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_0]) {
267 * The pointer to IFD_EXIF is in IFD_0. The pointer to
268 * IFD_INTEROPERABILITY is in IFD_EXIF.
270 if (data->ifd[EXIF_IFD_EXIF]->count || data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
273 /* The pointer to IFD_GPS is in IFD_0. */
274 if (data->ifd[EXIF_IFD_GPS]->count)
276 } else if ((ifd == data->ifd[EXIF_IFD_1]) && data->size) {
278 } else if (ifd == data->ifd[EXIF_IFD_EXIF]) {
279 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
284 * Allocate enough memory for all entries
285 * and the number of entries.
287 *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
288 *d = realloc (*d, sizeof (char) * *ds);
290 /* Save the number of entries */
291 exif_set_short (*d + 6 + offset, data->priv->order,
292 ifd->count + n_ptr + n_thumb);
295 printf ("Saving %i entries (offset: %i)...\n", ifd->count, offset);
298 /* Save each entry */
299 for (i = 0; i < ifd->count; i++)
300 exif_data_save_data_entry (data, ifd->entries[i],
301 d, ds, offset + 12 * i);
302 offset += 12 * ifd->count;
305 * The pointer to IFD_EXIF is in IFD_0.
306 * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
307 * therefore, if IFD_INTEROPERABILITY is not empty, we need
308 * IFD_EXIF even if latter is empty.
310 if (ifd == data->ifd[EXIF_IFD_0] && (
311 data->ifd[EXIF_IFD_EXIF]->count ||
312 data->ifd[EXIF_IFD_INTEROPERABILITY]->count)) {
313 exif_set_short (*d + 6 + offset + 0, data->priv->order,
314 EXIF_TAG_EXIF_IFD_POINTER);
315 exif_set_short (*d + 6 + offset + 2, data->priv->order,
317 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
318 exif_set_long (*d + 6 + offset + 8, data->priv->order,
320 exif_data_save_data_content (data, data->ifd[EXIF_IFD_EXIF], d,
325 /* The pointer to IFD_GPS is in IFD_0. */
326 if (ifd == data->ifd[EXIF_IFD_0] && data->ifd[EXIF_IFD_GPS]->count) {
327 exif_set_short (*d + 6 + offset + 0, data->priv->order,
328 EXIF_TAG_GPS_INFO_IFD_POINTER);
329 exif_set_short (*d + 6 + offset + 2, data->priv->order,
331 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
332 exif_set_long (*d + 6 + offset + 8, data->priv->order,
334 exif_data_save_data_content (data, data->ifd[EXIF_IFD_GPS], d, ds,
339 /* The pointer to IFD_INTEROPERABILITY is in IFD_EXIF. See above. */
340 if (ifd == data->ifd[EXIF_IFD_EXIF] && data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
341 exif_set_short (*d + 6 + offset + 0, data->priv->order,
342 EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
343 exif_set_short (*d + 6 + offset + 2, data->priv->order,
345 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
346 exif_set_long (*d + 6 + offset + 8, data->priv->order,
348 exif_data_save_data_content (data, data->ifd[EXIF_IFD_INTEROPERABILITY],
353 /* Information about the thumbnail (if any) is saved in IFD_1. */
354 if ((ifd == data->ifd[EXIF_IFD_1]) && data->size) {
356 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
357 exif_set_short (*d + 6 + offset + 0, data->priv->order,
358 EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
359 exif_set_short (*d + 6 + offset + 2, data->priv->order,
361 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
362 exif_set_long (*d + 6 + offset + 8, data->priv->order,
365 *d = realloc (*d, sizeof (char) * *ds);
366 memcpy (*d + *ds - data->size, data->data, data->size);
369 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
370 exif_set_short (*d + 6 + offset + 0, data->priv->order,
371 EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
372 exif_set_short (*d + 6 + offset + 2, data->priv->order,
374 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
375 exif_set_long (*d + 6 + offset + 8, data->priv->order,
380 if (ifd == data->ifd[EXIF_IFD_0] && (data->ifd[EXIF_IFD_1]->count ||
384 * We are saving IFD 0. Tell where IFD 1 starts and save
387 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
388 exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
391 exif_set_long (*d + 6 + offset, data->priv->order, 0);
395 exif_data_load_data (ExifData *data, const unsigned char *d, unsigned int size)
397 unsigned int l, len = size;
407 printf ("Parsing %i byte(s) EXIF data...\n", size);
411 * It can be that the data starts with the EXIF header. If it does
412 * not, search the EXIF marker.
416 printf ("Size too small.\n");
420 if (!memcmp (d, ExifHeader, 6)) {
422 printf ("Found EXIF header.\n");
426 printf ("Data begins with 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x "
427 "0x%x...\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6]);
430 while ((d[0] == 0xff) && size) {
435 /* JPEG_MARKER_SOI */
436 if (d[0] == JPEG_MARKER_SOI) {
442 /* JPEG_MARKER_APP0 */
443 if (d[0] == JPEG_MARKER_APP0) {
446 l = (d[0] << 8) | d[1];
454 /* JPEG_MARKER_APP1 */
455 if (d[0] == JPEG_MARKER_APP1)
458 /* Unknown marker or data. Give up. */
460 printf ("EXIF marker not found.\n");
468 printf ("Size too small.\n");
472 len = (d[0] << 8) | d[1];
474 printf ("We have to deal with %i byte(s) of EXIF data.\n", len);
481 * Verify the exif header
482 * (offset 2, length 6).
486 printf ("Size too small.\n");
490 if (memcmp (d, ExifHeader, 6)) {
492 printf ("EXIF header not found.\n");
498 printf ("Found EXIF header.\n");
501 /* Byte order (offset 6, length 2) */
504 if (!memcmp (d + 6, "II", 2))
505 data->priv->order = EXIF_BYTE_ORDER_INTEL;
506 else if (!memcmp (d + 6, "MM", 2))
507 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
512 if (exif_get_short (d + 8, data->priv->order) != 0x002a)
516 offset = exif_get_long (d + 10, data->priv->order);
518 printf ("IFD 0 at %i.\n", (int) offset);
521 /* Parse the actual exif data (offset 14) */
522 exif_data_load_data_content (data, data->ifd[EXIF_IFD_0], d + 6,
526 n = exif_get_short (d + 6 + offset, data->priv->order);
527 offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
530 printf ("IFD 1 at %i.\n", (int) offset);
534 if (offset > size - 6) {
536 printf ("Bogus offset!\n");
541 exif_data_load_data_content (data, data->ifd[EXIF_IFD_1], d + 6,
547 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
556 *d = malloc (sizeof (char) * *ds);
557 memcpy (*d, ExifHeader, 6);
559 /* Order (offset 6) */
561 *d = realloc (*d, sizeof (char) * *ds);
562 if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
563 memcpy (*d + 6, "II", 2);
565 memcpy (*d + 6, "MM", 2);
568 /* Fixed value (2 bytes, offset 8) */
570 *d = realloc (*d, sizeof (char) * *ds);
571 exif_set_short (*d + 8, data->priv->order, 0x002a);
574 * IFD 0 offset (4 bytes, offset 10).
575 * We will start 8 bytes after the
576 * EXIF header (2 bytes for order, another 2 for the test, and
577 * 4 bytes for the IFD 0 offset make 8 bytes together).
580 *d = realloc (*d, sizeof (char) * *ds);
581 exif_set_long (*d + 10, data->priv->order, 8);
583 /* Now save IFD 0. IFD 1 will be saved automatically. */
585 printf ("Saving IFDs...\n");
587 exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds, *ds - 6);
590 printf ("Saved %i byte(s) EXIF data.\n", *ds);
595 exif_data_new_from_file (const char *path)
603 f = fopen (path, "rb");
608 while ((marker = fgetc (f)) == 0xff);
610 /* JPEG_MARKER_SOI */
611 if (marker == JPEG_MARKER_SOI)
614 /* JPEG_MARKER_APP0 */
615 if (marker == JPEG_MARKER_APP0) {
618 size = (lh << 8) | ll;
619 if (fseek (f, size - 2, SEEK_CUR) < 0)
624 /* JPEG_MARKER_APP1 */
625 if (marker == JPEG_MARKER_APP1)
628 /* Unknown marker or data. Give up. */
632 /* EXIF data found. Allocate the necessary memory and read the data. */
635 size = (lh << 8) | ll;
636 data = malloc (sizeof (char) * size);
639 if (fread (data, 1, size, f) != size) {
644 edata = exif_data_new_from_data (data, size);
653 exif_data_ref (ExifData *data)
658 data->priv->ref_count++;
662 exif_data_unref (ExifData *data)
667 data->priv->ref_count--;
668 if (!data->priv->ref_count)
669 exif_data_free (data);
673 exif_data_free (ExifData *data)
680 for (i = 0; i < EXIF_IFD_COUNT; i++) {
682 exif_content_unref (data->ifd[i]);
698 exif_data_dump (ExifData *data)
705 for (i = 0; i < EXIF_IFD_COUNT; i++) {
706 if (data->ifd[i] && data->ifd[i]->count) {
707 printf ("Dumping IFD '%s'...\n",
708 exif_ifd_get_name (i));
709 exif_content_dump (data->ifd[i], 0);
714 printf ("%i byte(s) thumbnail data available.", data->size);
715 if (data->size >= 4) {
716 printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
717 data->data[0], data->data[1],
718 data->data[data->size - 2],
719 data->data[data->size - 1]);
725 exif_data_get_byte_order (ExifData *data)
730 return (data->priv->order);
734 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
742 for (i = 0; i < EXIF_IFD_COUNT; i++)
743 func (data->ifd[i], user_data);
746 typedef struct _ByteOrderChangeData ByteOrderChangeData;
747 struct _ByteOrderChangeData {
748 ExifByteOrder old, new;
752 entry_set_byte_order (ExifEntry *e, void *data)
754 ByteOrderChangeData *d = data;
766 case EXIF_FORMAT_SHORT:
767 for (i = 0; i < e->components; i++) {
768 s = exif_get_short (e->data +
769 (i * exif_format_get_size (e->format)),
771 exif_set_short (e->data +
772 (i * exif_format_get_size (e->format)),
776 case EXIF_FORMAT_LONG:
777 for (i = 0; i < e->components; i++) {
778 l = exif_get_long (e->data +
779 (i * exif_format_get_size (e->format)),
781 exif_set_long (e->data +
782 (i * exif_format_get_size (e->format)),
786 case EXIF_FORMAT_RATIONAL:
787 for (i = 0; i < e->components; i++) {
788 r = exif_get_rational (e->data +
789 (i * exif_format_get_size (e->format)),
791 exif_set_rational (e->data +
792 (i * exif_format_get_size (e->format)),
796 case EXIF_FORMAT_SLONG:
797 for (i = 0; i < e->components; i++) {
798 sl = exif_get_slong (e->data +
799 (i * exif_format_get_size (e->format)),
801 exif_set_slong (e->data +
802 (i * exif_format_get_size (e->format)),
806 case EXIF_FORMAT_SRATIONAL:
807 for (i = 0; i < e->components; i++) {
808 sr = exif_get_srational (e->data +
809 (i * exif_format_get_size (e->format)),
811 exif_set_srational (e->data +
812 (i * exif_format_get_size (e->format)),
816 case EXIF_FORMAT_UNDEFINED:
817 case EXIF_FORMAT_BYTE:
818 case EXIF_FORMAT_ASCII:
826 content_set_byte_order (ExifContent *content, void *data)
828 exif_content_foreach_entry (content, entry_set_byte_order, data);
832 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
834 ByteOrderChangeData d;
836 if (!data || (order == data->priv->order))
839 d.old = data->priv->order;
841 exif_data_foreach_content (data, content_set_byte_order, &d);
842 data->priv->order = order;