exif-data.c

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

Generated on Tue Dec 19 14:33:53 2006 for EXIF library (libexif) Internals by  doxygen 1.5.1