exif-data.c

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00001 /* exif-data.c
00002  *
00003  * Copyright © 2001 Lutz Müller <lutz@users.sourceforge.net>
00004  *
00005  * This library is free software; you can redistribute it and/or
00006  * modify it under the terms of the GNU Lesser General Public
00007  * License as published by the Free Software Foundation; either
00008  * version 2 of the License, or (at your option) any later version.
00009  *
00010  * This library is distributed in the hope that it will be useful,
00011  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013  * Lesser General Public License for more details.
00014  *
00015  * You should have received a copy of the GNU Lesser General Public
00016  * License along with this library; if not, write to the
00017  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
00018  * Boston, MA 02111-1307, USA.
00019  */
00020 
00021 #include <config.h>
00022 
00023 #include <libexif/exif-mnote-data.h>
00024 #include <libexif/exif-data.h>
00025 #include <libexif/exif-ifd.h>
00026 #include <libexif/exif-mnote-data-priv.h>
00027 #include <libexif/exif-utils.h>
00028 #include <libexif/exif-loader.h>
00029 #include <libexif/exif-log.h>
00030 #include <libexif/i18n.h>
00031 
00032 #include <libexif/olympus/exif-mnote-data-olympus.h>
00033 #include <libexif/canon/exif-mnote-data-canon.h>
00034 #include <libexif/pentax/exif-mnote-data-pentax.h>
00035 
00036 #include <stdlib.h>
00037 #include <stdio.h>
00038 #include <string.h>
00039 
00040 #undef MAX
00041 #define MAX(a, b)  (((a) > (b)) ? (a) : (b))
00042 
00043 #if defined(__WATCOMC__) || defined(_MSC_VER)
00044 #      define strncasecmp strnicmp
00045 #endif
00046 
00047 #undef JPEG_MARKER_SOI
00048 #define JPEG_MARKER_SOI  0xd8
00049 #undef JPEG_MARKER_APP0
00050 #define JPEG_MARKER_APP0 0xe0
00051 #undef JPEG_MARKER_APP1
00052 #define JPEG_MARKER_APP1 0xe1
00053 
00054 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
00055 
00056 struct _ExifDataPrivate
00057 {
00058         ExifByteOrder order;
00059 
00060         ExifMnoteData *md;
00061 
00062         ExifLog *log;
00063         ExifMem *mem;
00064 
00065         unsigned int ref_count;
00066 
00067         /* Temporarily used while loading data */
00068         unsigned int offset_mnote;
00069 
00070         ExifDataOption options;
00071         ExifDataType data_type;
00072 };
00073 
00074 static void *
00075 exif_data_alloc (ExifData *data, unsigned int i)
00076 {
00077         void *d;
00078 
00079         if (!data || !i) 
00080                 return NULL;
00081 
00082         d = exif_mem_alloc (data->priv->mem, i);
00083         if (d) 
00084                 return d;
00085 
00086         EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", i);
00087         return NULL;
00088 }
00089 
00090 ExifMnoteData *
00091 exif_data_get_mnote_data (ExifData *d)
00092 {
00093         return (d && d->priv) ? d->priv->md : NULL;
00094 }
00095 
00096 ExifData *
00097 exif_data_new (void)
00098 {
00099         ExifMem *mem = exif_mem_new_default ();
00100         ExifData *d = exif_data_new_mem (mem);
00101 
00102         exif_mem_unref (mem);
00103 
00104         return d;
00105 }
00106 
00107 ExifData *
00108 exif_data_new_mem (ExifMem *mem)
00109 {
00110         ExifData *data;
00111         unsigned int i;
00112 
00113         if (!mem) 
00114                 return NULL;
00115 
00116         data = exif_mem_alloc (mem, sizeof (ExifData));
00117         if (!data) 
00118                 return (NULL);
00119         data->priv = exif_mem_alloc (mem, sizeof (ExifDataPrivate));
00120         if (!data->priv) { 
00121                 exif_mem_free (mem, data); 
00122                 return (NULL); 
00123         }
00124         data->priv->ref_count = 1;
00125 
00126         data->priv->mem = mem;
00127         exif_mem_ref (mem);
00128 
00129         for (i = 0; i < EXIF_IFD_COUNT; i++) {
00130                 data->ifd[i] = exif_content_new_mem (data->priv->mem);
00131                 if (!data->ifd[i]) {
00132                         exif_data_free (data);
00133                         return (NULL);
00134                 }
00135                 data->ifd[i]->parent = data;
00136         }
00137 
00138         /* Default options */
00139         exif_data_set_option (data, EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS);
00140         exif_data_set_option (data, EXIF_DATA_OPTION_FOLLOW_SPECIFICATION);
00141 
00142         /* Default data type: none */
00143         exif_data_set_data_type (data, EXIF_DATA_TYPE_COUNT);
00144 
00145         return (data);
00146 }
00147 
00148 ExifData *
00149 exif_data_new_from_data (const unsigned char *data, unsigned int size)
00150 {
00151         ExifData *edata;
00152 
00153         edata = exif_data_new ();
00154         exif_data_load_data (edata, data, size);
00155         return (edata);
00156 }
00157 
00158 static int
00159 exif_data_load_data_entry (ExifData *data, ExifEntry *entry,
00160                            const unsigned char *d,
00161                            unsigned int size, unsigned int offset)
00162 {
00163         unsigned int s, doff;
00164 
00165         entry->tag        = exif_get_short (d + offset + 0, data->priv->order);
00166         entry->format     = exif_get_short (d + offset + 2, data->priv->order);
00167         entry->components = exif_get_long  (d + offset + 4, data->priv->order);
00168 
00169         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00170                   "Loading entry 0x%x ('%s')...", entry->tag,
00171                   exif_tag_get_name (entry->tag));
00172 
00173         /*
00174          * Size? If bigger than 4 bytes, the actual data is not
00175          * in the entry but somewhere else (offset).
00176          */
00177         s = exif_format_get_size (entry->format) * entry->components;
00178         if (!s)
00179                 return 0;
00180         if (s > 4)
00181                 doff = exif_get_long (d + offset + 8, data->priv->order);
00182         else
00183                 doff = offset + 8;
00184 
00185         /* Sanity check */
00186         if (size < doff + s)
00187                 return 0;
00188 
00189         entry->data = exif_data_alloc (data, s);
00190         if (entry->data) {
00191                 entry->size = s;
00192                 memcpy (entry->data, d + doff, s);
00193         }
00194 
00195         /* If this is the MakerNote, remember the offset */
00196         if (entry->tag == EXIF_TAG_MAKER_NOTE) {
00197                 if (entry->size > 6) exif_log (data->priv->log,
00198                                                EXIF_LOG_CODE_DEBUG, "ExifData",
00199                                                "MakerNote found (%02x %02x %02x %02x "
00200                                                "%02x %02x %02x...).",
00201                                                entry->data[0], entry->data[1], entry->data[2],
00202                                                entry->data[3], entry->data[4], entry->data[5],
00203                                                entry->data[6]);
00204                 data->priv->offset_mnote = doff;
00205         }
00206         return 1;
00207 }
00208 
00209 static void
00210 exif_data_save_data_entry (ExifData *data, ExifEntry *e,
00211                            unsigned char **d, unsigned int *ds,
00212                            unsigned int offset)
00213 {
00214         unsigned int doff, s;
00215 
00216         if (!data || !data->priv) 
00217                 return;
00218 
00219         /*
00220          * Each entry is 12 bytes long. The memory for the entry has
00221          * already been allocated.
00222          */
00223         exif_set_short (*d + 6 + offset + 0,
00224                         data->priv->order, (ExifShort) e->tag);
00225         exif_set_short (*d + 6 + offset + 2,
00226                         data->priv->order, (ExifShort) e->format);
00227 
00228 #ifndef EXIF_DONT_CHANGE_MAKER_NOTE
00229         /* If this is the maker note tag, update it. */
00230         if ((e->tag == EXIF_TAG_MAKER_NOTE) && data->priv->md) {
00231                 exif_mem_free (data->priv->mem, e->data);
00232                 e->data = NULL;
00233                 e->size = 0;
00234                 exif_mnote_data_set_offset (data->priv->md, *ds - 6);
00235                 exif_mnote_data_save (data->priv->md, &e->data, &e->size);
00236                 e->components = e->size;
00237         }
00238 #endif
00239 
00240         exif_set_long  (*d + 6 + offset + 4,
00241                         data->priv->order, e->components);
00242 
00243         /*
00244          * Size? If bigger than 4 bytes, the actual data is not in
00245          * the entry but somewhere else.
00246          */
00247         s = exif_format_get_size (e->format) * e->components;
00248         if (s > 4) {
00249                 doff = *ds - 6;
00250                 *ds += s;
00251 
00252                 /*
00253                  * According to the TIFF specification,
00254                  * the offset must be an even number. If we need to introduce
00255                  * a padding byte, we set it to 0.
00256                  */
00257                 if (s & 1) 
00258                         (*ds)++;
00259                 *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00260                 if (!*d) {
00261                         EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
00262                         return;
00263                 }
00264                 exif_set_long (*d + 6 + offset + 8, data->priv->order, doff);
00265                 if (s & 1) 
00266                         *(*d + *ds - 1) = '\0';
00267 
00268         } else
00269                 doff = offset + 8;
00270 
00271         /* Write the data. Fill unneeded bytes with 0. */
00272         memcpy (*d + 6 + doff, e->data, s);
00273         if (s < 4) 
00274                 memset (*d + 6 + doff + s, 0, (4 - s));
00275 }
00276 
00277 static void
00278 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
00279                                unsigned int ds, ExifLong offset, ExifLong size)
00280 {
00281         if (ds < offset + size) {
00282                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00283                           "Bogus thumbnail offset and size: %i < %i + %i.",
00284                           (int) ds, (int) offset, (int) size);
00285                 return;
00286         }
00287         if (data->data) 
00288                 exif_mem_free (data->priv->mem, data->data);
00289         data->size = size;
00290         data->data = exif_data_alloc (data, data->size);
00291         if (!data->data) 
00292                 return;
00293         memcpy (data->data, d + offset, data->size);
00294 }
00295 
00296 #undef CHECK_REC
00297 #define CHECK_REC(i)                                    \
00298 if ((i) == ifd) {                               \
00299         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
00300                 "ExifData", "Recursive entry in IFD "   \
00301                 "'%s' detected. Skipping...",           \
00302                 exif_ifd_get_name (i));                 \
00303         break;                                          \
00304 }                                                       \
00305 if (data->ifd[(i)]->count) {                            \
00306         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
00307                 "ExifData", "Attemt to load IFD "       \
00308                 "'%s' multiple times detected. "        \
00309                 "Skipping...",                          \
00310                 exif_ifd_get_name (i));                 \
00311         break;                                          \
00312 }
00313 
00314 static void
00315 exif_data_load_data_content (ExifData *data, ExifIfd ifd,
00316                              const unsigned char *d,
00317                              unsigned int ds, unsigned int offset, unsigned int recursion_depth)
00318 {
00319         ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
00320         ExifShort n;
00321         ExifEntry *entry;
00322         unsigned int i;
00323         ExifTag tag;
00324 
00325         if (!data || !data->priv) 
00326                 return;
00327         if ((ifd < 0) || (ifd >= EXIF_IFD_COUNT)) 
00328                 return;
00329 
00330         if (recursion_depth > 150) {
00331                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData",
00332                           "Deep recursion detected!");
00333                 return;
00334         }
00335 
00336         /* Read the number of entries */
00337         if (offset >= ds - 1) 
00338                 return;
00339         n = exif_get_short (d + offset, data->priv->order);
00340         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00341                   "Loading %i entries...", n);
00342         offset += 2;
00343 
00344         /* Check if we have enough data. */
00345         if (offset + 12 * n > ds) 
00346                 n = (ds - offset) / 12;
00347 
00348         for (i = 0; i < n; i++) {
00349 
00350                 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
00351                 switch (tag) {
00352                 case EXIF_TAG_EXIF_IFD_POINTER:
00353                 case EXIF_TAG_GPS_INFO_IFD_POINTER:
00354                 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
00355                 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
00356                 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
00357                         o = exif_get_long (d + offset + 12 * i + 8,
00358                                            data->priv->order);
00359                         switch (tag) {
00360                         case EXIF_TAG_EXIF_IFD_POINTER:
00361                                 CHECK_REC (EXIF_IFD_EXIF);
00362                                 exif_data_load_data_content (data, EXIF_IFD_EXIF, d, ds, o, recursion_depth + 1);
00363                                 break;
00364                         case EXIF_TAG_GPS_INFO_IFD_POINTER:
00365                                 CHECK_REC (EXIF_IFD_GPS);
00366                                 exif_data_load_data_content (data, EXIF_IFD_GPS, d, ds, o, recursion_depth + 1);
00367                                 break;
00368                         case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
00369                                 CHECK_REC (EXIF_IFD_INTEROPERABILITY);
00370                                 exif_data_load_data_content (data, EXIF_IFD_INTEROPERABILITY, d, ds, o, recursion_depth + 1);
00371                                 break;
00372                         case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
00373                                 thumbnail_offset = o;
00374                                 if (thumbnail_offset && thumbnail_length)
00375                                         exif_data_load_data_thumbnail (data, d,
00376                                                                        ds, thumbnail_offset,
00377                                                                        thumbnail_length);
00378                                 break;
00379                         case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
00380                                 thumbnail_length = o;
00381                                 if (thumbnail_offset && thumbnail_length)
00382                                         exif_data_load_data_thumbnail (data, d,
00383                                                                        ds, thumbnail_offset,
00384                                                                        thumbnail_length);
00385                                 break;
00386                         default:
00387                                 return;
00388                         }
00389                         break;
00390                 default:
00391 
00392                         /*
00393                          * If we don't know the tag, don't fail. It could be that new 
00394                          * versions of the standard have defined additional tags. Note that
00395                          * 0 is a valid tag in the GPS IFD.
00396                          */
00397                         if (!exif_tag_get_name_in_ifd (tag, ifd)) {
00398 
00399                                 /*
00400                                  * Special case: Tag and format 0. That's against specification.
00401                                  * At least up to 2.2. But Photoshop writes it anyways.
00402                                  */
00403                                 if (!memcmp (d + offset + 12 * i, "\0\0\0\0", 4)) {
00404                                         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00405                                                   "Skipping empty entry at position %i in '%s'.", i, 
00406                                                   exif_ifd_get_name (ifd));
00407                                         break;
00408                                 }
00409                                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00410                                           "Unknown tag 0x%04x (entry %i in '%s'). Please report this tag "
00411                                           "to <libexif-devel@lists.sourceforge.net>.", tag, i,
00412                                           exif_ifd_get_name (ifd));
00413                                 if (data->priv->options & EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS)
00414                                         break;
00415                         }
00416                         entry = exif_entry_new_mem (data->priv->mem);
00417                         if (exif_data_load_data_entry (data, entry, d, ds,
00418                                                    offset + 12 * i))
00419                                 exif_content_add_entry (data->ifd[ifd], entry);
00420                         exif_entry_unref (entry);
00421                         break;
00422                 }
00423         }
00424 }
00425 
00426 static int
00427 cmp_func (const unsigned char *p1, const unsigned char *p2, ExifByteOrder o)
00428 {
00429         ExifShort tag1 = exif_get_short (p1, o);
00430         ExifShort tag2 = exif_get_short (p2, o);
00431 
00432         return (tag1 < tag2) ? -1 : (tag1 > tag2) ? 1 : 0;
00433 }
00434 
00435 static int
00436 cmp_func_intel (const void *elem1, const void *elem2)
00437 {
00438         return cmp_func ((const unsigned char *) elem1,
00439                          (const unsigned char *) elem2, EXIF_BYTE_ORDER_INTEL);
00440 }
00441 
00442 static int
00443 cmp_func_motorola (const void *elem1, const void *elem2)
00444 {
00445         return cmp_func ((const unsigned char *) elem1,
00446                          (const unsigned char *) elem2, EXIF_BYTE_ORDER_MOTOROLA);
00447 }
00448 
00449 static void
00450 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
00451                              unsigned char **d, unsigned int *ds,
00452                              unsigned int offset)
00453 {
00454         unsigned int j, n_ptr = 0, n_thumb = 0;
00455         ExifIfd i;
00456 
00457         if (!data || !data->priv || !ifd || !d || !ds) 
00458                 return;
00459 
00460         for (i = 0; i < EXIF_IFD_COUNT; i++)
00461                 if (ifd == data->ifd[i])
00462                         break;
00463         if (i == EXIF_IFD_COUNT)
00464                 return;
00465 
00466         /*
00467          * Check if we need some extra entries for pointers or the thumbnail.
00468          */
00469         switch (i) {
00470         case EXIF_IFD_0:
00471 
00472                 /*
00473                  * The pointer to IFD_EXIF is in IFD_0. The pointer to
00474                  * IFD_INTEROPERABILITY is in IFD_EXIF.
00475                  */
00476                 if (data->ifd[EXIF_IFD_EXIF]->count ||
00477                     data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
00478                         n_ptr++;
00479 
00480                 /* The pointer to IFD_GPS is in IFD_0. */
00481                 if (data->ifd[EXIF_IFD_GPS]->count)
00482                         n_ptr++;
00483 
00484                 break;
00485         case EXIF_IFD_1:
00486                 if (data->size)
00487                         n_thumb = 2;
00488                 break;
00489         case EXIF_IFD_EXIF:
00490                 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
00491                         n_ptr++;
00492         default:
00493                 break;
00494         }
00495 
00496         /*
00497          * Allocate enough memory for all entries
00498          * and the number of entries.
00499          */
00500         *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
00501         *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00502         if (!*d) {
00503                 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
00504                 return;
00505         }
00506 
00507         /* Save the number of entries */
00508         exif_set_short (*d + 6 + offset, data->priv->order,
00509                         (ExifShort) (ifd->count + n_ptr + n_thumb));
00510         offset += 2;
00511 
00512         /* Save each entry */
00513         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00514                   "Saving %i entries (IFD '%s', offset: %i)...",
00515                   ifd->count, exif_ifd_get_name (i), offset);
00516         for (j = 0; j < ifd->count; j++)
00517                 exif_data_save_data_entry (data, ifd->entries[j], d, ds, offset + 12 * j);
00518 
00519         offset += 12 * ifd->count;
00520 
00521         /* Now save special entries. */
00522         switch (i) {
00523         case EXIF_IFD_0:
00524 
00525                 /*
00526                  * The pointer to IFD_EXIF is in IFD_0.
00527                  * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
00528                  * therefore, if IFD_INTEROPERABILITY is not empty, we need
00529                  * IFD_EXIF even if latter is empty.
00530                  */
00531                 if (data->ifd[EXIF_IFD_EXIF]->count ||
00532                     data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
00533                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00534                                         EXIF_TAG_EXIF_IFD_POINTER);
00535                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00536                                         EXIF_FORMAT_LONG);
00537                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00538                                         1);
00539                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00540                                         *ds - 6);
00541                         exif_data_save_data_content (data,
00542                                                      data->ifd[EXIF_IFD_EXIF], d, ds, *ds - 6);
00543                         offset += 12;
00544                 }
00545 
00546                 /* The pointer to IFD_GPS is in IFD_0, too. */
00547                 if (data->ifd[EXIF_IFD_GPS]->count) {
00548                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00549                                         EXIF_TAG_GPS_INFO_IFD_POINTER);
00550                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00551                                         EXIF_FORMAT_LONG);
00552                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00553                                         1);
00554                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00555                                         *ds - 6);
00556                         exif_data_save_data_content (data,
00557                                                      data->ifd[EXIF_IFD_GPS], d, ds, *ds - 6);
00558                         offset += 12;
00559                 }
00560 
00561                 break;
00562         case EXIF_IFD_EXIF:
00563 
00564                 /*
00565                  * The pointer to IFD_INTEROPERABILITY is in IFD_EXIF.
00566                  * See note above.
00567                  */
00568                 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
00569                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00570                                         EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
00571                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00572                                         EXIF_FORMAT_LONG);
00573                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00574                                         1);
00575                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00576                                         *ds - 6);
00577                         exif_data_save_data_content (data,
00578                                                      data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds,
00579                                                      *ds - 6);
00580                         offset += 12;
00581                 }
00582 
00583                 break;
00584         case EXIF_IFD_1:
00585 
00586                 /*
00587                  * Information about the thumbnail (if any) is saved in
00588                  * IFD_1.
00589                  */
00590                 if (data->size) {
00591 
00592                         /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
00593                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00594                                         EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
00595                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00596                                         EXIF_FORMAT_LONG);
00597                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00598                                         1);
00599                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00600                                         *ds - 6);
00601                         *ds += data->size;
00602                         *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00603                         if (!*d) {
00604                                 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData",
00605                                                     *ds);
00606                                 return;
00607                         }
00608                         memcpy (*d + *ds - data->size, data->data, data->size);
00609                         offset += 12;
00610 
00611                         /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
00612                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00613                                         EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
00614                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00615                                         EXIF_FORMAT_LONG);
00616                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00617                                         1);
00618                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00619                                         data->size);
00620                         offset += 12;
00621                 }
00622 
00623                 break;
00624         default:
00625                 break;
00626         }
00627 
00628         /* Sort the directory according to TIFF specification */
00629         qsort (*d + 6 + offset - (ifd->count + n_ptr + n_thumb) * 12,
00630                (ifd->count + n_ptr + n_thumb), 12,
00631                (data->priv->order == EXIF_BYTE_ORDER_INTEL) ? cmp_func_intel : cmp_func_motorola);
00632 
00633         /* Correctly terminate the directory */
00634         if (i == EXIF_IFD_0 && (data->ifd[EXIF_IFD_1]->count ||
00635                                 data->size)) {
00636 
00637                 /*
00638                  * We are saving IFD 0. Tell where IFD 1 starts and save
00639                  * IFD 1.
00640                  */
00641                 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
00642                 exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
00643                                              *ds - 6);
00644         } else
00645                 exif_set_long (*d + 6 + offset, data->priv->order, 0);
00646 }
00647 
00648 typedef enum {
00649         EXIF_DATA_TYPE_MAKER_NOTE_NONE          = 0,
00650         EXIF_DATA_TYPE_MAKER_NOTE_CANON         = 1,
00651         EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS       = 2,
00652         EXIF_DATA_TYPE_MAKER_NOTE_PENTAX        = 3
00653 } ExifDataTypeMakerNote;
00654 
00655 static ExifDataTypeMakerNote
00656 exif_data_get_type_maker_note (ExifData *d)
00657 {
00658         ExifEntry *e, *em;
00659         char value[1024];
00660 
00661         if (!d) 
00662                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00663         
00664         e = exif_data_get_entry (d, EXIF_TAG_MAKER_NOTE);
00665         if (!e) 
00666                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00667 
00668         /* Olympus & Nikon */
00669         if ((e->size >= 5) && (!memcmp (e->data, "OLYMP", 5) ||
00670                                !memcmp (e->data, "Nikon", 5)))
00671                 return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
00672 
00673         em = exif_data_get_entry (d, EXIF_TAG_MAKE);
00674         if (!em) 
00675                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00676 
00677         /* Canon */
00678         if (!strcmp (exif_entry_get_value (em, value, sizeof (value)), "Canon"))
00679                 return EXIF_DATA_TYPE_MAKER_NOTE_CANON;
00680 
00681         /* Pentax & some variant of Nikon */
00682         if ((e->size >= 2) && (e->data[0] == 0x00) && (e->data[1] == 0x1b)) {
00683                 if (!strncasecmp (
00684                             exif_entry_get_value (em, value, sizeof(value)),
00685                             "Nikon", 5))
00686                         return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
00687                 else
00688                         return EXIF_DATA_TYPE_MAKER_NOTE_PENTAX;
00689         }
00690 
00691         return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00692 }
00693 
00694 #define LOG_TOO_SMALL \
00695 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData", \
00696                 _("Size of data too small to allow for EXIF data."));
00697 
00698 void
00699 exif_data_load_data (ExifData *data, const unsigned char *d_orig,
00700                      unsigned int ds_orig)
00701 {
00702         unsigned int l;
00703         ExifLong offset;
00704         ExifShort n;
00705         const unsigned char *d = d_orig;
00706         unsigned int ds = ds_orig, len;
00707 
00708         if (!data || !data->priv || !d || !ds) 
00709                 return;
00710 
00711         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00712                   "Parsing %i byte(s) EXIF data...\n", ds);
00713 
00714         /*
00715          * It can be that the data starts with the EXIF header. If it does
00716          * not, search the EXIF marker.
00717          */
00718         if (ds < 6) {
00719                 LOG_TOO_SMALL;
00720                 return;
00721         }
00722         if (!memcmp (d, ExifHeader, 6)) {
00723                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00724                           "Found EXIF header.");
00725         } else {
00726                 while (1) {
00727                         while ((d[0] == 0xff) && ds) {
00728                                 d++;
00729                                 ds--;
00730                         }
00731 
00732                         /* JPEG_MARKER_SOI */
00733                         if (d[0] == JPEG_MARKER_SOI) {
00734                                 d++;
00735                                 ds--;
00736                                 continue;
00737                         }
00738 
00739                         /* JPEG_MARKER_APP0 */
00740                         if (d[0] == JPEG_MARKER_APP0) {
00741                                 d++;
00742                                 ds--;
00743                                 l = (d[0] << 8) | d[1];
00744                                 if (l > ds)
00745                                         return;
00746                                 d += l;
00747                                 ds -= l;
00748                                 continue;
00749                         }
00750 
00751                         /* JPEG_MARKER_APP1 */
00752                         if (d[0] == JPEG_MARKER_APP1)
00753                                 break;
00754 
00755                         /* Unknown marker or data. Give up. */
00756                         exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00757                                   "ExifData", _("EXIF marker not found."));
00758                         return;
00759                 }
00760                 d++;
00761                 ds--;
00762                 if (ds < 2) {
00763                         LOG_TOO_SMALL;
00764                         return;
00765                 }
00766                 len = (d[0] << 8) | d[1];
00767                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00768                           "We have to deal with %i byte(s) of EXIF data.",
00769                           len);
00770                 d += 2;
00771                 ds -= 2;
00772         }
00773 
00774         /*
00775          * Verify the exif header
00776          * (offset 2, length 6).
00777          */
00778         if (ds < 6) {
00779                 LOG_TOO_SMALL;
00780                 return;
00781         }
00782         if (memcmp (d, ExifHeader, 6)) {
00783                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00784                           "ExifData", _("EXIF header not found."));
00785                 return;
00786         }
00787 
00788         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00789                   "Found EXIF header.");
00790 
00791         /* Byte order (offset 6, length 2) */
00792         if (ds < 14)
00793                 return;
00794         if (!memcmp (d + 6, "II", 2))
00795                 data->priv->order = EXIF_BYTE_ORDER_INTEL;
00796         else if (!memcmp (d + 6, "MM", 2))
00797                 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
00798         else {
00799                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00800                           "ExifData", _("Unknown encoding."));
00801                 return;
00802         }
00803 
00804         /* Fixed value */
00805         if (exif_get_short (d + 8, data->priv->order) != 0x002a)
00806                 return;
00807 
00808         /* IFD 0 offset */
00809         offset = exif_get_long (d + 10, data->priv->order);
00810         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", 
00811                   "IFD 0 at %i.", (int) offset);
00812 
00813         /* Parse the actual exif data (usually offset 14 from start) */
00814         exif_data_load_data_content (data, EXIF_IFD_0, d + 6, ds - 6, offset, 0);
00815 
00816         /* IFD 1 offset */
00817         if (offset + 6 + 2 > ds) {
00818                 return;
00819         }
00820         n = exif_get_short (d + 6 + offset, data->priv->order);
00821         if (offset + 6 + 2 + 12 * n + 4 > ds) {
00822                 return;
00823         }
00824         offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
00825         if (offset) {
00826                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00827                           "IFD 1 at %i.", (int) offset);
00828 
00829                 /* Sanity check. */
00830                 if (offset > ds - 6) {
00831                         exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00832                                   "ExifData", "Bogus offset.");
00833                         return;
00834                 }
00835 
00836                 exif_data_load_data_content (data, EXIF_IFD_1, d + 6, ds - 6, offset, 0);
00837         }
00838 
00839         /*
00840          * If we got an EXIF_TAG_MAKER_NOTE, try to interpret it. Some
00841          * cameras use pointers in the maker note tag that point to the
00842          * space between IFDs. Here is the only place where we have access
00843          * to that data.
00844          */
00845         switch (exif_data_get_type_maker_note (data)) {
00846         case EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS:
00847                 data->priv->md = exif_mnote_data_olympus_new (data->priv->mem);
00848                 break;
00849         case EXIF_DATA_TYPE_MAKER_NOTE_PENTAX:
00850                 data->priv->md = exif_mnote_data_pentax_new (data->priv->mem);
00851                 break;
00852         case EXIF_DATA_TYPE_MAKER_NOTE_CANON:
00853                 data->priv->md = exif_mnote_data_canon_new (data->priv->mem);
00854                 break;
00855         default:
00856                 break;
00857         }
00858 
00859         /* 
00860          * If we are able to interpret the maker note, do so.
00861          */
00862         if (data->priv->md) {
00863                 exif_mnote_data_log (data->priv->md, data->priv->log);
00864                 exif_mnote_data_set_byte_order (data->priv->md,
00865                                                 data->priv->order);
00866                 exif_mnote_data_set_offset (data->priv->md,
00867                                             data->priv->offset_mnote);
00868                 exif_mnote_data_load (data->priv->md, d, ds);
00869         }
00870 
00871         if (data->priv->options & EXIF_DATA_OPTION_FOLLOW_SPECIFICATION)
00872                 exif_data_fix (data);
00873 }
00874 
00875 void
00876 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
00877 {
00878         if (!data || !d || !ds)
00879                 return;
00880 
00881         /* Header */
00882         *ds = 14;
00883         *d = exif_data_alloc (data, *ds);
00884         if (!*d) 
00885                 return;
00886         memcpy (*d, ExifHeader, 6);
00887 
00888         /* Order (offset 6) */
00889         if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
00890                 memcpy (*d + 6, "II", 2);
00891         } else {
00892                 memcpy (*d + 6, "MM", 2);
00893         }
00894 
00895         /* Fixed value (2 bytes, offset 8) */
00896         exif_set_short (*d + 8, data->priv->order, 0x002a);
00897 
00898         /*
00899          * IFD 0 offset (4 bytes, offset 10).
00900          * We will start 8 bytes after the
00901          * EXIF header (2 bytes for order, another 2 for the test, and
00902          * 4 bytes for the IFD 0 offset make 8 bytes together).
00903          */
00904         exif_set_long (*d + 10, data->priv->order, 8);
00905 
00906         /* Now save IFD 0. IFD 1 will be saved automatically. */
00907         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00908                   "Saving IFDs...");
00909         exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds,
00910                                      *ds - 6);
00911         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00912                   "Saved %i byte(s) EXIF data.", *ds);
00913 }
00914 
00915 ExifData *
00916 exif_data_new_from_file (const char *path)
00917 {
00918         ExifData *edata;
00919         ExifLoader *loader;
00920 
00921         loader = exif_loader_new ();
00922         exif_loader_write_file (loader, path);
00923         edata = exif_loader_get_data (loader);
00924         exif_loader_unref (loader);
00925 
00926         return (edata);
00927 }
00928 
00929 void
00930 exif_data_ref (ExifData *data)
00931 {
00932         if (!data)
00933                 return;
00934 
00935         data->priv->ref_count++;
00936 }
00937 
00938 void
00939 exif_data_unref (ExifData *data)
00940 {
00941         if (!data) 
00942                 return;
00943 
00944         data->priv->ref_count--;
00945         if (!data->priv->ref_count) 
00946                 exif_data_free (data);
00947 }
00948 
00949 void
00950 exif_data_free (ExifData *data)
00951 {
00952         unsigned int i;
00953         ExifMem *mem = (data && data->priv) ? data->priv->mem : NULL;
00954 
00955         if (!data) 
00956                 return;
00957 
00958         for (i = 0; i < EXIF_IFD_COUNT; i++) {
00959                 if (data->ifd[i]) {
00960                         exif_content_unref (data->ifd[i]);
00961                         data->ifd[i] = NULL;
00962                 }
00963         }
00964 
00965         if (data->data) {
00966                 exif_mem_free (mem, data->data);
00967                 data->data = NULL;
00968         }
00969 
00970         if (data->priv) {
00971                 if (data->priv->log) {
00972                         exif_log_unref (data->priv->log);
00973                         data->priv->log = NULL;
00974                 }
00975                 if (data->priv->md) {
00976                         exif_mnote_data_unref (data->priv->md);
00977                         data->priv->md = NULL;
00978                 }
00979                 exif_mem_free (mem, data->priv);
00980                 exif_mem_free (mem, data);
00981         }
00982 
00983         exif_mem_unref (mem);
00984 }
00985 
00986 void
00987 exif_data_dump (ExifData *data)
00988 {
00989         unsigned int i;
00990 
00991         if (!data)
00992                 return;
00993 
00994         for (i = 0; i < EXIF_IFD_COUNT; i++) {
00995                 if (data->ifd[i] && data->ifd[i]->count) {
00996                         printf ("Dumping IFD '%s'...\n",
00997                                 exif_ifd_get_name (i));
00998                         exif_content_dump (data->ifd[i], 0);
00999                 }
01000         }
01001 
01002         if (data->data) {
01003                 printf ("%i byte(s) thumbnail data available.", data->size);
01004                 if (data->size >= 4) {
01005                         printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
01006                                 data->data[0], data->data[1],
01007                                 data->data[data->size - 2],
01008                                 data->data[data->size - 1]);
01009                 }
01010         }
01011 }
01012 
01013 ExifByteOrder
01014 exif_data_get_byte_order (ExifData *data)
01015 {
01016         if (!data)
01017                 return (0);
01018 
01019         return (data->priv->order);
01020 }
01021 
01022 void
01023 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
01024                            void *user_data)
01025 {
01026         unsigned int i;
01027 
01028         if (!data || !func)
01029                 return;
01030 
01031         for (i = 0; i < EXIF_IFD_COUNT; i++)
01032                 func (data->ifd[i], user_data);
01033 }
01034 
01035 typedef struct _ByteOrderChangeData ByteOrderChangeData;
01036 struct _ByteOrderChangeData {
01037         ExifByteOrder old, new;
01038 };
01039 
01040 static void
01041 entry_set_byte_order (ExifEntry *e, void *data)
01042 {
01043         ByteOrderChangeData *d = data;
01044 
01045         if (!e)
01046                 return;
01047 
01048         exif_array_set_byte_order (e->format, e->data, e->components, d->old, d->new);
01049 }
01050 
01051 static void
01052 content_set_byte_order (ExifContent *content, void *data)
01053 {
01054         exif_content_foreach_entry (content, entry_set_byte_order, data);
01055 }
01056 
01057 void
01058 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
01059 {
01060         ByteOrderChangeData d;
01061 
01062         if (!data || (order == data->priv->order))
01063                 return;
01064 
01065         d.old = data->priv->order;
01066         d.new = order;
01067         exif_data_foreach_content (data, content_set_byte_order, &d);
01068         data->priv->order = order;
01069         if (data->priv->md)
01070                 exif_mnote_data_set_byte_order (data->priv->md, order);
01071 }
01072 
01073 void
01074 exif_data_log (ExifData *data, ExifLog *log)
01075 {
01076         unsigned int i;
01077 
01078         if (!data || !data->priv) 
01079                 return;
01080         exif_log_unref (data->priv->log);
01081         data->priv->log = log;
01082         exif_log_ref (log);
01083 
01084         for (i = 0; i < EXIF_IFD_COUNT; i++)
01085                 exif_content_log (data->ifd[i], log);
01086 }
01087 
01088 /* Used internally within libexif */
01089 ExifLog *exif_data_get_log (ExifData *);
01090 ExifLog *
01091 exif_data_get_log (ExifData *data)
01092 {
01093         if (!data || !data->priv) 
01094                 return NULL;
01095         return data->priv->log;
01096 }
01097 
01098 static struct {
01099         ExifDataOption option;
01100         const char *name;
01101         const char *description;
01102 } exif_data_option[] = {
01103         {EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS, N_("Ignore unknown tags"),
01104          N_("Ignore unknown tags when loading EXIF data.")},
01105         {EXIF_DATA_OPTION_FOLLOW_SPECIFICATION, N_("Follow specification"),
01106          N_("Add, correct and remove entries to get EXIF data that follows "
01107             "the specification.")},
01108         {0, NULL, NULL}
01109 };
01110 
01111 const char *
01112 exif_data_option_get_name (ExifDataOption o)
01113 {
01114         unsigned int i;
01115 
01116         for (i = 0; exif_data_option[i].name; i++)
01117                 if (exif_data_option[i].option == o) 
01118                         break;
01119         return _(exif_data_option[i].name);
01120 }
01121 
01122 const char *
01123 exif_data_option_get_description (ExifDataOption o)
01124 {
01125         unsigned int i;
01126 
01127         for (i = 0; exif_data_option[i].description; i++)
01128                 if (exif_data_option[i].option == o) 
01129                         break;
01130         return _(exif_data_option[i].description);
01131 }
01132 
01133 void
01134 exif_data_set_option (ExifData *d, ExifDataOption o)
01135 {
01136         if (!d) 
01137                 return;
01138 
01139         d->priv->options |= o;
01140 }
01141 
01142 void
01143 exif_data_unset_option (ExifData *d, ExifDataOption o)
01144 {
01145         if (!d) 
01146                 return;
01147 
01148         d->priv->options &= ~o;
01149 }
01150 
01151 static void
01152 fix_func (ExifContent *c, void *data)
01153 {
01154         switch (exif_content_get_ifd (c)) {
01155         case EXIF_IFD_1:
01156                 if (c->parent->data)
01157                         exif_content_fix (c);
01158                 else {
01159                         exif_log (c->parent->priv->log, EXIF_LOG_CODE_DEBUG, "exif-data",
01160                                   "No thumbnail but entries on thumbnail. These entries have been "
01161                                   "removed.");
01162                         while (c->count)
01163                                 exif_content_remove_entry (c, c->entries[c->count - 1]);
01164                 }
01165                 break;
01166         default:
01167                 exif_content_fix (c);
01168         }
01169 }
01170 
01171 void
01172 exif_data_fix (ExifData *d)
01173 {
01174         exif_data_foreach_content (d, fix_func, NULL);
01175 }
01176 
01177 void
01178 exif_data_set_data_type (ExifData *d, ExifDataType dt)
01179 {
01180         if (!d || !d->priv) 
01181                 return;
01182 
01183         d->priv->data_type = dt;
01184 }
01185 
01186 ExifDataType
01187 exif_data_get_data_type (ExifData *d)
01188 {
01189         return (d && d->priv) ? d->priv->data_type : EXIF_DATA_TYPE_COUNT;
01190 }

Generated on Thu Aug 10 21:29:49 2006 for EXIF library (libexif) Internals by  doxygen 1.4.7