3 * Copyright (C) 2001 Lutz Müller <lutz@users.sourceforge.net>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
21 #include "exif-data.h"
27 #include <libjpeg/jpeg-marker.h>
29 #include <libexif/exif-utils.h>
32 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
36 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
38 struct _ExifDataPrivate
42 unsigned int ref_count;
50 data = malloc (sizeof (ExifData));
53 memset (data, 0, sizeof (ExifData));
54 data->priv = malloc (sizeof (ExifDataPrivate));
59 memset (data->priv, 0, sizeof (ExifDataPrivate));
60 data->priv->ref_count = 1;
62 data->ifd0 = exif_content_new ();
63 data->ifd1 = exif_content_new ();
64 data->ifd_exif = exif_content_new ();
65 data->ifd_gps = exif_content_new ();
66 data->ifd_interoperability = exif_content_new ();
67 if (!data->ifd_exif || !data->ifd_gps || !data->ifd_interoperability ||
68 !data->ifd0 || !data->ifd1) {
69 exif_data_free (data);
72 data->ifd0->parent = data;
73 data->ifd1->parent = data;
74 data->ifd_exif->parent = data;
75 data->ifd_gps->parent = data;
76 data->ifd_interoperability->parent = data;
82 exif_data_new_from_data (const unsigned char *data, unsigned int size)
86 edata = exif_data_new ();
87 exif_data_load_data (edata, data, size);
92 exif_data_load_data_entry (ExifData *data, ExifEntry *entry,
93 const unsigned char *d,
94 unsigned int size, unsigned int offset)
98 entry->tag = exif_get_short (d + offset + 0, data->priv->order);
99 entry->format = exif_get_short (d + offset + 2, data->priv->order);
100 entry->components = exif_get_long (d + offset + 4, data->priv->order);
103 * Size? If bigger than 4 bytes, the actual data is not
104 * in the entry but somewhere else (offset).
106 s = exif_format_get_size (entry->format) * entry->components;
110 doff = exif_get_long (d + offset + 8, data->priv->order);
118 entry->data = malloc (sizeof (char) * s);
122 memcpy (entry->data, d + doff, s);
126 exif_data_save_data_entry (ExifData *data, ExifEntry *entry,
127 unsigned char **d, unsigned int *ds,
130 unsigned int doff, s;
133 * Each entry is 12 bytes long. The memory for the entry has
134 * already been allocated.
136 exif_set_short (*d + 6 + offset + 0,
137 data->priv->order, entry->tag);
138 exif_set_short (*d + 6 + offset + 2,
139 data->priv->order, entry->format);
140 exif_set_long (*d + 6 + offset + 4,
141 data->priv->order, entry->components);
144 * Size? If bigger than 4 bytes, the actual data is not in
145 * the entry but somewhere else.
147 s = exif_format_get_size (entry->format) * entry->components;
152 *d = realloc (*d, sizeof (char) * *ds);
153 doff = *ds - 6 - entry->size;
154 exif_set_long (*d + 6 + offset + 8,
155 data->priv->order, doff);
158 memcpy (*d + 6 + doff, entry->data, entry->size);
162 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
163 unsigned int ds, ExifLong offset, ExifLong size)
165 if (ds < offset + size) {
167 printf ("Bogus thumbnail offset and size: %i < %i + %i.\n",
168 (int) ds, (int) offset, (int) size);
175 data->data = malloc (sizeof (char) * data->size);
176 memcpy (data->data, d + offset, data->size);
180 exif_data_load_data_content (ExifData *data, ExifContent *ifd,
181 const unsigned char *d,
182 unsigned int ds, unsigned int offset)
184 ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
190 /* Read the number of entries */
191 n = exif_get_short (d + offset, data->priv->order);
193 printf ("Loading %i entries...\n", n);
196 for (i = 0; i < n; i++) {
198 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
200 printf ("Loading entry '%s' (%i of %i)...\n",
201 exif_tag_get_name (tag), i + 1, n);
204 case EXIF_TAG_EXIF_IFD_POINTER:
205 case EXIF_TAG_GPS_INFO_IFD_POINTER:
206 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
207 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
208 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
209 o = exif_get_long (d + offset + 12 * i + 8,
212 case EXIF_TAG_EXIF_IFD_POINTER:
213 exif_data_load_data_content (data,
214 data->ifd_exif, d, ds, o);
216 case EXIF_TAG_GPS_INFO_IFD_POINTER:
217 exif_data_load_data_content (data,
218 data->ifd_gps, d, ds, o);
220 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
221 exif_data_load_data_content (data,
222 data->ifd_interoperability, d, ds, o);
224 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
226 printf ("Thumbnail at %i.\n", (int) o);
228 thumbnail_offset = o;
229 if (thumbnail_offset && thumbnail_length)
230 exif_data_load_data_thumbnail (data, d,
231 ds, thumbnail_offset,
234 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
236 printf ("Thumbnail size: %i.\n", (int) o);
238 thumbnail_length = o;
239 if (thumbnail_offset && thumbnail_length)
240 exif_data_load_data_thumbnail (data, d,
241 ds, thumbnail_offset,
249 entry = exif_entry_new ();
250 exif_content_add_entry (ifd, entry);
251 exif_data_load_data_entry (data, entry, d, ds,
253 exif_entry_unref (entry);
260 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
261 unsigned char **d, unsigned int *ds,
264 unsigned int i, n_ptr = 0, n_thumb = 0;
266 /* If we are to save IFD 0 or 1, we need some extra entries. */
267 if (ifd == data->ifd0) {
268 if (data->ifd_exif->count)
270 if (data->ifd_gps->count)
272 } else if (ifd == data->ifd1) {
273 if (data->ifd_interoperability->count)
278 * If we are to save IFD 1, we can point to the thumbnail if it
281 if ((ifd == data->ifd1) && data->data)
285 * Allocate enough memory for all entries
286 * and the number of entries.
288 *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
289 *d = realloc (*d, sizeof (char) * *ds);
291 /* Save the number of entries */
292 exif_set_short (*d + 6 + offset, data->priv->order,
293 ifd->count + n_ptr + n_thumb);
296 printf ("Saving %i entries (offset: %i)...\n", ifd->count, offset);
299 /* Save each entry */
300 for (i = 0; i < ifd->count; i++)
301 exif_data_save_data_entry (data, ifd->entries[i],
302 d, ds, offset + 12 * i);
303 offset += 12 * ifd->count;
305 /* Save special entries */
306 if (ifd == data->ifd0 && data->ifd_exif->count) {
308 /* EXIF_TAG_EXIF_IFD_POINTER */
309 exif_set_short (*d + 6 + offset + 0, data->priv->order,
310 EXIF_TAG_EXIF_IFD_POINTER);
311 exif_set_short (*d + 6 + offset + 2, data->priv->order,
313 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
314 exif_set_long (*d + 6 + offset + 8, data->priv->order,
316 exif_data_save_data_content (data, data->ifd_exif, d, ds,
321 if (ifd == data->ifd0 && data->ifd_gps->count) {
323 /* EXIF_TAG_GPS_INFO_IFD_POINTER */
324 exif_set_short (*d + 6 + offset + 0, data->priv->order,
325 EXIF_TAG_GPS_INFO_IFD_POINTER);
326 exif_set_short (*d + 6 + offset + 2, data->priv->order,
328 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
329 exif_set_long (*d + 6 + offset + 8, data->priv->order,
331 exif_data_save_data_content (data, data->ifd_gps, d, ds,
336 if (ifd == data->ifd1 && data->ifd_interoperability->count) {
338 /* EXIF_TAG_INTEROPERABILITY_IFD_POINTER */
339 exif_set_short (*d + 6 + offset + 0, data->priv->order,
340 EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
341 exif_set_short (*d + 6 + offset + 2, data->priv->order,
343 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
344 exif_set_long (*d + 6 + offset + 8, data->priv->order,
346 exif_data_save_data_content (data, data->ifd_interoperability,
353 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
354 exif_set_short (*d + 6 + offset + 0, data->priv->order,
355 EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
356 exif_set_short (*d + 6 + offset + 2, data->priv->order,
358 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
359 exif_set_long (*d + 6 + offset + 8, data->priv->order,
363 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
364 exif_set_short (*d + 6 + offset + 0, data->priv->order,
365 EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
366 exif_set_short (*d + 6 + offset + 2, data->priv->order,
368 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
369 exif_set_long (*d + 6 + offset + 8, data->priv->order,
372 *d = realloc (*d, sizeof (char) * *ds);
373 memcpy (*d + *ds - data->size, data->data, data->size);
377 if (ifd == data->ifd0 && (data->ifd1->count ||
378 data->ifd_interoperability->count)) {
380 * We are saving IFD 0. Tell where IFD 1 starts and save
383 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
384 exif_data_save_data_content (data, data->ifd1, d, ds,
387 exif_set_long (*d + 6 + offset, data->priv->order, 0);
391 exif_data_load_data (ExifData *data, const unsigned char *d, unsigned int size)
393 unsigned int l, len = size;
403 printf ("Parsing %i byte(s) EXIF data...\n", size);
407 * It can be that the data starts with the EXIF header. If it does
408 * not, search the EXIF marker.
412 printf ("Size too small.\n");
416 if (!memcmp (d, ExifHeader, 6)) {
418 printf ("Found EXIF header.\n");
422 printf ("Data begins with 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x "
423 "0x%x...\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6]);
426 while ((d[0] == 0xff) && size) {
431 /* JPEG_MARKER_SOI */
432 if (d[0] == JPEG_MARKER_SOI) {
438 /* JPEG_MARKER_APP0 */
439 if (d[0] == JPEG_MARKER_APP0) {
442 l = (d[0] << 8) | d[1];
450 /* JPEG_MARKER_APP1 */
451 if (d[0] == JPEG_MARKER_APP1)
454 /* Unknown marker or data. Give up. */
456 printf ("EXIF marker not found.\n");
464 printf ("Size too small.\n");
468 len = (d[0] << 8) | d[1];
470 printf ("We have to deal with %i byte(s) of EXIF data.\n", len);
477 * Verify the exif header
478 * (offset 2, length 6).
482 printf ("Size too small.\n");
486 if (memcmp (d, ExifHeader, 6)) {
488 printf ("EXIF header not found.\n");
494 printf ("Found EXIF header.\n");
497 /* Byte order (offset 6, length 2) */
500 if (!memcmp (d + 6, "II", 2))
501 data->priv->order = EXIF_BYTE_ORDER_INTEL;
502 else if (!memcmp (d + 6, "MM", 2))
503 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
508 if (exif_get_short (d + 8, data->priv->order) != 0x002a)
512 offset = exif_get_long (d + 10, data->priv->order);
514 printf ("IFD 0 at %i.\n", (int) offset);
517 /* Parse the actual exif data (offset 14) */
518 exif_data_load_data_content (data, data->ifd0, d + 6,
522 n = exif_get_short (d + 6 + offset, data->priv->order);
523 offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
526 printf ("IFD 1 at %i.\n", (int) offset);
528 exif_data_load_data_content (data, data->ifd1, d + 6,
534 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
543 *d = malloc (sizeof (char) * *ds);
544 memcpy (*d, ExifHeader, 6);
546 /* Order (offset 6) */
548 *d = realloc (*d, sizeof (char) * *ds);
549 if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
550 memcpy (*d + 6, "II", 2);
552 memcpy (*d + 6, "MM", 2);
555 /* Fixed value (2 bytes, offset 8) */
557 *d = realloc (*d, sizeof (char) * *ds);
558 exif_set_short (*d + 8, data->priv->order, 0x002a);
561 * IFD 0 offset (4 bytes, offset 10).
562 * We will start 8 bytes after the
563 * EXIF header (2 bytes for order, another 2 for the test, and
564 * 4 bytes for the IFD 0 offset make 8 bytes together).
567 *d = realloc (*d, sizeof (char) * *ds);
568 exif_set_long (*d + 10, data->priv->order, 8);
570 /* Now save IFD 0. IFD 1 will be saved automatically. */
572 printf ("Saving IFDs...\n");
574 exif_data_save_data_content (data, data->ifd0, d, ds, *ds - 6);
577 printf ("Saved %i byte(s) EXIF data.\n", *ds);
582 exif_data_new_from_file (const char *path)
590 f = fopen (path, "rb");
595 while ((marker = fgetc (f)) == 0xff);
597 /* JPEG_MARKER_SOI */
598 if (marker == JPEG_MARKER_SOI)
601 /* JPEG_MARKER_APP0 */
602 if (marker == JPEG_MARKER_APP0) {
605 size = (lh << 8) | ll;
606 if (fseek (f, size - 2, SEEK_CUR) < 0)
611 /* JPEG_MARKER_APP1 */
612 if (marker == JPEG_MARKER_APP1)
615 /* Unknown marker or data. Give up. */
619 /* EXIF data found. Allocate the necessary memory and read the data. */
622 size = (lh << 8) | ll;
623 data = malloc (sizeof (char) * size);
626 if (fread (data, 1, size, f) != size) {
631 edata = exif_data_new_from_data (data, size);
640 exif_data_ref (ExifData *data)
645 data->priv->ref_count++;
649 exif_data_unref (ExifData *data)
654 data->priv->ref_count--;
655 if (!data->priv->ref_count)
656 exif_data_free (data);
660 exif_data_free (ExifData *data)
663 exif_content_unref (data->ifd0);
665 exif_content_unref (data->ifd1);
673 exif_data_dump (ExifData *data)
678 if (data->ifd0->count) {
679 printf ("Dumping IFD 0...\n");
680 exif_content_dump (data->ifd0, 0);
683 if (data->ifd1->count) {
684 printf ("Dumping IFD 1...\n");
685 exif_content_dump (data->ifd1, 0);
688 if (data->ifd_exif->count) {
689 printf ("Dumping IFD EXIF...\n");
690 exif_content_dump (data->ifd_exif, 0);
693 if (data->ifd_gps->count) {
694 printf ("Dumping IFD GPS...\n");
695 exif_content_dump (data->ifd_gps, 0);
698 if (data->ifd_interoperability->count) {
699 printf ("Dumping IFD Interoperability...\n");
700 exif_content_dump (data->ifd_interoperability, 0);
704 printf ("%i byte(s) thumbnail data available.", data->size);
705 if (data->size >= 4) {
706 printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
707 data->data[0], data->data[1],
708 data->data[data->size - 2],
709 data->data[data->size - 1]);
715 exif_data_get_byte_order (ExifData *data)
720 return (data->priv->order);
724 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
730 func (data->ifd0, user_data);
731 func (data->ifd1, user_data);
732 func (data->ifd_exif, user_data);
733 func (data->ifd_gps, user_data);
734 func (data->ifd_interoperability, user_data);
737 typedef struct _ByteOrderChangeData ByteOrderChangeData;
738 struct _ByteOrderChangeData {
739 ExifByteOrder old, new;
743 entry_set_byte_order (ExifEntry *e, void *data)
745 ByteOrderChangeData *d = data;
757 case EXIF_FORMAT_SHORT:
758 for (i = 0; i < e->components; i++) {
759 s = exif_get_short (e->data +
760 (i * exif_format_get_size (e->format)),
762 exif_set_short (e->data +
763 (i * exif_format_get_size (e->format)),
767 case EXIF_FORMAT_LONG:
768 for (i = 0; i < e->components; i++) {
769 l = exif_get_long (e->data +
770 (i * exif_format_get_size (e->format)),
772 exif_set_long (e->data +
773 (i * exif_format_get_size (e->format)),
777 case EXIF_FORMAT_RATIONAL:
778 for (i = 0; i < e->components; i++) {
779 r = exif_get_rational (e->data +
780 (i * exif_format_get_size (e->format)),
782 exif_set_rational (e->data +
783 (i * exif_format_get_size (e->format)),
787 case EXIF_FORMAT_SLONG:
788 for (i = 0; i < e->components; i++) {
789 sl = exif_get_slong (e->data +
790 (i * exif_format_get_size (e->format)),
792 exif_set_slong (e->data +
793 (i * exif_format_get_size (e->format)),
797 case EXIF_FORMAT_SRATIONAL:
798 for (i = 0; i < e->components; i++) {
799 sr = exif_get_srational (e->data +
800 (i * exif_format_get_size (e->format)),
802 exif_set_srational (e->data +
803 (i * exif_format_get_size (e->format)),
807 case EXIF_FORMAT_UNDEFINED:
808 case EXIF_FORMAT_BYTE:
809 case EXIF_FORMAT_ASCII:
817 content_set_byte_order (ExifContent *content, void *data)
819 exif_content_foreach_entry (content, entry_set_byte_order, data);
823 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
825 ByteOrderChangeData d;
827 if (!data || (order == data->priv->order))
830 d.old = data->priv->order;
832 exif_data_foreach_content (data, content_set_byte_order, &d);
833 data->priv->order = order;