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

Generated on Mon Oct 31 16:21:47 2005 for EXIF library (libexif) Internals by  doxygen 1.4.4