4
* Copyright (C) 1991-1998, Thomas G. Lane.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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* This file contains routines to write JPEG datastream markers.
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#define JPEG_INTERNALS
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typedef enum { /* JPEG marker codes */
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struct jpeg_marker_writer pub; /* public fields */
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unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
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typedef my_marker_writer * my_marker_ptr;
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* Basic output routines.
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* Note that we do not support suspension while writing a marker.
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* Therefore, an application using suspension must ensure that there is
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* enough buffer space for the initial markers (typ. 600-700 bytes) before
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* calling jpeg_start_compress, and enough space to write the trailing EOI
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* (a few bytes) before calling jpeg_finish_compress. Multipass compression
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* modes are not supported at all with suspension, so those two are the only
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* points where markers will be written.
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emit_byte (j_compress_ptr cinfo, int val)
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struct jpeg_destination_mgr * dest = cinfo->dest;
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*(dest->next_output_byte)++ = (JOCTET) val;
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if (--dest->free_in_buffer == 0) {
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if (! (*dest->empty_output_buffer) (cinfo))
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ERREXIT(cinfo, JERR_CANT_SUSPEND);
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emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
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/* Emit a marker code */
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emit_byte(cinfo, 0xFF);
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emit_byte(cinfo, (int) mark);
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emit_2bytes (j_compress_ptr cinfo, int value)
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/* Emit a 2-byte integer; these are always MSB first in JPEG files */
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emit_byte(cinfo, (value >> 8) & 0xFF);
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emit_byte(cinfo, value & 0xFF);
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* Routines to write specific marker types.
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emit_dqt (j_compress_ptr cinfo, int index)
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/* Emit a DQT marker */
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/* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
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JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
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ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
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for (i = 0; i < DCTSIZE2; i++) {
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if (qtbl->quantval[i] > 255)
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if (! qtbl->sent_table) {
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emit_marker(cinfo, M_DQT);
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emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
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emit_byte(cinfo, index + (prec<<4));
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for (i = 0; i < DCTSIZE2; i++) {
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/* The table entries must be emitted in zigzag order. */
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unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
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emit_byte(cinfo, (int) (qval >> 8));
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emit_byte(cinfo, (int) (qval & 0xFF));
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qtbl->sent_table = TRUE;
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emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
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/* Emit a DHT marker */
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htbl = cinfo->ac_huff_tbl_ptrs[index];
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index += 0x10; /* output index has AC bit set */
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htbl = cinfo->dc_huff_tbl_ptrs[index];
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ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
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if (! htbl->sent_table) {
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emit_marker(cinfo, M_DHT);
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for (i = 1; i <= 16; i++)
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length += htbl->bits[i];
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emit_2bytes(cinfo, length + 2 + 1 + 16);
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emit_byte(cinfo, index);
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for (i = 1; i <= 16; i++)
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emit_byte(cinfo, htbl->bits[i]);
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for (i = 0; i < length; i++)
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emit_byte(cinfo, htbl->huffval[i]);
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htbl->sent_table = TRUE;
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emit_dac (j_compress_ptr cinfo)
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/* Emit a DAC marker */
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/* Since the useful info is so small, we want to emit all the tables in */
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/* one DAC marker. Therefore this routine does its own scan of the table. */
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#ifdef C_ARITH_CODING_SUPPORTED
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char dc_in_use[NUM_ARITH_TBLS];
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char ac_in_use[NUM_ARITH_TBLS];
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jpeg_component_info *compptr;
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for (i = 0; i < NUM_ARITH_TBLS; i++)
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dc_in_use[i] = ac_in_use[i] = 0;
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for (i = 0; i < cinfo->comps_in_scan; i++) {
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compptr = cinfo->cur_comp_info[i];
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dc_in_use[compptr->dc_tbl_no] = 1;
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ac_in_use[compptr->ac_tbl_no] = 1;
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for (i = 0; i < NUM_ARITH_TBLS; i++)
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length += dc_in_use[i] + ac_in_use[i];
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emit_marker(cinfo, M_DAC);
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emit_2bytes(cinfo, length*2 + 2);
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for (i = 0; i < NUM_ARITH_TBLS; i++) {
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emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
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emit_byte(cinfo, i + 0x10);
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emit_byte(cinfo, cinfo->arith_ac_K[i]);
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#endif /* C_ARITH_CODING_SUPPORTED */
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emit_dri (j_compress_ptr cinfo)
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/* Emit a DRI marker */
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emit_marker(cinfo, M_DRI);
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emit_2bytes(cinfo, 4); /* fixed length */
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emit_2bytes(cinfo, (int) cinfo->restart_interval);
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emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
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/* Emit a SOF marker */
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jpeg_component_info *compptr;
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emit_marker(cinfo, code);
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emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
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/* Make sure image isn't bigger than SOF field can handle */
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if ((long) cinfo->image_height > 65535L ||
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(long) cinfo->image_width > 65535L)
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ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
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emit_byte(cinfo, cinfo->data_precision);
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emit_2bytes(cinfo, (int) cinfo->image_height);
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emit_2bytes(cinfo, (int) cinfo->image_width);
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emit_byte(cinfo, cinfo->num_components);
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for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
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emit_byte(cinfo, compptr->component_id);
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emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
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emit_byte(cinfo, compptr->quant_tbl_no);
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emit_sos (j_compress_ptr cinfo)
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/* Emit a SOS marker */
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jpeg_component_info *compptr;
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emit_marker(cinfo, M_SOS);
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emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
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emit_byte(cinfo, cinfo->comps_in_scan);
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for (i = 0; i < cinfo->comps_in_scan; i++) {
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compptr = cinfo->cur_comp_info[i];
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emit_byte(cinfo, compptr->component_id);
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td = compptr->dc_tbl_no;
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ta = compptr->ac_tbl_no;
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if (cinfo->progressive_mode) {
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/* Progressive mode: only DC or only AC tables are used in one scan;
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* furthermore, Huffman coding of DC refinement uses no table at all.
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* We emit 0 for unused field(s); this is recommended by the P&M text
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* but does not seem to be specified in the standard.
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if (cinfo->Ss == 0) {
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ta = 0; /* DC scan */
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if (cinfo->Ah != 0 && !cinfo->arith_code)
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td = 0; /* no DC table either */
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td = 0; /* AC scan */
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emit_byte(cinfo, (td << 4) + ta);
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emit_byte(cinfo, cinfo->Ss);
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emit_byte(cinfo, cinfo->Se);
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emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
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emit_jfif_app0 (j_compress_ptr cinfo)
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/* Emit a JFIF-compliant APP0 marker */
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* Length of APP0 block (2 bytes)
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* Block ID (4 bytes - ASCII "JFIF")
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* Zero byte (1 byte to terminate the ID string)
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* Version Major, Minor (2 bytes - major first)
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* Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
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* Xdpu (2 bytes - dots per unit horizontal)
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* Ydpu (2 bytes - dots per unit vertical)
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* Thumbnail X size (1 byte)
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* Thumbnail Y size (1 byte)
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emit_marker(cinfo, M_APP0);
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emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
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emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */
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emit_byte(cinfo, 0x46);
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emit_byte(cinfo, 0x49);
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emit_byte(cinfo, 0x46);
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emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
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emit_byte(cinfo, cinfo->JFIF_minor_version);
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emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
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emit_2bytes(cinfo, (int) cinfo->X_density);
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emit_2bytes(cinfo, (int) cinfo->Y_density);
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emit_byte(cinfo, 0); /* No thumbnail image */
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emit_adobe_app14 (j_compress_ptr cinfo)
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/* Emit an Adobe APP14 marker */
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* Length of APP14 block (2 bytes)
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* Block ID (5 bytes - ASCII "Adobe")
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* Version Number (2 bytes - currently 100)
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* Flags0 (2 bytes - currently 0)
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* Flags1 (2 bytes - currently 0)
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* Color transform (1 byte)
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* Although Adobe TN 5116 mentions Version = 101, all the Adobe files
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* now in circulation seem to use Version = 100, so that's what we write.
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* We write the color transform byte as 1 if the JPEG color space is
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* YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with
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* whether the encoder performed a transformation, which is pretty useless.
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emit_marker(cinfo, M_APP14);
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emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
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emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */
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emit_byte(cinfo, 0x64);
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emit_byte(cinfo, 0x6F);
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emit_byte(cinfo, 0x62);
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emit_byte(cinfo, 0x65);
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emit_2bytes(cinfo, 100); /* Version */
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emit_2bytes(cinfo, 0); /* Flags0 */
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emit_2bytes(cinfo, 0); /* Flags1 */
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switch (cinfo->jpeg_color_space) {
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emit_byte(cinfo, 1); /* Color transform = 1 */
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emit_byte(cinfo, 2); /* Color transform = 2 */
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emit_byte(cinfo, 0); /* Color transform = 0 */
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* These routines allow writing an arbitrary marker with parameters.
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* The only intended use is to emit COM or APPn markers after calling
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* write_file_header and before calling write_frame_header.
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* Other uses are not guaranteed to produce desirable results.
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* Counting the parameter bytes properly is the caller's responsibility.
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write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
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/* Emit an arbitrary marker header */
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if (datalen > (unsigned int) 65533) /* safety check */
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ERREXIT(cinfo, JERR_BAD_LENGTH);
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emit_marker(cinfo, (JPEG_MARKER) marker);
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emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */
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write_marker_byte (j_compress_ptr cinfo, int val)
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/* Emit one byte of marker parameters following write_marker_header */
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emit_byte(cinfo, val);
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* Write datastream header.
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* This consists of an SOI and optional APPn markers.
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* We recommend use of the JFIF marker, but not the Adobe marker,
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* when using YCbCr or grayscale data. The JFIF marker should NOT
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* be used for any other JPEG colorspace. The Adobe marker is helpful
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* to distinguish RGB, CMYK, and YCCK colorspaces.
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* Note that an application can write additional header markers after
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* jpeg_start_compress returns.
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write_file_header (j_compress_ptr cinfo)
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my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
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emit_marker(cinfo, M_SOI); /* first the SOI */
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/* SOI is defined to reset restart interval to 0 */
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marker->last_restart_interval = 0;
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if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */
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emit_jfif_app0(cinfo);
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if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
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emit_adobe_app14(cinfo);
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* Write frame header.
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* This consists of DQT and SOFn markers.
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* Note that we do not emit the SOF until we have emitted the DQT(s).
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* This avoids compatibility problems with incorrect implementations that
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* try to error-check the quant table numbers as soon as they see the SOF.
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write_frame_header (j_compress_ptr cinfo)
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jpeg_component_info *compptr;
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/* Emit DQT for each quantization table.
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* Note that emit_dqt() suppresses any duplicate tables.
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for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
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prec += emit_dqt(cinfo, compptr->quant_tbl_no);
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/* now prec is nonzero iff there are any 16-bit quant tables. */
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/* Check for a non-baseline specification.
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* Note we assume that Huffman table numbers won't be changed later.
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if (cinfo->arith_code || cinfo->progressive_mode ||
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cinfo->data_precision != 8) {
518
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
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if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
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if (prec && is_baseline) {
525
/* If it's baseline except for quantizer size, warn the user */
526
TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
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/* Emit the proper SOF marker */
531
if (cinfo->arith_code) {
532
emit_sof(cinfo, M_SOF9); /* SOF code for arithmetic coding */
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if (cinfo->progressive_mode)
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emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */
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else if (is_baseline)
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emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */
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emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */
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* This consists of DHT or DAC markers, optional DRI, and SOS.
547
* Compressed data will be written following the SOS.
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write_scan_header (j_compress_ptr cinfo)
553
my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
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jpeg_component_info *compptr;
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if (cinfo->arith_code) {
558
/* Emit arith conditioning info. We may have some duplication
559
* if the file has multiple scans, but it's so small it's hardly
560
* worth worrying about.
564
/* Emit Huffman tables.
565
* Note that emit_dht() suppresses any duplicate tables.
567
for (i = 0; i < cinfo->comps_in_scan; i++) {
568
compptr = cinfo->cur_comp_info[i];
569
if (cinfo->progressive_mode) {
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/* Progressive mode: only DC or only AC tables are used in one scan */
571
if (cinfo->Ss == 0) {
572
if (cinfo->Ah == 0) /* DC needs no table for refinement scan */
573
emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
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emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
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/* Sequential mode: need both DC and AC tables */
579
emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
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emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
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/* Emit DRI if required --- note that DRI value could change for each scan.
586
* We avoid wasting space with unnecessary DRIs, however.
588
if (cinfo->restart_interval != marker->last_restart_interval) {
590
marker->last_restart_interval = cinfo->restart_interval;
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* Write datastream trailer.
602
write_file_trailer (j_compress_ptr cinfo)
604
emit_marker(cinfo, M_EOI);
609
* Write an abbreviated table-specification datastream.
610
* This consists of SOI, DQT and DHT tables, and EOI.
611
* Any table that is defined and not marked sent_table = TRUE will be
612
* emitted. Note that all tables will be marked sent_table = TRUE at exit.
616
write_tables_only (j_compress_ptr cinfo)
620
emit_marker(cinfo, M_SOI);
622
for (i = 0; i < NUM_QUANT_TBLS; i++) {
623
if (cinfo->quant_tbl_ptrs[i] != NULL)
624
(void) emit_dqt(cinfo, i);
627
if (! cinfo->arith_code) {
628
for (i = 0; i < NUM_HUFF_TBLS; i++) {
629
if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
630
emit_dht(cinfo, i, FALSE);
631
if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
632
emit_dht(cinfo, i, TRUE);
636
emit_marker(cinfo, M_EOI);
641
* Initialize the marker writer module.
645
jinit_marker_writer (j_compress_ptr cinfo)
647
my_marker_ptr marker;
649
/* Create the subobject */
650
marker = (my_marker_ptr)
651
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
652
SIZEOF(my_marker_writer));
653
cinfo->marker = (struct jpeg_marker_writer *) marker;
654
/* Initialize method pointers */
655
marker->pub.write_file_header = write_file_header;
656
marker->pub.write_frame_header = write_frame_header;
657
marker->pub.write_scan_header = write_scan_header;
658
marker->pub.write_file_trailer = write_file_trailer;
659
marker->pub.write_tables_only = write_tables_only;
660
marker->pub.write_marker_header = write_marker_header;
661
marker->pub.write_marker_byte = write_marker_byte;
662
/* Initialize private state */
663
marker->last_restart_interval = 0;
added
removed
FreeImage/Source/LibJPEG/jcmarker.c
