3 * Copyright (c) 2001 Lutz Mueller <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., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301 USA.
23 #include <libexif/exif-mnote-data.h>
24 #include <libexif/exif-data.h>
25 #include <libexif/exif-ifd.h>
26 #include <libexif/exif-mnote-data-priv.h>
27 #include <libexif/exif-utils.h>
28 #include <libexif/exif-loader.h>
29 #include <libexif/exif-log.h>
30 #include <libexif/i18n.h>
31 #include <libexif/exif-system.h>
33 #include <libexif/canon/exif-mnote-data-canon.h>
34 #include <libexif/fuji/exif-mnote-data-fuji.h>
35 #include <libexif/olympus/exif-mnote-data-olympus.h>
36 #include <libexif/pentax/exif-mnote-data-pentax.h>
42 #undef JPEG_MARKER_SOI
43 #define JPEG_MARKER_SOI 0xd8
44 #undef JPEG_MARKER_APP0
45 #define JPEG_MARKER_APP0 0xe0
46 #undef JPEG_MARKER_APP1
47 #define JPEG_MARKER_APP1 0xe1
49 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
51 struct _ExifDataPrivate
60 unsigned int ref_count;
62 /* Temporarily used while loading data */
63 unsigned int offset_mnote;
65 ExifDataOption options;
66 ExifDataType data_type;
70 exif_data_alloc (ExifData *data, unsigned int i)
77 d = exif_mem_alloc (data->priv->mem, i);
81 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", i);
86 exif_data_get_mnote_data (ExifData *d)
88 return (d && d->priv) ? d->priv->md : NULL;
94 ExifMem *mem = exif_mem_new_default ();
95 ExifData *d = exif_data_new_mem (mem);
103 exif_data_new_mem (ExifMem *mem)
111 data = exif_mem_alloc (mem, sizeof (ExifData));
114 data->priv = exif_mem_alloc (mem, sizeof (ExifDataPrivate));
116 exif_mem_free (mem, data);
119 data->priv->ref_count = 1;
121 data->priv->mem = mem;
124 for (i = 0; i < EXIF_IFD_COUNT; i++) {
125 data->ifd[i] = exif_content_new_mem (data->priv->mem);
127 exif_data_free (data);
130 data->ifd[i]->parent = data;
133 /* Default options */
134 #ifndef NO_VERBOSE_TAG_STRINGS
136 * When the tag list is compiled away, setting this option prevents
137 * any tags from being loaded
139 exif_data_set_option (data, EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS);
141 exif_data_set_option (data, EXIF_DATA_OPTION_FOLLOW_SPECIFICATION);
143 /* Default data type: none */
144 exif_data_set_data_type (data, EXIF_DATA_TYPE_COUNT);
150 exif_data_new_from_data (const unsigned char *data, unsigned int size)
152 ExifData *edata = NULL;
154 edata = exif_data_new ();
155 exif_data_load_data (edata, data, size);
160 exif_data_load_data_entry (ExifData *data, ExifEntry *entry,
161 const unsigned char *d,
162 unsigned int size, unsigned int offset)
164 unsigned int s, doff;
166 entry->tag = exif_get_short (d + offset + 0, data->priv->order);
167 entry->format = exif_get_short (d + offset + 2, data->priv->order);
168 entry->components = exif_get_long (d + offset + 4, data->priv->order);
170 /* FIXME: should use exif_tag_get_name_in_ifd here but entry->parent
171 * has not been set yet
173 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
174 "Loading entry 0x%x ('%s')...", entry->tag,
175 exif_tag_get_name (entry->tag));
177 /* {0,1,2,4,8} x { 0x00000000 .. 0xffffffff }
178 * -> { 0x000000000 .. 0x7fffffff8 } */
179 s = exif_format_get_size(entry->format) * entry->components;
180 if ((s < entry->components) || (s == 0)){
185 * Size? If bigger than 4 bytes, the actual data is not
186 * in the entry but somewhere else (offset).
189 doff = exif_get_long (d + offset + 8, data->priv->order);
194 if ((doff + s < doff) || (doff + s < s) || (doff + s > size)) {
195 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
196 "Tag data past end of buffer (%u > %u)", doff+s, size);
200 entry->data = exif_data_alloc (data, s);
203 memcpy (entry->data, d + doff, s);
205 /* FIXME: What do our callers do if (entry->data == NULL)? */
206 EXIF_LOG_NO_MEMORY(data->priv->log, "ExifData", s);
209 /* If this is the MakerNote, remember the offset */
210 if (entry->tag == EXIF_TAG_MAKER_NOTE) {
212 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
213 "MakerNote found with empty data");
214 } else if (entry->size > 6) {
215 exif_log (data->priv->log,
216 EXIF_LOG_CODE_DEBUG, "ExifData",
217 "MakerNote found (%02x %02x %02x %02x "
218 "%02x %02x %02x...).",
219 entry->data[0], entry->data[1], entry->data[2],
220 entry->data[3], entry->data[4], entry->data[5],
223 data->priv->offset_mnote = doff;
229 exif_data_save_data_entry (ExifData *data, ExifEntry *e,
230 unsigned char **d, unsigned int *ds,
233 unsigned int doff, s;
236 if (!data || !data->priv)
240 * Each entry is 12 bytes long. The memory for the entry has
241 * already been allocated.
243 exif_set_short (*d + 6 + offset + 0,
244 data->priv->order, (ExifShort) e->tag);
245 exif_set_short (*d + 6 + offset + 2,
246 data->priv->order, (ExifShort) e->format);
248 if (!(data->priv->options & EXIF_DATA_OPTION_DONT_CHANGE_MAKER_NOTE)) {
249 /* If this is the maker note tag, update it. */
250 if ((e->tag == EXIF_TAG_MAKER_NOTE) && data->priv->md) {
251 /* TODO: this is using the wrong ExifMem to free e->data */
252 exif_mem_free (data->priv->mem, e->data);
255 exif_mnote_data_set_offset (data->priv->md, *ds - 6);
256 exif_mnote_data_save (data->priv->md, &e->data, &e->size);
257 e->components = e->size;
261 exif_set_long (*d + 6 + offset + 4,
262 data->priv->order, e->components);
265 * Size? If bigger than 4 bytes, the actual data is not in
266 * the entry but somewhere else.
268 s = exif_format_get_size (e->format) * e->components;
275 * According to the TIFF specification,
276 * the offset must be an even number. If we need to introduce
277 * a padding byte, we set it to 0.
281 t = exif_mem_realloc (data->priv->mem, *d, ts);
283 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", ts);
288 exif_set_long (*d + 6 + offset + 8, data->priv->order, doff);
290 *(*d + *ds - 1) = '\0';
295 /* Write the data. Fill unneeded bytes with 0. Do not crash with
298 memcpy (*d + 6 + doff, e->data, s);
300 memset (*d + 6 + doff, 0, s);
303 memset (*d + 6 + doff + s, 0, (4 - s));
307 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
308 unsigned int ds, ExifLong o, ExifLong s)
311 if ((o + s < o) || (o + s < s) || (o + s > ds) || (o > ds)) {
312 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
313 "Bogus thumbnail offset (%u) or size (%u).",
319 exif_mem_free (data->priv->mem, data->data);
320 if (!(data->data = exif_data_alloc (data, s))) {
321 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", s);
326 memcpy (data->data, d + o, s);
330 #define CHECK_REC(i) \
332 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
333 "ExifData", "Recursive entry in IFD " \
334 "'%s' detected. Skipping...", \
335 exif_ifd_get_name (i)); \
338 if (data->ifd[(i)]->count) { \
339 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
340 "ExifData", "Attempt to load IFD " \
341 "'%s' multiple times detected. " \
343 exif_ifd_get_name (i)); \
347 /*! Load data for an IFD.
349 * \param[in,out] data #ExifData
350 * \param[in] ifd IFD to load
351 * \param[in] d pointer to buffer containing raw IFD data
352 * \param[in] ds size of raw data in buffer at \c d
353 * \param[in] offset offset into buffer at \c d at which IFD starts
354 * \param[in] recursion_depth number of times this function has been
355 * recursively called without returning
358 exif_data_load_data_content (ExifData *data, ExifIfd ifd,
359 const unsigned char *d,
360 unsigned int ds, unsigned int offset, unsigned int recursion_depth)
362 ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
368 if (!data || !data->priv)
371 /* check for valid ExifIfd enum range */
372 if ((((int)ifd) < 0) || ( ((int)ifd) >= EXIF_IFD_COUNT))
375 if (recursion_depth > 30) {
376 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData",
377 "Deep recursion detected!");
381 /* Read the number of entries */
382 if ((offset + 2 < offset) || (offset + 2 < 2) || (offset + 2 > ds)) {
383 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData",
384 "Tag data past end of buffer (%u > %u)", offset+2, ds);
387 n = exif_get_short (d + offset, data->priv->order);
388 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
389 "Loading %hu entries...", n);
392 /* Check if we have enough data. */
393 if (offset + 12 * n > ds) {
394 n = (ds - offset) / 12;
395 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
396 "Short data; only loading %hu entries...", n);
399 for (i = 0; i < n; i++) {
401 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
403 case EXIF_TAG_EXIF_IFD_POINTER:
404 case EXIF_TAG_GPS_INFO_IFD_POINTER:
405 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
406 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
407 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
408 o = exif_get_long (d + offset + 12 * i + 8,
410 /* FIXME: IFD_POINTER tags aren't marked as being in a
411 * specific IFD, so exif_tag_get_name_in_ifd won't work
413 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
414 "Sub-IFD entry 0x%x ('%s') at %u.", tag,
415 exif_tag_get_name(tag), o);
417 case EXIF_TAG_EXIF_IFD_POINTER:
418 CHECK_REC (EXIF_IFD_EXIF);
419 exif_data_load_data_content (data, EXIF_IFD_EXIF, d, ds, o, recursion_depth + 1);
421 case EXIF_TAG_GPS_INFO_IFD_POINTER:
422 CHECK_REC (EXIF_IFD_GPS);
423 exif_data_load_data_content (data, EXIF_IFD_GPS, d, ds, o, recursion_depth + 1);
425 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
426 CHECK_REC (EXIF_IFD_INTEROPERABILITY);
427 exif_data_load_data_content (data, EXIF_IFD_INTEROPERABILITY, d, ds, o, recursion_depth + 1);
429 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
430 thumbnail_offset = o;
431 if (thumbnail_offset && thumbnail_length)
432 exif_data_load_data_thumbnail (data, d,
433 ds, thumbnail_offset,
436 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
437 thumbnail_length = o;
438 if (thumbnail_offset && thumbnail_length)
439 exif_data_load_data_thumbnail (data, d,
440 ds, thumbnail_offset,
450 * If we don't know the tag, don't fail. It could be that new
451 * versions of the standard have defined additional tags. Note that
452 * 0 is a valid tag in the GPS IFD.
454 if (!exif_tag_get_name_in_ifd (tag, ifd)) {
457 * Special case: Tag and format 0. That's against specification
458 * (at least up to 2.2). But Photoshop writes it anyways.
460 if (!memcmp (d + offset + 12 * i, "\0\0\0\0", 4)) {
461 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
462 "Skipping empty entry at position %u in '%s'.", i,
463 exif_ifd_get_name (ifd));
466 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
467 "Unknown tag 0x%04x (entry %u in '%s'). Please report this tag "
468 "to <libexif-devel@lists.sourceforge.net>.", tag, i,
469 exif_ifd_get_name (ifd));
470 if (data->priv->options & EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS)
473 entry = exif_entry_new_mem (data->priv->mem);
474 if (exif_data_load_data_entry (data, entry, d, ds,
476 exif_content_add_entry (data->ifd[ifd], entry);
477 exif_entry_unref (entry);
484 cmp_func (const unsigned char *p1, const unsigned char *p2, ExifByteOrder o)
486 ExifShort tag1 = exif_get_short (p1, o);
487 ExifShort tag2 = exif_get_short (p2, o);
489 return (tag1 < tag2) ? -1 : (tag1 > tag2) ? 1 : 0;
493 cmp_func_intel (const void *elem1, const void *elem2)
495 return cmp_func ((const unsigned char *) elem1,
496 (const unsigned char *) elem2, EXIF_BYTE_ORDER_INTEL);
500 cmp_func_motorola (const void *elem1, const void *elem2)
502 return cmp_func ((const unsigned char *) elem1,
503 (const unsigned char *) elem2, EXIF_BYTE_ORDER_MOTOROLA);
507 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
508 unsigned char **d, unsigned int *ds,
511 unsigned int j, n_ptr = 0, n_thumb = 0;
516 if (!data || !data->priv || !ifd || !d || !ds)
519 for (i = 0; i < EXIF_IFD_COUNT; i++)
520 if (ifd == data->ifd[i])
522 if (i == EXIF_IFD_COUNT)
526 * Check if we need some extra entries for pointers or the thumbnail.
532 * The pointer to IFD_EXIF is in IFD_0. The pointer to
533 * IFD_INTEROPERABILITY is in IFD_EXIF.
535 if (data->ifd[EXIF_IFD_EXIF]->count ||
536 data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
539 /* The pointer to IFD_GPS is in IFD_0. */
540 if (data->ifd[EXIF_IFD_GPS]->count)
549 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
556 * Allocate enough memory for all entries
557 * and the number of entries.
559 ts = *ds + (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
560 t = exif_mem_realloc (data->priv->mem, *d, ts);
562 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", ts);
568 /* Save the number of entries */
569 exif_set_short (*d + 6 + offset, data->priv->order,
570 (ExifShort) (ifd->count + n_ptr + n_thumb));
574 * Save each entry. Make sure that no memcpys from NULL pointers are
577 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
578 "Saving %i entries (IFD '%s', offset: %i)...",
579 ifd->count, exif_ifd_get_name (i), offset);
580 for (j = 0; j < ifd->count; j++) {
581 if (ifd->entries[j]) {
582 exif_data_save_data_entry (data, ifd->entries[j], d, ds,
587 offset += 12 * ifd->count;
589 /* Now save special entries. */
594 * The pointer to IFD_EXIF is in IFD_0.
595 * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
596 * therefore, if IFD_INTEROPERABILITY is not empty, we need
597 * IFD_EXIF even if latter is empty.
599 if (data->ifd[EXIF_IFD_EXIF]->count ||
600 data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
601 exif_set_short (*d + 6 + offset + 0, data->priv->order,
602 EXIF_TAG_EXIF_IFD_POINTER);
603 exif_set_short (*d + 6 + offset + 2, data->priv->order,
605 exif_set_long (*d + 6 + offset + 4, data->priv->order,
607 exif_set_long (*d + 6 + offset + 8, data->priv->order,
609 exif_data_save_data_content (data,
610 data->ifd[EXIF_IFD_EXIF], d, ds, *ds - 6);
614 /* The pointer to IFD_GPS is in IFD_0, too. */
615 if (data->ifd[EXIF_IFD_GPS]->count) {
616 exif_set_short (*d + 6 + offset + 0, data->priv->order,
617 EXIF_TAG_GPS_INFO_IFD_POINTER);
618 exif_set_short (*d + 6 + offset + 2, data->priv->order,
620 exif_set_long (*d + 6 + offset + 4, data->priv->order,
622 exif_set_long (*d + 6 + offset + 8, data->priv->order,
624 exif_data_save_data_content (data,
625 data->ifd[EXIF_IFD_GPS], d, ds, *ds - 6);
633 * The pointer to IFD_INTEROPERABILITY is in IFD_EXIF.
636 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
637 exif_set_short (*d + 6 + offset + 0, data->priv->order,
638 EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
639 exif_set_short (*d + 6 + offset + 2, data->priv->order,
641 exif_set_long (*d + 6 + offset + 4, data->priv->order,
643 exif_set_long (*d + 6 + offset + 8, data->priv->order,
645 exif_data_save_data_content (data,
646 data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds,
655 * Information about the thumbnail (if any) is saved in
660 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
661 exif_set_short (*d + 6 + offset + 0, data->priv->order,
662 EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
663 exif_set_short (*d + 6 + offset + 2, data->priv->order,
665 exif_set_long (*d + 6 + offset + 4, data->priv->order,
667 exif_set_long (*d + 6 + offset + 8, data->priv->order,
669 ts = *ds + data->size;
670 t = exif_mem_realloc (data->priv->mem, *d, ts);
672 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData",
678 memcpy (*d + *ds - data->size, data->data, data->size);
681 /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
682 exif_set_short (*d + 6 + offset + 0, data->priv->order,
683 EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
684 exif_set_short (*d + 6 + offset + 2, data->priv->order,
686 exif_set_long (*d + 6 + offset + 4, data->priv->order,
688 exif_set_long (*d + 6 + offset + 8, data->priv->order,
698 /* Sort the directory according to TIFF specification */
699 qsort (*d + 6 + offset - (ifd->count + n_ptr + n_thumb) * 12,
700 (ifd->count + n_ptr + n_thumb), 12,
701 (data->priv->order == EXIF_BYTE_ORDER_INTEL) ? cmp_func_intel : cmp_func_motorola);
703 /* Correctly terminate the directory */
704 if (i == EXIF_IFD_0 && (data->ifd[EXIF_IFD_1]->count ||
708 * We are saving IFD 0. Tell where IFD 1 starts and save
711 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
712 exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
715 exif_set_long (*d + 6 + offset, data->priv->order, 0);
719 EXIF_DATA_TYPE_MAKER_NOTE_NONE = 0,
720 EXIF_DATA_TYPE_MAKER_NOTE_CANON = 1,
721 EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS = 2,
722 EXIF_DATA_TYPE_MAKER_NOTE_PENTAX = 3,
723 EXIF_DATA_TYPE_MAKER_NOTE_NIKON = 4,
724 EXIF_DATA_TYPE_MAKER_NOTE_CASIO = 5,
725 EXIF_DATA_TYPE_MAKER_NOTE_FUJI = 6
726 } ExifDataTypeMakerNote;
728 /*! If MakerNote is recognized, load it.
730 * \param[in,out] data #ExifData
731 * \param[in] d pointer to raw EXIF data
732 * \param[in] ds length of data at d
735 interpret_maker_note(ExifData *data, const unsigned char *d, unsigned int ds)
738 ExifEntry* e = exif_data_get_entry (data, EXIF_TAG_MAKER_NOTE);
742 if ((mnoteid = exif_mnote_data_olympus_identify (data, e)) != 0) {
743 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,
744 "ExifData", "Olympus MakerNote variant type %d", mnoteid);
745 data->priv->md = exif_mnote_data_olympus_new (data->priv->mem);
747 } else if ((mnoteid = exif_mnote_data_canon_identify (data, e)) != 0) {
748 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,
749 "ExifData", "Canon MakerNote variant type %d", mnoteid);
750 data->priv->md = exif_mnote_data_canon_new (data->priv->mem, data->priv->options);
752 } else if ((mnoteid = exif_mnote_data_fuji_identify (data, e)) != 0) {
753 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,
754 "ExifData", "Fuji MakerNote variant type %d", mnoteid);
755 data->priv->md = exif_mnote_data_fuji_new (data->priv->mem);
757 /* NOTE: Must do Pentax detection last because some of the
758 * heuristics are pretty general. */
759 } else if ((mnoteid = exif_mnote_data_pentax_identify (data, e)) != 0) {
760 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,
761 "ExifData", "Pentax MakerNote variant type %d", mnoteid);
762 data->priv->md = exif_mnote_data_pentax_new (data->priv->mem);
766 * If we are able to interpret the maker note, do so.
768 if (data->priv->md) {
769 exif_mnote_data_log (data->priv->md, data->priv->log);
770 exif_mnote_data_set_byte_order (data->priv->md,
772 exif_mnote_data_set_offset (data->priv->md,
773 data->priv->offset_mnote);
774 exif_mnote_data_load (data->priv->md, d, ds);
778 #define LOG_TOO_SMALL \
779 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData", \
780 _("Size of data too small to allow for EXIF data."));
783 exif_data_load_data (ExifData *data, const unsigned char *d_orig,
789 const unsigned char *d = d_orig;
790 unsigned int len, fullds;
792 if (!data || !data->priv || !d || !ds)
795 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
796 "Parsing %i byte(s) EXIF data...\n", ds);
799 * It can be that the data starts with the EXIF header. If it does
800 * not, search the EXIF marker.
806 if (!memcmp (d, ExifHeader, 6)) {
807 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
808 "Found EXIF header.");
811 while (ds && (d[0] == 0xff)) {
816 /* JPEG_MARKER_SOI */
817 if (ds && d[0] == JPEG_MARKER_SOI) {
823 /* JPEG_MARKER_APP0 */
824 if (ds >= 3 && d[0] == JPEG_MARKER_APP0) {
827 l = (d[0] << 8) | d[1];
835 /* JPEG_MARKER_APP1 */
836 if (ds && d[0] == JPEG_MARKER_APP1)
839 /* Unknown marker or data. Give up. */
840 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
841 "ExifData", _("EXIF marker not found."));
850 len = (d[0] << 8) | d[1];
851 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
852 "We have to deal with %i byte(s) of EXIF data.",
859 * Verify the exif header
860 * (offset 2, length 6).
866 if (memcmp (d, ExifHeader, 6)) {
867 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
868 "ExifData", _("EXIF header not found."));
872 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
873 "Found EXIF header.");
875 /* Sanity check the data length */
879 /* The JPEG APP1 section can be no longer than 64 KiB (including a
880 16-bit length), so cap the data length to protect against overflow
881 in future offset calculations */
886 /* Byte order (offset 6, length 2) */
887 if (!memcmp (d + 6, "II", 2))
888 data->priv->order = EXIF_BYTE_ORDER_INTEL;
889 else if (!memcmp (d + 6, "MM", 2))
890 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
892 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
893 "ExifData", _("Unknown encoding."));
898 if (exif_get_short (d + 8, data->priv->order) != 0x002a)
902 offset = exif_get_long (d + 10, data->priv->order);
903 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
904 "IFD 0 at %i.", (int) offset);
906 /* Sanity check the offset, being careful about overflow */
907 if (offset > ds || offset + 6 + 2 > ds)
910 /* Parse the actual exif data (usually offset 14 from start) */
911 exif_data_load_data_content (data, EXIF_IFD_0, d + 6, ds - 6, offset, 0);
914 n = exif_get_short (d + 6 + offset, data->priv->order);
915 if (offset + 6 + 2 + 12 * n + 4 > ds)
918 offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
920 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
921 "IFD 1 at %i.", (int) offset);
924 if (offset > ds || offset + 6 > ds) {
925 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
926 "ExifData", "Bogus offset of IFD1.");
928 exif_data_load_data_content (data, EXIF_IFD_1, d + 6, ds - 6, offset, 0);
933 * If we got an EXIF_TAG_MAKER_NOTE, try to interpret it. Some
934 * cameras use pointers in the maker note tag that point to the
935 * space between IFDs. Here is the only place where we have access
938 interpret_maker_note(data, d, fullds);
940 /* Fixup tags if requested */
941 if (data->priv->options & EXIF_DATA_OPTION_FOLLOW_SPECIFICATION)
942 exif_data_fix (data);
946 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
949 *ds = 0; /* This means something went wrong */
951 if (!data || !d || !ds)
956 *d = exif_data_alloc (data, *ds);
961 memcpy (*d, ExifHeader, 6);
963 /* Order (offset 6) */
964 if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
965 memcpy (*d + 6, "II", 2);
967 memcpy (*d + 6, "MM", 2);
970 /* Fixed value (2 bytes, offset 8) */
971 exif_set_short (*d + 8, data->priv->order, 0x002a);
974 * IFD 0 offset (4 bytes, offset 10).
975 * We will start 8 bytes after the
976 * EXIF header (2 bytes for order, another 2 for the test, and
977 * 4 bytes for the IFD 0 offset make 8 bytes together).
979 exif_set_long (*d + 10, data->priv->order, 8);
981 /* Now save IFD 0. IFD 1 will be saved automatically. */
982 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
984 exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds,
986 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
987 "Saved %i byte(s) EXIF data.", *ds);
991 exif_data_new_from_file (const char *path)
996 loader = exif_loader_new ();
997 exif_loader_write_file (loader, path);
998 edata = exif_loader_get_data (loader);
999 exif_loader_unref (loader);
1005 exif_data_ref (ExifData *data)
1010 data->priv->ref_count++;
1014 exif_data_unref (ExifData *data)
1019 data->priv->ref_count--;
1020 if (!data->priv->ref_count)
1021 exif_data_free (data);
1025 exif_data_free (ExifData *data)
1028 ExifMem *mem = (data && data->priv) ? data->priv->mem : NULL;
1033 for (i = 0; i < EXIF_IFD_COUNT; i++) {
1035 exif_content_unref (data->ifd[i]);
1036 data->ifd[i] = NULL;
1041 exif_mem_free (mem, data->data);
1046 if (data->priv->log) {
1047 exif_log_unref (data->priv->log);
1048 data->priv->log = NULL;
1050 if (data->priv->md) {
1051 exif_mnote_data_unref (data->priv->md);
1052 data->priv->md = NULL;
1054 exif_mem_free (mem, data->priv);
1055 exif_mem_free (mem, data);
1058 exif_mem_unref (mem);
1062 exif_data_dump (ExifData *data)
1069 for (i = 0; i < EXIF_IFD_COUNT; i++) {
1070 if (data->ifd[i] && data->ifd[i]->count) {
1071 printf ("Dumping IFD '%s'...\n",
1072 exif_ifd_get_name (i));
1073 exif_content_dump (data->ifd[i], 0);
1078 printf ("%i byte(s) thumbnail data available.", data->size);
1079 if (data->size >= 4) {
1080 printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
1081 data->data[0], data->data[1],
1082 data->data[data->size - 2],
1083 data->data[data->size - 1]);
1089 exif_data_get_byte_order (ExifData *data)
1094 return (data->priv->order);
1098 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
1106 for (i = 0; i < EXIF_IFD_COUNT; i++)
1107 func (data->ifd[i], user_data);
1110 typedef struct _ByteOrderChangeData ByteOrderChangeData;
1111 struct _ByteOrderChangeData {
1112 ExifByteOrder old, new;
1116 entry_set_byte_order (ExifEntry *e, void *data)
1118 ByteOrderChangeData *d = data;
1123 exif_array_set_byte_order (e->format, e->data, e->components, d->old, d->new);
1127 content_set_byte_order (ExifContent *content, void *data)
1129 exif_content_foreach_entry (content, entry_set_byte_order, data);
1133 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
1135 ByteOrderChangeData d;
1137 if (!data || (order == data->priv->order))
1140 d.old = data->priv->order;
1142 exif_data_foreach_content (data, content_set_byte_order, &d);
1143 data->priv->order = order;
1145 exif_mnote_data_set_byte_order (data->priv->md, order);
1149 exif_data_log (ExifData *data, ExifLog *log)
1153 if (!data || !data->priv)
1155 exif_log_unref (data->priv->log);
1156 data->priv->log = log;
1159 for (i = 0; i < EXIF_IFD_COUNT; i++)
1160 exif_content_log (data->ifd[i], log);
1163 /* Used internally within libexif */
1164 ExifLog *exif_data_get_log (ExifData *);
1166 exif_data_get_log (ExifData *data)
1168 if (!data || !data->priv)
1170 return data->priv->log;
1173 static const struct {
1174 ExifDataOption option;
1176 const char *description;
1177 } exif_data_option[] = {
1178 {EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS, N_("Ignore unknown tags"),
1179 N_("Ignore unknown tags when loading EXIF data.")},
1180 {EXIF_DATA_OPTION_FOLLOW_SPECIFICATION, N_("Follow specification"),
1181 N_("Add, correct and remove entries to get EXIF data that follows "
1182 "the specification.")},
1183 {EXIF_DATA_OPTION_DONT_CHANGE_MAKER_NOTE, N_("Do not change maker note"),
1184 N_("When loading and resaving Exif data, save the maker note unmodified."
1185 " Be aware that the maker note can get corrupted.")},
1190 exif_data_option_get_name (ExifDataOption o)
1194 for (i = 0; exif_data_option[i].name; i++)
1195 if (exif_data_option[i].option == o)
1197 return _(exif_data_option[i].name);
1201 exif_data_option_get_description (ExifDataOption o)
1205 for (i = 0; exif_data_option[i].description; i++)
1206 if (exif_data_option[i].option == o)
1208 return _(exif_data_option[i].description);
1212 exif_data_set_option (ExifData *d, ExifDataOption o)
1217 d->priv->options |= o;
1221 exif_data_unset_option (ExifData *d, ExifDataOption o)
1226 d->priv->options &= ~o;
1230 fix_func (ExifContent *c, void *UNUSED(data))
1232 switch (exif_content_get_ifd (c)) {
1234 if (c->parent->data)
1235 exif_content_fix (c);
1236 else if (c->count) {
1237 exif_log (c->parent->priv->log, EXIF_LOG_CODE_DEBUG, "exif-data",
1238 "No thumbnail but entries on thumbnail. These entries have been "
1241 unsigned int cnt = c->count;
1242 exif_content_remove_entry (c, c->entries[c->count - 1]);
1243 if (cnt == c->count) {
1245 exif_log (c->parent->priv->log, EXIF_LOG_CODE_DEBUG, "exif-data",
1246 "failed to remove last entry from entries.");
1253 exif_content_fix (c);
1258 exif_data_fix (ExifData *d)
1260 exif_data_foreach_content (d, fix_func, NULL);
1264 exif_data_set_data_type (ExifData *d, ExifDataType dt)
1269 d->priv->data_type = dt;
1273 exif_data_get_data_type (ExifData *d)
1275 return (d && d->priv) ? d->priv->data_type : EXIF_DATA_TYPE_UNKNOWN;