    /*
     * 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, int 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;
      int 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;
    }