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>
30 #include <libexif/exif-ifd.h>
33 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
37 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
39 struct _ExifDataPrivate
43 unsigned int ref_count;
52 data = malloc (sizeof (ExifData));
55 memset (data, 0, sizeof (ExifData));
56 data->priv = malloc (sizeof (ExifDataPrivate));
61 memset (data->priv, 0, sizeof (ExifDataPrivate));
62 data->priv->ref_count = 1;
64 for (i = 0; i < EXIF_IFD_COUNT; i++) {
65 data->ifd[i] = exif_content_new ();
67 exif_data_free (data);
70 data->ifd[i]->parent = data;
77 exif_data_new_from_data (const unsigned char *data, unsigned int size)
81 edata = exif_data_new ();
82 exif_data_load_data (edata, data, size);
87 exif_data_load_data_entry (ExifData *data, ExifEntry *entry,
88 const unsigned char *d,
89 unsigned int size, unsigned int offset)
93 entry->tag = exif_get_short (d + offset + 0, data->priv->order);
94 entry->format = exif_get_short (d + offset + 2, data->priv->order);
95 entry->components = exif_get_long (d + offset + 4, data->priv->order);
98 * Size? If bigger than 4 bytes, the actual data is not
99 * in the entry but somewhere else (offset).
101 s = exif_format_get_size (entry->format) * entry->components;
105 doff = exif_get_long (d + offset + 8, data->priv->order);
113 entry->data = malloc (sizeof (char) * s);
117 memcpy (entry->data, d + doff, s);
121 exif_data_save_data_entry (ExifData *data, ExifEntry *entry,
122 unsigned char **d, unsigned int *ds,
125 unsigned int doff, s;
128 * Each entry is 12 bytes long. The memory for the entry has
129 * already been allocated.
131 exif_set_short (*d + 6 + offset + 0,
132 data->priv->order, entry->tag);
133 exif_set_short (*d + 6 + offset + 2,
134 data->priv->order, entry->format);
135 exif_set_long (*d + 6 + offset + 4,
136 data->priv->order, entry->components);
139 * Size? If bigger than 4 bytes, the actual data is not in
140 * the entry but somewhere else.
142 s = exif_format_get_size (entry->format) * entry->components;
147 *d = realloc (*d, sizeof (char) * *ds);
148 doff = *ds - 6 - entry->size;
149 exif_set_long (*d + 6 + offset + 8,
150 data->priv->order, doff);
153 memcpy (*d + 6 + doff, entry->data, entry->size);
157 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
158 unsigned int ds, ExifLong offset, ExifLong size)
160 if (ds < offset + size) {
162 printf ("Bogus thumbnail offset and size: %i < %i + %i.\n",
163 (int) ds, (int) offset, (int) size);
170 data->data = malloc (sizeof (char) * data->size);
171 memcpy (data->data, d + offset, data->size);
175 exif_data_load_data_content (ExifData *data, ExifContent *ifd,
176 const unsigned char *d,
177 unsigned int ds, unsigned int offset)
179 ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
185 /* Read the number of entries */
186 n = exif_get_short (d + offset, data->priv->order);
188 printf ("Loading %i entries...\n", n);
191 for (i = 0; i < n; i++) {
193 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
195 printf ("Loading entry '%s' (%i of %i)...\n",
196 exif_tag_get_name (tag), i + 1, n);
199 case EXIF_TAG_EXIF_IFD_POINTER:
200 case EXIF_TAG_GPS_INFO_IFD_POINTER:
201 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
202 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
203 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
204 o = exif_get_long (d + offset + 12 * i + 8,
207 case EXIF_TAG_EXIF_IFD_POINTER:
208 exif_data_load_data_content (data,
209 data->ifd[EXIF_IFD_EXIF], d, ds, o);
211 case EXIF_TAG_GPS_INFO_IFD_POINTER:
212 exif_data_load_data_content (data,
213 data->ifd[EXIF_IFD_GPS], d, ds, o);
215 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
216 exif_data_load_data_content (data,
217 data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds, o);
219 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
221 printf ("Thumbnail at %i.\n", (int) o);
223 thumbnail_offset = o;
224 if (thumbnail_offset && thumbnail_length)
225 exif_data_load_data_thumbnail (data, d,
226 ds, thumbnail_offset,
229 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
231 printf ("Thumbnail size: %i.\n", (int) o);
233 thumbnail_length = o;
234 if (thumbnail_offset && thumbnail_length)
235 exif_data_load_data_thumbnail (data, d,
236 ds, thumbnail_offset,
244 entry = exif_entry_new ();
245 exif_content_add_entry (ifd, entry);
246 exif_data_load_data_entry (data, entry, d, ds,
248 exif_entry_unref (entry);
255 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
256 unsigned char **d, unsigned int *ds,
259 unsigned int i, n_ptr = 0, n_thumb = 0;
262 * Check if we need some extra entries for pointers or the thumbnail.
264 if (ifd == data->ifd[EXIF_IFD_1]) {
265 if (data->ifd[EXIF_IFD_EXIF]->count || data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
267 if (data->ifd[EXIF_IFD_GPS]->count)
269 } else if (ifd == data->ifd[EXIF_IFD_1]) {
272 } else if (ifd == data->ifd[EXIF_IFD_EXIF]) {
273 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
278 * Allocate enough memory for all entries
279 * and the number of entries.
281 *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
282 *d = realloc (*d, sizeof (char) * *ds);
284 /* Save the number of entries */
285 exif_set_short (*d + 6 + offset, data->priv->order,
286 ifd->count + n_ptr + n_thumb);
289 printf ("Saving %i entries (offset: %i)...\n", ifd->count, offset);
292 /* Save each entry */
293 for (i = 0; i < ifd->count; i++)
294 exif_data_save_data_entry (data, ifd->entries[i],
295 d, ds, offset + 12 * i);
296 offset += 12 * ifd->count;
299 * The pointer to IFD_EXIF is in IFD_0.
300 * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
301 * therefore, if IFD_INTEROPERABILITY is not empty, we need
302 * IFD_EXIF even if latter is empty.
304 if (ifd == data->ifd[EXIF_IFD_0] && (
305 data->ifd[EXIF_IFD_EXIF]->count ||
306 data->ifd[EXIF_IFD_INTEROPERABILITY]->count)) {
307 exif_set_short (*d + 6 + offset + 0, data->priv->order,
308 EXIF_TAG_EXIF_IFD_POINTER);
309 exif_set_short (*d + 6 + offset + 2, data->priv->order,
311 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
312 exif_set_long (*d + 6 + offset + 8, data->priv->order,
314 exif_data_save_data_content (data, data->ifd[EXIF_IFD_EXIF], d,
319 /* The pointer to IFD_GPS is in IFD_0. */
320 if (ifd == data->ifd[EXIF_IFD_0] && data->ifd[EXIF_IFD_GPS]->count) {
321 exif_set_short (*d + 6 + offset + 0, data->priv->order,
322 EXIF_TAG_GPS_INFO_IFD_POINTER);
323 exif_set_short (*d + 6 + offset + 2, data->priv->order,
325 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
326 exif_set_long (*d + 6 + offset + 8, data->priv->order,
328 exif_data_save_data_content (data, data->ifd[EXIF_IFD_GPS], d, ds,
333 /* The pointer to IFD_INTEROPERABILITY is in IFD_EXIF. See above. */
334 if (ifd == data->ifd[EXIF_IFD_EXIF] && data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
335 exif_set_short (*d + 6 + offset + 0, data->priv->order,
336 EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
337 exif_set_short (*d + 6 + offset + 2, data->priv->order,
339 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
340 exif_set_long (*d + 6 + offset + 8, data->priv->order,
342 exif_data_save_data_content (data, data->ifd[EXIF_IFD_INTEROPERABILITY],
349 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
350 exif_set_short (*d + 6 + offset + 0, data->priv->order,
351 EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
352 exif_set_short (*d + 6 + offset + 2, data->priv->order,
354 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
355 exif_set_long (*d + 6 + offset + 8, data->priv->order,
359 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
360 exif_set_short (*d + 6 + offset + 0, data->priv->order,
361 EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
362 exif_set_short (*d + 6 + offset + 2, data->priv->order,
364 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
365 exif_set_long (*d + 6 + offset + 8, data->priv->order,
368 *d = realloc (*d, sizeof (char) * *ds);
369 memcpy (*d + *ds - data->size, data->data, data->size);
373 if (ifd == data->ifd[EXIF_IFD_0] && data->ifd[EXIF_IFD_1]->count) {
376 * We are saving IFD 0. Tell where IFD 1 starts and save
379 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
380 exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
383 exif_set_long (*d + 6 + offset, data->priv->order, 0);
387 exif_data_load_data (ExifData *data, const unsigned char *d, unsigned int size)
389 unsigned int l, len = size;
399 printf ("Parsing %i byte(s) EXIF data...\n", size);
403 * It can be that the data starts with the EXIF header. If it does
404 * not, search the EXIF marker.
408 printf ("Size too small.\n");
412 if (!memcmp (d, ExifHeader, 6)) {
414 printf ("Found EXIF header.\n");
418 printf ("Data begins with 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x "
419 "0x%x...\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6]);
422 while ((d[0] == 0xff) && size) {
427 /* JPEG_MARKER_SOI */
428 if (d[0] == JPEG_MARKER_SOI) {
434 /* JPEG_MARKER_APP0 */
435 if (d[0] == JPEG_MARKER_APP0) {
438 l = (d[0] << 8) | d[1];
446 /* JPEG_MARKER_APP1 */
447 if (d[0] == JPEG_MARKER_APP1)
450 /* Unknown marker or data. Give up. */
452 printf ("EXIF marker not found.\n");
460 printf ("Size too small.\n");
464 len = (d[0] << 8) | d[1];
466 printf ("We have to deal with %i byte(s) of EXIF data.\n", len);
473 * Verify the exif header
474 * (offset 2, length 6).
478 printf ("Size too small.\n");
482 if (memcmp (d, ExifHeader, 6)) {
484 printf ("EXIF header not found.\n");
490 printf ("Found EXIF header.\n");
493 /* Byte order (offset 6, length 2) */
496 if (!memcmp (d + 6, "II", 2))
497 data->priv->order = EXIF_BYTE_ORDER_INTEL;
498 else if (!memcmp (d + 6, "MM", 2))
499 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
504 if (exif_get_short (d + 8, data->priv->order) != 0x002a)
508 offset = exif_get_long (d + 10, data->priv->order);
510 printf ("IFD 0 at %i.\n", (int) offset);
513 /* Parse the actual exif data (offset 14) */
514 exif_data_load_data_content (data, data->ifd[EXIF_IFD_0], d + 6,
518 n = exif_get_short (d + 6 + offset, data->priv->order);
519 offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
522 printf ("IFD 1 at %i.\n", (int) offset);
524 exif_data_load_data_content (data, data->ifd[EXIF_IFD_1], d + 6,
530 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
539 *d = malloc (sizeof (char) * *ds);
540 memcpy (*d, ExifHeader, 6);
542 /* Order (offset 6) */
544 *d = realloc (*d, sizeof (char) * *ds);
545 if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
546 memcpy (*d + 6, "II", 2);
548 memcpy (*d + 6, "MM", 2);
551 /* Fixed value (2 bytes, offset 8) */
553 *d = realloc (*d, sizeof (char) * *ds);
554 exif_set_short (*d + 8, data->priv->order, 0x002a);
557 * IFD 0 offset (4 bytes, offset 10).
558 * We will start 8 bytes after the
559 * EXIF header (2 bytes for order, another 2 for the test, and
560 * 4 bytes for the IFD 0 offset make 8 bytes together).
563 *d = realloc (*d, sizeof (char) * *ds);
564 exif_set_long (*d + 10, data->priv->order, 8);
566 /* Now save IFD 0. IFD 1 will be saved automatically. */
568 printf ("Saving IFDs...\n");
570 exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds, *ds - 6);
573 printf ("Saved %i byte(s) EXIF data.\n", *ds);
578 exif_data_new_from_file (const char *path)
586 f = fopen (path, "rb");
591 while ((marker = fgetc (f)) == 0xff);
593 /* JPEG_MARKER_SOI */
594 if (marker == JPEG_MARKER_SOI)
597 /* JPEG_MARKER_APP0 */
598 if (marker == JPEG_MARKER_APP0) {
601 size = (lh << 8) | ll;
602 if (fseek (f, size - 2, SEEK_CUR) < 0)
607 /* JPEG_MARKER_APP1 */
608 if (marker == JPEG_MARKER_APP1)
611 /* Unknown marker or data. Give up. */
615 /* EXIF data found. Allocate the necessary memory and read the data. */
618 size = (lh << 8) | ll;
619 data = malloc (sizeof (char) * size);
622 if (fread (data, 1, size, f) != size) {
627 edata = exif_data_new_from_data (data, size);
636 exif_data_ref (ExifData *data)
641 data->priv->ref_count++;
645 exif_data_unref (ExifData *data)
650 data->priv->ref_count--;
651 if (!data->priv->ref_count)
652 exif_data_free (data);
656 exif_data_free (ExifData *data)
663 for (i = 0; i < EXIF_IFD_COUNT; i++) {
665 exif_content_unref (data->ifd[i]);
681 exif_data_dump (ExifData *data)
688 for (i = 0; i < EXIF_IFD_COUNT; i++) {
689 if (data->ifd[i] && data->ifd[i]->count) {
690 printf ("Dumping IFD '%s'...\n",
691 exif_ifd_get_name (i));
692 exif_content_dump (data->ifd[i], 0);
697 printf ("%i byte(s) thumbnail data available.", data->size);
698 if (data->size >= 4) {
699 printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
700 data->data[0], data->data[1],
701 data->data[data->size - 2],
702 data->data[data->size - 1]);
708 exif_data_get_byte_order (ExifData *data)
713 return (data->priv->order);
717 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
725 for (i = 0; i < EXIF_IFD_COUNT; i++)
726 func (data->ifd[i], user_data);
729 typedef struct _ByteOrderChangeData ByteOrderChangeData;
730 struct _ByteOrderChangeData {
731 ExifByteOrder old, new;
735 entry_set_byte_order (ExifEntry *e, void *data)
737 ByteOrderChangeData *d = data;
749 case EXIF_FORMAT_SHORT:
750 for (i = 0; i < e->components; i++) {
751 s = exif_get_short (e->data +
752 (i * exif_format_get_size (e->format)),
754 exif_set_short (e->data +
755 (i * exif_format_get_size (e->format)),
759 case EXIF_FORMAT_LONG:
760 for (i = 0; i < e->components; i++) {
761 l = exif_get_long (e->data +
762 (i * exif_format_get_size (e->format)),
764 exif_set_long (e->data +
765 (i * exif_format_get_size (e->format)),
769 case EXIF_FORMAT_RATIONAL:
770 for (i = 0; i < e->components; i++) {
771 r = exif_get_rational (e->data +
772 (i * exif_format_get_size (e->format)),
774 exif_set_rational (e->data +
775 (i * exif_format_get_size (e->format)),
779 case EXIF_FORMAT_SLONG:
780 for (i = 0; i < e->components; i++) {
781 sl = exif_get_slong (e->data +
782 (i * exif_format_get_size (e->format)),
784 exif_set_slong (e->data +
785 (i * exif_format_get_size (e->format)),
789 case EXIF_FORMAT_SRATIONAL:
790 for (i = 0; i < e->components; i++) {
791 sr = exif_get_srational (e->data +
792 (i * exif_format_get_size (e->format)),
794 exif_set_srational (e->data +
795 (i * exif_format_get_size (e->format)),
799 case EXIF_FORMAT_UNDEFINED:
800 case EXIF_FORMAT_BYTE:
801 case EXIF_FORMAT_ASCII:
809 content_set_byte_order (ExifContent *content, void *data)
811 exif_content_foreach_entry (content, entry_set_byte_order, data);
815 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
817 ByteOrderChangeData d;
819 if (!data || (order == data->priv->order))
822 d.old = data->priv->order;
824 exif_data_foreach_content (data, content_set_byte_order, &d);
825 data->priv->order = order;