[wxWidgets.git] / src / jpeg / jcmarker.c

/*
 * 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;
}
Commit	Line	Data
e1929140 RR	1	/*
	2	* jcmarker.c
	3	*
	4	* Copyright (C) 1991-1998, Thomas G. Lane.
	5	* This file is part of the Independent JPEG Group's software.
	6	* For conditions of distribution and use, see the accompanying README file.
	7	*
	8	* This file contains routines to write JPEG datastream markers.
	9	*/
	10
	11	#define JPEG_INTERNALS
	12	#include "jinclude.h"
	13	#include "jpeglib.h"
	14
	15
	16	typedef enum { /* JPEG marker codes */
	17	M_SOF0 = 0xc0,
	18	M_SOF1 = 0xc1,
	19	M_SOF2 = 0xc2,
	20	M_SOF3 = 0xc3,
	21
	22	M_SOF5 = 0xc5,
	23	M_SOF6 = 0xc6,
	24	M_SOF7 = 0xc7,
	25
	26	M_JPG = 0xc8,
	27	M_SOF9 = 0xc9,
	28	M_SOF10 = 0xca,
	29	M_SOF11 = 0xcb,
	30
	31	M_SOF13 = 0xcd,
	32	M_SOF14 = 0xce,
	33	M_SOF15 = 0xcf,
	34
	35	M_DHT = 0xc4,
	36
	37	M_DAC = 0xcc,
	38
	39	M_RST0 = 0xd0,
	40	M_RST1 = 0xd1,
	41	M_RST2 = 0xd2,
	42	M_RST3 = 0xd3,
	43	M_RST4 = 0xd4,
	44	M_RST5 = 0xd5,
	45	M_RST6 = 0xd6,
	46	M_RST7 = 0xd7,
	47
	48	M_SOI = 0xd8,
	49	M_EOI = 0xd9,
	50	M_SOS = 0xda,
	51	M_DQT = 0xdb,
	52	M_DNL = 0xdc,
	53	M_DRI = 0xdd,
	54	M_DHP = 0xde,
	55	M_EXP = 0xdf,
	56
	57	M_APP0 = 0xe0,
	58	M_APP1 = 0xe1,
	59	M_APP2 = 0xe2,
	60	M_APP3 = 0xe3,
	61	M_APP4 = 0xe4,
	62	M_APP5 = 0xe5,
	63	M_APP6 = 0xe6,
	64	M_APP7 = 0xe7,
65	M_APP8 = 0xe8,
66	M_APP9 = 0xe9,
67	M_APP10 = 0xea,
68	M_APP11 = 0xeb,
69	M_APP12 = 0xec,
70	M_APP13 = 0xed,
71	M_APP14 = 0xee,
72	M_APP15 = 0xef,
73
74	M_JPG0 = 0xf0,
75	M_JPG13 = 0xfd,
76	M_COM = 0xfe,
77
78	M_TEM = 0x01,
79
80	M_ERROR = 0x100
81	} JPEG_MARKER;
82
83
84	/* Private state */
85
86	typedef struct {
87	struct jpeg_marker_writer pub; /* public fields */
88
89	unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
90	} my_marker_writer;
91
92	typedef my_marker_writer * my_marker_ptr;
93
94
95	/*
96	* Basic output routines.
97	*
98	* Note that we do not support suspension while writing a marker.
99	* Therefore, an application using suspension must ensure that there is
100	* enough buffer space for the initial markers (typ. 600-700 bytes) before
101	* calling jpeg_start_compress, and enough space to write the trailing EOI
102	* (a few bytes) before calling jpeg_finish_compress. Multipass compression
103	* modes are not supported at all with suspension, so those two are the only
104	* points where markers will be written.
105	*/
106
107	LOCAL(void)
108	emit_byte (j_compress_ptr cinfo, int val)
109	/* Emit a byte */
110	{
111	struct jpeg_destination_mgr * dest = cinfo->dest;
112
113	*(dest->next_output_byte)++ = (JOCTET) val;
114	if (--dest->free_in_buffer == 0) {
115	if (! (*dest->empty_output_buffer) (cinfo))
116	ERREXIT(cinfo, JERR_CANT_SUSPEND);
117	}
118	}
119
120
121	LOCAL(void)
122	emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
123	/* Emit a marker code */
124	{
125	emit_byte(cinfo, 0xFF);
126	emit_byte(cinfo, (int) mark);
127	}
128
129
130	LOCAL(void)
131	emit_2bytes (j_compress_ptr cinfo, int value)
132	/* Emit a 2-byte integer; these are always MSB first in JPEG files */
133	{
134	emit_byte(cinfo, (value >> 8) & 0xFF);
135	emit_byte(cinfo, value & 0xFF);
136	}
137
138
139	/*
140	* Routines to write specific marker types.
141	*/
142
143	LOCAL(int)
144	emit_dqt (j_compress_ptr cinfo, int index)
145	/* Emit a DQT marker */
146	/* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
147	{
148	JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
149	int prec;
150	int i;
151
152	if (qtbl == NULL)
153	ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
154
155	prec = 0;
156	for (i = 0; i < DCTSIZE2; i++) {
157	if (qtbl->quantval[i] > 255)
158	prec = 1;
159	}
160
161	if (! qtbl->sent_table) {
162	emit_marker(cinfo, M_DQT);
163
164	emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
165
166	emit_byte(cinfo, index + (prec<<4));
167
168	for (i = 0; i < DCTSIZE2; i++) {
169	/* The table entries must be emitted in zigzag order. */
170	unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
171	if (prec)
172	emit_byte(cinfo, (int) (qval >> 8));
173	emit_byte(cinfo, (int) (qval & 0xFF));
174	}
175
176	qtbl->sent_table = TRUE;
177	}
178
179	return prec;
180	}
181
182
183	LOCAL(void)
184	emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
185	/* Emit a DHT marker */
186	{
187	JHUFF_TBL * htbl;
188	int length, i;
189
190	if (is_ac) {
191	htbl = cinfo->ac_huff_tbl_ptrs[index];
192	index += 0x10; /* output index has AC bit set */
193	} else {
194	htbl = cinfo->dc_huff_tbl_ptrs[index];
195	}
196
197	if (htbl == NULL)
198	ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
199
200	if (! htbl->sent_table) {
201	emit_marker(cinfo, M_DHT);
202
203	length = 0;
204	for (i = 1; i <= 16; i++)
205	length += htbl->bits[i];
206
207	emit_2bytes(cinfo, length + 2 + 1 + 16);
208	emit_byte(cinfo, index);
209
210	for (i = 1; i <= 16; i++)
211	emit_byte(cinfo, htbl->bits[i]);
212
213	for (i = 0; i < length; i++)
214	emit_byte(cinfo, htbl->huffval[i]);
215
216	htbl->sent_table = TRUE;
217	}
218	}
219
220
221	LOCAL(void)
222	emit_dac (j_compress_ptr cinfo)
223	/* Emit a DAC marker */
224	/* Since the useful info is so small, we want to emit all the tables in */
225	/* one DAC marker. Therefore this routine does its own scan of the table. */
226	{
227	#ifdef C_ARITH_CODING_SUPPORTED
228	char dc_in_use[NUM_ARITH_TBLS];
229	char ac_in_use[NUM_ARITH_TBLS];
230	int length, i;
231	jpeg_component_info *compptr;
232
233	for (i = 0; i < NUM_ARITH_TBLS; i++)
234	dc_in_use[i] = ac_in_use[i] = 0;
235
236	for (i = 0; i < cinfo->comps_in_scan; i++) {
237	compptr = cinfo->cur_comp_info[i];
238	dc_in_use[compptr->dc_tbl_no] = 1;
239	ac_in_use[compptr->ac_tbl_no] = 1;
240	}
241
242	length = 0;
243	for (i = 0; i < NUM_ARITH_TBLS; i++)
244	length += dc_in_use[i] + ac_in_use[i];
245
246	emit_marker(cinfo, M_DAC);
247
248	emit_2bytes(cinfo, length*2 + 2);
249
250	for (i = 0; i < NUM_ARITH_TBLS; i++) {
251	if (dc_in_use[i]) {
252	emit_byte(cinfo, i);
253	emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
254	}
255	if (ac_in_use[i]) {
256	emit_byte(cinfo, i + 0x10);
257	emit_byte(cinfo, cinfo->arith_ac_K[i]);
258	}
259	}
260	#endif /* C_ARITH_CODING_SUPPORTED */
261	}
262
263
264	LOCAL(void)
265	emit_dri (j_compress_ptr cinfo)
266	/* Emit a DRI marker */
267	{
268	emit_marker(cinfo, M_DRI);
269
270	emit_2bytes(cinfo, 4); /* fixed length */
271
272	emit_2bytes(cinfo, (int) cinfo->restart_interval);
273	}
274
275
276	LOCAL(void)
277	emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
278	/* Emit a SOF marker */
279	{
280	int ci;
281	jpeg_component_info *compptr;
282
283	emit_marker(cinfo, code);
284
285	emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
286
287	/* Make sure image isn't bigger than SOF field can handle */
288	if ((long) cinfo->image_height > 65535L \|\|
289	(long) cinfo->image_width > 65535L)
290	ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
291
292	emit_byte(cinfo, cinfo->data_precision);
293	emit_2bytes(cinfo, (int) cinfo->image_height);
294	emit_2bytes(cinfo, (int) cinfo->image_width);
295
296	emit_byte(cinfo, cinfo->num_components);
297
298	for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
299	ci++, compptr++) {
300	emit_byte(cinfo, compptr->component_id);
301	emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
302	emit_byte(cinfo, compptr->quant_tbl_no);
303	}
304	}
305
306
307	LOCAL(void)
308	emit_sos (j_compress_ptr cinfo)
309	/* Emit a SOS marker */
310	{
311	int i, td, ta;
312	jpeg_component_info *compptr;
313
314	emit_marker(cinfo, M_SOS);
315
316	emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
317
318	emit_byte(cinfo, cinfo->comps_in_scan);
319
320	for (i = 0; i < cinfo->comps_in_scan; i++) {
321	compptr = cinfo->cur_comp_info[i];
322	emit_byte(cinfo, compptr->component_id);
323	td = compptr->dc_tbl_no;
324	ta = compptr->ac_tbl_no;
325	if (cinfo->progressive_mode) {
326	/* Progressive mode: only DC or only AC tables are used in one scan;
327	* furthermore, Huffman coding of DC refinement uses no table at all.
328	* We emit 0 for unused field(s); this is recommended by the P&M text
329	* but does not seem to be specified in the standard.
330	*/
331	if (cinfo->Ss == 0) {
332	ta = 0; /* DC scan */
333	if (cinfo->Ah != 0 && !cinfo->arith_code)
334	td = 0; /* no DC table either */
335	} else {
336	td = 0; /* AC scan */
337	}
338	}
339	emit_byte(cinfo, (td << 4) + ta);
340	}
341
342	emit_byte(cinfo, cinfo->Ss);
343	emit_byte(cinfo, cinfo->Se);
344	emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
345	}
346
347
348	LOCAL(void)
349	emit_jfif_app0 (j_compress_ptr cinfo)
350	/* Emit a JFIF-compliant APP0 marker */
351	{
352	/*
353	* Length of APP0 block (2 bytes)
354	* Block ID (4 bytes - ASCII "JFIF")
355	* Zero byte (1 byte to terminate the ID string)
356	* Version Major, Minor (2 bytes - major first)
357	* Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
358	* Xdpu (2 bytes - dots per unit horizontal)
359	* Ydpu (2 bytes - dots per unit vertical)
360	* Thumbnail X size (1 byte)
361	* Thumbnail Y size (1 byte)
362	*/
363
364	emit_marker(cinfo, M_APP0);
365
366	emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
367
368	emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */
369	emit_byte(cinfo, 0x46);
370	emit_byte(cinfo, 0x49);
371	emit_byte(cinfo, 0x46);
372	emit_byte(cinfo, 0);
373	emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
374	emit_byte(cinfo, cinfo->JFIF_minor_version);
375	emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
376	emit_2bytes(cinfo, (int) cinfo->X_density);
377	emit_2bytes(cinfo, (int) cinfo->Y_density);
378	emit_byte(cinfo, 0); /* No thumbnail image */
379	emit_byte(cinfo, 0);
380	}
381
382
383	LOCAL(void)
384	emit_adobe_app14 (j_compress_ptr cinfo)
385	/* Emit an Adobe APP14 marker */
386	{
387	/*
388	* Length of APP14 block (2 bytes)
389	* Block ID (5 bytes - ASCII "Adobe")
390	* Version Number (2 bytes - currently 100)
391	* Flags0 (2 bytes - currently 0)
392	* Flags1 (2 bytes - currently 0)
393	* Color transform (1 byte)
394	*
395	* Although Adobe TN 5116 mentions Version = 101, all the Adobe files
396	* now in circulation seem to use Version = 100, so that's what we write.
397	*
398	* We write the color transform byte as 1 if the JPEG color space is
399	* YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with
400	* whether the encoder performed a transformation, which is pretty useless.
401	*/
402
403	emit_marker(cinfo, M_APP14);
404
405	emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
406
407	emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */
408	emit_byte(cinfo, 0x64);
409	emit_byte(cinfo, 0x6F);
410	emit_byte(cinfo, 0x62);
411	emit_byte(cinfo, 0x65);
412	emit_2bytes(cinfo, 100); /* Version */
413	emit_2bytes(cinfo, 0); /* Flags0 */
414	emit_2bytes(cinfo, 0); /* Flags1 */
415	switch (cinfo->jpeg_color_space) {
416	case JCS_YCbCr:
417	emit_byte(cinfo, 1); /* Color transform = 1 */
418	break;
419	case JCS_YCCK:
420	emit_byte(cinfo, 2); /* Color transform = 2 */
421	break;
422	default:
423	emit_byte(cinfo, 0); /* Color transform = 0 */
424	break;
425	}
426	}
427
428
429	/*
430	* These routines allow writing an arbitrary marker with parameters.
431	* The only intended use is to emit COM or APPn markers after calling
432	* write_file_header and before calling write_frame_header.
433	* Other uses are not guaranteed to produce desirable results.
434	* Counting the parameter bytes properly is the caller's responsibility.
435	*/
436
437	METHODDEF(void)
438	write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
439	/* Emit an arbitrary marker header */
440	{
441	if (datalen > (unsigned int) 65533) /* safety check */
442	ERREXIT(cinfo, JERR_BAD_LENGTH);
443
444	emit_marker(cinfo, (JPEG_MARKER) marker);
445
446	emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */
447	}
448
449	METHODDEF(void)
450	write_marker_byte (j_compress_ptr cinfo, int val)
451	/* Emit one byte of marker parameters following write_marker_header */
452	{
453	emit_byte(cinfo, val);
454	}
455
456
457	/*
458	* Write datastream header.
459	* This consists of an SOI and optional APPn markers.
460	* We recommend use of the JFIF marker, but not the Adobe marker,
461	* when using YCbCr or grayscale data. The JFIF marker should NOT
462	* be used for any other JPEG colorspace. The Adobe marker is helpful
463	* to distinguish RGB, CMYK, and YCCK colorspaces.
464	* Note that an application can write additional header markers after
465	* jpeg_start_compress returns.
466	*/
467
468	METHODDEF(void)
469	write_file_header (j_compress_ptr cinfo)
470	{
471	my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
472
473	emit_marker(cinfo, M_SOI); /* first the SOI */
474
475	/* SOI is defined to reset restart interval to 0 */
476	marker->last_restart_interval = 0;
477
478	if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */
479	emit_jfif_app0(cinfo);
480	if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
481	emit_adobe_app14(cinfo);
482	}
483
484
485	/*
486	* Write frame header.
487	* This consists of DQT and SOFn markers.
488	* Note that we do not emit the SOF until we have emitted the DQT(s).
489	* This avoids compatibility problems with incorrect implementations that
490	* try to error-check the quant table numbers as soon as they see the SOF.
491	*/
492
493	METHODDEF(void)
494	write_frame_header (j_compress_ptr cinfo)
495	{
496	int ci, prec;
497	boolean is_baseline;
498	jpeg_component_info *compptr;
499
500	/* Emit DQT for each quantization table.
501	* Note that emit_dqt() suppresses any duplicate tables.
502	*/
503	prec = 0;
504	for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
505	ci++, compptr++) {
506	prec += emit_dqt(cinfo, compptr->quant_tbl_no);
507	}
508	/* now prec is nonzero iff there are any 16-bit quant tables. */
509
510	/* Check for a non-baseline specification.
511	* Note we assume that Huffman table numbers won't be changed later.
512	*/
513	if (cinfo->arith_code \|\| cinfo->progressive_mode \|\|
514	cinfo->data_precision != 8) {
515	is_baseline = FALSE;
516	} else {
517	is_baseline = TRUE;
518	for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
519	ci++, compptr++) {
520	if (compptr->dc_tbl_no > 1 \|\| compptr->ac_tbl_no > 1)
521	is_baseline = FALSE;
522	}
523	if (prec && is_baseline) {
524	is_baseline = FALSE;
525	/* If it's baseline except for quantizer size, warn the user */
526	TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
527	}
528	}
529
530	/* Emit the proper SOF marker */
531	if (cinfo->arith_code) {
532	emit_sof(cinfo, M_SOF9); /* SOF code for arithmetic coding */
533	} else {
534	if (cinfo->progressive_mode)
535	emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */
536	else if (is_baseline)
537	emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */
538	else
539	emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */
540	}
541	}
542
543
544	/*
545	* Write scan header.
546	* This consists of DHT or DAC markers, optional DRI, and SOS.
547	* Compressed data will be written following the SOS.
548	*/
549
550	METHODDEF(void)
551	write_scan_header (j_compress_ptr cinfo)
552	{
553	my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
554	int i;
555	jpeg_component_info *compptr;
556
557	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.
561	*/
562	emit_dac(cinfo);
563	} else {
564	/* Emit Huffman tables.
565	* Note that emit_dht() suppresses any duplicate tables.
566	*/
567	for (i = 0; i < cinfo->comps_in_scan; i++) {
568	compptr = cinfo->cur_comp_info[i];
569	if (cinfo->progressive_mode) {
570	/* 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);
574	} else {
575	emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
576	}
577	} else {
578	/* Sequential mode: need both DC and AC tables */
579	emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
580	emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
581	}
582	}
583	}
584
585	/* Emit DRI if required --- note that DRI value could change for each scan.
586	* We avoid wasting space with unnecessary DRIs, however.
587	*/
588	if (cinfo->restart_interval != marker->last_restart_interval) {
589	emit_dri(cinfo);
590	marker->last_restart_interval = cinfo->restart_interval;
591	}
592
593	emit_sos(cinfo);
594	}
595
596
597	/*
598	* Write datastream trailer.
599	*/
600
601	METHODDEF(void)
602	write_file_trailer (j_compress_ptr cinfo)
603	{
604	emit_marker(cinfo, M_EOI);
605	}
606
607
608	/*
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.
613	*/
614
615	METHODDEF(void)
616	write_tables_only (j_compress_ptr cinfo)
617	{
618	int i;
619
620	emit_marker(cinfo, M_SOI);
621
622	for (i = 0; i < NUM_QUANT_TBLS; i++) {
623	if (cinfo->quant_tbl_ptrs[i] != NULL)
624	(void) emit_dqt(cinfo, i);
625	}
626
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);
633	}
634	}
635
636	emit_marker(cinfo, M_EOI);
637	}
638
639
640	/*
641	* Initialize the marker writer module.
642	*/
643
644	GLOBAL(void)
645	jinit_marker_writer (j_compress_ptr cinfo)
646	{
647	my_marker_ptr marker;
648
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;
664	}