#include "stdafx.h" #pragma hdrstop /* * jcmarker.c * * Copyright (C) 1991-1996, 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; /* * 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, qval >> 8); emit_byte(cinfo, 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 - 0x01, 0x01) * 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); /* We currently emit version code 1.01 since we use no 1.02 features. * This may avoid complaints from some older decoders. */ emit_byte(cinfo, 1); /* Major version */ emit_byte(cinfo, 1); /* 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; } } /* * This routine is exported for possible use by applications. * The intended use is to emit COM or APPn markers after calling * jpeg_start_compress() and before the first jpeg_write_scanlines() call * (hence, after write_file_header but before write_frame_header). * Other uses are not guaranteed to produce desirable results. */ METHODDEF(void) write_any_marker (j_compress_ptr cinfo, int marker, const JOCTET *dataptr, unsigned int datalen) /* Emit an arbitrary marker with parameters */ { if (datalen <= (unsigned int) 65533) { /* safety check */ emit_marker(cinfo, (JPEG_MARKER) marker); emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */ while (datalen--) { emit_byte(cinfo, *dataptr); dataptr++; } } } /* * 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) { emit_marker(cinfo, M_SOI); /* first the SOI */ 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) { 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. * If it doesn't, a tiny amount of space is wasted in multiple-scan files. * We assume DRI will never be nonzero for one scan and zero for a later one. */ if (cinfo->restart_interval) emit_dri(cinfo); 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; #ifdef NIFTY int ci, prec; jpeg_component_info *compptr; emit_marker(cinfo, M_SOI); /* 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); } 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); #else 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); #endif } /* * Initialize the marker writer module. */ GLOBAL(void) jinit_marker_writer (j_compress_ptr cinfo) { /* Create the subobject */ cinfo->marker = (struct jpeg_marker_writer *) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(struct jpeg_marker_writer)); /* Initialize method pointers */ cinfo->marker->write_any_marker = write_any_marker; cinfo->marker->write_file_header = write_file_header; cinfo->marker->write_frame_header = write_frame_header; cinfo->marker->write_scan_header = write_scan_header; cinfo->marker->write_file_trailer = write_file_trailer; cinfo->marker->write_tables_only = write_tables_only; }