libexif/exif-data.c

   1 /* exif-data.c
   2  *
   3  * Copyright © 2001 Lutz Müller <lutz@users.sourceforge.net>
   4  *
   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.
   9  *
  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.
  14  *
  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.
  19  */
  20
  21 #include <config.h>
  22
  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
  31 #include <libjpeg/jpeg-marker.h>
  32
  33 #include <libexif/olympus/exif-mnote-data-olympus.h>
  34 #include <libexif/canon/exif-mnote-data-canon.h>
  35 #include <libexif/pentax/exif-mnote-data-pentax.h>
  36
  37 #include <stdlib.h>
  38 #include <stdio.h>
  39 #include <string.h>
  40
  41 #undef MAX
  42 #define MAX(a, b)  (((a) > (b)) ? (a) : (b))
  43
  44 #if defined(__WATCOMC__) || defined(_MSC_VER)
  45 #      define strncasecmp strnicmp
  46 #endif
  47
  48 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
  49
  50 struct _ExifDataPrivate
  51 {
  52         ExifByteOrder order;
  53
  54         ExifMnoteData *md;
  55
  56         ExifLog *log;
  57         ExifMem *mem;
  58
  59         unsigned int ref_count;
  60
  61         /* Temporarily used while loading data */
  62         unsigned int offset_mnote;
  63 };
  64
  65 static void *
  66 exif_data_alloc (ExifData *data, unsigned int i)
  67 {
  68         void *d;
  69
  70         if (!data || !i) return NULL;
  71
  72         d = exif_mem_alloc (data->priv->mem, i);
  73         if (d) return d;
  74
  75         EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", i);
  76         return NULL;
  77 }
  78
  79 ExifMnoteData *
  80 exif_data_get_mnote_data (ExifData *d)
  81 {
  82         return (d && d->priv) ? d->priv->md : NULL;
  83 }
  84
  85 ExifData *
  86 exif_data_new (void)
  87 {
  88         ExifMem *mem = exif_mem_new_default ();
  89         ExifData *d = exif_data_new_mem (mem);
  90
  91         exif_mem_unref (mem);
  92
  93         return d;
  94 }
  95
  96 ExifData *
  97 exif_data_new_mem (ExifMem *mem)
  98 {
  99         ExifData *data;
 100         unsigned int i;
 101
 102         if (!mem) return NULL;
 103
 104         data = exif_mem_alloc (mem, sizeof (ExifData));
 105         if (!data) return (NULL);
 106         data->priv = exif_mem_alloc (mem, sizeof (ExifDataPrivate));
 107         if (!data->priv) { exif_mem_free (mem, data); return (NULL); }
 108         data->priv->ref_count = 1;
 109
 110         data->priv->mem = mem;
 111         exif_mem_ref (mem);
 112
 113         for (i = 0; i < EXIF_IFD_COUNT; i++) {
 114                 data->ifd[i] = exif_content_new_mem (data->priv->mem);
 115                 if (!data->ifd[i]) {
 116                         exif_data_free (data);
 117                         return (NULL);
 118                 }
 119                 data->ifd[i]->parent = data;
 120         }
 121
 122         return (data);
 123 }
 124
 125 ExifData *
 126 exif_data_new_from_data (const unsigned char *data, unsigned int size)
 127 {
 128         ExifData *edata;
 129
 130         edata = exif_data_new ();
 131         exif_data_load_data (edata, data, size);
 132         return (edata);
 133 }
 134
 135 static void
 136 exif_data_load_data_entry (ExifData *data, ExifEntry *entry,
 137                            const unsigned char *d,
 138                            unsigned int size, unsigned int offset)
 139 {
 140         unsigned int s, doff;
 141
 142         entry->tag        = exif_get_short (d + offset + 0, data->priv->order);
 143         entry->format     = exif_get_short (d + offset + 2, data->priv->order);
 144         entry->components = exif_get_long  (d + offset + 4, data->priv->order);
 145
 146         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 147                   "Loading entry 0x%x ('%s')...", entry->tag,
 148                   exif_tag_get_name (entry->tag));
 149
 150         /*
 151          * Size? If bigger than 4 bytes, the actual data is not
 152          * in the entry but somewhere else (offset).
 153          */
 154         s = exif_format_get_size (entry->format) * entry->components;
 155         if (!s)
 156                 return;
 157         if (s > 4)
 158                 doff = exif_get_long (d + offset + 8, data->priv->order);
 159         else
 160                 doff = offset + 8;
 161
 162         /* Sanity check */
 163         if (size < doff + s)
 164                 return;
 165
 166         entry->data = exif_data_alloc (data, s);
 167         if (entry->data) {
 168                 entry->size = s;
 169                 memcpy (entry->data, d + doff, s);
 170         }
 171
 172         /* If this is the MakerNote, remember the offset */
 173         if (entry->tag == EXIF_TAG_MAKER_NOTE) {
 174                 if (entry->size > 6) exif_log (data->priv->log,
 175                           EXIF_LOG_CODE_DEBUG, "ExifData",
 176                           "MakerNote found (%02x %02x %02x %02x "
 177                           "%02x %02x %02x...).",
 178                           entry->data[0], entry->data[1], entry->data[2],
 179                           entry->data[3], entry->data[4], entry->data[5],
 180                           entry->data[6]);
 181                 data->priv->offset_mnote = doff;
 182         }
 183
 184         exif_entry_fix (entry);
 185 }
 186
 187 static void
 188 exif_data_save_data_entry (ExifData *data, ExifEntry *e,
 189                            unsigned char **d, unsigned int *ds,
 190                            unsigned int offset)
 191 {
 192         unsigned int doff, s;
 193
 194         if (!data || !data->priv) return;
 195
 196         /*
 197          * Each entry is 12 bytes long. The memory for the entry has
 198          * already been allocated.
 199          */
 200         exif_set_short (*d + 6 + offset + 0,
 201                         data->priv->order, (ExifShort) e->tag);
 202         exif_set_short (*d + 6 + offset + 2,
 203                         data->priv->order, (ExifShort) e->format);
 204
 205 #ifndef EXIF_DONT_CHANGE_MAKER_NOTE
 206         /* If this is the maker note tag, update it. */
 207         if ((e->tag == EXIF_TAG_MAKER_NOTE) && data->priv->md) {
 208                 exif_mem_free (data->priv->mem, e->data);
 209                 e->data = NULL;
 210                 e->size = 0;
 211                 exif_mnote_data_set_offset (data->priv->md, *ds - 6);
 212                 exif_mnote_data_save (data->priv->md, &e->data, &e->size);
 213                 e->components = e->size;
 214         }
 215 #endif
 216
 217         exif_set_long  (*d + 6 + offset + 4,
 218                         data->priv->order, e->components);
 219
 220         /*
 221          * Size? If bigger than 4 bytes, the actual data is not in
 222          * the entry but somewhere else.
 223          */
 224         s = exif_format_get_size (e->format) * e->components;
 225         if (s > 4) {
 226                 doff = *ds - 6;
 227                 *ds += s;
 228                 *d = exif_mem_realloc (data->priv->mem, *d, *ds);
 229                 if (!*d) {
 230                         EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
 231                         return;
 232                 }
 233                 exif_set_long (*d + 6 + offset + 8,
 234                                data->priv->order, doff);
 235         } else
 236                 doff = offset + 8;
 237
 238         /* Write the data. Fill unneeded bytes with 0. */
 239         memcpy (*d + 6 + doff, e->data, s);
 240         if (s < 4) memset (*d + 6 + doff + s, 0, (4 - s));
 241 }
 242
 243 static void
 244 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
 245                                unsigned int ds, ExifLong offset, ExifLong size)
 246 {
 247         if (ds < offset + size) {
 248                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 249                           "Bogus thumbnail offset and size: %i < %i + %i.",
 250                           (int) ds, (int) offset, (int) size);
 251                 return;
 252         }
 253         if (data->data) exif_mem_free (data->priv->mem, data->data);
 254         data->size = size;
 255         data->data = exif_data_alloc (data, data->size);
 256         if (!data->data) return;
 257         memcpy (data->data, d + offset, data->size);
 258 }
 259
 260 #undef CHECK_REC
 261 #define CHECK_REC(i)                                    \
 262 if (data->ifd[(i)] == ifd) {                            \
 263         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
 264                 "ExifData", "Recursive entry in IFD "   \
 265                 "'%s' detected. Skipping...",           \
 266                 exif_ifd_get_name (i));                 \
 267         break;                                          \
 268 }                                                       \
 269 if (data->ifd[(i)]->count) {                            \
 270         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
 271                 "ExifData", "Attemt to load IFD "       \
 272                 "'%s' multiple times detected. "        \
 273                 "Skipping...",                          \
 274                 exif_ifd_get_name (i));                 \
 275         break;                                          \
 276 }
 277
 278 static void
 279 exif_data_load_data_content (ExifData *data, ExifContent *ifd,
 280                              const unsigned char *d,
 281                              unsigned int ds, unsigned int offset)
 282 {
 283         ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
 284         ExifShort n;
 285         ExifEntry *entry;
 286         unsigned int i;
 287         ExifTag tag;
 288
 289         if (!data || !data->priv) return;
 290
 291         /* Read the number of entries */
 292         if (offset >= ds - 1) return;
 293         n = exif_get_short (d + offset, data->priv->order);
 294         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 295                   "Loading %i entries...", n);
 296         offset += 2;
 297
 298         /* Check if we have enough data. */
 299         if (offset + 12 * n > ds) n = (ds - offset) / 12;
 300
 301         for (i = 0; i < n; i++) {
 302
 303                 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
 304                 switch (tag) {
 305                 case EXIF_TAG_EXIF_IFD_POINTER:
 306                 case EXIF_TAG_GPS_INFO_IFD_POINTER:
 307                 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
 308                 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
 309                 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
 310                         o = exif_get_long (d + offset + 12 * i + 8,
 311                                            data->priv->order);
 312                         switch (tag) {
 313                         case EXIF_TAG_EXIF_IFD_POINTER:
 314                                 CHECK_REC (EXIF_IFD_EXIF);
 315                                 exif_data_load_data_content (data,
 316                                         data->ifd[EXIF_IFD_EXIF], d, ds, o);
 317                                 break;
 318                         case EXIF_TAG_GPS_INFO_IFD_POINTER:
 319                                 CHECK_REC (EXIF_IFD_GPS);
 320                                 exif_data_load_data_content (data,
 321                                         data->ifd[EXIF_IFD_GPS], d, ds, o);
 322                                 break;
 323                         case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
 324                                 CHECK_REC (EXIF_IFD_INTEROPERABILITY);
 325                                 exif_data_load_data_content (data,
 326                                         data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds, o);
 327                                 break;
 328                         case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
 329                                 thumbnail_offset = o;
 330                                 if (thumbnail_offset && thumbnail_length)
 331                                         exif_data_load_data_thumbnail (data, d,
 332                                                 ds, thumbnail_offset,
 333                                                 thumbnail_length);
 334                                 break;
 335                         case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
 336                                 thumbnail_length = o;
 337                                 if (thumbnail_offset && thumbnail_length)
 338                                         exif_data_load_data_thumbnail (data, d,
 339                                                 ds, thumbnail_offset,
 340                                                 thumbnail_length);
 341                                 break;
 342                         default:
 343                                 return;
 344                         }
 345                         break;
 346                 default:
 347
 348                         /*
 349                          * If we don't know the tag, chances are high
 350                          * that the EXIF data does not follow the standard.
 351                          */
 352                         if (!exif_tag_get_name (tag)) {
 353                                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 354                                   "Unknown tag %x (entry %i)", tag, i);
 355                                 return;
 356                         }
 357                         entry = exif_entry_new_mem (data->priv->mem);
 358                         exif_data_load_data_entry (data, entry, d, ds,
 359                                                    offset + 12 * i);
 360                         exif_content_add_entry (ifd, entry);
 361                         exif_entry_unref (entry);
 362                         break;
 363                 }
 364         }
 365 }
 366
 367 static void
 368 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
 369                              unsigned char **d, unsigned int *ds,
 370                              unsigned int offset)
 371 {
 372         unsigned int j, n_ptr = 0, n_thumb = 0;
 373         ExifIfd i;
 374
 375         if (!data || !data->priv || !ifd || !d || !ds) return;
 376
 377         for (i = 0; i < EXIF_IFD_COUNT; i++)
 378                 if (ifd == data->ifd[i])
 379                         break;
 380         if (i == EXIF_IFD_COUNT)
 381                 return;
 382
 383         /*
 384          * Check if we need some extra entries for pointers or the thumbnail.
 385          */
 386         switch (i) {
 387         case EXIF_IFD_0:
 388
 389                 /*
 390                  * The pointer to IFD_EXIF is in IFD_0. The pointer to
 391                  * IFD_INTEROPERABILITY is in IFD_EXIF.
 392                  */
 393                 if (data->ifd[EXIF_IFD_EXIF]->count ||
 394                     data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
 395                         n_ptr++;
 396
 397                 /* The pointer to IFD_GPS is in IFD_0. */
 398                 if (data->ifd[EXIF_IFD_GPS]->count)
 399                         n_ptr++;
 400
 401                 break;
 402         case EXIF_IFD_1:
 403                 if (data->size)
 404                         n_thumb = 2;
 405                 break;
 406         case EXIF_IFD_EXIF:
 407                 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
 408                         n_ptr++;
 409         default:
 410                 break;
 411         }
 412
 413         /*
 414          * Allocate enough memory for all entries
 415          * and the number of entries.
 416          */
 417         *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
 418         *d = exif_mem_realloc (data->priv->mem, *d, *ds);
 419         if (!*d) {
 420                 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
 421                 return;
 422         }
 423
 424         /* Save the number of entries */
 425         exif_set_short (*d + 6 + offset, data->priv->order,
 426                         (ExifShort) (ifd->count + n_ptr + n_thumb));
 427         offset += 2;
 428
 429         /* Save each entry */
 430         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 431                   "Saving %i entries (IFD '%s', offset: %i)...",
 432                   ifd->count, exif_ifd_get_name (i), offset);
 433         for (j = 0; j < ifd->count; j++)
 434                 exif_data_save_data_entry (data, ifd->entries[j],
 435                                 d, ds, offset + 12 * j);
 436         offset += 12 * ifd->count;
 437
 438         /* Now save special entries. */
 439         switch (i) {
 440         case EXIF_IFD_0:
 441
 442                 /*
 443                  * The pointer to IFD_EXIF is in IFD_0.
 444                  * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
 445                  * therefore, if IFD_INTEROPERABILITY is not empty, we need
 446                  * IFD_EXIF even if latter is empty.
 447                  */
 448                 if (data->ifd[EXIF_IFD_EXIF]->count ||
 449                     data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
 450                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
 451                                         EXIF_TAG_EXIF_IFD_POINTER);
 452                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
 453                                         EXIF_FORMAT_LONG);
 454                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
 455                                         1);
 456                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
 457                                         *ds - 6);
 458                         exif_data_save_data_content (data,
 459                                 data->ifd[EXIF_IFD_EXIF], d, ds, *ds - 6);
 460                         offset += 12;
 461                 }
 462
 463                 /* The pointer to IFD_GPS is in IFD_0, too. */
 464                 if (data->ifd[EXIF_IFD_GPS]->count) {
 465                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
 466                                         EXIF_TAG_GPS_INFO_IFD_POINTER);
 467                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
 468                                         EXIF_FORMAT_LONG);
 469                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
 470                                         1);
 471                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
 472                                         *ds - 6);
 473                         exif_data_save_data_content (data,
 474                                 data->ifd[EXIF_IFD_GPS], d, ds, *ds - 6);
 475                         offset += 12;
 476                 }
 477
 478                 break;
 479         case EXIF_IFD_EXIF:
 480
 481                 /*
 482                  * The pointer to IFD_INTEROPERABILITY is in IFD_EXIF.
 483                  * See note above.
 484                  */
 485                 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
 486                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
 487                                         EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
 488                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
 489                                         EXIF_FORMAT_LONG);
 490                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
 491                                         1);
 492                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
 493                                         *ds - 6);
 494                         exif_data_save_data_content (data,
 495                                 data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds,
 496                                 *ds - 6);
 497                         offset += 12;
 498                 }
 499
 500                 break;
 501         case EXIF_IFD_1:
 502
 503                 /*
 504                  * Information about the thumbnail (if any) is saved in
 505                  * IFD_1.
 506                  */
 507                 if (data->size) {
 508
 509                         /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
 510                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
 511                                         EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
 512                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
 513                                         EXIF_FORMAT_LONG);
 514                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
 515                                         1);
 516                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
 517                                         *ds - 6);
 518                         *ds += data->size;
 519                         *d = exif_mem_realloc (data->priv->mem, *d, *ds);
 520                         if (!*d) {
 521                                 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData",
 522                                                     *ds);
 523                                 return;
 524                         }
 525                         memcpy (*d + *ds - data->size, data->data, data->size);
 526                         offset += 12;
 527
 528                         /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
 529                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
 530                                 EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
 531                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
 532                                         EXIF_FORMAT_LONG);
 533                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
 534                                         1);
 535                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
 536                                         data->size);
 537                         offset += 12;
 538                 }
 539
 540                 break;
 541         default:
 542                 break;
 543         }
 544
 545         /* Correctly terminate the directory */
 546         if (i == EXIF_IFD_0 && (data->ifd[EXIF_IFD_1]->count ||
 547                                              data->size)) {
 548
 549                 /*
 550                  * We are saving IFD 0. Tell where IFD 1 starts and save
 551                  * IFD 1.
 552                  */
 553                 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
 554                 exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
 555                                              *ds - 6);
 556         } else
 557                 exif_set_long (*d + 6 + offset, data->priv->order, 0);
 558 }
 559
 560 typedef enum {
 561         EXIF_DATA_TYPE_MAKER_NOTE_NONE          = 0,
 562         EXIF_DATA_TYPE_MAKER_NOTE_CANON         = 1,
 563         EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS       = 2,
 564         EXIF_DATA_TYPE_MAKER_NOTE_PENTAX        = 3
 565 } ExifDataTypeMakerNote;
 566
 567 static ExifDataTypeMakerNote
 568 exif_data_get_type_maker_note (ExifData *d)
 569 {
 570         ExifEntry *e, *em;
 571         char value[1024];
 572
 573         if (!d) return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
 574
 575         e = exif_data_get_entry (d, EXIF_TAG_MAKER_NOTE);
 576         if (!e) return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
 577
 578         /* Olympus & Nikon */
 579         if ((e->size >= 5) && (!memcmp (e->data, "OLYMP", 5) ||
 580                                !memcmp (e->data, "Nikon", 5)))
 581                 return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
 582
 583         em = exif_data_get_entry (d, EXIF_TAG_MAKE);
 584         if (!em) return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
 585
 586         /* Canon */
 587         if (!strcmp (exif_entry_get_value (em, value, sizeof(value)), "Canon"))
 588                 return EXIF_DATA_TYPE_MAKER_NOTE_CANON;
 589
 590         /* Pentax & some variant of Nikon */
 591         if ((e->size >= 2) && (e->data[0] == 0x00) && (e->data[1] == 0x1b)) {
 592                 if (!strncasecmp (
 593                         exif_entry_get_value (em, value, sizeof(value)),
 594                                               "Nikon", 5))
 595                         return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
 596                 else
 597                         return EXIF_DATA_TYPE_MAKER_NOTE_PENTAX;
 598         }
 599
 600         return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
 601 }
 602
 603 void
 604 exif_data_load_data (ExifData *data, const unsigned char *d_orig,
 605                      unsigned int ds_orig)
 606 {
 607         unsigned int l;
 608         ExifLong offset;
 609         ExifShort n;
 610         const unsigned char *d = d_orig;
 611         unsigned int ds = ds_orig, len;
 612
 613         if (!data || !data->priv || !d || !ds) return;
 614
 615         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 616                   "Parsing %i byte(s) EXIF data...\n", ds);
 617
 618         /*
 619          * It can be that the data starts with the EXIF header. If it does
 620          * not, search the EXIF marker.
 621          */
 622         if (ds < 6) {
 623                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 624                           "Size too small.");
 625                 return;
 626         }
 627         if (!memcmp (d, ExifHeader, 6)) {
 628                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 629                           "Found EXIF header.");
 630         } else {
 631                 while (1) {
 632                         while ((d[0] == 0xff) && ds) {
 633                                 d++;
 634                                 ds--;
 635                         }
 636
 637                         /* JPEG_MARKER_SOI */
 638                         if (d[0] == JPEG_MARKER_SOI) {
 639                                 d++;
 640                                 ds--;
 641                                 continue;
 642                         }
 643
 644                         /* JPEG_MARKER_APP0 */
 645                         if (d[0] == JPEG_MARKER_APP0) {
 646                                 d++;
 647                                 ds--;
 648                                 l = (d[0] << 8) | d[1];
 649                                 if (l > ds)
 650                                         return;
 651                                 d += l;
 652                                 ds -= l;
 653                                 continue;
 654                         }
 655
 656                         /* JPEG_MARKER_APP1 */
 657                         if (d[0] == JPEG_MARKER_APP1)
 658                                 break;
 659
 660                         /* Unknown marker or data. Give up. */
 661                         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,
 662                                   "ExifData", "EXIF marker not found.");
 663                         return;
 664                 }
 665                 d++;
 666                 ds--;
 667                 if (ds < 2) {
 668                         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,
 669                                   "ExifData", "Size too small.");
 670                         return;
 671                 }
 672                 len = (d[0] << 8) | d[1];
 673                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 674                           "We have to deal with %i byte(s) of EXIF data.",
 675                           len);
 676                 d += 2;
 677                 ds -= 2;
 678         }
 679
 680         /*
 681          * Verify the exif header
 682          * (offset 2, length 6).
 683          */
 684         if (ds < 6) {
 685                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 686                           "Size too small.");
 687                 return;
 688         }
 689         if (memcmp (d, ExifHeader, 6)) {
 690                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 691                           "EXIF header not found.");
 692                 return;
 693         }
 694
 695         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 696                   "Found EXIF header.");
 697
 698         /* Byte order (offset 6, length 2) */
 699         if (ds < 14)
 700                 return;
 701         if (!memcmp (d + 6, "II", 2))
 702                 data->priv->order = EXIF_BYTE_ORDER_INTEL;
 703         else if (!memcmp (d + 6, "MM", 2))
 704                 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
 705         else
 706                 return;
 707
 708         /* Fixed value */
 709         if (exif_get_short (d + 8, data->priv->order) != 0x002a)
 710                 return;
 711
 712         /* IFD 0 offset */
 713         offset = exif_get_long (d + 10, data->priv->order);
 714         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 715                   "IFD 0 at %i.", (int) offset);
 716
 717         /* Parse the actual exif data (usually offset 14 from start) */
 718         exif_data_load_data_content (data, data->ifd[EXIF_IFD_0], d + 6,
 719                                      ds - 6, offset);
 720
 721         /* IFD 1 offset */
 722         if (offset + 6 + 2 > ds) {
 723                 return;
 724         }
 725         n = exif_get_short (d + 6 + offset, data->priv->order);
 726         if (offset + 6 + 2 + 12 * n + 4 > ds) {
 727                 return;
 728         }
 729         offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
 730         if (offset) {
 731                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 732                           "IFD 1 at %i.", (int) offset);
 733
 734                 /* Sanity check. */
 735                 if (offset > ds - 6) {
 736                         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,
 737                                   "ExifData", "Bogus offset!");
 738                         return;
 739                 }
 740
 741                 exif_data_load_data_content (data, data->ifd[EXIF_IFD_1], d + 6,
 742                                              ds - 6, offset);
 743         }
 744
 745         /*
 746          * If we got an EXIF_TAG_MAKER_NOTE, try to interpret it. Some
 747          * cameras use pointers in the maker note tag that point to the
 748          * space between IFDs. Here is the only place where we have access
 749          * to that data.
 750          */
 751         switch (exif_data_get_type_maker_note (data)) {
 752         case EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS:
 753                 data->priv->md = exif_mnote_data_olympus_new (data->priv->mem);
 754                 break;
 755         case EXIF_DATA_TYPE_MAKER_NOTE_PENTAX:
 756                 data->priv->md = exif_mnote_data_pentax_new (data->priv->mem);
 757                 break;
 758         case EXIF_DATA_TYPE_MAKER_NOTE_CANON:
 759                 data->priv->md = exif_mnote_data_canon_new (data->priv->mem);
 760                 break;
 761         default:
 762                 break;
 763         }
 764
 765         /*
 766          * If we are able to interpret the maker note, do so.
 767          */
 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,
 771                                                 data->priv->order);
 772                 exif_mnote_data_set_offset (data->priv->md,
 773                                             data->priv->offset_mnote);
 774                 exif_mnote_data_load (data->priv->md, d, ds);
 775         }
 776 }
 777
 778 void
 779 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
 780 {
 781         if (!data || !d || !ds)
 782                 return;
 783
 784         /* Header */
 785         *ds = 14;
 786         *d = exif_data_alloc (data, *ds);
 787         if (!*d) return;
 788         memcpy (*d, ExifHeader, 6);
 789
 790         /* Order (offset 6) */
 791         if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
 792                 memcpy (*d + 6, "II", 2);
 793         } else {
 794                 memcpy (*d + 6, "MM", 2);
 795         }
 796
 797         /* Fixed value (2 bytes, offset 8) */
 798         exif_set_short (*d + 8, data->priv->order, 0x002a);
 799
 800         /*
 801          * IFD 0 offset (4 bytes, offset 10).
 802          * We will start 8 bytes after the
 803          * EXIF header (2 bytes for order, another 2 for the test, and
 804          * 4 bytes for the IFD 0 offset make 8 bytes together).
 805          */
 806         exif_set_long (*d + 10, data->priv->order, 8);
 807
 808         /* Now save IFD 0. IFD 1 will be saved automatically. */
 809         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 810                   "Saving IFDs...");
 811         exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds,
 812                                      *ds - 6);
 813         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
 814                   "Saved %i byte(s) EXIF data.", *ds);
 815 }
 816
 817 ExifData *
 818 exif_data_new_from_file (const char *path)
 819 {
 820         ExifData *edata;
 821         ExifLoader *loader;
 822
 823         loader = exif_loader_new ();
 824         exif_loader_write_file (loader, path);
 825         edata = exif_loader_get_data (loader);
 826         exif_loader_unref (loader);
 827
 828         return (edata);
 829 }
 830
 831 void
 832 exif_data_ref (ExifData *data)
 833 {
 834         if (!data)
 835                 return;
 836
 837         data->priv->ref_count++;
 838 }
 839
 840 void
 841 exif_data_unref (ExifData *data)
 842 {
 843         if (!data) return;
 844
 845         data->priv->ref_count--;
 846         if (!data->priv->ref_count) exif_data_free (data);
 847 }
 848
 849 void
 850 exif_data_free (ExifData *data)
 851 {
 852         unsigned int i;
 853         ExifMem *mem = (data && data->priv) ? data->priv->mem : NULL;
 854
 855         if (!data) return;
 856
 857         for (i = 0; i < EXIF_IFD_COUNT; i++) {
 858                 if (data->ifd[i]) {
 859                         exif_content_unref (data->ifd[i]);
 860                         data->ifd[i] = NULL;
 861                 }
 862         }
 863
 864         if (data->data) {
 865                 exif_mem_free (mem, data->data);
 866                 data->data = NULL;
 867         }
 868
 869         if (data->priv) {
 870                 if (data->priv->log) {
 871                         exif_log_unref (data->priv->log);
 872                         data->priv->log = NULL;
 873                 }
 874                 if (data->priv->md) {
 875                         exif_mnote_data_unref (data->priv->md);
 876                         data->priv->md = NULL;
 877                 }
 878                 exif_mem_free (mem, data->priv);
 879                 exif_mem_free (mem, data);
 880         }
 881
 882         exif_mem_unref (mem);
 883 }
 884
 885 void
 886 exif_data_dump (ExifData *data)
 887 {
 888         unsigned int i;
 889
 890         if (!data)
 891                 return;
 892
 893         for (i = 0; i < EXIF_IFD_COUNT; i++) {
 894                 if (data->ifd[i] && data->ifd[i]->count) {
 895                         printf ("Dumping IFD '%s'...\n",
 896                                 exif_ifd_get_name (i));
 897                         exif_content_dump (data->ifd[i], 0);
 898                 }
 899         }
 900
 901         if (data->data) {
 902                 printf ("%i byte(s) thumbnail data available.", data->size);
 903                 if (data->size >= 4) {
 904                         printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
 905                                 data->data[0], data->data[1],
 906                                 data->data[data->size - 2],
 907                                 data->data[data->size - 1]);
 908                 }
 909         }
 910 }
 911
 912 ExifByteOrder
 913 exif_data_get_byte_order (ExifData *data)
 914 {
 915         if (!data)
 916                 return (0);
 917
 918         return (data->priv->order);
 919 }
 920
 921 void
 922 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
 923                            void *user_data)
 924 {
 925         unsigned int i;
 926
 927         if (!data || !func)
 928                 return;
 929
 930         for (i = 0; i < EXIF_IFD_COUNT; i++)
 931                 func (data->ifd[i], user_data);
 932 }
 933
 934 typedef struct _ByteOrderChangeData ByteOrderChangeData;
 935 struct _ByteOrderChangeData {
 936         ExifByteOrder old, new;
 937 };
 938
 939 static void
 940 entry_set_byte_order (ExifEntry *e, void *data)
 941 {
 942         ByteOrderChangeData *d = data;
 943
 944         if (!e)
 945                 return;
 946
 947         exif_array_set_byte_order (e->format, e->data, e->components, d->old, d->new);
 948 }
 949
 950 static void
 951 content_set_byte_order (ExifContent *content, void *data)
 952 {
 953         exif_content_foreach_entry (content, entry_set_byte_order, data);
 954 }
 955
 956 void
 957 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
 958 {
 959         ByteOrderChangeData d;
 960
 961         if (!data || (order == data->priv->order))
 962                 return;
 963
 964         d.old = data->priv->order;
 965         d.new = order;
 966         exif_data_foreach_content (data, content_set_byte_order, &d);
 967         data->priv->order = order;
 968         if (data->priv->md)
 969                 exif_mnote_data_set_byte_order (data->priv->md, order);
 970 }
 971
 972 void
 973 exif_data_log (ExifData *data, ExifLog *log)
 974 {
 975         unsigned int i;
 976
 977         if (!data || !data->priv) return;
 978         exif_log_unref (data->priv->log);
 979         data->priv->log = log;
 980         exif_log_ref (log);
 981
 982         for (i = 0; i < EXIF_IFD_COUNT; i++)
 983                 exif_content_log (data->ifd[i], log);
 984 }
 985
 986 /* Used internally within libexif */
 987 ExifLog *exif_data_get_log (ExifData *);
 988 ExifLog *
 989 exif_data_get_log (ExifData *data)
 990 {
 991         if (!data || !data->priv) return NULL;
 992         return data->priv->log;
 993 }