3 * Copyright © 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.
22 #include "exif-data.h"
24 #include "exif-utils.h"
25 #include "exif-loader.h"
26 #include "jpeg-marker.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);
154 /* Write the data. Fill unneeded bytes with 0. */
155 memcpy (*d + 6 + doff, entry->data, entry->size);
156 if (s < 4) memset (*d + 6 + doff + s, 0, (4 - s));
160 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
161 unsigned int ds, ExifLong offset, ExifLong size)
163 if (ds < offset + size) {
165 printf ("Bogus thumbnail offset and size: %i < %i + %i.\n",
166 (int) ds, (int) offset, (int) size);
173 data->data = malloc (sizeof (char) * data->size);
174 memcpy (data->data, d + offset, data->size);
178 exif_data_load_data_content (ExifData *data, ExifContent *ifd,
179 const unsigned char *d,
180 unsigned int ds, unsigned int offset)
182 ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
188 /* Read the number of entries */
189 n = exif_get_short (d + offset, data->priv->order);
191 printf ("Loading %i entries...\n", n);
194 for (i = 0; i < n; i++) {
196 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
198 printf ("Loading entry '%s' (%i of %i)...\n",
199 exif_tag_get_name (tag), i + 1, n);
202 case EXIF_TAG_EXIF_IFD_POINTER:
203 case EXIF_TAG_GPS_INFO_IFD_POINTER:
204 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
205 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
206 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
207 o = exif_get_long (d + offset + 12 * i + 8,
210 case EXIF_TAG_EXIF_IFD_POINTER:
211 exif_data_load_data_content (data,
212 data->ifd[EXIF_IFD_EXIF], d, ds, o);
214 case EXIF_TAG_GPS_INFO_IFD_POINTER:
215 exif_data_load_data_content (data,
216 data->ifd[EXIF_IFD_GPS], d, ds, o);
218 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
219 exif_data_load_data_content (data,
220 data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds, o);
222 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
224 printf ("Thumbnail at %i.\n", (int) o);
226 thumbnail_offset = o;
227 if (thumbnail_offset && thumbnail_length)
228 exif_data_load_data_thumbnail (data, d,
229 ds, thumbnail_offset,
232 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
234 printf ("Thumbnail size: %i.\n", (int) o);
236 thumbnail_length = o;
237 if (thumbnail_offset && thumbnail_length)
238 exif_data_load_data_thumbnail (data, d,
239 ds, thumbnail_offset,
247 entry = exif_entry_new ();
248 exif_content_add_entry (ifd, entry);
249 exif_data_load_data_entry (data, entry, d, ds,
251 exif_entry_unref (entry);
258 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
259 unsigned char **d, unsigned int *ds,
262 unsigned int j, n_ptr = 0, n_thumb = 0;
265 if (!data || !ifd || !d || !ds)
268 for (i = 0; i < EXIF_IFD_COUNT; i++)
269 if (ifd == data->ifd[i])
271 if (i == EXIF_IFD_COUNT)
275 * Check if we need some extra entries for pointers or the thumbnail.
281 * The pointer to IFD_EXIF is in IFD_0. The pointer to
282 * IFD_INTEROPERABILITY is in IFD_EXIF.
284 if (data->ifd[EXIF_IFD_EXIF]->count ||
285 data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
288 /* The pointer to IFD_GPS is in IFD_0. */
289 if (data->ifd[EXIF_IFD_GPS]->count)
298 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
305 * Allocate enough memory for all entries
306 * and the number of entries.
308 *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
309 *d = realloc (*d, sizeof (char) * *ds);
311 /* Save the number of entries */
312 exif_set_short (*d + 6 + offset, data->priv->order,
313 ifd->count + n_ptr + n_thumb);
317 printf ("Saving %i entries (IFD '%s', offset: %i)...\n",
318 ifd->count, exif_ifd_get_name (i), offset);
321 /* Save each entry */
322 for (j = 0; j < ifd->count; j++)
323 exif_data_save_data_entry (data, ifd->entries[j],
324 d, ds, offset + 12 * j);
325 offset += 12 * ifd->count;
327 /* Now save special entries. */
332 * The pointer to IFD_EXIF is in IFD_0.
333 * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
334 * therefore, if IFD_INTEROPERABILITY is not empty, we need
335 * IFD_EXIF even if latter is empty.
337 if (data->ifd[EXIF_IFD_EXIF]->count ||
338 data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
339 exif_set_short (*d + 6 + offset + 0, data->priv->order,
340 EXIF_TAG_EXIF_IFD_POINTER);
341 exif_set_short (*d + 6 + offset + 2, data->priv->order,
343 exif_set_long (*d + 6 + offset + 4, data->priv->order,
345 exif_set_long (*d + 6 + offset + 8, data->priv->order,
347 exif_data_save_data_content (data,
348 data->ifd[EXIF_IFD_EXIF], d, ds, *ds - 6);
352 /* The pointer to IFD_GPS is in IFD_0, too. */
353 if (data->ifd[EXIF_IFD_GPS]->count) {
354 exif_set_short (*d + 6 + offset + 0, data->priv->order,
355 EXIF_TAG_GPS_INFO_IFD_POINTER);
356 exif_set_short (*d + 6 + offset + 2, data->priv->order,
358 exif_set_long (*d + 6 + offset + 4, data->priv->order,
360 exif_set_long (*d + 6 + offset + 8, data->priv->order,
362 exif_data_save_data_content (data,
363 data->ifd[EXIF_IFD_GPS], d, ds, *ds - 6);
371 * The pointer to IFD_INTEROPERABILITY is in IFD_EXIF.
374 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
375 exif_set_short (*d + 6 + offset + 0, data->priv->order,
376 EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
377 exif_set_short (*d + 6 + offset + 2, data->priv->order,
379 exif_set_long (*d + 6 + offset + 4, data->priv->order,
381 exif_set_long (*d + 6 + offset + 8, data->priv->order,
383 exif_data_save_data_content (data,
384 data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds,
393 * Information about the thumbnail (if any) is saved in
398 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
399 exif_set_short (*d + 6 + offset + 0, data->priv->order,
400 EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
401 exif_set_short (*d + 6 + offset + 2, data->priv->order,
403 exif_set_long (*d + 6 + offset + 4, data->priv->order,
405 exif_set_long (*d + 6 + offset + 8, data->priv->order,
408 *d = realloc (*d, sizeof (char) * *ds);
409 memcpy (*d + *ds - data->size, data->data, data->size);
412 printf ("Wrote %i bytes of thumbnail data at offset "
413 "%i.\n", data->size, *ds - data->size);
414 printf ("We currently have %i bytes EXIF data.\n", *ds);
417 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
418 exif_set_short (*d + 6 + offset + 0, data->priv->order,
419 EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
420 exif_set_short (*d + 6 + offset + 2, data->priv->order,
422 exif_set_long (*d + 6 + offset + 4, data->priv->order,
424 exif_set_long (*d + 6 + offset + 8, data->priv->order,
434 /* Correctly terminate the directory */
435 if (i == EXIF_IFD_0 && (data->ifd[EXIF_IFD_1]->count ||
439 * We are saving IFD 0. Tell where IFD 1 starts and save
442 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
443 exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
446 exif_set_long (*d + 6 + offset, data->priv->order, 0);
450 exif_data_load_data (ExifData *data, const unsigned char *d, unsigned int size)
452 unsigned int l, len = size;
462 printf ("Parsing %i byte(s) EXIF data...\n", size);
466 * It can be that the data starts with the EXIF header. If it does
467 * not, search the EXIF marker.
471 printf ("Size too small.\n");
475 if (!memcmp (d, ExifHeader, 6)) {
477 printf ("Found EXIF header.\n");
481 printf ("Data begins with 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x "
482 "0x%x...\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6]);
485 while ((d[0] == 0xff) && size) {
490 /* JPEG_MARKER_SOI */
491 if (d[0] == JPEG_MARKER_SOI) {
497 /* JPEG_MARKER_APP0 */
498 if (d[0] == JPEG_MARKER_APP0) {
501 l = (d[0] << 8) | d[1];
509 /* JPEG_MARKER_APP1 */
510 if (d[0] == JPEG_MARKER_APP1)
513 /* Unknown marker or data. Give up. */
515 printf ("EXIF marker not found.\n");
523 printf ("Size too small.\n");
527 len = (d[0] << 8) | d[1];
529 printf ("We have to deal with %i byte(s) of EXIF data.\n", len);
536 * Verify the exif header
537 * (offset 2, length 6).
541 printf ("Size too small.\n");
545 if (memcmp (d, ExifHeader, 6)) {
547 printf ("EXIF header not found.\n");
553 printf ("Found EXIF header.\n");
556 /* Byte order (offset 6, length 2) */
559 if (!memcmp (d + 6, "II", 2))
560 data->priv->order = EXIF_BYTE_ORDER_INTEL;
561 else if (!memcmp (d + 6, "MM", 2))
562 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
567 if (exif_get_short (d + 8, data->priv->order) != 0x002a)
571 offset = exif_get_long (d + 10, data->priv->order);
573 printf ("IFD 0 at %i.\n", (int) offset);
576 /* Parse the actual exif data (offset 14) */
577 exif_data_load_data_content (data, data->ifd[EXIF_IFD_0], d + 6,
581 n = exif_get_short (d + 6 + offset, data->priv->order);
582 offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
585 printf ("IFD 1 at %i.\n", (int) offset);
589 if (offset > size - 6) {
591 printf ("Bogus offset!\n");
596 exif_data_load_data_content (data, data->ifd[EXIF_IFD_1], d + 6,
602 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
611 *d = malloc (sizeof (char) * *ds);
612 memcpy (*d, ExifHeader, 6);
614 /* Order (offset 6) */
616 *d = realloc (*d, sizeof (char) * *ds);
617 if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
618 memcpy (*d + 6, "II", 2);
620 memcpy (*d + 6, "MM", 2);
623 /* Fixed value (2 bytes, offset 8) */
625 *d = realloc (*d, sizeof (char) * *ds);
626 exif_set_short (*d + 8, data->priv->order, 0x002a);
629 * IFD 0 offset (4 bytes, offset 10).
630 * We will start 8 bytes after the
631 * EXIF header (2 bytes for order, another 2 for the test, and
632 * 4 bytes for the IFD 0 offset make 8 bytes together).
635 *d = realloc (*d, sizeof (char) * *ds);
636 exif_set_long (*d + 10, data->priv->order, 8);
638 /* Now save IFD 0. IFD 1 will be saved automatically. */
640 printf ("Saving IFDs...\n");
642 exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds,
646 printf ("Saved %i byte(s) EXIF data.\n", *ds);
651 exif_data_new_from_file (const char *path)
657 unsigned char data[1024];
659 f = fopen (path, "rb");
663 loader = exif_loader_new ();
665 size = fread (data, 1, 1024, f);
666 if (size <= 0) break;
667 if (!exif_loader_write (loader, data, size)) break;
671 edata = exif_loader_get_data (loader);
672 exif_loader_unref (loader);
678 exif_data_ref (ExifData *data)
683 data->priv->ref_count++;
687 exif_data_unref (ExifData *data)
692 data->priv->ref_count--;
693 if (!data->priv->ref_count)
694 exif_data_free (data);
698 exif_data_free (ExifData *data)
705 for (i = 0; i < EXIF_IFD_COUNT; i++) {
707 exif_content_unref (data->ifd[i]);
723 exif_data_dump (ExifData *data)
730 for (i = 0; i < EXIF_IFD_COUNT; i++) {
731 if (data->ifd[i] && data->ifd[i]->count) {
732 printf ("Dumping IFD '%s'...\n",
733 exif_ifd_get_name (i));
734 exif_content_dump (data->ifd[i], 0);
739 printf ("%i byte(s) thumbnail data available.", data->size);
740 if (data->size >= 4) {
741 printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
742 data->data[0], data->data[1],
743 data->data[data->size - 2],
744 data->data[data->size - 1]);
750 exif_data_get_byte_order (ExifData *data)
755 return (data->priv->order);
759 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
767 for (i = 0; i < EXIF_IFD_COUNT; i++)
768 func (data->ifd[i], user_data);
771 typedef struct _ByteOrderChangeData ByteOrderChangeData;
772 struct _ByteOrderChangeData {
773 ExifByteOrder old, new;
777 entry_set_byte_order (ExifEntry *e, void *data)
779 ByteOrderChangeData *d = data;
791 case EXIF_FORMAT_SHORT:
792 for (i = 0; i < e->components; i++) {
793 s = exif_get_short (e->data +
794 (i * exif_format_get_size (e->format)),
796 exif_set_short (e->data +
797 (i * exif_format_get_size (e->format)),
801 case EXIF_FORMAT_LONG:
802 for (i = 0; i < e->components; i++) {
803 l = exif_get_long (e->data +
804 (i * exif_format_get_size (e->format)),
806 exif_set_long (e->data +
807 (i * exif_format_get_size (e->format)),
811 case EXIF_FORMAT_RATIONAL:
812 for (i = 0; i < e->components; i++) {
813 r = exif_get_rational (e->data +
814 (i * exif_format_get_size (e->format)),
816 exif_set_rational (e->data +
817 (i * exif_format_get_size (e->format)),
821 case EXIF_FORMAT_SLONG:
822 for (i = 0; i < e->components; i++) {
823 sl = exif_get_slong (e->data +
824 (i * exif_format_get_size (e->format)),
826 exif_set_slong (e->data +
827 (i * exif_format_get_size (e->format)),
831 case EXIF_FORMAT_SRATIONAL:
832 for (i = 0; i < e->components; i++) {
833 sr = exif_get_srational (e->data +
834 (i * exif_format_get_size (e->format)),
836 exif_set_srational (e->data +
837 (i * exif_format_get_size (e->format)),
841 case EXIF_FORMAT_UNDEFINED:
842 case EXIF_FORMAT_BYTE:
843 case EXIF_FORMAT_ASCII:
851 content_set_byte_order (ExifContent *content, void *data)
853 exif_content_foreach_entry (content, entry_set_byte_order, data);
857 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
859 ByteOrderChangeData d;
861 if (!data || (order == data->priv->order))
864 d.old = data->priv->order;
866 exif_data_foreach_content (data, content_set_byte_order, &d);
867 data->priv->order = order;