diff -urN jpeg-6b/transupp.c jpeg-6b-exif/transupp.c --- jpeg-6b/transupp.c 1997-08-10 02:15:26.000000000 +0200 +++ jpeg-6b-exif/transupp.c 2001-01-08 00:25:36.000000000 +0100 @@ -717,6 +717,162 @@ } +/* 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 output image parameters as needed. * * This must be called after jpeg_copy_critical_parameters() @@ -799,6 +955,27 @@ break; } + /* 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); + } + /* Return the appropriate output data set */ if (info->workspace_coef_arrays != NULL) return info->workspace_coef_arrays;