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Diffstat (limited to 'src/libjpeg/jcmarker.c')
| -rw-r--r-- | src/libjpeg/jcmarker.c | 664 |
1 files changed, 664 insertions, 0 deletions
diff --git a/src/libjpeg/jcmarker.c b/src/libjpeg/jcmarker.c new file mode 100644 index 0000000..3d1e6c6 --- /dev/null +++ b/src/libjpeg/jcmarker.c @@ -0,0 +1,664 @@ +/* + * jcmarker.c + * + * Copyright (C) 1991-1998, Thomas G. Lane. + * 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. + */ + +#define JPEG_INTERNALS +#include "jinclude.h" +#include "jpeglib.h" + + +typedef enum { /* JPEG marker codes */ + M_SOF0 = 0xc0, + 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, + M_RST3 = 0xd3, + M_RST4 = 0xd4, + M_RST5 = 0xd5, + M_RST6 = 0xd6, + M_RST7 = 0xd7, + + M_SOI = 0xd8, + M_EOI = 0xd9, + M_SOS = 0xda, + M_DQT = 0xdb, + M_DNL = 0xdc, + M_DRI = 0xdd, + M_DHP = 0xde, + M_EXP = 0xdf, + + M_APP0 = 0xe0, + M_APP1 = 0xe1, + M_APP2 = 0xe2, + M_APP3 = 0xe3, + M_APP4 = 0xe4, + M_APP5 = 0xe5, + M_APP6 = 0xe6, + M_APP7 = 0xe7, + M_APP8 = 0xe8, + M_APP9 = 0xe9, + M_APP10 = 0xea, + M_APP11 = 0xeb, + M_APP12 = 0xec, + 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; + + +/* Private state */ + +typedef struct { + struct jpeg_marker_writer pub; /* public fields */ + + unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */ +} my_marker_writer; + +typedef my_marker_writer * my_marker_ptr; + + +/* + * Basic output routines. + * + * Note that we do not support suspension while writing a marker. + * Therefore, an application using suspension must ensure that there is + * enough buffer space for the initial markers (typ. 600-700 bytes) before + * calling jpeg_start_compress, and enough space to write the trailing EOI + * (a few bytes) before calling jpeg_finish_compress. Multipass compression + * modes are not supported at all with suspension, so those two are the only + * points where markers will be written. + */ + +LOCAL(void) +emit_byte (j_compress_ptr cinfo, int val) +/* Emit a byte */ +{ + struct jpeg_destination_mgr * dest = cinfo->dest; + + *(dest->next_output_byte)++ = (JOCTET) val; + if (--dest->free_in_buffer == 0) { + if (! (*dest->empty_output_buffer) (cinfo)) + ERREXIT(cinfo, JERR_CANT_SUSPEND); + } +} + + +LOCAL(void) +emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark) +/* Emit a marker code */ +{ + emit_byte(cinfo, 0xFF); + emit_byte(cinfo, (int) mark); +} + + +LOCAL(void) +emit_2bytes (j_compress_ptr cinfo, int value) +/* Emit a 2-byte integer; these are always MSB first in JPEG files */ +{ + emit_byte(cinfo, (value >> 8) & 0xFF); + emit_byte(cinfo, value & 0xFF); +} + + +/* + * Routines to write specific marker types. + */ + +LOCAL(int) +emit_dqt (j_compress_ptr cinfo, int index) +/* Emit a DQT marker */ +/* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */ +{ + JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index]; + int prec; + int i; + + if (qtbl == NULL) + ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index); + + prec = 0; + for (i = 0; i < DCTSIZE2; i++) { + if (qtbl->quantval[i] > 255) + prec = 1; + } + + if (! qtbl->sent_table) { + emit_marker(cinfo, M_DQT); + + emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2); + + emit_byte(cinfo, index + (prec<<4)); + + for (i = 0; i < DCTSIZE2; i++) { + /* The table entries must be emitted in zigzag order. */ + unsigned int qval = qtbl->quantval[jpeg_natural_order[i]]; + if (prec) + emit_byte(cinfo, (int) (qval >> 8)); + emit_byte(cinfo, (int) (qval & 0xFF)); + } + + qtbl->sent_table = TRUE; + } + + return prec; +} + + +LOCAL(void) +emit_dht (j_compress_ptr cinfo, int index, boolean is_ac) +/* Emit a DHT marker */ +{ + JHUFF_TBL * htbl; + int length, i; + + if (is_ac) { + htbl = cinfo->ac_huff_tbl_ptrs[index]; + index += 0x10; /* output index has AC bit set */ + } else { + htbl = cinfo->dc_huff_tbl_ptrs[index]; + } + + if (htbl == NULL) + ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index); + + if (! htbl->sent_table) { + emit_marker(cinfo, M_DHT); + + length = 0; + for (i = 1; i <= 16; i++) + length += htbl->bits[i]; + + emit_2bytes(cinfo, length + 2 + 1 + 16); + emit_byte(cinfo, index); + + for (i = 1; i <= 16; i++) + emit_byte(cinfo, htbl->bits[i]); + + for (i = 0; i < length; i++) + emit_byte(cinfo, htbl->huffval[i]); + + htbl->sent_table = TRUE; + } +} + + +LOCAL(void) +emit_dac (j_compress_ptr cinfo) +/* Emit a DAC marker */ +/* Since the useful info is so small, we want to emit all the tables in */ +/* one DAC marker. Therefore this routine does its own scan of the table. */ +{ +#ifdef C_ARITH_CODING_SUPPORTED + char dc_in_use[NUM_ARITH_TBLS]; + 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; + } + + 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]); + } + } +#endif /* C_ARITH_CODING_SUPPORTED */ +} + + +LOCAL(void) +emit_dri (j_compress_ptr cinfo) +/* Emit a DRI marker */ +{ + emit_marker(cinfo, M_DRI); + + emit_2bytes(cinfo, 4); /* fixed length */ + + emit_2bytes(cinfo, (int) cinfo->restart_interval); +} + + +LOCAL(void) +emit_sof (j_compress_ptr cinfo, JPEG_MARKER code) +/* Emit a SOF marker */ +{ + int ci; + jpeg_component_info *compptr; + + emit_marker(cinfo, code); + + emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */ + + /* Make sure image isn't bigger than SOF field can handle */ + if ((long) cinfo->image_height > 65535L || + (long) cinfo->image_width > 65535L) + ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535); + + emit_byte(cinfo, cinfo->data_precision); + emit_2bytes(cinfo, (int) cinfo->image_height); + emit_2bytes(cinfo, (int) cinfo->image_width); + + emit_byte(cinfo, cinfo->num_components); + + for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; + ci++, compptr++) { + emit_byte(cinfo, compptr->component_id); + emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor); + emit_byte(cinfo, compptr->quant_tbl_no); + } +} + + +LOCAL(void) +emit_sos (j_compress_ptr cinfo) +/* Emit a SOS marker */ +{ + int i, td, ta; + jpeg_component_info *compptr; + + emit_marker(cinfo, M_SOS); + + emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */ + + emit_byte(cinfo, cinfo->comps_in_scan); + + 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 */ + } + } + emit_byte(cinfo, (td << 4) + ta); + } + + emit_byte(cinfo, cinfo->Ss); + emit_byte(cinfo, cinfo->Se); + emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al); +} + + +LOCAL(void) +emit_jfif_app0 (j_compress_ptr cinfo) +/* Emit a JFIF-compliant APP0 marker */ +{ + /* + * Length of APP0 block (2 bytes) + * Block ID (4 bytes - ASCII "JFIF") + * Zero byte (1 byte to terminate the ID string) + * Version Major, Minor (2 bytes - major first) + * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm) + * Xdpu (2 bytes - dots per unit horizontal) + * Ydpu (2 bytes - dots per unit vertical) + * Thumbnail X size (1 byte) + * Thumbnail Y size (1 byte) + */ + + emit_marker(cinfo, M_APP0); + + emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */ + + emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */ + emit_byte(cinfo, 0x46); + emit_byte(cinfo, 0x49); + emit_byte(cinfo, 0x46); + emit_byte(cinfo, 0); + emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */ + emit_byte(cinfo, cinfo->JFIF_minor_version); + emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */ + emit_2bytes(cinfo, (int) cinfo->X_density); + emit_2bytes(cinfo, (int) cinfo->Y_density); + emit_byte(cinfo, 0); /* No thumbnail image */ + emit_byte(cinfo, 0); +} + + +LOCAL(void) +emit_adobe_app14 (j_compress_ptr cinfo) +/* Emit an Adobe APP14 marker */ +{ + /* + * Length of APP14 block (2 bytes) + * Block ID (5 bytes - ASCII "Adobe") + * Version Number (2 bytes - currently 100) + * Flags0 (2 bytes - currently 0) + * Flags1 (2 bytes - currently 0) + * Color transform (1 byte) + * + * Although Adobe TN 5116 mentions Version = 101, all the Adobe files + * now in circulation seem to use Version = 100, so that's what we write. + * + * We write the color transform byte as 1 if the JPEG color space is + * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with + * whether the encoder performed a transformation, which is pretty useless. + */ + + emit_marker(cinfo, M_APP14); + + emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */ + + emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */ + emit_byte(cinfo, 0x64); + emit_byte(cinfo, 0x6F); + emit_byte(cinfo, 0x62); + emit_byte(cinfo, 0x65); + emit_2bytes(cinfo, 100); /* Version */ + emit_2bytes(cinfo, 0); /* Flags0 */ + emit_2bytes(cinfo, 0); /* Flags1 */ + switch (cinfo->jpeg_color_space) { + case JCS_YCbCr: + emit_byte(cinfo, 1); /* Color transform = 1 */ + break; + case JCS_YCCK: + emit_byte(cinfo, 2); /* Color transform = 2 */ + break; + default: + emit_byte(cinfo, 0); /* Color transform = 0 */ + break; + } +} + + +/* + * These routines allow writing an arbitrary marker with parameters. + * The only intended use is to emit COM or APPn markers after calling + * write_file_header and before calling write_frame_header. + * Other uses are not guaranteed to produce desirable results. + * Counting the parameter bytes properly is the caller's responsibility. + */ + +METHODDEF(void) +write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen) +/* Emit an arbitrary marker header */ +{ + if (datalen > (unsigned int) 65533) /* safety check */ + ERREXIT(cinfo, JERR_BAD_LENGTH); + + emit_marker(cinfo, (JPEG_MARKER) marker); + + emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */ +} + +METHODDEF(void) +write_marker_byte (j_compress_ptr cinfo, int val) +/* Emit one byte of marker parameters following write_marker_header */ +{ + emit_byte(cinfo, val); +} + + +/* + * Write datastream header. + * This consists of an SOI and optional APPn markers. + * We recommend use of the JFIF marker, but not the Adobe marker, + * when using YCbCr or grayscale data. The JFIF marker should NOT + * be used for any other JPEG colorspace. The Adobe marker is helpful + * to distinguish RGB, CMYK, and YCCK colorspaces. + * Note that an application can write additional header markers after + * jpeg_start_compress returns. + */ + +METHODDEF(void) +write_file_header (j_compress_ptr cinfo) +{ + my_marker_ptr marker = (my_marker_ptr) cinfo->marker; + + emit_marker(cinfo, M_SOI); /* first the SOI */ + + /* SOI is defined to reset restart interval to 0 */ + marker->last_restart_interval = 0; + + if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */ + emit_jfif_app0(cinfo); + if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */ + emit_adobe_app14(cinfo); +} + + +/* + * Write frame header. + * This consists of DQT and SOFn markers. + * Note that we do not emit the SOF until we have emitted the DQT(s). + * This avoids compatibility problems with incorrect implementations that + * try to error-check the quant table numbers as soon as they see the SOF. + */ + +METHODDEF(void) +write_frame_header (j_compress_ptr cinfo) +{ + int ci, prec; + boolean is_baseline; + jpeg_component_info *compptr; + + /* Emit DQT for each quantization table. + * Note that emit_dqt() suppresses any duplicate tables. + */ + prec = 0; + for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; + ci++, compptr++) { + prec += emit_dqt(cinfo, compptr->quant_tbl_no); + } + /* now prec is nonzero iff there are any 16-bit quant tables. */ + + /* Check for a non-baseline specification. + * Note we assume that Huffman table numbers won't be changed later. + */ + if (cinfo->arith_code || cinfo->progressive_mode || + cinfo->data_precision != 8) { + is_baseline = FALSE; + } else { + is_baseline = TRUE; + for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; + ci++, compptr++) { + if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1) + is_baseline = FALSE; + } + if (prec && is_baseline) { + is_baseline = FALSE; + /* If it's baseline except for quantizer size, warn the user */ + TRACEMS(cinfo, 0, JTRC_16BIT_TABLES); + } + } + + /* Emit the proper SOF marker */ + if (cinfo->arith_code) { + emit_sof(cinfo, M_SOF9); /* SOF code for arithmetic coding */ + } else { + if (cinfo->progressive_mode) + emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */ + else if (is_baseline) + emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */ + else + emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */ + } +} + + +/* + * Write scan header. + * This consists of DHT or DAC markers, optional DRI, and SOS. + * Compressed data will be written following the SOS. + */ + +METHODDEF(void) +write_scan_header (j_compress_ptr cinfo) +{ + my_marker_ptr marker = (my_marker_ptr) cinfo->marker; + int i; + jpeg_component_info *compptr; + + if (cinfo->arith_code) { + /* Emit arith conditioning info. We may have some duplication + * if the file has multiple scans, but it's so small it's hardly + * worth worrying about. + */ + emit_dac(cinfo); + } else { + /* Emit Huffman tables. + * Note that emit_dht() suppresses any duplicate tables. + */ + 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 */ + emit_dht(cinfo, compptr->dc_tbl_no, FALSE); + emit_dht(cinfo, compptr->ac_tbl_no, TRUE); + } + } + } + + /* Emit DRI if required --- note that DRI value could change for each scan. + * We avoid wasting space with unnecessary DRIs, however. + */ + if (cinfo->restart_interval != marker->last_restart_interval) { + emit_dri(cinfo); + marker->last_restart_interval = cinfo->restart_interval; + } + + emit_sos(cinfo); +} + + +/* + * Write datastream trailer. + */ + +METHODDEF(void) +write_file_trailer (j_compress_ptr cinfo) +{ + emit_marker(cinfo, M_EOI); +} + + +/* + * Write an abbreviated table-specification datastream. + * This consists of SOI, DQT and DHT tables, and EOI. + * Any table that is defined and not marked sent_table = TRUE will be + * emitted. Note that all tables will be marked sent_table = TRUE at exit. + */ + +METHODDEF(void) +write_tables_only (j_compress_ptr cinfo) +{ + int i; + + emit_marker(cinfo, M_SOI); + + for (i = 0; i < NUM_QUANT_TBLS; i++) { + if (cinfo->quant_tbl_ptrs[i] != NULL) + (void) emit_dqt(cinfo, i); + } + + if (! cinfo->arith_code) { + for (i = 0; i < NUM_HUFF_TBLS; i++) { + if (cinfo->dc_huff_tbl_ptrs[i] != NULL) + emit_dht(cinfo, i, FALSE); + if (cinfo->ac_huff_tbl_ptrs[i] != NULL) + emit_dht(cinfo, i, TRUE); + } + } + + emit_marker(cinfo, M_EOI); +} + + +/* + * Initialize the marker writer module. + */ + +GLOBAL(void) +jinit_marker_writer (j_compress_ptr cinfo) +{ + my_marker_ptr marker; + + /* Create the subobject */ + marker = (my_marker_ptr) + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, + SIZEOF(my_marker_writer)); + cinfo->marker = (struct jpeg_marker_writer *) marker; + /* Initialize method pointers */ + marker->pub.write_file_header = write_file_header; + marker->pub.write_frame_header = write_frame_header; + marker->pub.write_scan_header = write_scan_header; + marker->pub.write_file_trailer = write_file_trailer; + marker->pub.write_tables_only = write_tables_only; + marker->pub.write_marker_header = write_marker_header; + marker->pub.write_marker_byte = write_marker_byte; + /* Initialize private state */ + marker->last_restart_interval = 0; +} |