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>
30 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
34 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
36 struct _ExifDataPrivate
40 unsigned int ref_count;
48 data = malloc (sizeof (ExifData));
51 memset (data, 0, sizeof (ExifData));
52 data->priv = malloc (sizeof (ExifDataPrivate));
57 memset (data->priv, 0, sizeof (ExifDataPrivate));
58 data->priv->ref_count = 1;
60 data->ifd0 = exif_content_new ();
61 data->ifd1 = exif_content_new ();
62 data->ifd_exif = exif_content_new ();
63 data->ifd_gps = exif_content_new ();
64 data->ifd_interoperability = exif_content_new ();
65 if (!data->ifd_exif || !data->ifd_gps || !data->ifd_interoperability ||
66 !data->ifd0 || !data->ifd1) {
67 exif_data_free (data);
75 exif_data_new_from_data (const unsigned char *data, unsigned int size)
79 edata = exif_data_new ();
80 exif_data_load_data (edata, data, size);
85 exif_data_load_data_entry (ExifData *data, ExifEntry *entry,
86 const unsigned char *d,
87 unsigned int size, unsigned int offset)
91 entry->order = data->priv->order;
92 entry->tag = exif_get_short (d + offset + 0, data->priv->order);
93 entry->format = exif_get_short (d + offset + 2, data->priv->order);
94 entry->components = exif_get_long (d + offset + 4, data->priv->order);
97 * Size? If bigger than 4 bytes, the actual data is not
98 * in the entry but somewhere else (offset).
100 s = exif_format_get_size (entry->format) * entry->components;
104 doff = exif_get_long (d + offset + 8, data->priv->order);
112 entry->data = malloc (sizeof (char) * s);
116 memcpy (entry->data, d + doff, s);
120 exif_data_save_data_entry (ExifData *data, ExifEntry *entry,
121 unsigned char **d, unsigned int *ds,
124 unsigned int doff, s;
127 * Each entry is 12 bytes long. The memory for the entry has
128 * already been allocated.
130 exif_set_short (*d + 6 + offset + 0,
131 data->priv->order, entry->tag);
132 exif_set_short (*d + 6 + offset + 2,
133 data->priv->order, entry->format);
134 exif_set_long (*d + 6 + offset + 4,
135 data->priv->order, entry->components);
138 * Size? If bigger than 4 bytes, the actual data is not in
139 * the entry but somewhere else.
141 s = exif_format_get_size (entry->format) * entry->components;
146 *d = realloc (*d, sizeof (char) * *ds);
147 doff = *ds - 6 - entry->size;
148 exif_set_long (*d + 6 + offset + 8,
149 data->priv->order, doff);
152 memcpy (*d + 6 + doff, entry->data, entry->size);
156 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
157 unsigned int ds, ExifLong offset, ExifLong size)
159 if (ds < offset + size) {
161 printf ("Bogus thumbnail offset and size: %i < %i + %i.\n",
162 (int) ds, (int) offset, (int) size);
169 data->data = malloc (sizeof (char) * data->size);
170 memcpy (data->data, d + offset, data->size);
174 exif_data_load_data_content (ExifData *data, ExifContent *ifd,
175 const unsigned char *d,
176 unsigned int ds, unsigned int offset)
178 ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
184 ifd->order = data->priv->order;
186 /* Read the number of entries */
187 n = exif_get_short (d + offset, data->priv->order);
189 printf ("Loading %i entries...\n", n);
192 for (i = 0; i < n; i++) {
194 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
196 printf ("Loading entry '%s' (%i of %i)...\n",
197 exif_tag_get_name (tag), i + 1, n);
200 case EXIF_TAG_EXIF_IFD_POINTER:
201 case EXIF_TAG_GPS_INFO_IFD_POINTER:
202 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
203 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
204 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
205 o = exif_get_long (d + offset + 12 * i + 8,
208 case EXIF_TAG_EXIF_IFD_POINTER:
209 exif_data_load_data_content (data,
210 data->ifd_exif, d, ds, o);
212 case EXIF_TAG_GPS_INFO_IFD_POINTER:
213 exif_data_load_data_content (data,
214 data->ifd_gps, d, ds, o);
216 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
217 exif_data_load_data_content (data,
218 data->ifd_interoperability, d, ds, o);
220 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
222 printf ("Thumbnail at %i.\n", (int) o);
224 thumbnail_offset = o;
225 if (thumbnail_offset && thumbnail_length)
226 exif_data_load_data_thumbnail (data, d,
227 ds, thumbnail_offset,
230 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
232 printf ("Thumbnail size: %i.\n", (int) o);
234 thumbnail_length = o;
235 if (thumbnail_offset && thumbnail_length)
236 exif_data_load_data_thumbnail (data, d,
237 ds, thumbnail_offset,
245 entry = exif_entry_new ();
246 exif_content_add_entry (ifd, entry);
247 exif_data_load_data_entry (data, entry, d, ds,
249 exif_entry_unref (entry);
256 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
257 unsigned char **d, unsigned int *ds,
260 unsigned int i, n_ptr = 0, n_thumb = 0;
262 /* If we are to save IFD 0, we need some extra entries. */
263 if (ifd == data->ifd0)
267 * If we are to save IFD 1, we can point to the thumbnail if it
270 if ((ifd == data->ifd1) && data->data)
274 * Allocate enough memory for all entries
275 * and the number of entries.
277 *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + (n_ptr ? 4 : 0));
278 *d = realloc (*d, sizeof (char) * *ds);
280 /* Save the number of entries */
281 exif_set_short (*d + 6 + offset, data->priv->order,
282 ifd->count + n_ptr + n_thumb);
285 printf ("Saving %i entries (offset: %i)...\n", ifd->count, offset);
288 /* Save each entry */
289 for (i = 0; i < ifd->count; i++)
290 exif_data_save_data_entry (data, ifd->entries[i],
291 d, ds, offset + 12 * i);
292 offset += 12 * ifd->count;
294 /* Save special entries */
297 /* EXIF_TAG_EXIF_IFD_POINTER */
298 exif_set_short (*d + 6 + offset + 0, data->priv->order,
299 EXIF_TAG_EXIF_IFD_POINTER);
300 exif_set_short (*d + 6 + offset + 2, data->priv->order,
302 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
303 exif_set_long (*d + 6 + offset + 8, data->priv->order,
305 exif_data_save_data_content (data, data->ifd_exif, d, ds,
309 /* EXIF_TAG_GPS_INFO_IFD_POINTER */
310 exif_set_short (*d + 6 + offset + 0, data->priv->order,
311 EXIF_TAG_GPS_INFO_IFD_POINTER);
312 exif_set_short (*d + 6 + offset + 2, data->priv->order,
314 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
315 exif_set_long (*d + 6 + offset + 8, data->priv->order,
317 exif_data_save_data_content (data, data->ifd_gps, d, ds,
321 /* EXIF_TAG_INTEROPERABILITY_IFD_POINTER */
322 exif_set_short (*d + 6 + offset + 0, data->priv->order,
323 EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
324 exif_set_short (*d + 6 + offset + 2, data->priv->order,
326 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
327 exif_set_long (*d + 6 + offset + 8, data->priv->order,
329 exif_data_save_data_content (data, data->ifd_interoperability,
334 * We are saving IFD 0. Tell where IFD 1 starts and save
337 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
338 exif_data_save_data_content (data, data->ifd1, d, ds,
344 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
345 exif_set_short (*d + 6 + offset + 0, data->priv->order,
346 EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
347 exif_set_short (*d + 6 + offset + 2, data->priv->order,
349 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
350 exif_set_long (*d + 6 + offset + 8, data->priv->order,
354 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
355 exif_set_short (*d + 6 + offset + 0, data->priv->order,
356 EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
357 exif_set_short (*d + 6 + offset + 2, data->priv->order,
359 exif_set_long (*d + 6 + offset + 4, data->priv->order, 1);
360 exif_set_long (*d + 6 + offset + 8, data->priv->order,
363 *d = realloc (*d, sizeof (char) * *ds);
364 memcpy (*d + *ds - data->size, data->data, data->size);
369 exif_data_load_data (ExifData *data, const unsigned char *d, unsigned int size)
371 unsigned int l, len = size;
381 printf ("Parsing %i byte(s) EXIF data...\n", size);
385 * It can be that the data starts with the EXIF header. If it does
386 * not, search the EXIF marker.
390 printf ("Size too small.\n");
394 if (!memcmp (d, ExifHeader, 6)) {
396 printf ("Found EXIF header.\n");
400 printf ("Data begins with 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x "
401 "0x%x...\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6]);
404 while ((d[0] == 0xff) && size) {
409 /* JPEG_MARKER_SOI */
410 if (d[0] == JPEG_MARKER_SOI) {
416 /* JPEG_MARKER_APP0 */
417 if (d[0] == JPEG_MARKER_APP0) {
420 l = (d[0] << 8) | d[1];
428 /* JPEG_MARKER_APP1 */
429 if (d[0] == JPEG_MARKER_APP1)
432 /* Unknown marker or data. Give up. */
433 printf ("EXIF marker not found.\n");
440 printf ("Size too small.\n");
444 len = (d[0] << 8) | d[1];
446 printf ("We have to deal with %i byte(s) of EXIF data.\n", len);
453 * Verify the exif header
454 * (offset 2, length 6).
458 printf ("Size too small.\n");
462 if (memcmp (d, ExifHeader, 6)) {
464 printf ("EXIF header not found.\n");
470 printf ("Found EXIF header.\n");
473 /* Byte order (offset 6, length 2) */
476 if (!memcmp (d + 6, "II", 2))
477 data->priv->order = EXIF_BYTE_ORDER_INTEL;
478 else if (!memcmp (d + 6, "MM", 2))
479 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
484 if (exif_get_short (d + 8, data->priv->order) != 0x002a)
488 offset = exif_get_long (d + 10, data->priv->order);
490 printf ("IFD 0 at %i.\n", (int) offset);
493 /* Parse the actual exif data (offset 14) */
494 exif_data_load_data_content (data, data->ifd0, d + 6,
498 n = exif_get_short (d + 6 + offset, data->priv->order);
499 offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
502 printf ("IFD 1 at %i.\n", (int) offset);
504 exif_data_load_data_content (data, data->ifd1, d + 6,
510 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
519 *d = malloc (sizeof (char) * *ds);
520 memcpy (*d, ExifHeader, 6);
522 /* Order (offset 6) */
524 *d = realloc (*d, sizeof (char) * *ds);
525 if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
526 memcpy (*d + 6, "II", 2);
528 memcpy (*d + 6, "MM", 2);
531 /* Fixed value (2 bytes, offset 8) */
533 *d = realloc (*d, sizeof (char) * *ds);
534 exif_set_short (*d + 8, data->priv->order, 0x002a);
537 * IFD 0 offset (4 bytes, offset 10).
538 * We will start 8 bytes after the
539 * EXIF header (2 bytes for order, another 2 for the test, and
540 * 4 bytes for the IFD 0 offset make 8 bytes together).
543 *d = realloc (*d, sizeof (char) * *ds);
544 exif_set_long (*d + 10, data->priv->order, 8);
546 /* Now save IFD 0. IFD 1 will be saved automatically. */
548 printf ("Saving IFDs...\n");
550 exif_data_save_data_content (data, data->ifd0, d, ds, *ds - 6);
553 printf ("Saved %i byte(s) EXIF data.\n", *ds);
558 exif_data_new_from_file (const char *path)
565 f = fopen (path, "r");
569 /* For now, we read the data into memory. Patches welcome... */
570 fseek (f, 0, SEEK_END);
572 fseek (f, 0, SEEK_SET);
573 data = malloc (sizeof (char) * size);
576 if (fread (data, 1, size, f) != size) {
581 edata = exif_data_new_from_data (data, size);
590 exif_data_ref (ExifData *data)
595 data->priv->ref_count++;
599 exif_data_unref (ExifData *data)
604 data->priv->ref_count--;
605 if (!data->priv->ref_count)
606 exif_data_free (data);
610 exif_data_free (ExifData *data)
613 exif_content_unref (data->ifd0);
615 exif_content_unref (data->ifd1);
623 exif_data_dump (ExifData *data)
628 if (data->ifd0->count) {
629 printf ("Dumping IFD 0...\n");
630 exif_content_dump (data->ifd0, 0);
633 if (data->ifd1->count) {
634 printf ("Dumping IFD 1...\n");
635 exif_content_dump (data->ifd1, 0);
638 if (data->ifd_exif->count) {
639 printf ("Dumping IFD EXIF...\n");
640 exif_content_dump (data->ifd_exif, 0);
643 if (data->ifd_gps->count) {
644 printf ("Dumping IFD GPS...\n");
645 exif_content_dump (data->ifd_gps, 0);
648 if (data->ifd_interoperability->count) {
649 printf ("Dumping IFD Interoperability...\n");
650 exif_content_dump (data->ifd_interoperability, 0);
654 printf ("%i byte(s) thumbnail data available.", data->size);
655 if (data->size >= 4) {
656 printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
657 data->data[0], data->data[1],
658 data->data[data->size - 2],
659 data->data[data->size - 1]);