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         /* {0,1,2,4,8} x { 0x00000000 .. 0xffffffff }
00178          *   -> { 0x000000000 .. 0x7fffffff8 } */
00179         s = exif_format_get_size(entry->format) * entry->components;
00180         if (s < entry->components) {
00181                 return 0;
00182         }
00183         if (0 == s)
00184                 return 0;
00185 
00186         if (s > 4)
00187                 doff = exif_get_long (d + offset + 8, data->priv->order);
00188         else
00189                 doff = offset + 8;
00190 
00191         /* Sanity checks */
00192         if ((doff + s < doff) || (doff + s < s))
00193                 return 0;
00194         if (size < doff + s)
00195                 return 0;
00196 
00197         entry->data = exif_data_alloc (data, s);
00198         if (entry->data) {
00199                 entry->size = s;
00200                 memcpy (entry->data, d + doff, s);
00201         }
00202 
00203         /* If this is the MakerNote, remember the offset */
00204         if (entry->tag == EXIF_TAG_MAKER_NOTE) {
00205                 if (entry->size > 6) exif_log (data->priv->log,
00206                                                EXIF_LOG_CODE_DEBUG, "ExifData",
00207                                                "MakerNote found (%02x %02x %02x %02x "
00208                                                "%02x %02x %02x...).",
00209                                                entry->data[0], entry->data[1], entry->data[2],
00210                                                entry->data[3], entry->data[4], entry->data[5],
00211                                                entry->data[6]);
00212                 data->priv->offset_mnote = doff;
00213         }
00214 
00215         return 1;
00216 }
00217 
00218 static void
00219 exif_data_save_data_entry (ExifData *data, ExifEntry *e,
00220                            unsigned char **d, unsigned int *ds,
00221                            unsigned int offset)
00222 {
00223         unsigned int doff, s;
00224 
00225         if (!data || !data->priv) 
00226                 return;
00227 
00228         /*
00229          * Each entry is 12 bytes long. The memory for the entry has
00230          * already been allocated.
00231          */
00232         exif_set_short (*d + 6 + offset + 0,
00233                         data->priv->order, (ExifShort) e->tag);
00234         exif_set_short (*d + 6 + offset + 2,
00235                         data->priv->order, (ExifShort) e->format);
00236 
00237 #ifndef EXIF_DONT_CHANGE_MAKER_NOTE
00238         /* If this is the maker note tag, update it. */
00239         if ((e->tag == EXIF_TAG_MAKER_NOTE) && data->priv->md) {
00240                 exif_mem_free (data->priv->mem, e->data);
00241                 e->data = NULL;
00242                 e->size = 0;
00243                 exif_mnote_data_set_offset (data->priv->md, *ds - 6);
00244                 exif_mnote_data_save (data->priv->md, &e->data, &e->size);
00245                 e->components = e->size;
00246         }
00247 #endif
00248 
00249         exif_set_long  (*d + 6 + offset + 4,
00250                         data->priv->order, e->components);
00251 
00252         /*
00253          * Size? If bigger than 4 bytes, the actual data is not in
00254          * the entry but somewhere else.
00255          */
00256         s = exif_format_get_size (e->format) * e->components;
00257         if (s > 4) {
00258                 doff = *ds - 6;
00259                 *ds += s;
00260 
00261                 /*
00262                  * According to the TIFF specification,
00263                  * the offset must be an even number. If we need to introduce
00264                  * a padding byte, we set it to 0.
00265                  */
00266                 if (s & 1) 
00267                         (*ds)++;
00268                 *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00269                 if (!*d) {
00270                         EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
00271                         return;
00272                 }
00273                 exif_set_long (*d + 6 + offset + 8, data->priv->order, doff);
00274                 if (s & 1) 
00275                         *(*d + *ds - 1) = '\0';
00276 
00277         } else
00278                 doff = offset + 8;
00279 
00280         /* Write the data. Fill unneeded bytes with 0. */
00281         memcpy (*d + 6 + doff, e->data, s);
00282         if (s < 4) 
00283                 memset (*d + 6 + doff + s, 0, (4 - s));
00284 }
00285 
00286 static void
00287 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
00288                                unsigned int ds, ExifLong offset, ExifLong size)
00289 {
00290         if ((ds < offset + size) || (offset < 0) || (size < 0) || (offset + size < offset)) {
00291                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00292                           "Bogus thumbnail offset and size");
00293                 return;
00294         }
00295         if (data->data) 
00296                 exif_mem_free (data->priv->mem, data->data);
00297         data->size = size;
00298         data->data = exif_data_alloc (data, data->size);
00299         if (!data->data) 
00300                 return;
00301         memcpy (data->data, d + offset, data->size);
00302 }
00303 
00304 #undef CHECK_REC
00305 #define CHECK_REC(i)                                    \
00306 if ((i) == ifd) {                               \
00307         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
00308                 "ExifData", "Recursive entry in IFD "   \
00309                 "'%s' detected. Skipping...",           \
00310                 exif_ifd_get_name (i));                 \
00311         break;                                          \
00312 }                                                       \
00313 if (data->ifd[(i)]->count) {                            \
00314         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
00315                 "ExifData", "Attemt to load IFD "       \
00316                 "'%s' multiple times detected. "        \
00317                 "Skipping...",                          \
00318                 exif_ifd_get_name (i));                 \
00319         break;                                          \
00320 }
00321 
00322 static void
00323 exif_data_load_data_content (ExifData *data, ExifIfd ifd,
00324                              const unsigned char *d,
00325                              unsigned int ds, unsigned int offset, unsigned int recursion_depth)
00326 {
00327         ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
00328         ExifShort n;
00329         ExifEntry *entry;
00330         unsigned int i;
00331         ExifTag tag;
00332 
00333         if (!data || !data->priv) 
00334                 return;
00335         if ((ifd < 0) || (ifd >= EXIF_IFD_COUNT)) 
00336                 return;
00337 
00338         if (recursion_depth > 150) {
00339                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData",
00340                           "Deep recursion detected!");
00341                 return;
00342         }
00343 
00344         /* Read the number of entries */
00345         if (offset >= ds - 1) 
00346                 return;
00347         n = exif_get_short (d + offset, data->priv->order);
00348         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00349                   "Loading %i entries...", n);
00350         offset += 2;
00351 
00352         /* Check if we have enough data. */
00353         if (offset + 12 * n > ds) 
00354                 n = (ds - offset) / 12;
00355 
00356         for (i = 0; i < n; i++) {
00357 
00358                 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
00359                 switch (tag) {
00360                 case EXIF_TAG_EXIF_IFD_POINTER:
00361                 case EXIF_TAG_GPS_INFO_IFD_POINTER:
00362                 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
00363                 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
00364                 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
00365                         o = exif_get_long (d + offset + 12 * i + 8,
00366                                            data->priv->order);
00367                         switch (tag) {
00368                         case EXIF_TAG_EXIF_IFD_POINTER:
00369                                 CHECK_REC (EXIF_IFD_EXIF);
00370                                 exif_data_load_data_content (data, EXIF_IFD_EXIF, d, ds, o, recursion_depth + 1);
00371                                 break;
00372                         case EXIF_TAG_GPS_INFO_IFD_POINTER:
00373                                 CHECK_REC (EXIF_IFD_GPS);
00374                                 exif_data_load_data_content (data, EXIF_IFD_GPS, d, ds, o, recursion_depth + 1);
00375                                 break;
00376                         case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
00377                                 CHECK_REC (EXIF_IFD_INTEROPERABILITY);
00378                                 exif_data_load_data_content (data, EXIF_IFD_INTEROPERABILITY, d, ds, o, recursion_depth + 1);
00379                                 break;
00380                         case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
00381                                 thumbnail_offset = o;
00382                                 if (thumbnail_offset && thumbnail_length)
00383                                         exif_data_load_data_thumbnail (data, d,
00384                                                                        ds, thumbnail_offset,
00385                                                                        thumbnail_length);
00386                                 break;
00387                         case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
00388                                 thumbnail_length = o;
00389                                 if (thumbnail_offset && thumbnail_length)
00390                                         exif_data_load_data_thumbnail (data, d,
00391                                                                        ds, thumbnail_offset,
00392                                                                        thumbnail_length);
00393                                 break;
00394                         default:
00395                                 return;
00396                         }
00397                         break;
00398                 default:
00399 
00400                         /*
00401                          * If we don't know the tag, don't fail. It could be that new 
00402                          * versions of the standard have defined additional tags. Note that
00403                          * 0 is a valid tag in the GPS IFD.
00404                          */
00405                         if (!exif_tag_get_name_in_ifd (tag, ifd)) {
00406 
00407                                 /*
00408                                  * Special case: Tag and format 0. That's against specification.
00409                                  * At least up to 2.2. But Photoshop writes it anyways.
00410                                  */
00411                                 if (!memcmp (d + offset + 12 * i, "\0\0\0\0", 4)) {
00412                                         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00413                                                   "Skipping empty entry at position %i in '%s'.", i, 
00414                                                   exif_ifd_get_name (ifd));
00415                                         break;
00416                                 }
00417                                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00418                                           "Unknown tag 0x%04x (entry %i in '%s'). Please report this tag "
00419                                           "to <libexif-devel@lists.sourceforge.net>.", tag, i,
00420                                           exif_ifd_get_name (ifd));
00421                                 if (data->priv->options & EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS)
00422                                         break;
00423                         }
00424                         entry = exif_entry_new_mem (data->priv->mem);
00425                         if (exif_data_load_data_entry (data, entry, d, ds,
00426                                                        offset + 12 * i))
00427                                 exif_content_add_entry (data->ifd[ifd], entry);
00428                         exif_entry_unref (entry);
00429                         break;
00430                 }
00431         }
00432 }
00433 
00434 static int
00435 cmp_func (const unsigned char *p1, const unsigned char *p2, ExifByteOrder o)
00436 {
00437         ExifShort tag1 = exif_get_short (p1, o);
00438         ExifShort tag2 = exif_get_short (p2, o);
00439 
00440         return (tag1 < tag2) ? -1 : (tag1 > tag2) ? 1 : 0;
00441 }
00442 
00443 static int
00444 cmp_func_intel (const void *elem1, const void *elem2)
00445 {
00446         return cmp_func ((const unsigned char *) elem1,
00447                          (const unsigned char *) elem2, EXIF_BYTE_ORDER_INTEL);
00448 }
00449 
00450 static int
00451 cmp_func_motorola (const void *elem1, const void *elem2)
00452 {
00453         return cmp_func ((const unsigned char *) elem1,
00454                          (const unsigned char *) elem2, EXIF_BYTE_ORDER_MOTOROLA);
00455 }
00456 
00457 static void
00458 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
00459                              unsigned char **d, unsigned int *ds,
00460                              unsigned int offset)
00461 {
00462         unsigned int j, n_ptr = 0, n_thumb = 0;
00463         ExifIfd i;
00464 
00465         if (!data || !data->priv || !ifd || !d || !ds) 
00466                 return;
00467 
00468         for (i = 0; i < EXIF_IFD_COUNT; i++)
00469                 if (ifd == data->ifd[i])
00470                         break;
00471         if (i == EXIF_IFD_COUNT)
00472                 return;
00473 
00474         /*
00475          * Check if we need some extra entries for pointers or the thumbnail.
00476          */
00477         switch (i) {
00478         case EXIF_IFD_0:
00479 
00480                 /*
00481                  * The pointer to IFD_EXIF is in IFD_0. The pointer to
00482                  * IFD_INTEROPERABILITY is in IFD_EXIF.
00483                  */
00484                 if (data->ifd[EXIF_IFD_EXIF]->count ||
00485                     data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
00486                         n_ptr++;
00487 
00488                 /* The pointer to IFD_GPS is in IFD_0. */
00489                 if (data->ifd[EXIF_IFD_GPS]->count)
00490                         n_ptr++;
00491 
00492                 break;
00493         case EXIF_IFD_1:
00494                 if (data->size)
00495                         n_thumb = 2;
00496                 break;
00497         case EXIF_IFD_EXIF:
00498                 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
00499                         n_ptr++;
00500         default:
00501                 break;
00502         }
00503 
00504         /*
00505          * Allocate enough memory for all entries
00506          * and the number of entries.
00507          */
00508         *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
00509         *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00510         if (!*d) {
00511                 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
00512                 return;
00513         }
00514 
00515         /* Save the number of entries */
00516         exif_set_short (*d + 6 + offset, data->priv->order,
00517                         (ExifShort) (ifd->count + n_ptr + n_thumb));
00518         offset += 2;
00519 
00520         /* Save each entry */
00521         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00522                   "Saving %i entries (IFD '%s', offset: %i)...",
00523                   ifd->count, exif_ifd_get_name (i), offset);
00524         for (j = 0; j < ifd->count; j++)
00525                 exif_data_save_data_entry (data, ifd->entries[j], d, ds, offset + 12 * j);
00526 
00527         offset += 12 * ifd->count;
00528 
00529         /* Now save special entries. */
00530         switch (i) {
00531         case EXIF_IFD_0:
00532 
00533                 /*
00534                  * The pointer to IFD_EXIF is in IFD_0.
00535                  * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
00536                  * therefore, if IFD_INTEROPERABILITY is not empty, we need
00537                  * IFD_EXIF even if latter is empty.
00538                  */
00539                 if (data->ifd[EXIF_IFD_EXIF]->count ||
00540                     data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
00541                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00542                                         EXIF_TAG_EXIF_IFD_POINTER);
00543                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00544                                         EXIF_FORMAT_LONG);
00545                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00546                                         1);
00547                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00548                                         *ds - 6);
00549                         exif_data_save_data_content (data,
00550                                                      data->ifd[EXIF_IFD_EXIF], d, ds, *ds - 6);
00551                         offset += 12;
00552                 }
00553 
00554                 /* The pointer to IFD_GPS is in IFD_0, too. */
00555                 if (data->ifd[EXIF_IFD_GPS]->count) {
00556                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00557                                         EXIF_TAG_GPS_INFO_IFD_POINTER);
00558                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00559                                         EXIF_FORMAT_LONG);
00560                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00561                                         1);
00562                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00563                                         *ds - 6);
00564                         exif_data_save_data_content (data,
00565                                                      data->ifd[EXIF_IFD_GPS], d, ds, *ds - 6);
00566                         offset += 12;
00567                 }
00568 
00569                 break;
00570         case EXIF_IFD_EXIF:
00571 
00572                 /*
00573                  * The pointer to IFD_INTEROPERABILITY is in IFD_EXIF.
00574                  * See note above.
00575                  */
00576                 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
00577                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00578                                         EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
00579                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00580                                         EXIF_FORMAT_LONG);
00581                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00582                                         1);
00583                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00584                                         *ds - 6);
00585                         exif_data_save_data_content (data,
00586                                                      data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds,
00587                                                      *ds - 6);
00588                         offset += 12;
00589                 }
00590 
00591                 break;
00592         case EXIF_IFD_1:
00593 
00594                 /*
00595                  * Information about the thumbnail (if any) is saved in
00596                  * IFD_1.
00597                  */
00598                 if (data->size) {
00599 
00600                         /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
00601                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00602                                         EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
00603                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00604                                         EXIF_FORMAT_LONG);
00605                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00606                                         1);
00607                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00608                                         *ds - 6);
00609                         *ds += data->size;
00610                         *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00611                         if (!*d) {
00612                                 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData",
00613                                                     *ds);
00614                                 return;
00615                         }
00616                         memcpy (*d + *ds - data->size, data->data, data->size);
00617                         offset += 12;
00618 
00619                         /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
00620                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00621                                         EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
00622                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00623                                         EXIF_FORMAT_LONG);
00624                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00625                                         1);
00626                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00627                                         data->size);
00628                         offset += 12;
00629                 }
00630 
00631                 break;
00632         default:
00633                 break;
00634         }
00635 
00636         /* Sort the directory according to TIFF specification */
00637         qsort (*d + 6 + offset - (ifd->count + n_ptr + n_thumb) * 12,
00638                (ifd->count + n_ptr + n_thumb), 12,
00639                (data->priv->order == EXIF_BYTE_ORDER_INTEL) ? cmp_func_intel : cmp_func_motorola);
00640 
00641         /* Correctly terminate the directory */
00642         if (i == EXIF_IFD_0 && (data->ifd[EXIF_IFD_1]->count ||
00643                                 data->size)) {
00644 
00645                 /*
00646                  * We are saving IFD 0. Tell where IFD 1 starts and save
00647                  * IFD 1.
00648                  */
00649                 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
00650                 exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
00651                                              *ds - 6);
00652         } else
00653                 exif_set_long (*d + 6 + offset, data->priv->order, 0);
00654 }
00655 
00656 typedef enum {
00657         EXIF_DATA_TYPE_MAKER_NOTE_NONE          = 0,
00658         EXIF_DATA_TYPE_MAKER_NOTE_CANON         = 1,
00659         EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS       = 2,
00660         EXIF_DATA_TYPE_MAKER_NOTE_PENTAX        = 3
00661 } ExifDataTypeMakerNote;
00662 
00663 static ExifDataTypeMakerNote
00664 exif_data_get_type_maker_note (ExifData *d)
00665 {
00666         ExifEntry *e, *em;
00667         char value[1024];
00668 
00669         if (!d) 
00670                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00671         
00672         e = exif_data_get_entry (d, EXIF_TAG_MAKER_NOTE);
00673         if (!e) 
00674                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00675 
00676         /* Olympus & Nikon */
00677         if ((e->size >= 5) && (!memcmp (e->data, "OLYMP", 5) ||
00678                                !memcmp (e->data, "Nikon", 5)))
00679                 return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
00680 
00681         em = exif_data_get_entry (d, EXIF_TAG_MAKE);
00682         if (!em) 
00683                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00684 
00685         /* Canon */
00686         if (!strcmp (exif_entry_get_value (em, value, sizeof (value)), "Canon"))
00687                 return EXIF_DATA_TYPE_MAKER_NOTE_CANON;
00688 
00689         /* Pentax & some variant of Nikon */
00690         if ((e->size >= 2) && (e->data[0] == 0x00) && (e->data[1] == 0x1b)) {
00691                 if (!strncasecmp (
00692                             exif_entry_get_value (em, value, sizeof(value)),
00693                             "Nikon", 5))
00694                         return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
00695                 else
00696                         return EXIF_DATA_TYPE_MAKER_NOTE_PENTAX;
00697         }
00698 
00699         return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00700 }
00701 
00702 #define LOG_TOO_SMALL \
00703 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData", \
00704                 _("Size of data too small to allow for EXIF data."));
00705 
00706 void
00707 exif_data_load_data (ExifData *data, const unsigned char *d_orig,
00708                      unsigned int ds_orig)
00709 {
00710         unsigned int l;
00711         ExifLong offset;
00712         ExifShort n;
00713         const unsigned char *d = d_orig;
00714         unsigned int ds = ds_orig, len;
00715 
00716         if (!data || !data->priv || !d || !ds) 
00717                 return;
00718 
00719         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00720                   "Parsing %i byte(s) EXIF data...\n", ds);
00721 
00722         /*
00723          * It can be that the data starts with the EXIF header. If it does
00724          * not, search the EXIF marker.
00725          */
00726         if (ds < 6) {
00727                 LOG_TOO_SMALL;
00728                 return;
00729         }
00730         if (!memcmp (d, ExifHeader, 6)) {
00731                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00732                           "Found EXIF header.");
00733         } else {
00734                 while (1) {
00735                         while ((d[0] == 0xff) && ds) {
00736                                 d++;
00737                                 ds--;
00738                         }
00739 
00740                         /* JPEG_MARKER_SOI */
00741                         if (d[0] == JPEG_MARKER_SOI) {
00742                                 d++;
00743                                 ds--;
00744                                 continue;
00745                         }
00746 
00747                         /* JPEG_MARKER_APP0 */
00748                         if (d[0] == JPEG_MARKER_APP0) {
00749                                 d++;
00750                                 ds--;
00751                                 l = (d[0] << 8) | d[1];
00752                                 if (l > ds)
00753                                         return;
00754                                 d += l;
00755                                 ds -= l;
00756                                 continue;
00757                         }
00758 
00759                         /* JPEG_MARKER_APP1 */
00760                         if (d[0] == JPEG_MARKER_APP1)
00761                                 break;
00762 
00763                         /* Unknown marker or data. Give up. */
00764                         exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00765                                   "ExifData", _("EXIF marker not found."));
00766                         return;
00767                 }
00768                 d++;
00769                 ds--;
00770                 if (ds < 2) {
00771                         LOG_TOO_SMALL;
00772                         return;
00773                 }
00774                 len = (d[0] << 8) | d[1];
00775                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00776                           "We have to deal with %i byte(s) of EXIF data.",
00777                           len);
00778                 d += 2;
00779                 ds -= 2;
00780         }
00781 
00782         /*
00783          * Verify the exif header
00784          * (offset 2, length 6).
00785          */
00786         if (ds < 6) {
00787                 LOG_TOO_SMALL;
00788                 return;
00789         }
00790         if (memcmp (d, ExifHeader, 6)) {
00791                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00792                           "ExifData", _("EXIF header not found."));
00793                 return;
00794         }
00795 
00796         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00797                   "Found EXIF header.");
00798 
00799         /* Byte order (offset 6, length 2) */
00800         if (ds < 14)
00801                 return;
00802         if (!memcmp (d + 6, "II", 2))
00803                 data->priv->order = EXIF_BYTE_ORDER_INTEL;
00804         else if (!memcmp (d + 6, "MM", 2))
00805                 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
00806         else {
00807                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00808                           "ExifData", _("Unknown encoding."));
00809                 return;
00810         }
00811 
00812         /* Fixed value */
00813         if (exif_get_short (d + 8, data->priv->order) != 0x002a)
00814                 return;
00815 
00816         /* IFD 0 offset */
00817         offset = exif_get_long (d + 10, data->priv->order);
00818         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", 
00819                   "IFD 0 at %i.", (int) offset);
00820 
00821         /* Parse the actual exif data (usually offset 14 from start) */
00822         exif_data_load_data_content (data, EXIF_IFD_0, d + 6, ds - 6, offset, 0);
00823 
00824         /* IFD 1 offset */
00825         if (offset + 6 + 2 > ds) {
00826                 return;
00827         }
00828         n = exif_get_short (d + 6 + offset, data->priv->order);
00829         if (offset + 6 + 2 + 12 * n + 4 > ds) {
00830                 return;
00831         }
00832         offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
00833         if (offset) {
00834                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00835                           "IFD 1 at %i.", (int) offset);
00836 
00837                 /* Sanity check. */
00838                 if (offset > ds - 6) {
00839                         exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00840                                   "ExifData", "Bogus offset.");
00841                         return;
00842                 }
00843 
00844                 exif_data_load_data_content (data, EXIF_IFD_1, d + 6, ds - 6, offset, 0);
00845         }
00846 
00847         /*
00848          * If we got an EXIF_TAG_MAKER_NOTE, try to interpret it. Some
00849          * cameras use pointers in the maker note tag that point to the
00850          * space between IFDs. Here is the only place where we have access
00851          * to that data.
00852          */
00853         switch (exif_data_get_type_maker_note (data)) {
00854         case EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS:
00855                 data->priv->md = exif_mnote_data_olympus_new (data->priv->mem);
00856                 break;
00857         case EXIF_DATA_TYPE_MAKER_NOTE_PENTAX:
00858                 data->priv->md = exif_mnote_data_pentax_new (data->priv->mem);
00859                 break;
00860         case EXIF_DATA_TYPE_MAKER_NOTE_CANON:
00861                 data->priv->md = exif_mnote_data_canon_new (data->priv->mem);
00862                 break;
00863         default:
00864                 break;
00865         }
00866 
00867         /* 
00868          * If we are able to interpret the maker note, do so.
00869          */
00870         if (data->priv->md) {
00871                 exif_mnote_data_log (data->priv->md, data->priv->log);
00872                 exif_mnote_data_set_byte_order (data->priv->md,
00873                                                 data->priv->order);
00874                 exif_mnote_data_set_offset (data->priv->md,
00875                                             data->priv->offset_mnote);
00876                 exif_mnote_data_load (data->priv->md, d, ds);
00877         }
00878 
00879         if (data->priv->options & EXIF_DATA_OPTION_FOLLOW_SPECIFICATION)
00880                 exif_data_fix (data);
00881 }
00882 
00883 void
00884 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
00885 {
00886         if (!data || !d || !ds)
00887                 return;
00888 
00889         /* Header */
00890         *ds = 14;
00891         *d = exif_data_alloc (data, *ds);
00892         if (!*d) 
00893                 return;
00894         memcpy (*d, ExifHeader, 6);
00895 
00896         /* Order (offset 6) */
00897         if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
00898                 memcpy (*d + 6, "II", 2);
00899         } else {
00900                 memcpy (*d + 6, "MM", 2);
00901         }
00902 
00903         /* Fixed value (2 bytes, offset 8) */
00904         exif_set_short (*d + 8, data->priv->order, 0x002a);
00905 
00906         /*
00907          * IFD 0 offset (4 bytes, offset 10).
00908          * We will start 8 bytes after the
00909          * EXIF header (2 bytes for order, another 2 for the test, and
00910          * 4 bytes for the IFD 0 offset make 8 bytes together).
00911          */
00912         exif_set_long (*d + 10, data->priv->order, 8);
00913 
00914         /* Now save IFD 0. IFD 1 will be saved automatically. */
00915         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00916                   "Saving IFDs...");
00917         exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds,
00918                                      *ds - 6);
00919         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00920                   "Saved %i byte(s) EXIF data.", *ds);
00921 }
00922 
00923 ExifData *
00924 exif_data_new_from_file (const char *path)
00925 {
00926         ExifData *edata;
00927         ExifLoader *loader;
00928 
00929         loader = exif_loader_new ();
00930         exif_loader_write_file (loader, path);
00931         edata = exif_loader_get_data (loader);
00932         exif_loader_unref (loader);
00933 
00934         return (edata);
00935 }
00936 
00937 void
00938 exif_data_ref (ExifData *data)
00939 {
00940         if (!data)
00941                 return;
00942 
00943         data->priv->ref_count++;
00944 }
00945 
00946 void
00947 exif_data_unref (ExifData *data)
00948 {
00949         if (!data) 
00950                 return;
00951 
00952         data->priv->ref_count--;
00953         if (!data->priv->ref_count) 
00954                 exif_data_free (data);
00955 }
00956 
00957 void
00958 exif_data_free (ExifData *data)
00959 {
00960         unsigned int i;
00961         ExifMem *mem = (data && data->priv) ? data->priv->mem : NULL;
00962 
00963         if (!data) 
00964                 return;
00965 
00966         for (i = 0; i < EXIF_IFD_COUNT; i++) {
00967                 if (data->ifd[i]) {
00968                         exif_content_unref (data->ifd[i]);
00969                         data->ifd[i] = NULL;
00970                 }
00971         }
00972 
00973         if (data->data) {
00974                 exif_mem_free (mem, data->data);
00975                 data->data = NULL;
00976         }
00977 
00978         if (data->priv) {
00979                 if (data->priv->log) {
00980                         exif_log_unref (data->priv->log);
00981                         data->priv->log = NULL;
00982                 }
00983                 if (data->priv->md) {
00984                         exif_mnote_data_unref (data->priv->md);
00985                         data->priv->md = NULL;
00986                 }
00987                 exif_mem_free (mem, data->priv);
00988                 exif_mem_free (mem, data);
00989         }
00990 
00991         exif_mem_unref (mem);
00992 }
00993 
00994 void
00995 exif_data_dump (ExifData *data)
00996 {
00997         unsigned int i;
00998 
00999         if (!data)
01000                 return;
01001 
01002         for (i = 0; i < EXIF_IFD_COUNT; i++) {
01003                 if (data->ifd[i] && data->ifd[i]->count) {
01004                         printf ("Dumping IFD '%s'...\n",
01005                                 exif_ifd_get_name (i));
01006                         exif_content_dump (data->ifd[i], 0);
01007                 }
01008         }
01009 
01010         if (data->data) {
01011                 printf ("%i byte(s) thumbnail data available.", data->size);
01012                 if (data->size >= 4) {
01013                         printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
01014                                 data->data[0], data->data[1],
01015                                 data->data[data->size - 2],
01016                                 data->data[data->size - 1]);
01017                 }
01018         }
01019 }
01020 
01021 ExifByteOrder
01022 exif_data_get_byte_order (ExifData *data)
01023 {
01024         if (!data)
01025                 return (0);
01026 
01027         return (data->priv->order);
01028 }
01029 
01030 void
01031 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
01032                            void *user_data)
01033 {
01034         unsigned int i;
01035 
01036         if (!data || !func)
01037                 return;
01038 
01039         for (i = 0; i < EXIF_IFD_COUNT; i++)
01040                 func (data->ifd[i], user_data);
01041 }
01042 
01043 typedef struct _ByteOrderChangeData ByteOrderChangeData;
01044 struct _ByteOrderChangeData {
01045         ExifByteOrder old, new;
01046 };
01047 
01048 static void
01049 entry_set_byte_order (ExifEntry *e, void *data)
01050 {
01051         ByteOrderChangeData *d = data;
01052 
01053         if (!e)
01054                 return;
01055 
01056         exif_array_set_byte_order (e->format, e->data, e->components, d->old, d->new);
01057 }
01058 
01059 static void
01060 content_set_byte_order (ExifContent *content, void *data)
01061 {
01062         exif_content_foreach_entry (content, entry_set_byte_order, data);
01063 }
01064 
01065 void
01066 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
01067 {
01068         ByteOrderChangeData d;
01069 
01070         if (!data || (order == data->priv->order))
01071                 return;
01072 
01073         d.old = data->priv->order;
01074         d.new = order;
01075         exif_data_foreach_content (data, content_set_byte_order, &d);
01076         data->priv->order = order;
01077         if (data->priv->md)
01078                 exif_mnote_data_set_byte_order (data->priv->md, order);
01079 }
01080 
01081 void
01082 exif_data_log (ExifData *data, ExifLog *log)
01083 {
01084         unsigned int i;
01085 
01086         if (!data || !data->priv) 
01087                 return;
01088         exif_log_unref (data->priv->log);
01089         data->priv->log = log;
01090         exif_log_ref (log);
01091 
01092         for (i = 0; i < EXIF_IFD_COUNT; i++)
01093                 exif_content_log (data->ifd[i], log);
01094 }
01095 
01096 /* Used internally within libexif */
01097 ExifLog *exif_data_get_log (ExifData *);
01098 ExifLog *
01099 exif_data_get_log (ExifData *data)
01100 {
01101         if (!data || !data->priv) 
01102                 return NULL;
01103         return data->priv->log;
01104 }
01105 
01106 static struct {
01107         ExifDataOption option;
01108         const char *name;
01109         const char *description;
01110 } exif_data_option[] = {
01111         {EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS, N_("Ignore unknown tags"),
01112          N_("Ignore unknown tags when loading EXIF data.")},
01113         {EXIF_DATA_OPTION_FOLLOW_SPECIFICATION, N_("Follow specification"),
01114          N_("Add, correct and remove entries to get EXIF data that follows "
01115             "the specification.")},
01116         {0, NULL, NULL}
01117 };
01118 
01119 const char *
01120 exif_data_option_get_name (ExifDataOption o)
01121 {
01122         unsigned int i;
01123 
01124         for (i = 0; exif_data_option[i].name; i++)
01125                 if (exif_data_option[i].option == o) 
01126                         break;
01127         return _(exif_data_option[i].name);
01128 }
01129 
01130 const char *
01131 exif_data_option_get_description (ExifDataOption o)
01132 {
01133         unsigned int i;
01134 
01135         for (i = 0; exif_data_option[i].description; i++)
01136                 if (exif_data_option[i].option == o) 
01137                         break;
01138         return _(exif_data_option[i].description);
01139 }
01140 
01141 void
01142 exif_data_set_option (ExifData *d, ExifDataOption o)
01143 {
01144         if (!d) 
01145                 return;
01146 
01147         d->priv->options |= o;
01148 }
01149 
01150 void
01151 exif_data_unset_option (ExifData *d, ExifDataOption o)
01152 {
01153         if (!d) 
01154                 return;
01155 
01156         d->priv->options &= ~o;
01157 }
01158 
01159 static void
01160 fix_func (ExifContent *c, void *data)
01161 {
01162         switch (exif_content_get_ifd (c)) {
01163         case EXIF_IFD_1:
01164                 if (c->parent->data)
01165                         exif_content_fix (c);
01166                 else {
01167                         exif_log (c->parent->priv->log, EXIF_LOG_CODE_DEBUG, "exif-data",
01168                                   "No thumbnail but entries on thumbnail. These entries have been "
01169                                   "removed.");
01170                         while (c->count)
01171                                 exif_content_remove_entry (c, c->entries[c->count - 1]);
01172                 }
01173                 break;
01174         default:
01175                 exif_content_fix (c);
01176         }
01177 }
01178 
01179 void
01180 exif_data_fix (ExifData *d)
01181 {
01182         exif_data_foreach_content (d, fix_func, NULL);
01183 }
01184 
01185 void
01186 exif_data_set_data_type (ExifData *d, ExifDataType dt)
01187 {
01188         if (!d || !d->priv) 
01189                 return;
01190 
01191         d->priv->data_type = dt;
01192 }
01193 
01194 ExifDataType
01195 exif_data_get_data_type (ExifData *d)
01196 {
01197         return (d && d->priv) ? d->priv->data_type : EXIF_DATA_TYPE_COUNT;
01198 }

Generated on Wed Jan 9 12:52:07 2008 for EXIF library (libexif) Internals by  doxygen 1.4.7