view release on metacpan or  search on metacpan

src/Source/LibJPEG/rdbmp.c  view on Meta::CPAN

    ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
    break;
  }
}


/*
 * Read one row of pixels.
 * The image has been read into the whole_image array, but is otherwise
 * unprocessed.  We must read it out in top-to-bottom row order, and if
 * it is an 8-bit image, we must expand colormapped pixels to 24bit format.
 */

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

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

  /* Expand the colormap indexes to real data */
  inptr = image_ptr[0];
  outptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    t = GETJSAMPLE(*inptr++);
    *outptr++ = colormap[0][t];	/* can omit GETJSAMPLE() safely */
    *outptr++ = colormap[1][t];
    *outptr++ = colormap[2][t];
  }

  return 1;
}


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

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

  /* Transfer data.  Note source values are in BGR order
   * (even though Microsoft's own documents say the opposite).
   */
  inptr = image_ptr[0];
  outptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    outptr[2] = *inptr++;	/* can omit GETJSAMPLE() safely */
    outptr[1] = *inptr++;
    outptr[0] = *inptr++;
    outptr += 3;
  }

  return 1;
}


METHODDEF(JDIMENSION)
get_32bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading 32-bit pixels */
{
  bmp_source_ptr source = (bmp_source_ptr) sinfo;
  JSAMPARRAY image_ptr;
  register JSAMPROW inptr, outptr;
  register JDIMENSION col;

  /* Fetch next row from virtual array */
  source->source_row--;
  image_ptr = (*cinfo->mem->access_virt_sarray)
    ((j_common_ptr) cinfo, source->whole_image,
     source->source_row, (JDIMENSION) 1, FALSE);
  /* Transfer data.  Note source values are in BGR order
   * (even though Microsoft's own documents say the opposite).
   */
  inptr = image_ptr[0];
  outptr = source->pub.buffer[0];
  for (col = cinfo->image_width; col > 0; col--) {
    outptr[2] = *inptr++;	/* can omit GETJSAMPLE() safely */
    outptr[1] = *inptr++;
    outptr[0] = *inptr++;
    inptr++;			/* skip the 4th byte (Alpha channel) */
    outptr += 3;
  }

  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_8bit_row, get_24bit_row, or get_32bit_row on subsequent calls.
 */

METHODDEF(JDIMENSION)
preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
  bmp_source_ptr source = (bmp_source_ptr) sinfo;
  register FILE *infile = source->pub.input_file;
  register int c;
  register JSAMPROW out_ptr;
  JSAMPARRAY image_ptr;
  JDIMENSION row, col;
  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);
    }
    image_ptr = (*cinfo->mem->access_virt_sarray)
      ((j_common_ptr) cinfo, source->whole_image,
       row, (JDIMENSION) 1, TRUE);
    out_ptr = image_ptr[0];
    for (col = source->row_width; col > 0; col--) {
      /* inline copy of read_byte() for speed */
      if ((c = getc(infile)) == EOF)
	ERREXIT(cinfo, JERR_INPUT_EOF);
      *out_ptr++ = (JSAMPLE) c;
    }
  }
  if (progress != NULL)
    progress->completed_extra_passes++;

  /* Set up to read from the virtual array in top-to-bottom order */
  switch (source->bits_per_pixel) {
  case 8:
    source->pub.get_pixel_rows = get_8bit_row;
    break;
  case 24:
    source->pub.get_pixel_rows = get_24bit_row;