Attachment #23968: Patch for jpeg-6b jpegtran utility for bug #38503

/* Adjust Exif image parameters.

 *

 * We try to adjust the Tags ExifImageWidth and ExifImageHeight if possible.

 */

LOCAL(void)

adjust_exif_parameters (JOCTET FAR * data, unsigned int length,

			JDIMENSION new_width, JDIMENSION new_height)

{

  boolean is_motorola; /* Flag for byte order */

  unsigned int number_of_tags, tagnum;

  unsigned int firstoffset, offset;

  JDIMENSION new_value;

  if (length < 12) return; /* Length of an IFD entry */

  /* Discover byte order */

  if (GETJOCTET(data[0]) == 0x49 && GETJOCTET(data[1]) == 0x49)

    is_motorola = FALSE;

  else if (GETJOCTET(data[0]) == 0x4D && GETJOCTET(data[1]) == 0x4D)

    is_motorola = TRUE;

  else

    return;

  /* Check Tag Mark */

  if (is_motorola) {

    if (GETJOCTET(data[2]) != 0) return;

    if (GETJOCTET(data[3]) != 0x2A) return;

  } else {

    if (GETJOCTET(data[3]) != 0) return;

    if (GETJOCTET(data[2]) != 0x2A) return;

  }

  /* Get first IFD offset (offset to IFD0) */

  if (is_motorola) {

    if (GETJOCTET(data[4]) != 0) return;

    if (GETJOCTET(data[5]) != 0) return;

    firstoffset = GETJOCTET(data[6]);

    firstoffset <<= 8;

    firstoffset += GETJOCTET(data[7]);

  } else {

    if (GETJOCTET(data[7]) != 0) return;

    if (GETJOCTET(data[6]) != 0) return;

    firstoffset = GETJOCTET(data[5]);

    firstoffset <<= 8;

    firstoffset += GETJOCTET(data[4]);

  }

  if (firstoffset > length - 2) return; /* check end of data segment */

  /* Get the number of directory entries contained in this IFD */

  if (is_motorola) {

    number_of_tags = GETJOCTET(data[firstoffset]);

    number_of_tags <<= 8;

    number_of_tags += GETJOCTET(data[firstoffset+1]);

  } else {

    number_of_tags = GETJOCTET(data[firstoffset+1]);

    number_of_tags <<= 8;

    number_of_tags += GETJOCTET(data[firstoffset]);

  }

  if (number_of_tags == 0) return;

  firstoffset += 2;

  /* Search for ExifSubIFD offset Tag in IFD0 */

  for (;;) {

    if (firstoffset > length - 12) return; /* check end of data segment */

    /* Get Tag number */

    if (is_motorola) {

      tagnum = GETJOCTET(data[firstoffset]);

      tagnum <<= 8;

      tagnum += GETJOCTET(data[firstoffset+1]);

    } else {

      tagnum = GETJOCTET(data[firstoffset+1]);

      tagnum <<= 8;

      tagnum += GETJOCTET(data[firstoffset]);

    }

    if (tagnum == 0x8769) break; /* found ExifSubIFD offset Tag */

    if (--number_of_tags == 0) return;

    firstoffset += 12;

  }

  /* Get the ExifSubIFD offset */

  if (is_motorola) {

    if (GETJOCTET(data[firstoffset+8]) != 0) return;

    if (GETJOCTET(data[firstoffset+9]) != 0) return;

    offset = GETJOCTET(data[firstoffset+10]);

    offset <<= 8;

    offset += GETJOCTET(data[firstoffset+11]);

  } else {

    if (GETJOCTET(data[firstoffset+11]) != 0) return;

    if (GETJOCTET(data[firstoffset+10]) != 0) return;

    offset = GETJOCTET(data[firstoffset+9]);

    offset <<= 8;

    offset += GETJOCTET(data[firstoffset+8]);

  }

  if (offset > length - 2) return; /* check end of data segment */

  /* Get the number of directory entries contained in this SubIFD */

  if (is_motorola) {

    number_of_tags = GETJOCTET(data[offset]);

    number_of_tags <<= 8;

    number_of_tags += GETJOCTET(data[offset+1]);

  } else {

    number_of_tags = GETJOCTET(data[offset+1]);

    number_of_tags <<= 8;

    number_of_tags += GETJOCTET(data[offset]);

  }

  if (number_of_tags < 2) return;

  offset += 2;

  /* Search for ExifImageWidth and ExifImageHeight Tags in this SubIFD */

  do {

    if (offset > length - 12) return; /* check end of data segment */

    /* Get Tag number */

    if (is_motorola) {

      tagnum = GETJOCTET(data[offset]);

      tagnum <<= 8;

      tagnum += GETJOCTET(data[offset+1]);

    } else {

      tagnum = GETJOCTET(data[offset+1]);

      tagnum <<= 8;

      tagnum += GETJOCTET(data[offset]);

    }

    if (tagnum == 0xA002 || tagnum == 0xA003) {

      if (tagnum == 0xA002)

	new_value = new_width; /* ExifImageWidth Tag */

      else

	new_value = new_height; /* ExifImageHeight Tag */

      if (is_motorola) {

	data[offset+2] = 0; /* Format = unsigned long (4 octets) */

	data[offset+3] = 4;

	data[offset+4] = 0; /* Number Of Components = 1 */

	data[offset+5] = 0;

	data[offset+6] = 0;

	data[offset+7] = 1;

	data[offset+8] = 0;

	data[offset+9] = 0;

	data[offset+10] = (JOCTET)((new_value >> 8) & 0xFF);

	data[offset+11] = (JOCTET)(new_value & 0xFF);

      } else {

	data[offset+2] = 4; /* Format = unsigned long (4 octets) */

	data[offset+3] = 0;

	data[offset+4] = 1; /* Number Of Components = 1 */

	data[offset+5] = 0;

	data[offset+6] = 0;

	data[offset+7] = 0;

	data[offset+8] = (JOCTET)(new_value & 0xFF);

	data[offset+9] = (JOCTET)((new_value >> 8) & 0xFF);

	data[offset+10] = 0;

	data[offset+11] = 0;

      }

    }

    offset += 12;

  } while (--number_of_tags);

}

  /* Adjust Exif properties */

  if (srcinfo->marker_list != NULL &&

      srcinfo->marker_list->marker == JPEG_APP0+1 &&

      srcinfo->marker_list->data_length >= 6 &&

      GETJOCTET(srcinfo->marker_list->data[0]) == 0x45 &&

      GETJOCTET(srcinfo->marker_list->data[1]) == 0x78 &&

      GETJOCTET(srcinfo->marker_list->data[2]) == 0x69 &&

      GETJOCTET(srcinfo->marker_list->data[3]) == 0x66 &&

      GETJOCTET(srcinfo->marker_list->data[4]) == 0 &&

      GETJOCTET(srcinfo->marker_list->data[5]) == 0) {

    /* Suppress output of JFIF marker */

    dstinfo->write_JFIF_header = FALSE;

    /* Adjust Exif image parameters */

    if (dstinfo->image_width != srcinfo->image_width ||

	dstinfo->image_height != srcinfo->image_height)

      /* Align data segment to start of TIFF structure for parsing */

      adjust_exif_parameters(srcinfo->marker_list->data + 6,

	srcinfo->marker_list->data_length - 6,

	dstinfo->image_width, dstinfo->image_height);

  }