compress_ptr cinfo) for (i = 0; i < cinfo->comps_in_scan; i++) { compptr = cinfo->cur_comp_info[i]; emit_byte(cinfo, compptr->component_id); - td = compptr->dc_tbl_no; - ta = compptr->ac_tbl_no; - if (cinfo->progressive_mode) { - /* Progressive mode: only DC or only AC tables are used in one scan; - * furthermore, Huffman coding of DC refinement uses no table at all. - * We emit 0 for unused field(s); this is recommended by the P&M text - * but does not seem to be specified in the standard. - */ - if (cinfo->Ss == 0) { - ta = 0; /* DC scan */ - if (cinfo->Ah != 0 && !cinfo->arith_code) - td = 0; /* no DC table either */ - } else { - td = 0; /* AC scan */ - } - } + + /* We emit 0 for unused field(s); this is recommended by the P&M text + * but does not seem to be specified in the standard. + */ + + /* DC needs no table for refinement scan */ + td = cinfo->Ss == 0 && cinfo->Ah == 0 ? compptr->dc_tbl_no : 0; + /* AC needs no table when not present */ + ta = cinfo->Se ? compptr->ac_tbl_no : 0; + emit_byte(cinfo, (td << 4) + ta); } @@ -531,7 +533,10 @@ write_frame_header (j_compress_ptr cinfo) /* Emit the proper SOF marker */ if (cinfo->arith_code) { - emit_sof(cinfo, M_SOF9); /* SOF code for arithmetic coding */ + if (cinfo->progressive_mode) + emit_sof(cinfo, M_SOF10); /* SOF code for progressive arithmetic */ + else + emit_sof(cinfo, M_SOF9); /* SOF code for sequential arithmetic */ } else { if (cinfo->progressive_mode) emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */ @@ -568,19 +573,12 @@ write_scan_header (j_compress_ptr cinfo) */ for (i = 0; i < cinfo->comps_in_scan; i++) { compptr = cinfo->cur_comp_info[i]; - if (cinfo->progressive_mode) { - /* Progressive mode: only DC or only AC tables are used in one scan */ - if (cinfo->Ss == 0) { - if (cinfo->Ah == 0) /* DC needs no table for refinement scan */ - emit_dht(cinfo, compptr->dc_tbl_no, FALSE); - } else { - emit_dht(cinfo, compptr->ac_tbl_no, TRUE); - } - } else { - /* Sequential mode: need both DC and AC tables */ + /* DC needs no table for refinement scan */ + if (cinfo->Ss == 0 && cinfo->Ah == 0) emit_dht(cinfo, compptr->dc_tbl_no, FALSE); + /* AC needs no table when not present */ + if (cinfo->Se) emit_dht(cinfo, compptr->ac_tbl_no, TRUE); - } } } |