code:
/*
 * rdppm.c
 *
 * Copyright (C) 1991-1997, 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 read input images in PPM/PGM format.
 * The extended 2-byte-per-sample raw PPM/PGM formats are supported.
 * The PBMPLUS library is NOT required to compile this software
 * (but it is highly useful as a set of PPM image manipulation programs).
 *
 * These routines may need modification for non-Unix environments or
 * specialized applications.  As they stand, they assume input from
 * an ordinary stdio stream.  They further assume that reading begins
 * at the start of the file; start_input may need work if the
 * user interface has already read some data (e.g., to determine that
 * the file is indeed PPM format).
 */

#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */

#ifdef PPM_SUPPORTED

/* Portions of this code are based on the PBMPLUS library, which is:
**
** Copyright (C) 1988 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

/* Macros to deal with unsigned chars as efficiently as compiler allows */

#ifdef HAVE_UNSIGNED_CHAR
typedef unsigned char U_CHAR;
#define UCH(x)	((int) (x))
#else /* !HAVE_UNSIGNED_CHAR */
#ifdef CHAR_IS_UNSIGNED
typedef char U_CHAR;
#define UCH(x)	((int) (x))
#else
typedef char U_CHAR;
#define UCH(x)	((int) (x) & 0xFF)
#endif
#endif /* HAVE_UNSIGNED_CHAR */

#define	ReadOK(file,buffer,len)	(JFREAD(file,buffer,len) == ((size_t) (len)))

/*
 * On most systems, reading individual bytes with getc() is drastically less
 * efficient than buffering a row at a time with fread().  On PCs, we must
 * allocate the buffer in near data space, because we are assuming small-data
 * memory model, wherein fread() can't reach far memory.  If you need to
 * process very wide images on a PC, you might have to compile in large-memory
 * model, or else replace fread() with a getc() loop --- which will be much
 * slower.
 */

/* Private version of data source object */

typedef struct {
  struct cjpeg_source_struct pub; /* public fields */

  U_CHAR *iobuffer;		/* non-FAR pointer to I/O buffer */
  JSAMPROW pixrow;		/* FAR pointer to same */
  size_t buffer_width;		/* width of I/O buffer */
  JSAMPLE *rescale;		/* => maxval-remapping array, or NULL */
} ppm_source_struct;

typedef ppm_source_struct * ppm_source_ptr;

LOCAL(int)
pbm_getc (FILE * infile)
/* Read next char, skipping over any comments */
/* A comment/newline sequence is returned as a newline */
{
  register int ch;

  ch = getc(infile);
  if (ch == '#') {
    do {
      ch = getc(infile);
    } while (ch != '\n' && ch != EOF);
  }
  return ch;
}

LOCAL(unsigned int)
read_pbm_integer (j_compress_ptr cinfo, FILE * infile)
/* Read an unsigned decimal integer from the PPM file */
/* Swallows one trailing character after the integer */
/* Note that on a 16-bit-int machine, only values up to 64k can be read. */
/* This should not be a problem in practice. */
{
  register int ch;
  register unsigned int val;

  /* Skip any leading whitespace */
  do {
    ch = pbm_getc(infile);
    if (ch == EOF)
      ERREXIT(cinfo, JERR_INPUT_EOF);
  } while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r');

  if (ch < '0' || ch > '9')
    ERREXIT(cinfo, JERR_PPM_NONNUMERIC);

  val = ch - '0';
  while ((ch = pbm_getc(infile)) >= '0' && ch <= '9') {
    val *= 10;
    val += ch - '0';
  }
  return val;
}

/*
 * Read one row of pixels.
 *
 * We provide several different versions depending on input file format.
 * In all cases, input is scaled to the size of JSAMPLE.
 *
 * A really fast path is provided for reading byte/sample raw files with
 * maxval = MAXJSAMPLE, which is the normal case for 8-bit data.
 */

METHODDEF(JDIMENSION)
get_text_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading text-format PGM files with any maxval */
{
  ppm_source_ptr source = (ppm_source_ptr) sinfo;
  FILE * infile = source->pub.input_file;
  register JSAMPROW ptr;
  register JSAMPLE *rescale = source->rescale;
  JDIMENSION col;

  ptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    *ptr++ = rescale[read_pbm_integer(cinfo, infile)];
  }
  return 1;
}

METHODDEF(JDIMENSION)
get_text_rgb_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading text-format PPM files with any maxval */
{
  ppm_source_ptr source = (ppm_source_ptr) sinfo;
  FILE * infile = source->pub.input_file;
  register JSAMPROW ptr;
  register JSAMPLE *rescale = source->rescale;
  JDIMENSION col;

  ptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    *ptr++ = rescale[read_pbm_integer(cinfo, infile)];
    *ptr++ = rescale[read_pbm_integer(cinfo, infile)];
    *ptr++ = rescale[read_pbm_integer(cinfo, infile)];
  }
  return 1;
}

METHODDEF(JDIMENSION)
get_scaled_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading raw-byte-format PGM files with any maxval */
{
  ppm_source_ptr source = (ppm_source_ptr) sinfo;
  register JSAMPROW ptr;
  register U_CHAR * bufferptr;
  register JSAMPLE *rescale = source->rescale;
  JDIMENSION col;

  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
    ERREXIT(cinfo, JERR_INPUT_EOF);
  ptr = source->pub.buffer[0];
  bufferptr = source->iobuffer;
  for (col = cinfo->image_width; col > 0; col--) {
    *ptr++ = rescale[UCH(*bufferptr++)];
  }
  return 1;
}

METHODDEF(JDIMENSION)
get_scaled_rgb_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading raw-byte-format PPM files with any maxval */
{
  ppm_source_ptr source = (ppm_source_ptr) sinfo;
  register JSAMPROW ptr;
  register U_CHAR * bufferptr;
  register JSAMPLE *rescale = source->rescale;
  JDIMENSION col;

  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
    ERREXIT(cinfo, JERR_INPUT_EOF);
  ptr = source->pub.buffer[0];
  bufferptr = source->iobuffer;
  for (col = cinfo->image_width; col > 0; col--) {
    *ptr++ = rescale[UCH(*bufferptr++)];
    *ptr++ = rescale[UCH(*bufferptr++)];
    *ptr++ = rescale[UCH(*bufferptr++)];
  }
  return 1;
}

METHODDEF(JDIMENSION)
get_raw_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading raw-byte-format files with maxval = MAXJSAMPLE.
 * In this case we just read right into the JSAMPLE buffer!
 * Note that same code works for PPM and PGM files.
 */
{
  ppm_source_ptr source = (ppm_source_ptr) sinfo;

  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
    ERREXIT(cinfo, JERR_INPUT_EOF);
  return 1;
}

METHODDEF(JDIMENSION)
get_word_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading raw-word-format PGM files with any maxval */
{
  ppm_source_ptr source = (ppm_source_ptr) sinfo;
  register JSAMPROW ptr;
  register U_CHAR * bufferptr;
  register JSAMPLE *rescale = source->rescale;
  JDIMENSION col;

  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
    ERREXIT(cinfo, JERR_INPUT_EOF);
  ptr = source->pub.buffer[0];
  bufferptr = source->iobuffer;
  for (col = cinfo->image_width; col > 0; col--) {
    register int temp;
    temp  = UCH(*bufferptr++);
    temp |= UCH(*bufferptr++) << 8;
    *ptr++ = rescale[temp];
  }
  return 1;
}

METHODDEF(JDIMENSION)
get_word_rgb_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading raw-word-format PPM files with any maxval */
{
  ppm_source_ptr source = (ppm_source_ptr) sinfo;
  register JSAMPROW ptr;
  register U_CHAR * bufferptr;
  register JSAMPLE *rescale = source->rescale;
  JDIMENSION col;

  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
    ERREXIT(cinfo, JERR_INPUT_EOF);
  ptr = source->pub.buffer[0];
  bufferptr = source->iobuffer;
  for (col = cinfo->image_width; col > 0; col--) {
    register int temp;
    temp  = UCH(*bufferptr++);
    temp |= UCH(*bufferptr++) << 8;
    *ptr++ = rescale[temp];
    temp  = UCH(*bufferptr++);
    temp |= UCH(*bufferptr++) << 8;
    *ptr++ = rescale[temp];
    temp  = UCH(*bufferptr++);
    temp |= UCH(*bufferptr++) << 8;
    *ptr++ = rescale[temp];
  }
  return 1;
}

/*
 * Read the file header; return image size and component count.
 */

METHODDEF(void)
start_input_ppm (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  ppm_source_ptr source = (ppm_source_ptr) sinfo;
  int c;
  unsigned int w, h, maxval;
  boolean need_iobuffer, use_raw_buffer, need_rescale;

  if (getc(source->pub.input_file) != 'P')
    ERREXIT(cinfo, JERR_PPM_NOT);

  c = getc(source->pub.input_file); /* subformat discriminator character */

  /* detect unsupported variants (ie, PBM) before trying to read header */
  switch (c) {
  case '2':			/* it's a text-format PGM file */
  case '3':			/* it's a text-format PPM file */
  case '5':			/* it's a raw-format PGM file */
  case '6':			/* it's a raw-format PPM file */
    break;
  default:
    ERREXIT(cinfo, JERR_PPM_NOT);
    break;
  }

  /* fetch the remaining header info */
  w = read_pbm_integer(cinfo, source->pub.input_file);
  h = read_pbm_integer(cinfo, source->pub.input_file);
  maxval = read_pbm_integer(cinfo, source->pub.input_file);

  if (w <= 0 || h <= 0 || maxval <= 0) /* error check */
    ERREXIT(cinfo, JERR_PPM_NOT);

  cinfo->data_precision = BITS_IN_JSAMPLE; /* we always rescale data to this */
  cinfo->image_width = (JDIMENSION) w;
  cinfo->image_height = (JDIMENSION) h;

  /* initialize flags to most common settings */
  need_iobuffer = TRUE;		/* do we need an I/O buffer? */
  use_raw_buffer = FALSE;	/* do we map input buffer onto I/O buffer? */
  need_rescale = TRUE;		/* do we need a rescale array? */

  switch (c) {
  case '2':			/* it's a text-format PGM file */
    cinfo->input_components = 1;
    cinfo->in_color_space = JCS_GRAYSCALE;
    TRACEMS2(cinfo, 1, JTRC_PGM_TEXT, w, h);
    source->pub.get_pixel_rows = get_text_gray_row;
    need_iobuffer = FALSE;
    break;

  case '3':			/* it's a text-format PPM file */
    cinfo->input_components = 3;
    cinfo->in_color_space = JCS_RGB;
    TRACEMS2(cinfo, 1, JTRC_PPM_TEXT, w, h);
    source->pub.get_pixel_rows = get_text_rgb_row;
    need_iobuffer = FALSE;
    break;

  case '5':			/* it's a raw-format PGM file */
    cinfo->input_components = 1;
    cinfo->in_color_space = JCS_GRAYSCALE;
    TRACEMS2(cinfo, 1, JTRC_PGM, w, h);
    if (maxval > 255) {
      source->pub.get_pixel_rows = get_word_gray_row;
    } else if (maxval == MAXJSAMPLE && SIZEOF(JSAMPLE) == SIZEOF(U_CHAR)) {
      source->pub.get_pixel_rows = get_raw_row;
      use_raw_buffer = TRUE;
      need_rescale = FALSE;
    } else {
      source->pub.get_pixel_rows = get_scaled_gray_row;
    }
    break;

  case '6':			/* it's a raw-format PPM file */
    cinfo->input_components = 3;
    cinfo->in_color_space = JCS_RGB;
    TRACEMS2(cinfo, 1, JTRC_PPM, w, h);
    if (maxval > 255) {
      source->pub.get_pixel_rows = get_word_rgb_row;
    } else if (maxval == MAXJSAMPLE && SIZEOF(JSAMPLE) == SIZEOF(U_CHAR)) {
      source->pub.get_pixel_rows = get_raw_row;
      use_raw_buffer = TRUE;
      need_rescale = FALSE;
    } else {
      source->pub.get_pixel_rows = get_scaled_rgb_row;
    }
    break;
  }

  /* Allocate space for I/O buffer: 1 or 3 bytes or words/pixel. */
  if (need_iobuffer) {
    source->buffer_width = (size_t) w * cinfo->input_components *
      ((maxval<=255) ? SIZEOF(U_CHAR) : (2*SIZEOF(U_CHAR)));
    source->iobuffer = (U_CHAR *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
				  source->buffer_width);
  }

  /* Create compressor input buffer. */
  if (use_raw_buffer) {
    /* For unscaled raw-input case, we can just map it onto the I/O buffer. */
    /* Synthesize a JSAMPARRAY pointer structure */
    /* Cast here implies near->far pointer conversion on PCs */
    source->pixrow = (JSAMPROW) source->iobuffer;
    source->pub.buffer = & source->pixrow;
    source->pub.buffer_height = 1;
  } else {
    /* Need to translate anyway, so make a separate sample buffer. */
    source->pub.buffer = (*cinfo->mem->alloc_sarray)
      ((j_common_ptr) cinfo, JPOOL_IMAGE,
       (JDIMENSION) w * cinfo->input_components, (JDIMENSION) 1);
    source->pub.buffer_height = 1;
  }

  /* Compute the rescaling array if required. */
  if (need_rescale) {
    INT32 val, half_maxval;

    /* On 16-bit-int machines we have to be careful of maxval = 65535 */
    source->rescale = (JSAMPLE *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
				  (size_t) (((long) maxval + 1L) * SIZEOF(JSAMPLE)));
    half_maxval = maxval / 2;
    for (val = 0; val <= (INT32) maxval; val++) {
      /* The multiplication here must be done in 32 bits to avoid overflow */
      source->rescale[val] = (JSAMPLE) ((val*MAXJSAMPLE + half_maxval)/maxval);
    }
  }
}

/*
 * Finish up at the end of the file.
 */

METHODDEF(void)
finish_input_ppm (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  /* no work */
}

/*
 * The module selection routine for PPM format input.
 */

GLOBAL(cjpeg_source_ptr)
jinit_read_ppm (j_compress_ptr cinfo)
{
  ppm_source_ptr source;

  /* Create module interface object */
  source = (ppm_source_ptr)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
				  SIZEOF(ppm_source_struct));
  /* Fill in method ptrs, except get_pixel_rows which start_input sets */
  source->pub.start_input = start_input_ppm;
  source->pub.finish_input = finish_input_ppm;

  return (cjpeg_source_ptr) source;
}

#endif /* PPM_SUPPORTED */


code:
/*
 * rdrle.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 read input images in Utah RLE format.
 * The Utah Raster Toolkit library is required (version 3.1 or later).
 *
 * These routines may need modification for non-Unix environments or
 * specialized applications.  As they stand, they assume input from
 * an ordinary stdio stream.  They further assume that reading begins
 * at the start of the file; start_input may need work if the
 * user interface has already read some data (e.g., to determine that
 * the file is indeed RLE format).
 *
 * Based on code contributed by Mike Lijewski,
 * with updates from Robert Hutchinson.
 */

#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */

#ifdef RLE_SUPPORTED

/* rle.h is provided by the Utah Raster Toolkit. */

#include <rle.h>

/*
 * We assume that JSAMPLE has the same representation as rle_pixel,
 * to wit, "unsigned char".  Hence we can't cope with 12- or 16-bit samples.
 */

#if BITS_IN_JSAMPLE != 8
  Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
#endif

/*
 * We support the following types of RLE files:
 *
 *   GRAYSCALE   - 8 bits, no colormap
 *   MAPPEDGRAY  - 8 bits, 1 channel colomap
 *   PSEUDOCOLOR - 8 bits, 3 channel colormap
 *   TRUECOLOR   - 24 bits, 3 channel colormap
 *   DIRECTCOLOR - 24 bits, no colormap
 *
 * For now, we ignore any alpha channel in the image.
 */

typedef enum
  { GRAYSCALE, MAPPEDGRAY, PSEUDOCOLOR, TRUECOLOR, DIRECTCOLOR } rle_kind;

/*
 * Since RLE stores scanlines bottom-to-top, we have to invert the image
 * to conform to JPEG's top-to-bottom order.  To do this, we read the
 * incoming image into a virtual array on the first get_pixel_rows call,
 * then fetch the required row from the virtual array on subsequent calls.
 */

typedef struct _rle_source_struct * rle_source_ptr;

typedef struct _rle_source_struct {
  struct cjpeg_source_struct pub; /* public fields */

  rle_kind visual;              /* actual type of input file */
  jvirt_sarray_ptr image;       /* virtual array to hold the image */
  JDIMENSION row;		/* current row # in the virtual array */
  rle_hdr header;               /* Input file information */
  rle_pixel** rle_row;          /* holds a row returned by rle_getrow() */

} rle_source_struct;

/*
 * Read the file header; return image size and component count.
 */

METHODDEF(void)
start_input_rle (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  rle_source_ptr source = (rle_source_ptr) sinfo;
  JDIMENSION width, height;
#ifdef PROGRESS_REPORT
  cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
#endif

  /* Use RLE library routine to get the header info */
  source->header = *rle_hdr_init(NULL);
  source->header.rle_file = source->pub.input_file;
  switch (rle_get_setup(&(source->header))) {
  case RLE_SUCCESS:
    /* A-OK */
    break;
  case RLE_NOT_RLE:
    ERREXIT(cinfo, JERR_RLE_NOT);
    break;
  case RLE_NO_SPACE:
    ERREXIT(cinfo, JERR_RLE_MEM);
    break;
  case RLE_EMPTY:
    ERREXIT(cinfo, JERR_RLE_EMPTY);
    break;
  case RLE_EOF:
    ERREXIT(cinfo, JERR_RLE_EOF);
    break;
  default:
    ERREXIT(cinfo, JERR_RLE_BADERROR);
    break;
  }

  /* Figure out what we have, set private vars and return values accordingly */

  width  = source->header.xmax - source->header.xmin + 1;
  height = source->header.ymax - source->header.ymin + 1;
  source->header.xmin = 0;		/* realign horizontally */
  source->header.xmax = width-1;

  cinfo->image_width      = width;
  cinfo->image_height     = height;
  cinfo->data_precision   = 8;  /* we can only handle 8 bit data */

  if (source->header.ncolors == 1 && source->header.ncmap == 0) {
    source->visual     = GRAYSCALE;
    TRACEMS2(cinfo, 1, JTRC_RLE_GRAY, width, height);
  } else if (source->header.ncolors == 1 && source->header.ncmap == 1) {
    source->visual     = MAPPEDGRAY;
    TRACEMS3(cinfo, 1, JTRC_RLE_MAPGRAY, width, height,
             1 << source->header.cmaplen);
  } else if (source->header.ncolors == 1 && source->header.ncmap == 3) {
    source->visual     = PSEUDOCOLOR;
    TRACEMS3(cinfo, 1, JTRC_RLE_MAPPED, width, height,
	     1 << source->header.cmaplen);
  } else if (source->header.ncolors == 3 && source->header.ncmap == 3) {
    source->visual     = TRUECOLOR;
    TRACEMS3(cinfo, 1, JTRC_RLE_FULLMAP, width, height,
	     1 << source->header.cmaplen);
  } else if (source->header.ncolors == 3 && source->header.ncmap == 0) {
    source->visual     = DIRECTCOLOR;
    TRACEMS2(cinfo, 1, JTRC_RLE, width, height);
  } else
    ERREXIT(cinfo, JERR_RLE_UNSUPPORTED);

  if (source->visual == GRAYSCALE || source->visual == MAPPEDGRAY) {
    cinfo->in_color_space   = JCS_GRAYSCALE;
    cinfo->input_components = 1;
  } else {
    cinfo->in_color_space   = JCS_RGB;
    cinfo->input_components = 3;
  }

  /*
   * A place to hold each scanline while it's converted.
   * (GRAYSCALE scanlines don't need converting)
   */
  if (source->visual != GRAYSCALE) {
    source->rle_row = (rle_pixel**) (*cinfo->mem->alloc_sarray)
      ((j_common_ptr) cinfo, JPOOL_IMAGE,
       (JDIMENSION) width, (JDIMENSION) cinfo->input_components);
  }

  /* request a virtual array to hold the image */
  source->image = (*cinfo->mem->request_virt_sarray)
    ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
     (JDIMENSION) (width * source->header.ncolors),
     (JDIMENSION) height, (JDIMENSION) 1);

#ifdef PROGRESS_REPORT
  if (progress != NULL) {
    /* count file input as separate pass */
    progress->total_extra_passes++;
  }
#endif

  source->pub.buffer_height = 1;
}

/*
 * Read one row of pixels.
 * Called only after load_image has read the image into the virtual array.
 * Used for GRAYSCALE, MAPPEDGRAY, TRUECOLOR, and DIRECTCOLOR images.
 */

METHODDEF(JDIMENSION)
get_rle_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  rle_source_ptr source = (rle_source_ptr) sinfo;

  source->row--;
  source->pub.buffer = (*cinfo->mem->access_virt_sarray)
    ((j_common_ptr) cinfo, source->image, source->row, (JDIMENSION) 1, FALSE);

  return 1;
}

/*
 * Read one row of pixels.
 * Called only after load_image has read the image into the virtual array.
 * Used for PSEUDOCOLOR images.
 */

METHODDEF(JDIMENSION)
get_pseudocolor_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  rle_source_ptr source = (rle_source_ptr) sinfo;
  JSAMPROW src_row, dest_row;
  JDIMENSION col;
  rle_map *colormap;
  int val;

  colormap = source->header.cmap;
  dest_row = source->pub.buffer[0];
  source->row--;
  src_row = * (*cinfo->mem->access_virt_sarray)
    ((j_common_ptr) cinfo, source->image, source->row, (JDIMENSION) 1, FALSE);

  for (col = cinfo->image_width; col > 0; col--) {
    val = GETJSAMPLE(*src_row++);
    *dest_row++ = (JSAMPLE) (colormap[val      ] >> 8);
    *dest_row++ = (JSAMPLE) (colormap[val + 256] >> 8);
    *dest_row++ = (JSAMPLE) (colormap[val + 512] >> 8);
  }

  return 1;
}

/*
 * Load the image into a virtual array.  We have to do this because RLE
 * files start at the lower left while the JPEG standard has them starting
 * in the upper left.  This is called the first time we want to get a row
 * of input.  What we do is load the RLE data into the array and then call
 * the appropriate routine to read one row from the array.  Before returning,
 * we set source->pub.get_pixel_rows so that subsequent calls go straight to
 * the appropriate row-reading routine.
 */

METHODDEF(JDIMENSION)
load_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  rle_source_ptr source = (rle_source_ptr) sinfo;
  JDIMENSION row, col;
  JSAMPROW  scanline, red_ptr, green_ptr, blue_ptr;
  rle_pixel **rle_row;
  rle_map *colormap;
  char channel;
#ifdef PROGRESS_REPORT
  cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
#endif

  colormap = source->header.cmap;
  rle_row = source->rle_row;

  /* Read the RLE data into our virtual array.
   * We assume here that (a) rle_pixel is represented the same as JSAMPLE,
   * and (b) we are not on a machine where FAR pointers differ from regular.
   */
  RLE_CLR_BIT(source->header, RLE_ALPHA); /* don't read the alpha channel */

#ifdef PROGRESS_REPORT
  if (progress != NULL) {
    progress->pub.pass_limit = cinfo->image_height;
    progress->pub.pass_counter = 0;
    (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
  }
#endif

  switch (source->visual) {

  case GRAYSCALE:
  case PSEUDOCOLOR:
    for (row = 0; row < cinfo->image_height; row++) {
      rle_row = (rle_pixel **) (*cinfo->mem->access_virt_sarray)
         ((j_common_ptr) cinfo, source->image, row, (JDIMENSION) 1, TRUE);
      rle_getrow(&source->header, rle_row);
#ifdef PROGRESS_REPORT
      if (progress != NULL) {
        progress->pub.pass_counter++;
        (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
      }
#endif
    }
    break;

  case MAPPEDGRAY:
  case TRUECOLOR:
    for (row = 0; row < cinfo->image_height; row++) {
      scanline = * (*cinfo->mem->access_virt_sarray)
        ((j_common_ptr) cinfo, source->image, row, (JDIMENSION) 1, TRUE);
      rle_row = source->rle_row;
      rle_getrow(&source->header, rle_row);

      for (col = 0; col < cinfo->image_width; col++) {
        for (channel = 0; channel < source->header.ncolors; channel++) {
          *scanline++ = (JSAMPLE)
            (colormap[GETJSAMPLE(rle_row[channel][col]) + 256 * channel] >> 8);
        }
      }

#ifdef PROGRESS_REPORT
      if (progress != NULL) {
        progress->pub.pass_counter++;
        (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
      }
#endif
    }
    break;

  case DIRECTCOLOR:
    for (row = 0; row < cinfo->image_height; row++) {
      scanline = * (*cinfo->mem->access_virt_sarray)
        ((j_common_ptr) cinfo, source->image, row, (JDIMENSION) 1, TRUE);
      rle_getrow(&source->header, rle_row);

      red_ptr   = rle_row[0];
      green_ptr = rle_row[1];
      blue_ptr  = rle_row[2];

      for (col = cinfo->image_width; col > 0; col--) {
        *scanline++ = *red_ptr++;
        *scanline++ = *green_ptr++;
        *scanline++ = *blue_ptr++;
      }

#ifdef PROGRESS_REPORT
      if (progress != NULL) {
        progress->pub.pass_counter++;
        (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
      }
#endif
    }
  }

#ifdef PROGRESS_REPORT
  if (progress != NULL)
    progress->completed_extra_passes++;
#endif

  /* Set up to call proper row-extraction routine in future */
  if (source->visual == PSEUDOCOLOR) {
    source->pub.buffer = source->rle_row;
    source->pub.get_pixel_rows = get_pseudocolor_row;
  } else {
    source->pub.get_pixel_rows = get_rle_row;
  }
  source->row = cinfo->image_height;

  /* And fetch the topmost (bottommost) row */
  return (*source->pub.get_pixel_rows) (cinfo, sinfo);
}

/*
 * Finish up at the end of the file.
 */

METHODDEF(void)
finish_input_rle (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  /* no work */
}

/*
 * The module selection routine for RLE format input.
 */

GLOBAL(cjpeg_source_ptr)
jinit_read_rle (j_compress_ptr cinfo)
{
  rle_source_ptr source;

  /* Create module interface object */
  source = (rle_source_ptr)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
                                  SIZEOF(rle_source_struct));
  /* Fill in method ptrs */
  source->pub.start_input = start_input_rle;
  source->pub.finish_input = finish_input_rle;
  source->pub.get_pixel_rows = load_image;

  return (cjpeg_source_ptr) source;
}

#endif /* RLE_SUPPORTED */

license: mit


code:
/*
 * rdswitch.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 process some of cjpeg's more complicated
 * command-line switches.  Switches processed here are:
 *	-qtables file		Read quantization tables from text file
 *	-scans file		Read scan script from text file
 *	-qslots N[,N,...]	Set component quantization table selectors
 *	-sample HxV[,HxV,...]	Set component sampling factors
 */

#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */
#include <ctype.h>		/* to declare isdigit(), isspace() */

LOCAL(int)
text_getc (FILE * file)
/* Read next char, skipping over any comments (# to end of line) */
/* A comment/newline sequence is returned as a newline */
{
  register int ch;

  ch = getc(file);
  if (ch == '#') {
    do {
      ch = getc(file);
    } while (ch != '\n' && ch != EOF);
  }
  return ch;
}

LOCAL(boolean)
read_text_integer (FILE * file, long * result, int * termchar)
/* Read an unsigned decimal integer from a file, store it in result */
/* Reads one trailing character after the integer; returns it in termchar */
{
  register int ch;
  register long val;

  /* Skip any leading whitespace, detect EOF */
  do {
    ch = text_getc(file);
    if (ch == EOF) {
      *termchar = ch;
      return FALSE;
    }
  } while (isspace(ch));

  if (! isdigit(ch)) {
    *termchar = ch;
    return FALSE;
  }

  val = ch - '0';
  while ((ch = text_getc(file)) != EOF) {
    if (! isdigit(ch))
      break;
    val *= 10;
    val += ch - '0';
  }
  *result = val;
  *termchar = ch;
  return TRUE;
}

GLOBAL(boolean)
read_quant_tables (j_compress_ptr cinfo, char * filename,
		   int scale_factor, boolean force_baseline)
/* Read a set of quantization tables from the specified file.
 * The file is plain ASCII text: decimal numbers with whitespace between.
 * Comments preceded by '#' may be included in the file.
 * There may be one to NUM_QUANT_TBLS tables in the file, each of 64 values.
 * The tables are implicitly numbered 0,1,etc.
 * NOTE: does not affect the qslots mapping, which will default to selecting
 * table 0 for luminance (or primary) components, 1 for chrominance components.
 * You must use -qslots if you want a different component->table mapping.
 */
{
  FILE * fp;
  int tblno, i, termchar;
  long val;
  unsigned int table[DCTSIZE2];

  if ((fp = fopen(filename, "r")) == NULL) {
    fprintf(stderr, "Can't open table file %s\n", filename);
    return FALSE;
  }
  tblno = 0;

  while (read_text_integer(fp, &val, &termchar)) { /* read 1st element of table */
    if (tblno >= NUM_QUANT_TBLS) {
      fprintf(stderr, "Too many tables in file %s\n", filename);
      fclose(fp);
      return FALSE;
    }
    table[0] = (unsigned int) val;
    for (i = 1; i < DCTSIZE2; i++) {
      if (! read_text_integer(fp, &val, &termchar)) {
	fprintf(stderr, "Invalid table data in file %s\n", filename);
	fclose(fp);
	return FALSE;
      }
      table[i] = (unsigned int) val;
    }
    jpeg_add_quant_table(cinfo, tblno, table, scale_factor, force_baseline);
    tblno++;
  }

  if (termchar != EOF) {
    fprintf(stderr, "Non-numeric data in file %s\n", filename);
    fclose(fp);
    return FALSE;
  }

  fclose(fp);
  return TRUE;
}

#ifdef C_MULTISCAN_FILES_SUPPORTED

LOCAL(boolean)
read_scan_integer (FILE * file, long * result, int * termchar)
/* Variant of read_text_integer that always looks for a non-space termchar;
 * this simplifies parsing of punctuation in scan scripts.
 */
{
  register int ch;

  if (! read_text_integer(file, result, termchar))
    return FALSE;
  ch = *termchar;
  while (ch != EOF && isspace(ch))
    ch = text_getc(file);
  if (isdigit(ch)) {		/* oops, put it back */
    if (ungetc(ch, file) == EOF)
      return FALSE;
    ch = ' ';
  } else {
    /* Any separators other than ';' and ':' are ignored;
     * this allows user to insert commas, etc, if desired.
     */
    if (ch != EOF && ch != ';' && ch != ':')
      ch = ' ';
  }
  *termchar = ch;
  return TRUE;
}

GLOBAL(boolean)
read_scan_script (j_compress_ptr cinfo, char * filename)
/* Read a scan script from the specified text file.
 * Each entry in the file defines one scan to be emitted.
 * Entries are separated by semicolons ';'.
 * An entry contains one to four component indexes,
 * optionally followed by a colon ':' and four progressive-JPEG parameters.
 * The component indexes denote which component(s) are to be transmitted
 * in the current scan.  The first component has index 0.
 * Sequential JPEG is used if the progressive-JPEG parameters are omitted.
 * The file is free format text: any whitespace may appear between numbers
 * and the ':' and ';' punctuation marks.  Also, other punctuation (such
 * as commas or dashes) can be placed between numbers if desired.
 * Comments preceded by '#' may be included in the file.
 * Note: we do very little validity checking here;
 * jcmaster.c will validate the script parameters.
 */
{
  FILE * fp;
  int scanno, ncomps, termchar;
  long val;
  jpeg_scan_info * scanptr;
#define MAX_SCANS  100		/* quite arbitrary limit */
  jpeg_scan_info scans[MAX_SCANS];

  if ((fp = fopen(filename, "r")) == NULL) {
    fprintf(stderr, "Can't open scan definition file %s\n", filename);
    return FALSE;
  }
  scanptr = scans;
  scanno = 0;

  while (read_scan_integer(fp, &val, &termchar)) {
    if (scanno >= MAX_SCANS) {
      fprintf(stderr, "Too many scans defined in file %s\n", filename);
      fclose(fp);
      return FALSE;
    }
    scanptr->component_index[0] = (int) val;
    ncomps = 1;
    while (termchar == ' ') {
      if (ncomps >= MAX_COMPS_IN_SCAN) {
	fprintf(stderr, "Too many components in one scan in file %s\n",
		filename);
	fclose(fp);
	return FALSE;
      }
      if (! read_scan_integer(fp, &val, &termchar))
	goto bogus;
      scanptr->component_index[ncomps] = (int) val;
      ncomps++;
    }
    scanptr->comps_in_scan = ncomps;
    if (termchar == ':') {
      if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
	goto bogus;
      scanptr->Ss = (int) val;
      if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
	goto bogus;
      scanptr->Se = (int) val;
      if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
	goto bogus;
      scanptr->Ah = (int) val;
      if (! read_scan_integer(fp, &val, &termchar))
	goto bogus;
      scanptr->Al = (int) val;
    } else {
      /* set non-progressive parameters */
      scanptr->Ss = 0;
      scanptr->Se = DCTSIZE2-1;
      scanptr->Ah = 0;
      scanptr->Al = 0;
    }
    if (termchar != ';' && termchar != EOF) {
bogus:
      fprintf(stderr, "Invalid scan entry format in file %s\n", filename);
      fclose(fp);
      return FALSE;
    }
    scanptr++, scanno++;
  }

  if (termchar != EOF) {
    fprintf(stderr, "Non-numeric data in file %s\n", filename);
    fclose(fp);
    return FALSE;
  }

  if (scanno > 0) {
    /* Stash completed scan list in cinfo structure.
     * NOTE: for cjpeg's use, JPOOL_IMAGE is the right lifetime for this data,
     * but if you want to compress multiple images you'd want JPOOL_PERMANENT.
     */
    scanptr = (jpeg_scan_info *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
				  scanno * SIZEOF(jpeg_scan_info));
    MEMCOPY(scanptr, scans, scanno * SIZEOF(jpeg_scan_info));
    cinfo->scan_info = scanptr;
    cinfo->num_scans = scanno;
  }

  fclose(fp);
  return TRUE;
}

#endif /* C_MULTISCAN_FILES_SUPPORTED */

GLOBAL(boolean)
set_quant_slots (j_compress_ptr cinfo, char *arg)
/* Process a quantization-table-selectors parameter string, of the form
 *     N[,N,...]
 * If there are more components than parameters, the last value is replicated.
 */
{
  int val = 0;			/* default table # */
  int ci;
  char ch;

  for (ci = 0; ci < MAX_COMPONENTS; ci++) {
    if (*arg) {
      ch = ',';			/* if not set by sscanf, will be ',' */
      if (sscanf(arg, "%d%c", &val, &ch) < 1)
	return FALSE;
      if (ch != ',')		/* syntax check */
	return FALSE;
      if (val < 0 || val >= NUM_QUANT_TBLS) {
	fprintf(stderr, "JPEG quantization tables are numbered 0..%d\n",
		NUM_QUANT_TBLS-1);
	return FALSE;
      }
      cinfo->comp_info[ci].quant_tbl_no = val;
      while (*arg && *arg++ != ',') /* advance to next segment of arg string */
	;
    } else {
      /* reached end of parameter, set remaining components to last table */
      cinfo->comp_info[ci].quant_tbl_no = val;
    }
  }
  return TRUE;
}

GLOBAL(boolean)
set_sample_factors (j_compress_ptr cinfo, char *arg)
/* Process a sample-factors parameter string, of the form
 *     HxV[,HxV,...]
 * If there are more components than parameters, "1x1" is assumed for the rest.
 */
{
  int ci, val1, val2;
  char ch1, ch2;

  for (ci = 0; ci < MAX_COMPONENTS; ci++) {
    if (*arg) {
      ch2 = ',';		/* if not set by sscanf, will be ',' */
      if (sscanf(arg, "%d%c%d%c", &val1, &ch1, &val2, &ch2) < 3)
	return FALSE;
      if ((ch1 != 'x' && ch1 != 'X') || ch2 != ',') /* syntax check */
	return FALSE;
      if (val1 <= 0 || val1 > 4 || val2 <= 0 || val2 > 4) {
	fprintf(stderr, "JPEG sampling factors must be 1..4\n");
	return FALSE;
      }
      cinfo->comp_info[ci].h_samp_factor = val1;
      cinfo->comp_info[ci].v_samp_factor = val2;
      while (*arg && *arg++ != ',') /* advance to next segment of arg string */
	;
    } else {
      /* reached end of parameter, set remaining components to 1x1 sampling */
      cinfo->comp_info[ci].h_samp_factor = 1;
      cinfo->comp_info[ci].v_samp_factor = 1;
    }
  }
  return TRUE;
}


code:
/*
 * rdtarga.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 read input images in Targa format.
 *
 * These routines may need modification for non-Unix environments or
 * specialized applications.  As they stand, they assume input from
 * an ordinary stdio stream.  They further assume that reading begins
 * at the start of the file; start_input may need work if the
 * user interface has already read some data (e.g., to determine that
 * the file is indeed Targa format).
 *
 * Based on code contributed by Lee Daniel Crocker.
 */

#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */

#ifdef TARGA_SUPPORTED

/* Macros to deal with unsigned chars as efficiently as compiler allows */

#ifdef HAVE_UNSIGNED_CHAR
typedef unsigned char U_CHAR;
#define UCH(x)	((int) (x))
#else /* !HAVE_UNSIGNED_CHAR */
#ifdef CHAR_IS_UNSIGNED
typedef char U_CHAR;
#define UCH(x)	((int) (x))
#else
typedef char U_CHAR;
#define UCH(x)	((int) (x) & 0xFF)
#endif
#endif /* HAVE_UNSIGNED_CHAR */

#define	ReadOK(file,buffer,len)	(JFREAD(file,buffer,len) == ((size_t) (len)))

/* Private version of data source object */

typedef struct _tga_source_struct * tga_source_ptr;

typedef struct _tga_source_struct {
  struct cjpeg_source_struct pub; /* public fields */

  j_compress_ptr cinfo;		/* back link saves passing separate parm */

  JSAMPARRAY colormap;		/* Targa colormap (converted to my format) */

  jvirt_sarray_ptr whole_image;	/* Needed if funny input row order */
  JDIMENSION current_row;	/* Current logical row number to read */

  /* Pointer to routine to extract next Targa pixel from input file */
  JMETHOD(void, read_pixel, (tga_source_ptr sinfo));

  /* Result of read_pixel is delivered here: */
  U_CHAR tga_pixel[4];

  int pixel_size;		/* Bytes per Targa pixel (1 to 4) */

  /* State info for reading RLE-coded pixels; both counts must be init to 0 */
  int block_count;		/* # of pixels remaining in RLE block */
  int dup_pixel_count;		/* # of times to duplicate previous pixel */

  /* This saves the correct pixel-row-expansion method for preload_image */
  JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo,
				       cjpeg_source_ptr sinfo));
} tga_source_struct;

/* For expanding 5-bit pixel values to 8-bit with best rounding */

static const UINT8 c5to8bits[32] = {
    0,   8,  16,  25,  33,  41,  49,  58,
   66,  74,  82,  90,  99, 107, 115, 123,
  132, 140, 148, 156, 165, 173, 181, 189,
  197, 206, 214, 222, 230, 239, 247, 255
};

LOCAL(int)
read_byte (tga_source_ptr sinfo)
/* Read next byte from Targa file */
{
  register FILE *infile = sinfo->pub.input_file;
  register int c;

  if ((c = getc(infile)) == EOF)
    ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
  return c;
}

LOCAL(void)
read_colormap (tga_source_ptr sinfo, int cmaplen, int mapentrysize)
/* Read the colormap from a Targa file */
{
  int i;

  /* Presently only handles 24-bit BGR format */
  if (mapentrysize != 24)
    ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP);

  for (i = 0; i < cmaplen; i++) {
    sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
    sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
    sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
  }
}

/*
 * read_pixel methods: get a single pixel from Targa file into tga_pixel[]
 */

METHODDEF(void)
read_non_rle_pixel (tga_source_ptr sinfo)
/* Read one Targa pixel from the input file; no RLE expansion */
{
  register FILE *infile = sinfo->pub.input_file;
  register int i;

  for (i = 0; i < sinfo->pixel_size; i++) {
    sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
  }
}

METHODDEF(void)
read_rle_pixel (tga_source_ptr sinfo)
/* Read one Targa pixel from the input file, expanding RLE data as needed */
{
  register FILE *infile = sinfo->pub.input_file;
  register int i;

  /* Duplicate previously read pixel? */
  if (sinfo->dup_pixel_count > 0) {
    sinfo->dup_pixel_count--;
    return;
  }

  /* Time to read RLE block header? */
  if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */
    i = read_byte(sinfo);
    if (i & 0x80) {		/* Start of duplicate-pixel block? */
      sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */
      sinfo->block_count = 0;	/* then read new block header */
    } else {
      sinfo->block_count = i & 0x7F; /* number of pixels after this one */
    }
  }

  /* Read next pixel */
  for (i = 0; i < sinfo->pixel_size; i++) {
    sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
  }
}

/*
 * Read one row of pixels.
 *
 * We provide several different versions depending on input file format.
 */

METHODDEF(JDIMENSION)
get_8bit_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading 8-bit grayscale pixels */
{
  tga_source_ptr source = (tga_source_ptr) sinfo;
  register JSAMPROW ptr;
  register JDIMENSION col;

  ptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
    *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
  }
  return 1;
}

METHODDEF(JDIMENSION)
get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading 8-bit colormap indexes */
{
  tga_source_ptr source = (tga_source_ptr) sinfo;
  register int t;
  register JSAMPROW ptr;
  register JDIMENSION col;
  register JSAMPARRAY colormap = source->colormap;

  ptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
    t = UCH(source->tga_pixel[0]);
    *ptr++ = colormap[0][t];
    *ptr++ = colormap[1][t];
    *ptr++ = colormap[2][t];
  }
  return 1;
}

METHODDEF(JDIMENSION)
get_16bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading 16-bit pixels */
{
  tga_source_ptr source = (tga_source_ptr) sinfo;
  register int t;
  register JSAMPROW ptr;
  register JDIMENSION col;

  ptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
    t = UCH(source->tga_pixel[0]);
    t += UCH(source->tga_pixel[1]) << 8;
    /* We expand 5 bit data to 8 bit sample width.
     * The format of the 16-bit (LSB first) input word is
     *     xRRRRRGGGGGBBBBB
     */
    ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F];
    t >>= 5;
    ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F];
    t >>= 5;
    ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F];
    ptr += 3;
  }
  return 1;
}

METHODDEF(JDIMENSION)
get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading 24-bit pixels */
{
  tga_source_ptr source = (tga_source_ptr) sinfo;
  register JSAMPROW ptr;
  register JDIMENSION col;

  ptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
    *ptr++ = (JSAMPLE) UCH(source->tga_pixel[2]); /* change BGR to RGB order */
    *ptr++ = (JSAMPLE) UCH(source->tga_pixel[1]);
    *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
  }
  return 1;
}

/*
 * Targa also defines a 32-bit pixel format with order B,G,R,A.
 * We presently ignore the attribute byte, so the code for reading
 * these pixels is identical to the 24-bit routine above.
 * This works because the actual pixel length is only known to read_pixel.
 */

#define get_32bit_row  get_24bit_row

/*
 * This method is for re-reading the input data in standard top-down
 * row order.  The entire image has already been read into whole_image
 * with proper conversion of pixel format, but it's in a funny row order.
 */

METHODDEF(JDIMENSION)
get_memory_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  tga_source_ptr source = (tga_source_ptr) sinfo;
  JDIMENSION source_row;

  /* Compute row of source that maps to current_row of normal order */
  /* For now, assume image is bottom-up and not interlaced. */
  /* NEEDS WORK to support interlaced images! */
  source_row = cinfo->image_height - source->current_row - 1;

  /* Fetch that row from virtual array */
  source->pub.buffer = (*cinfo->mem->access_virt_sarray)
    ((j_common_ptr) cinfo, source->whole_image,
     source_row, (JDIMENSION) 1, FALSE);

  source->current_row++;
  return 1;
}

/*
 * This method loads the image into whole_image during the first call on
 * get_pixel_rows.  The get_pixel_rows pointer is then adjusted to call
 * get_memory_row on subsequent calls.
 */

METHODDEF(JDIMENSION)
preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  tga_source_ptr source = (tga_source_ptr) sinfo;
  JDIMENSION row;
  cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;

  /* Read the data into a virtual array in input-file row order. */
  for (row = 0; row < cinfo->image_height; row++) {
    if (progress != NULL) {
      progress->pub.pass_counter = (long) row;
      progress->pub.pass_limit = (long) cinfo->image_height;
      (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
    }
    source->pub.buffer = (*cinfo->mem->access_virt_sarray)
      ((j_common_ptr) cinfo, source->whole_image, row, (JDIMENSION) 1, TRUE);
    (*source->get_pixel_rows) (cinfo, sinfo);
  }
  if (progress != NULL)
    progress->completed_extra_passes++;

  /* Set up to read from the virtual array in unscrambled order */
  source->pub.get_pixel_rows = get_memory_row;
  source->current_row = 0;
  /* And read the first row */
  return get_memory_row(cinfo, sinfo);
}

/*
 * Read the file header; return image size and component count.
 */

METHODDEF(void)
start_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  tga_source_ptr source = (tga_source_ptr) sinfo;
  U_CHAR targaheader[18];
  int idlen, cmaptype, subtype, flags, interlace_type, components;
  unsigned int width, height, maplen;
  boolean is_bottom_up;

#define GET_2B(offset)	((unsigned int) UCH(targaheader[offset]) + \
			 (((unsigned int) UCH(targaheader[offset+1])) << 8))

  if (! ReadOK(source->pub.input_file, targaheader, 18))
    ERREXIT(cinfo, JERR_INPUT_EOF);

  /* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */
  if (targaheader[16] == 15)
    targaheader[16] = 16;

  idlen = UCH(targaheader[0]);
  cmaptype = UCH(targaheader[1]);
  subtype = UCH(targaheader[2]);
  maplen = GET_2B(5);
  width = GET_2B(12);
  height = GET_2B(14);
  source->pixel_size = UCH(targaheader[16]) >> 3;
  flags = UCH(targaheader[17]);	/* Image Descriptor byte */

  is_bottom_up = ((flags & 0x20) == 0);	/* bit 5 set => top-down */
  interlace_type = flags >> 6;	/* bits 6/7 are interlace code */

  if (cmaptype > 1 ||		/* cmaptype must be 0 or 1 */
      source->pixel_size < 1 || source->pixel_size > 4 ||
      (UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */
      interlace_type != 0)	/* currently don't allow interlaced image */
    ERREXIT(cinfo, JERR_TGA_BADPARMS);

  if (subtype > 8) {
    /* It's an RLE-coded file */
    source->read_pixel = read_rle_pixel;
    source->block_count = source->dup_pixel_count = 0;
    subtype -= 8;
  } else {
    /* Non-RLE file */
    source->read_pixel = read_non_rle_pixel;
  }

  /* Now should have subtype 1, 2, or 3 */
  components = 3;		/* until proven different */
  cinfo->in_color_space = JCS_RGB;

  switch (subtype) {
  case 1:			/* Colormapped image */
    if (source->pixel_size == 1 && cmaptype == 1)
      source->get_pixel_rows = get_8bit_row;
    else
      ERREXIT(cinfo, JERR_TGA_BADPARMS);
    TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height);
    break;
  case 2:			/* RGB image */
    switch (source->pixel_size) {
    case 2:
      source->get_pixel_rows = get_16bit_row;
      break;
    case 3:
      source->get_pixel_rows = get_24bit_row;
      break;
    case 4:
      source->get_pixel_rows = get_32bit_row;
      break;
    default:
      ERREXIT(cinfo, JERR_TGA_BADPARMS);
      break;
    }
    TRACEMS2(cinfo, 1, JTRC_TGA, width, height);
    break;
  case 3:			/* Grayscale image */
    components = 1;
    cinfo->in_color_space = JCS_GRAYSCALE;
    if (source->pixel_size == 1)
      source->get_pixel_rows = get_8bit_gray_row;
    else
      ERREXIT(cinfo, JERR_TGA_BADPARMS);
    TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height);
    break;
  default:
    ERREXIT(cinfo, JERR_TGA_BADPARMS);
    break;
  }

  if (is_bottom_up) {
    /* Create a virtual array to buffer the upside-down image. */
    source->whole_image = (*cinfo->mem->request_virt_sarray)
      ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
       (JDIMENSION) width * components, (JDIMENSION) height, (JDIMENSION) 1);
    if (cinfo->progress != NULL) {
      cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
      progress->total_extra_passes++; /* count file input as separate pass */
    }
    /* source->pub.buffer will point to the virtual array. */
    source->pub.buffer_height = 1; /* in case anyone looks at it */
    source->pub.get_pixel_rows = preload_image;
  } else {
    /* Don't need a virtual array, but do need a one-row input buffer. */
    source->whole_image = NULL;
    source->pub.buffer = (*cinfo->mem->alloc_sarray)
      ((j_common_ptr) cinfo, JPOOL_IMAGE,
       (JDIMENSION) width * components, (JDIMENSION) 1);
    source->pub.buffer_height = 1;
    source->pub.get_pixel_rows = source->get_pixel_rows;
  }

  while (idlen--)		/* Throw away ID field */
    (void) read_byte(source);

  if (maplen > 0) {
    if (maplen > 256 || GET_2B(3) != 0)
      ERREXIT(cinfo, JERR_TGA_BADCMAP);
    /* Allocate space to store the colormap */
    source->colormap = (*cinfo->mem->alloc_sarray)
      ((j_common_ptr) cinfo, JPOOL_IMAGE, (JDIMENSION) maplen, (JDIMENSION) 3);
    /* and read it from the file */
    read_colormap(source, (int) maplen, UCH(targaheader[7]));
  } else {
    if (cmaptype)		/* but you promised a cmap! */
      ERREXIT(cinfo, JERR_TGA_BADPARMS);
    source->colormap = NULL;
  }

  cinfo->input_components = components;
  cinfo->data_precision = 8;
  cinfo->image_width = width;
  cinfo->image_height = height;
}

/*
 * Finish up at the end of the file.
 */

METHODDEF(void)
finish_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  /* no work */
}

/*
 * The module selection routine for Targa format input.
 */

GLOBAL(cjpeg_source_ptr)
jinit_read_targa (j_compress_ptr cinfo)
{
  tga_source_ptr source;

  /* Create module interface object */
  source = (tga_source_ptr)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
				  SIZEOF(tga_source_struct));
  source->cinfo = cinfo;	/* make back link for subroutines */
  /* Fill in method ptrs, except get_pixel_rows which start_input sets */
  source->pub.start_input = start_input_tga;
  source->pub.finish_input = finish_input_tga;

  return (cjpeg_source_ptr) source;
}

#endif /* TARGA_SUPPORTED */


code:
/*
 * transupp.c
 *
 * Copyright (C) 1997, 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 image transformation routines and other utility code
 * used by the jpegtran sample application.  These are NOT part of the core
 * JPEG library.  But we keep these routines separate from jpegtran.c to
 * ease the task of maintaining jpegtran-like programs that have other user
 * interfaces.
 */

/* Although this file really shouldn't have access to the library internals,
 * it's helpful to let it call jround_up() and jcopy_block_row().
 */
#define JPEG_INTERNALS

#include "jinclude.h"
#include "jpeglib.h"
#include "transupp.h"		/* My own external interface */

#if TRANSFORMS_SUPPORTED

/*
 * Lossless image transformation routines.  These routines work on DCT
 * coefficient arrays and thus do not require any lossy decompression
 * or recompression of the image.
 * Thanks to Guido Vollbeding for the initial design and code of this feature.
 *
 * Horizontal flipping is done in-place, using a single top-to-bottom
 * pass through the virtual source array.  It will thus be much the
 * fastest option for images larger than main memory.
 *
 * The other routines require a set of destination virtual arrays, so they
 * need twice as much memory as jpegtran normally does.  The destination
 * arrays are always written in normal scan order (top to bottom) because
 * the virtual array manager expects this.  The source arrays will be scanned
 * in the corresponding order, which means multiple passes through the source
 * arrays for most of the transforms.  That could result in much thrashing
 * if the image is larger than main memory.
 *
 * Some notes about the operating environment of the individual transform
 * routines:
 * 1. Both the source and destination virtual arrays are allocated from the
 *    source JPEG object, and therefore should be manipulated by calling the
 *    source's memory manager.
 * 2. The destination's component count should be used.  It may be smaller
 *    than the source's when forcing to grayscale.
 * 3. Likewise the destination's sampling factors should be used.  When
 *    forcing to grayscale the destination's sampling factors will be all 1,
 *    and we may as well take that as the effective iMCU size.
 * 4. When "trim" is in effect, the destination's dimensions will be the
 *    trimmed values but the source's will be untrimmed.
 * 5. All the routines assume that the source and destination buffers are
 *    padded out to a full iMCU boundary.  This is true, although for the
 *    source buffer it is an undocumented property of jdcoefct.c.
 * Notes 2,3,4 boil down to this: generally we should use the destination's
 * dimensions and ignore the source's.
 */

LOCAL(void)
do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	   jvirt_barray_ptr *src_coef_arrays)
/* Horizontal flip; done in-place, so no separate dest array is required */
{
  JDIMENSION MCU_cols, comp_width, blk_x, blk_y;
  int ci, k, offset_y;
  JBLOCKARRAY buffer;
  JCOEFPTR ptr1, ptr2;
  JCOEF temp1, temp2;
  jpeg_component_info *compptr;

  /* Horizontal mirroring of DCT blocks is accomplished by swapping
   * pairs of blocks in-place.  Within a DCT block, we perform horizontal
   * mirroring by changing the signs of odd-numbered columns.
   * Partial iMCUs at the right edge are left untouched.
   */
  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    for (blk_y = 0; blk_y < compptr->height_in_blocks;
	 blk_y += compptr->v_samp_factor) {
      buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
	  ptr1 = buffer[offset_y][blk_x];
	  ptr2 = buffer[offset_y][comp_width - blk_x - 1];
	  /* this unrolled loop doesn't need to know which row it's on... */
	  for (k = 0; k < DCTSIZE2; k += 2) {
	    temp1 = *ptr1;	/* swap even column */
	    temp2 = *ptr2;
	    *ptr1++ = temp2;
	    *ptr2++ = temp1;
	    temp1 = *ptr1;	/* swap odd column with sign change */
	    temp2 = *ptr2;
	    *ptr1++ = -temp2;
	    *ptr2++ = -temp1;
	  }
	}
      }
    }
  }
}

LOCAL(void)
do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	   jvirt_barray_ptr *src_coef_arrays,
	   jvirt_barray_ptr *dst_coef_arrays)
/* Vertical flip */
{
  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
  int ci, i, j, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JBLOCKROW src_row_ptr, dst_row_ptr;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* We output into a separate array because we can't touch different
   * rows of the source virtual array simultaneously.  Otherwise, this
   * is a pretty straightforward analog of horizontal flip.
   * Within a DCT block, vertical mirroring is done by changing the signs
   * of odd-numbered rows.
   * Partial iMCUs at the bottom edge are copied verbatim.
   */
  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_height = MCU_rows * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      if (dst_blk_y < comp_height) {
	/* Row is within the mirrorable area. */
	src_buffer = (*srcinfo->mem->access_virt_barray)
	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	   comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
	   (JDIMENSION) compptr->v_samp_factor, FALSE);
      } else {
	/* Bottom-edge blocks will be copied verbatim. */
	src_buffer = (*srcinfo->mem->access_virt_barray)
	  ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
	   (JDIMENSION) compptr->v_samp_factor, FALSE);
      }
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	if (dst_blk_y < comp_height) {
	  /* Row is within the mirrorable area. */
	  dst_row_ptr = dst_buffer[offset_y];
	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	       dst_blk_x++) {
	    dst_ptr = dst_row_ptr[dst_blk_x];
	    src_ptr = src_row_ptr[dst_blk_x];
	    for (i = 0; i < DCTSIZE; i += 2) {
	      /* copy even row */
	      for (j = 0; j < DCTSIZE; j++)
		*dst_ptr++ = *src_ptr++;
	      /* copy odd row with sign change */
	      for (j = 0; j < DCTSIZE; j++)
		*dst_ptr++ = - *src_ptr++;
	    }
	  }
	} else {
	  /* Just copy row verbatim. */
	  jcopy_block_row(src_buffer[offset_y], dst_buffer[offset_y],
			  compptr->width_in_blocks);
	}
      }
    }
  }
}

LOCAL(void)
do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	      jvirt_barray_ptr *src_coef_arrays,
	      jvirt_barray_ptr *dst_coef_arrays)
/* Transpose source into destination */
{
  JDIMENSION dst_blk_x, dst_blk_y;
  int ci, i, j, offset_x, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* Transposing pixels within a block just requires transposing the
   * DCT coefficients.
   * Partial iMCUs at the edges require no special treatment; we simply
   * process all the available DCT blocks for every component.
   */
  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	     dst_blk_x += compptr->h_samp_factor) {
	  src_buffer = (*srcinfo->mem->access_virt_barray)
	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
	     (JDIMENSION) compptr->h_samp_factor, FALSE);
	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
	    for (i = 0; i < DCTSIZE; i++)
	      for (j = 0; j < DCTSIZE; j++)
		dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
	  }
	}
      }
    }
  }
}

LOCAL(void)
do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	   jvirt_barray_ptr *src_coef_arrays,
	   jvirt_barray_ptr *dst_coef_arrays)
/* 90 degree rotation is equivalent to
 *   1. Transposing the image;
 *   2. Horizontal mirroring.
 * These two steps are merged into a single processing routine.
 */
{
  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
  int ci, i, j, offset_x, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* Because of the horizontal mirror step, we can't process partial iMCUs
   * at the (output) right edge properly.  They just get transposed and
   * not mirrored.
   */
  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	     dst_blk_x += compptr->h_samp_factor) {
	  src_buffer = (*srcinfo->mem->access_virt_barray)
	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
	     (JDIMENSION) compptr->h_samp_factor, FALSE);
	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
	    if (dst_blk_x < comp_width) {
	      /* Block is within the mirrorable area. */
	      dst_ptr = dst_buffer[offset_y]
		[comp_width - dst_blk_x - offset_x - 1];
	      for (i = 0; i < DCTSIZE; i++) {
		for (j = 0; j < DCTSIZE; j++)
		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		i++;
		for (j = 0; j < DCTSIZE; j++)
		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
	      }
	    } else {
	      /* Edge blocks are transposed but not mirrored. */
	      dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
	      for (i = 0; i < DCTSIZE; i++)
		for (j = 0; j < DCTSIZE; j++)
		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
	    }
	  }
	}
      }
    }
  }
}

LOCAL(void)
do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	    jvirt_barray_ptr *src_coef_arrays,
	    jvirt_barray_ptr *dst_coef_arrays)
/* 270 degree rotation is equivalent to
 *   1. Horizontal mirroring;
 *   2. Transposing the image.
 * These two steps are merged into a single processing routine.
 */
{
  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
  int ci, i, j, offset_x, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* Because of the horizontal mirror step, we can't process partial iMCUs
   * at the (output) bottom edge properly.  They just get transposed and
   * not mirrored.
   */
  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_height = MCU_rows * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	     dst_blk_x += compptr->h_samp_factor) {
	  src_buffer = (*srcinfo->mem->access_virt_barray)
	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
	     (JDIMENSION) compptr->h_samp_factor, FALSE);
	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
	    if (dst_blk_y < comp_height) {
	      /* Block is within the mirrorable area. */
	      src_ptr = src_buffer[offset_x]
		[comp_height - dst_blk_y - offset_y - 1];
	      for (i = 0; i < DCTSIZE; i++) {
		for (j = 0; j < DCTSIZE; j++) {
		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		  j++;
		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		}
	      }
	    } else {
	      /* Edge blocks are transposed but not mirrored. */
	      src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
	      for (i = 0; i < DCTSIZE; i++)
		for (j = 0; j < DCTSIZE; j++)
		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
	    }
	  }
	}
      }
    }
  }
}

LOCAL(void)
do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	    jvirt_barray_ptr *src_coef_arrays,
	    jvirt_barray_ptr *dst_coef_arrays)
/* 180 degree rotation is equivalent to
 *   1. Vertical mirroring;
 *   2. Horizontal mirroring.
 * These two steps are merged into a single processing routine.
 */
{
  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
  int ci, i, j, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JBLOCKROW src_row_ptr, dst_row_ptr;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    comp_height = MCU_rows * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      if (dst_blk_y < comp_height) {
	/* Row is within the vertically mirrorable area. */
	src_buffer = (*srcinfo->mem->access_virt_barray)
	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	   comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
	   (JDIMENSION) compptr->v_samp_factor, FALSE);
      } else {
	/* Bottom-edge rows are only mirrored horizontally. */
	src_buffer = (*srcinfo->mem->access_virt_barray)
	  ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
	   (JDIMENSION) compptr->v_samp_factor, FALSE);
      }
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	if (dst_blk_y < comp_height) {
	  /* Row is within the mirrorable area. */
	  dst_row_ptr = dst_buffer[offset_y];
	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
	  /* Process the blocks that can be mirrored both ways. */
	  for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
	    dst_ptr = dst_row_ptr[dst_blk_x];
	    src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
	    for (i = 0; i < DCTSIZE; i += 2) {
	      /* For even row, negate every odd column. */
	      for (j = 0; j < DCTSIZE; j += 2) {
		*dst_ptr++ = *src_ptr++;
		*dst_ptr++ = - *src_ptr++;
	      }
	      /* For odd row, negate every even column. */
	      for (j = 0; j < DCTSIZE; j += 2) {
		*dst_ptr++ = - *src_ptr++;
		*dst_ptr++ = *src_ptr++;
	      }
	    }
	  }
	  /* Any remaining right-edge blocks are only mirrored vertically. */
	  for (; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
	    dst_ptr = dst_row_ptr[dst_blk_x];
	    src_ptr = src_row_ptr[dst_blk_x];
	    for (i = 0; i < DCTSIZE; i += 2) {
	      for (j = 0; j < DCTSIZE; j++)
		*dst_ptr++ = *src_ptr++;
	      for (j = 0; j < DCTSIZE; j++)
		*dst_ptr++ = - *src_ptr++;
	    }
	  }
	} else {
	  /* Remaining rows are just mirrored horizontally. */
	  dst_row_ptr = dst_buffer[offset_y];
	  src_row_ptr = src_buffer[offset_y];
	  /* Process the blocks that can be mirrored. */
	  for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
	    dst_ptr = dst_row_ptr[dst_blk_x];
	    src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
	    for (i = 0; i < DCTSIZE2; i += 2) {
	      *dst_ptr++ = *src_ptr++;
	      *dst_ptr++ = - *src_ptr++;
	    }
	  }
	  /* Any remaining right-edge blocks are only copied. */
	  for (; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
	    dst_ptr = dst_row_ptr[dst_blk_x];
	    src_ptr = src_row_ptr[dst_blk_x];
	    for (i = 0; i < DCTSIZE2; i++)
	      *dst_ptr++ = *src_ptr++;
	  }
	}
      }
    }
  }
}

LOCAL(void)
do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	       jvirt_barray_ptr *src_coef_arrays,
	       jvirt_barray_ptr *dst_coef_arrays)
/* Transverse transpose is equivalent to
 *   1. 180 degree rotation;
 *   2. Transposition;
 * or
 *   1. Horizontal mirroring;
 *   2. Transposition;
 *   3. Horizontal mirroring.
 * These steps are merged into a single processing routine.
 */
{
  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
  int ci, i, j, offset_x, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    comp_height = MCU_rows * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	     dst_blk_x += compptr->h_samp_factor) {
	  src_buffer = (*srcinfo->mem->access_virt_barray)
	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
	     (JDIMENSION) compptr->h_samp_factor, FALSE);
	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
	    if (dst_blk_y < comp_height) {
	      src_ptr = src_buffer[offset_x]
		[comp_height - dst_blk_y - offset_y - 1];
	      if (dst_blk_x < comp_width) {
		/* Block is within the mirrorable area. */
		dst_ptr = dst_buffer[offset_y]
		  [comp_width - dst_blk_x - offset_x - 1];
		for (i = 0; i < DCTSIZE; i++) {
		  for (j = 0; j < DCTSIZE; j++) {
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		    j++;
		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		  }
		  i++;
		  for (j = 0; j < DCTSIZE; j++) {
		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		    j++;
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		  }
		}
	      } else {
		/* Right-edge blocks are mirrored in y only */
		dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
		for (i = 0; i < DCTSIZE; i++) {
		  for (j = 0; j < DCTSIZE; j++) {
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		    j++;
		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		  }
		}
	      }
	    } else {
	      src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
	      if (dst_blk_x < comp_width) {
		/* Bottom-edge blocks are mirrored in x only */
		dst_ptr = dst_buffer[offset_y]
		  [comp_width - dst_blk_x - offset_x - 1];
		for (i = 0; i < DCTSIZE; i++) {
		  for (j = 0; j < DCTSIZE; j++)
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		  i++;
		  for (j = 0; j < DCTSIZE; j++)
		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		}
	      } else {
		/* At lower right corner, just transpose, no mirroring */
		dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
		for (i = 0; i < DCTSIZE; i++)
		  for (j = 0; j < DCTSIZE; j++)
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
	      }
	    }
	  }
	}
      }
    }
  }
}

/* Request any required workspace.
 *
 * We allocate the workspace virtual arrays from the source decompression
 * object, so that all the arrays (both the original data and the workspace)
 * will be taken into account while making memory management decisions.
 * Hence, this routine must be called after jpeg_read_header (which reads
 * the image dimensions) and before jpeg_read_coefficients (which realizes
 * the source's virtual arrays).
 */

GLOBAL(void)
jtransform_request_workspace (j_decompress_ptr srcinfo,
			      jpeg_transform_info *info)
{
  jvirt_barray_ptr *coef_arrays = NULL;
  jpeg_component_info *compptr;
  int ci;

  if (info->force_grayscale &&
      srcinfo->jpeg_color_space == JCS_YCbCr &&
      srcinfo->num_components == 3) {
    /* We'll only process the first component */
    info->num_components = 1;
  } else {
    /* Process all the components */
    info->num_components = srcinfo->num_components;
  }

  switch (info->transform) {
  case JXFORM_NONE:
  case JXFORM_FLIP_H:
    /* Don't need a workspace array */
    break;
  case JXFORM_FLIP_V:
  case JXFORM_ROT_180:
    /* Need workspace arrays having same dimensions as source image.
     * Note that we allocate arrays padded out to the next iMCU boundary,
     * so that transform routines need not worry about missing edge blocks.
     */
    coef_arrays = (jvirt_barray_ptr *)
      (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
	SIZEOF(jvirt_barray_ptr) * info->num_components);
    for (ci = 0; ci < info->num_components; ci++) {
      compptr = srcinfo->comp_info + ci;
      coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
	((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
	 (JDIMENSION) jround_up((long) compptr->width_in_blocks,
				(long) compptr->h_samp_factor),
	 (JDIMENSION) jround_up((long) compptr->height_in_blocks,
				(long) compptr->v_samp_factor),
	 (JDIMENSION) compptr->v_samp_factor);
    }
    break;
  case JXFORM_TRANSPOSE:
  case JXFORM_TRANSVERSE:
  case JXFORM_ROT_90:
  case JXFORM_ROT_270:
    /* Need workspace arrays having transposed dimensions.
     * Note that we allocate arrays padded out to the next iMCU boundary,
     * so that transform routines need not worry about missing edge blocks.
     */
    coef_arrays = (jvirt_barray_ptr *)
      (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
	SIZEOF(jvirt_barray_ptr) * info->num_components);
    for (ci = 0; ci < info->num_components; ci++) {
      compptr = srcinfo->comp_info + ci;
      coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
	((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
	 (JDIMENSION) jround_up((long) compptr->height_in_blocks,
				(long) compptr->v_samp_factor),
	 (JDIMENSION) jround_up((long) compptr->width_in_blocks,
				(long) compptr->h_samp_factor),
	 (JDIMENSION) compptr->h_samp_factor);
    }
    break;
  }
  info->workspace_coef_arrays = coef_arrays;
}

/* Transpose destination image parameters */

LOCAL(void)
transpose_critical_parameters (j_compress_ptr dstinfo)
{
  int tblno, i, j, ci, itemp;
  jpeg_component_info *compptr;
  JQUANT_TBL *qtblptr;
  JDIMENSION dtemp;
  UINT16 qtemp;

  /* Transpose basic image dimensions */
  dtemp = dstinfo->image_width;
  dstinfo->image_width = dstinfo->image_height;
  dstinfo->image_height = dtemp;

  /* Transpose sampling factors */
  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    itemp = compptr->h_samp_factor;
    compptr->h_samp_factor = compptr->v_samp_factor;
    compptr->v_samp_factor = itemp;
  }

  /* Transpose quantization tables */
  for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
    qtblptr = dstinfo->quant_tbl_ptrs[tblno];
    if (qtblptr != NULL) {
      for (i = 0; i < DCTSIZE; i++) {
	for (j = 0; j < i; j++) {
	  qtemp = qtblptr->quantval[i*DCTSIZE+j];
	  qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];
	  qtblptr->quantval[j*DCTSIZE+i] = qtemp;
	}
      }
    }
  }
}

/* Trim off any partial iMCUs on the indicated destination edge */

LOCAL(void)
trim_right_edge (j_compress_ptr dstinfo)
{
  int ci, max_h_samp_factor;
  JDIMENSION MCU_cols;

  /* We have to compute max_h_samp_factor ourselves,
   * because it hasn't been set yet in the destination
   * (and we don't want to use the source's value).
   */
  max_h_samp_factor = 1;
  for (ci = 0; ci < dstinfo->num_components; ci++) {
    int h_samp_factor = dstinfo->comp_info[ci].h_samp_factor;
    max_h_samp_factor = MAX(max_h_samp_factor, h_samp_factor);
  }
  MCU_cols = dstinfo->image_width / (max_h_samp_factor * DCTSIZE);
  if (MCU_cols > 0)		/* can't trim to 0 pixels */
    dstinfo->image_width = MCU_cols * (max_h_samp_factor * DCTSIZE);
}

LOCAL(void)
trim_bottom_edge (j_compress_ptr dstinfo)
{
  int ci, max_v_samp_factor;
  JDIMENSION MCU_rows;

  /* We have to compute max_v_samp_factor ourselves,
   * because it hasn't been set yet in the destination
   * (and we don't want to use the source's value).
   */
  max_v_samp_factor = 1;
  for (ci = 0; ci < dstinfo->num_components; ci++) {
    int v_samp_factor = dstinfo->comp_info[ci].v_samp_factor;
    max_v_samp_factor = MAX(max_v_samp_factor, v_samp_factor);
  }
  MCU_rows = dstinfo->image_height / (max_v_samp_factor * DCTSIZE);
  if (MCU_rows > 0)		/* can't trim to 0 pixels */
    dstinfo->image_height = MCU_rows * (max_v_samp_factor * DCTSIZE);
}

/* Adjust output image parameters as needed.
 *
 * This must be called after jpeg_copy_critical_parameters()
 * and before jpeg_write_coefficients().
 *
 * The return value is the set of virtual coefficient arrays to be written
 * (either the ones allocated by jtransform_request_workspace, or the
 * original source data arrays).  The caller will need to pass this value
 * to jpeg_write_coefficients().
 */

GLOBAL(jvirt_barray_ptr *)
jtransform_adjust_parameters (j_decompress_ptr srcinfo,
			      j_compress_ptr dstinfo,
			      jvirt_barray_ptr *src_coef_arrays,
			      jpeg_transform_info *info)
{
  /* If force-to-grayscale is requested, adjust destination parameters */
  if (info->force_grayscale) {
    /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
     * properly.  Among other things, the target h_samp_factor & v_samp_factor
     * will get set to 1, which typically won't match the source.
     * In fact we do this even if the source is already grayscale; that
     * provides an easy way of coercing a grayscale JPEG with funny sampling
     * factors to the customary 1,1.  (Some decoders fail on other factors.)
     */
    if ((dstinfo->jpeg_color_space == JCS_YCbCr &&
	 dstinfo->num_components == 3) ||
	(dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
	 dstinfo->num_components == 1)) {
      /* We have to preserve the source's quantization table number. */
      int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
      jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
      dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
    } else {
      /* Sorry, can't do it */
      ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
    }
  }

  /* Correct the destination's image dimensions etc if necessary */
  switch (info->transform) {
  case JXFORM_NONE:
    /* Nothing to do */
    break;
  case JXFORM_FLIP_H:
    if (info->trim)
      trim_right_edge(dstinfo);
    break;
  case JXFORM_FLIP_V:
    if (info->trim)
      trim_bottom_edge(dstinfo);
    break;
  case JXFORM_TRANSPOSE:
    transpose_critical_parameters(dstinfo);
    /* transpose does NOT have to trim anything */
    break;
  case JXFORM_TRANSVERSE:
    transpose_critical_parameters(dstinfo);
    if (info->trim) {
      trim_right_edge(dstinfo);
      trim_bottom_edge(dstinfo);
    }
    break;
  case JXFORM_ROT_90:
    transpose_critical_parameters(dstinfo);
    if (info->trim)
      trim_right_edge(dstinfo);
    break;
  case JXFORM_ROT_180:
    if (info->trim) {
      trim_right_edge(dstinfo);
      trim_bottom_edge(dstinfo);
    }
    break;
  case JXFORM_ROT_270:
    transpose_critical_parameters(dstinfo);
    if (info->trim)
      trim_bottom_edge(dstinfo);
    break;
  }

  /* Return the appropriate output data set */
  if (info->workspace_coef_arrays != NULL)
    return info->workspace_coef_arrays;
  return src_coef_arrays;
}

/* Execute the actual transformation, if any.
 *
 * This must be called *after* jpeg_write_coefficients, because it depends
 * on jpeg_write_coefficients to have computed subsidiary values such as
 * the per-component width and height fields in the destination object.
 *
 * Note that some transformations will modify the source data arrays!
 */

GLOBAL(void)
jtransform_execute_transformation (j_decompress_ptr srcinfo,
				   j_compress_ptr dstinfo,
				   jvirt_barray_ptr *src_coef_arrays,
				   jpeg_transform_info *info)
{
  jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;

  switch (info->transform) {
  case JXFORM_NONE:
    break;
  case JXFORM_FLIP_H:
    do_flip_h(srcinfo, dstinfo, src_coef_arrays);
    break;
  case JXFORM_FLIP_V:
    do_flip_v(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_TRANSPOSE:
    do_transpose(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_TRANSVERSE:
    do_transverse(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_ROT_90:
    do_rot_90(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_ROT_180:
    do_rot_180(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_ROT_270:
    do_rot_270(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
    break;
  }
}

#endif /* TRANSFORMS_SUPPORTED */

/* Setup decompression object to save desired markers in memory.
 * This must be called before jpeg_read_header() to have the desired effect.
 */

GLOBAL(void)
jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)
{
#ifdef SAVE_MARKERS_SUPPORTED
  int m;

  /* Save comments except under NONE option */
  if (option != JCOPYOPT_NONE) {
    jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
  }
  /* Save all types of APPn markers iff ALL option */
  if (option == JCOPYOPT_ALL) {
    for (m = 0; m < 16; m++)
      jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
  }
#endif /* SAVE_MARKERS_SUPPORTED */
}

/* Copy markers saved in the given source object to the destination object.
 * This should be called just after jpeg_start_compress() or
 * jpeg_write_coefficients().
 * Note that those routines will have written the SOI, and also the
 * JFIF APP0 or Adobe APP14 markers if selected.
 */

GLOBAL(void)
jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
		       JCOPY_OPTION option)
{
  jpeg_saved_marker_ptr marker;

  /* In the current implementation, we don't actually need to examine the
   * option flag here; we just copy everything that got saved.
   * But to avoid confusion, we do not output JFIF and Adobe APP14 markers
   * if the encoder library already wrote one.
   */
  for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {
    if (dstinfo->write_JFIF_header &&
	marker->marker == JPEG_APP0 &&
	marker->data_length >= 5 &&
	GETJOCTET(marker->data[0]) == 0x4A &&
	GETJOCTET(marker->data[1]) == 0x46 &&
	GETJOCTET(marker->data[2]) == 0x49 &&
	GETJOCTET(marker->data[3]) == 0x46 &&
	GETJOCTET(marker->data[4]) == 0)
      continue;			/* reject duplicate JFIF */
    if (dstinfo->write_Adobe_marker &&
	marker->marker == JPEG_APP0+14 &&
	marker->data_length >= 5 &&
	GETJOCTET(marker->data[0]) == 0x41 &&
	GETJOCTET(marker->data[1]) == 0x64 &&
	GETJOCTET(marker->data[2]) == 0x6F &&
	GETJOCTET(marker->data[3]) == 0x62 &&
	GETJOCTET(marker->data[4]) == 0x65)
      continue;			/* reject duplicate Adobe */
#ifdef NEED_FAR_POINTERS
    /* We could use jpeg_write_marker if the data weren't FAR... */
    {
      unsigned int i;
      jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);
      for (i = 0; i < marker->data_length; i++)
	jpeg_write_m_byte(dstinfo, marker->data[i]);
    }
#else
    jpeg_write_marker(dstinfo, marker->marker,
		      marker->data, marker->data_length);
#endif
  }
}


code:
/*
 * transupp.h
 *
 * Copyright (C) 1997, 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 declarations for image transformation routines and
 * other utility code used by the jpegtran sample application.  These are
 * NOT part of the core JPEG library.  But we keep these routines separate
 * from jpegtran.c to ease the task of maintaining jpegtran-like programs
 * that have other user interfaces.
 *
 * NOTE: all the routines declared here have very specific requirements
 * about when they are to be executed during the reading and writing of the
 * source and destination files.  See the comments in transupp.c, or see
 * jpegtran.c for an example of correct usage.
 */

/* If you happen not to want the image transform support, disable it here */
#ifndef TRANSFORMS_SUPPORTED
#define TRANSFORMS_SUPPORTED 1		/* 0 disables transform code */
#endif

/* Short forms of external names for systems with brain-damaged linkers. */

#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jtransform_request_workspace		jTrRequest
#define jtransform_adjust_parameters		jTrAdjust
#define jtransform_execute_transformation	jTrExec
#define jcopy_markers_setup			jCMrkSetup
#define jcopy_markers_execute			jCMrkExec
#endif /* NEED_SHORT_EXTERNAL_NAMES */

/*
 * Codes for supported types of image transformations.
 */

typedef enum {
	JXFORM_NONE,		/* no transformation */
	JXFORM_FLIP_H,		/* horizontal flip */
	JXFORM_FLIP_V,		/* vertical flip */
	JXFORM_TRANSPOSE,	/* transpose across UL-to-LR axis */
	JXFORM_TRANSVERSE,	/* transpose across UR-to-LL axis */
	JXFORM_ROT_90,		/* 90-degree clockwise rotation */
	JXFORM_ROT_180,		/* 180-degree rotation */
	JXFORM_ROT_270		/* 270-degree clockwise (or 90 ccw) */
} JXFORM_CODE;

/*
 * Although rotating and flipping data expressed as DCT coefficients is not
 * hard, there is an asymmetry in the JPEG format specification for images
 * whose dimensions aren't multiples of the iMCU size.  The right and bottom
 * image edges are padded out to the next iMCU boundary with junk data; but
 * no padding is possible at the top and left edges.  If we were to flip
 * the whole image including the pad data, then pad garbage would become
 * visible at the top and/or left, and real pixels would disappear into the
 * pad margins --- perhaps permanently, since encoders & decoders may not
 * bother to preserve DCT blocks that appear to be completely outside the
 * nominal image area.  So, we have to exclude any partial iMCUs from the
 * basic transformation.
 *
 * Transpose is the only transformation that can handle partial iMCUs at the
 * right and bottom edges completely cleanly.  flip_h can flip partial iMCUs
 * at the bottom, but leaves any partial iMCUs at the right edge untouched.
 * Similarly flip_v leaves any partial iMCUs at the bottom edge untouched.
 * The other transforms are defined as combinations of these basic transforms
 * and process edge blocks in a way that preserves the equivalence.
 *
 * The "trim" option causes untransformable partial iMCUs to be dropped;
 * this is not strictly lossless, but it usually gives the best-looking
 * result for odd-size images.  Note that when this option is active,
 * the expected mathematical equivalences between the transforms may not hold.
 * (For example, -rot 270 -trim trims only the bottom edge, but -rot 90 -trim
 * followed by -rot 180 -trim trims both edges.)
 *
 * We also offer a "force to grayscale" option, which simply discards the
 * chrominance channels of a YCbCr image.  This is lossless in the sense that
 * the luminance channel is preserved exactly.  It's not the same kind of
 * thing as the rotate/flip transformations, but it's convenient to handle it
 * as part of this package, mainly because the transformation routines have to
 * be aware of the option to know how many components to work on.
 */

typedef struct {
  /* Options: set by caller */
  JXFORM_CODE transform;	/* image transform operator */
  boolean trim;			/* if TRUE, trim partial MCUs as needed */
  boolean force_grayscale;	/* if TRUE, convert color image to grayscale */

  /* Internal workspace: caller should not touch these */
  int num_components;		/* # of components in workspace */
  jvirt_barray_ptr * workspace_coef_arrays; /* workspace for transformations */
} jpeg_transform_info;

#if TRANSFORMS_SUPPORTED

/* Request any required workspace */
EXTERN(void) jtransform_request_workspace
	JPP((j_decompress_ptr srcinfo, jpeg_transform_info *info));
/* Adjust output image parameters */
EXTERN(jvirt_barray_ptr *) jtransform_adjust_parameters
	JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	     jvirt_barray_ptr *src_coef_arrays,
	     jpeg_transform_info *info));
/* Execute the actual transformation, if any */
EXTERN(void) jtransform_execute_transformation
	JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	     jvirt_barray_ptr *src_coef_arrays,
	     jpeg_transform_info *info));

#endif /* TRANSFORMS_SUPPORTED */

/*
 * Support for copying optional markers from source to destination file.
 */

typedef enum {
	JCOPYOPT_NONE,		/* copy no optional markers */
	JCOPYOPT_COMMENTS,	/* copy only comment (COM) markers */
	JCOPYOPT_ALL		/* copy all optional markers */
} JCOPY_OPTION;

#define JCOPYOPT_DEFAULT  JCOPYOPT_COMMENTS	/* recommended default */

/* Setup decompression object to save desired markers in memory */
EXTERN(void) jcopy_markers_setup
	JPP((j_decompress_ptr srcinfo, JCOPY_OPTION option));
/* Copy markers saved in the given source object to the destination object */
EXTERN(void) jcopy_markers_execute
	JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	     JCOPY_OPTION option));