exif-data.c

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00001 /* exif-data.c
00002  *
00003  * Copyright © 2001 Lutz Müller <lutz@users.sourceforge.net>
00004  *
00005  * This library is free software; you can redistribute it and/or
00006  * modify it under the terms of the GNU Lesser General Public
00007  * License as published by the Free Software Foundation; either
00008  * version 2 of the License, or (at your option) any later version.
00009  *
00010  * This library is distributed in the hope that it will be useful,
00011  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013  * Lesser General Public License for more details.
00014  *
00015  * You should have received a copy of the GNU Lesser General Public
00016  * License along with this library; if not, write to the
00017  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
00018  * Boston, MA 02111-1307, USA.
00019  */
00020 
00021 #include <config.h>
00022 
00023 #include <libexif/exif-mnote-data.h>
00024 #include <libexif/exif-data.h>
00025 #include <libexif/exif-ifd.h>
00026 #include <libexif/exif-mnote-data-priv.h>
00027 #include <libexif/exif-utils.h>
00028 #include <libexif/exif-loader.h>
00029 #include <libexif/exif-log.h>
00030 #include <libexif/i18n.h>
00031 
00032 #include <libexif/olympus/exif-mnote-data-olympus.h>
00033 #include <libexif/canon/exif-mnote-data-canon.h>
00034 #include <libexif/pentax/exif-mnote-data-pentax.h>
00035 
00036 #include <stdlib.h>
00037 #include <stdio.h>
00038 #include <string.h>
00039 
00040 #undef MAX
00041 #define MAX(a, b)  (((a) > (b)) ? (a) : (b))
00042 
00043 #if defined(__WATCOMC__) || defined(_MSC_VER)
00044 #      define strncasecmp strnicmp
00045 #endif
00046 
00047 #undef JPEG_MARKER_SOI
00048 #define JPEG_MARKER_SOI  0xd8
00049 #undef JPEG_MARKER_APP0
00050 #define JPEG_MARKER_APP0 0xe0
00051 #undef JPEG_MARKER_APP1
00052 #define JPEG_MARKER_APP1 0xe1
00053 
00054 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
00055 
00056 struct _ExifDataPrivate
00057 {
00058         ExifByteOrder order;
00059 
00060         ExifMnoteData *md;
00061 
00062         ExifLog *log;
00063         ExifMem *mem;
00064 
00065         unsigned int ref_count;
00066 
00067         /* Temporarily used while loading data */
00068         unsigned int offset_mnote;
00069 
00070         ExifDataOption options;
00071         ExifDataType data_type;
00072 };
00073 
00074 static void *
00075 exif_data_alloc (ExifData *data, unsigned int i)
00076 {
00077         void *d;
00078 
00079         if (!data || !i) 
00080                 return NULL;
00081 
00082         d = exif_mem_alloc (data->priv->mem, i);
00083         if (d) 
00084                 return d;
00085 
00086         EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", i);
00087         return NULL;
00088 }
00089 
00090 ExifMnoteData *
00091 exif_data_get_mnote_data (ExifData *d)
00092 {
00093         return (d && d->priv) ? d->priv->md : NULL;
00094 }
00095 
00096 ExifData *
00097 exif_data_new (void)
00098 {
00099         ExifMem *mem = exif_mem_new_default ();
00100         ExifData *d = exif_data_new_mem (mem);
00101 
00102         exif_mem_unref (mem);
00103 
00104         return d;
00105 }
00106 
00107 ExifData *
00108 exif_data_new_mem (ExifMem *mem)
00109 {
00110         ExifData *data;
00111         unsigned int i;
00112 
00113         if (!mem) 
00114                 return NULL;
00115 
00116         data = exif_mem_alloc (mem, sizeof (ExifData));
00117         if (!data) 
00118                 return (NULL);
00119         data->priv = exif_mem_alloc (mem, sizeof (ExifDataPrivate));
00120         if (!data->priv) { 
00121                 exif_mem_free (mem, data); 
00122                 return (NULL); 
00123         }
00124         data->priv->ref_count = 1;
00125 
00126         data->priv->mem = mem;
00127         exif_mem_ref (mem);
00128 
00129         for (i = 0; i < EXIF_IFD_COUNT; i++) {
00130                 data->ifd[i] = exif_content_new_mem (data->priv->mem);
00131                 if (!data->ifd[i]) {
00132                         exif_data_free (data);
00133                         return (NULL);
00134                 }
00135                 data->ifd[i]->parent = data;
00136         }
00137 
00138         /* Default options */
00139         exif_data_set_option (data, EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS);
00140         exif_data_set_option (data, EXIF_DATA_OPTION_FOLLOW_SPECIFICATION);
00141 
00142         /* Default data type: none */
00143         exif_data_set_data_type (data, EXIF_DATA_TYPE_COUNT);
00144 
00145         return (data);
00146 }
00147 
00148 ExifData *
00149 exif_data_new_from_data (const unsigned char *data, unsigned int size)
00150 {
00151         ExifData *edata;
00152 
00153         edata = exif_data_new ();
00154         exif_data_load_data (edata, data, size);
00155         return (edata);
00156 }
00157 
00158 static 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        /* {0,1,2,4,8} x { 0x00000000 .. 0xffffffff }                           
00174         *   -> { 0x000000000 .. 0x7fffffff8 } */                               
00175        s = exif_format_get_size(entry->format) * entry->components;            
00176        if (s < entry->components) {                                            
00177                return 0;                                                       
00178        }                                                                       
00179        if (0 == s)                                                             
00180                return 0;           
00181 
00182         /*
00183          * Size? If bigger than 4 bytes, the actual data is not
00184          * in the entry but somewhere else (offset).
00185          */
00186         if (s > 4)
00187                 doff = exif_get_long (d + offset + 8, data->priv->order);
00188         else
00189                 doff = offset + 8;
00190 
00191         /* Sanity check */
00192         if ((doff + s < doff) || (doff + s < s))
00193                 return;
00194         if (size < doff + s)
00195                 return;
00196 
00197         entry->data = exif_data_alloc (data, s);
00198         if (entry->data) {
00199                 entry->size = s;
00200                 memcpy (entry->data, d + doff, s);
00201         }
00202 
00203         /* If this is the MakerNote, remember the offset */
00204         if (entry->tag == EXIF_TAG_MAKER_NOTE) {
00205                 if (!entry->data) {
00206                         exif_log (data->priv->log,
00207                                                EXIF_LOG_CODE_DEBUG, "ExifData",
00208                                                "MakerNote found with NULL data");       
00209                 }
00210                 else if (entry->size > 6) 
00211                         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,
00212                                                "MakerNote found (%02x %02x %02x %02x "
00213                                                "%02x %02x %02x...).",
00214                                                entry->data[0], entry->data[1], entry->data[2],
00215                                                entry->data[3], entry->data[4], entry->data[5],
00216                                                entry->data[6]);
00217                 data->priv->offset_mnote = doff;
00218         }
00219 }
00220 
00221 static void
00222 exif_data_save_data_entry (ExifData *data, ExifEntry *e,
00223                            unsigned char **d, unsigned int *ds,
00224                            unsigned int offset)
00225 {
00226         unsigned int doff, s;
00227 
00228         if (!data || !data->priv) 
00229                 return;
00230 
00231         /*
00232          * Each entry is 12 bytes long. The memory for the entry has
00233          * already been allocated.
00234          */
00235         exif_set_short (*d + 6 + offset + 0,
00236                         data->priv->order, (ExifShort) e->tag);
00237         exif_set_short (*d + 6 + offset + 2,
00238                         data->priv->order, (ExifShort) e->format);
00239 
00240 #ifndef EXIF_DONT_CHANGE_MAKER_NOTE
00241         /* If this is the maker note tag, update it. */
00242         if ((e->tag == EXIF_TAG_MAKER_NOTE) && data->priv->md) {
00243                 exif_mem_free (data->priv->mem, e->data);
00244                 e->data = NULL;
00245                 e->size = 0;
00246                 exif_mnote_data_set_offset (data->priv->md, *ds - 6);
00247                 exif_mnote_data_save (data->priv->md, &e->data, &e->size);
00248                 e->components = e->size;
00249         }
00250 #endif
00251 
00252         exif_set_long  (*d + 6 + offset + 4,
00253                         data->priv->order, e->components);
00254 
00255         /*
00256          * Size? If bigger than 4 bytes, the actual data is not in
00257          * the entry but somewhere else.
00258          */
00259         s = exif_format_get_size (e->format) * e->components;
00260         if (s > 4) {
00261                 doff = *ds - 6;
00262                 *ds += s;
00263 
00264                 /*
00265                  * According to the TIFF specification,
00266                  * the offset must be an even number. If we need to introduce
00267                  * a padding byte, we set it to 0.
00268                  */
00269                 if (s & 1) 
00270                         (*ds)++;
00271                 *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00272                 if (!*d) {
00273                         EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
00274                         return;
00275                 }
00276                 exif_set_long (*d + 6 + offset + 8, data->priv->order, doff);
00277                 if (s & 1) 
00278                         *(*d + *ds - 1) = '\0';
00279 
00280         } else
00281                 doff = offset + 8;
00282 
00283         /* Write the data. Fill unneeded bytes with 0. */
00284         memcpy (*d + 6 + doff, e->data, s);
00285         if (s < 4) 
00286                 memset (*d + 6 + doff + s, 0, (4 - s));
00287 }
00288 
00289 static void
00290 exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
00291                                unsigned int ds, ExifLong offset, ExifLong size)
00292 {
00293        if ((ds < offset + size) || (offset < 0) || (offset > ds)) {
00294                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00295                          "Bogus thumbnail offset and size.");
00296                 return;
00297         }
00298         if (data->data) 
00299                 exif_mem_free (data->priv->mem, data->data);
00300         data->size = size;
00301         data->data = exif_data_alloc (data, data->size);
00302         if (!data->data) 
00303                 return;
00304         memcpy (data->data, d + offset, data->size);
00305 }
00306 
00307 #undef CHECK_REC
00308 #define CHECK_REC(i)                                    \
00309 if ((i) == ifd) {                               \
00310         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
00311                 "ExifData", "Recursive entry in IFD "   \
00312                 "'%s' detected. Skipping...",           \
00313                 exif_ifd_get_name (i));                 \
00314         break;                                          \
00315 }                                                       \
00316 if (data->ifd[(i)]->count) {                            \
00317         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
00318                 "ExifData", "Attemt to load IFD "       \
00319                 "'%s' multiple times detected. "        \
00320                 "Skipping...",                          \
00321                 exif_ifd_get_name (i));                 \
00322         break;                                          \
00323 }
00324 
00325 static void
00326 exif_data_load_data_content (ExifData *data, ExifIfd ifd,
00327                              const unsigned char *d,
00328                              unsigned int ds, unsigned int offset, unsigned int recursion_depth)
00329 {
00330         ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
00331         ExifShort n;
00332         ExifEntry *entry;
00333         unsigned int i;
00334         ExifTag tag;
00335 
00336         if (!data || !data->priv) 
00337                 return;
00338         if ((ifd < 0) || (ifd >= EXIF_IFD_COUNT)) 
00339                 return;
00340 
00341         if (recursion_depth > 150) {
00342                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData",
00343                           "Deep recursion detected!");
00344                 return;
00345         }
00346 
00347         /* Read the number of entries */
00348         if (offset >= ds - 1) 
00349                 return;
00350         n = exif_get_short (d + offset, data->priv->order);
00351         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00352                   "Loading %i entries...", n);
00353         offset += 2;
00354 
00355         /* Check if we have enough data. */
00356         if (offset + 12 * n > ds) 
00357                 n = (ds - offset) / 12;
00358 
00359         for (i = 0; i < n; i++) {
00360 
00361                 tag = exif_get_short (d + offset + 12 * i, data->priv->order);
00362                 switch (tag) {
00363                 case EXIF_TAG_EXIF_IFD_POINTER:
00364                 case EXIF_TAG_GPS_INFO_IFD_POINTER:
00365                 case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
00366                 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
00367                 case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
00368                         o = exif_get_long (d + offset + 12 * i + 8,
00369                                            data->priv->order);
00370                         switch (tag) {
00371                         case EXIF_TAG_EXIF_IFD_POINTER:
00372                                 CHECK_REC (EXIF_IFD_EXIF);
00373                                 exif_data_load_data_content (data, EXIF_IFD_EXIF, d, ds, o, recursion_depth + 1);
00374                                 break;
00375                         case EXIF_TAG_GPS_INFO_IFD_POINTER:
00376                                 CHECK_REC (EXIF_IFD_GPS);
00377                                 exif_data_load_data_content (data, EXIF_IFD_GPS, d, ds, o, recursion_depth + 1);
00378                                 break;
00379                         case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
00380                                 CHECK_REC (EXIF_IFD_INTEROPERABILITY);
00381                                 exif_data_load_data_content (data, EXIF_IFD_INTEROPERABILITY, d, ds, o, recursion_depth + 1);
00382                                 break;
00383                         case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
00384                                 thumbnail_offset = o;
00385                                 if (thumbnail_offset && thumbnail_length)
00386                                         exif_data_load_data_thumbnail (data, d,
00387                                                                        ds, thumbnail_offset,
00388                                                                        thumbnail_length);
00389                                 break;
00390                         case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
00391                                 thumbnail_length = o;
00392                                 if (thumbnail_offset && thumbnail_length)
00393                                         exif_data_load_data_thumbnail (data, d,
00394                                                                        ds, thumbnail_offset,
00395                                                                        thumbnail_length);
00396                                 break;
00397                         default:
00398                                 return;
00399                         }
00400                         break;
00401                 default:
00402 
00403                         /*
00404                          * If we don't know the tag, don't fail. It could be that new 
00405                          * versions of the standard have defined additional tags. Note that
00406                          * 0 is a valid tag in the GPS IFD.
00407                          */
00408                         if (!exif_tag_get_name_in_ifd (tag, ifd)) {
00409 
00410                                 /*
00411                                  * Special case: Tag and format 0. That's against specification.
00412                                  * At least up to 2.2. But Photoshop writes it anyways.
00413                                  */
00414                                 if (!memcmp (d + offset + 12 * i, "\0\0\0\0", 4)) {
00415                                         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00416                                                   "Skipping empty entry at position %i in '%s'.", i, 
00417                                                   exif_ifd_get_name (ifd));
00418                                         break;
00419                                 }
00420                                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00421                                           "Unknown tag 0x%04x (entry %i in '%s'). Please report this tag "
00422                                           "to <libexif-devel@lists.sourceforge.net>.", tag, i,
00423                                           exif_ifd_get_name (ifd));
00424                                 if (data->priv->options & EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS)
00425                                         break;
00426                         }
00427                         entry = exif_entry_new_mem (data->priv->mem);
00428                         exif_data_load_data_entry (data, entry, d, ds,
00429                                                    offset + 12 * i);
00430                         exif_content_add_entry (data->ifd[ifd], entry);
00431                         exif_entry_unref (entry);
00432                         break;
00433                 }
00434         }
00435 }
00436 
00437 static int
00438 cmp_func (const unsigned char *p1, const unsigned char *p2, ExifByteOrder o)
00439 {
00440         ExifShort tag1 = exif_get_short (p1, o);
00441         ExifShort tag2 = exif_get_short (p2, o);
00442 
00443         return (tag1 < tag2) ? -1 : (tag1 > tag2) ? 1 : 0;
00444 }
00445 
00446 static int
00447 cmp_func_intel (const void *elem1, const void *elem2)
00448 {
00449         return cmp_func ((const unsigned char *) elem1,
00450                          (const unsigned char *) elem2, EXIF_BYTE_ORDER_INTEL);
00451 }
00452 
00453 static int
00454 cmp_func_motorola (const void *elem1, const void *elem2)
00455 {
00456         return cmp_func ((const unsigned char *) elem1,
00457                          (const unsigned char *) elem2, EXIF_BYTE_ORDER_MOTOROLA);
00458 }
00459 
00460 static void
00461 exif_data_save_data_content (ExifData *data, ExifContent *ifd,
00462                              unsigned char **d, unsigned int *ds,
00463                              unsigned int offset)
00464 {
00465         unsigned int j, n_ptr = 0, n_thumb = 0;
00466         ExifIfd i;
00467 
00468         if (!data || !data->priv || !ifd || !d || !ds) 
00469                 return;
00470 
00471         for (i = 0; i < EXIF_IFD_COUNT; i++)
00472                 if (ifd == data->ifd[i])
00473                         break;
00474         if (i == EXIF_IFD_COUNT)
00475                 return;
00476 
00477         /*
00478          * Check if we need some extra entries for pointers or the thumbnail.
00479          */
00480         switch (i) {
00481         case EXIF_IFD_0:
00482 
00483                 /*
00484                  * The pointer to IFD_EXIF is in IFD_0. The pointer to
00485                  * IFD_INTEROPERABILITY is in IFD_EXIF.
00486                  */
00487                 if (data->ifd[EXIF_IFD_EXIF]->count ||
00488                     data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
00489                         n_ptr++;
00490 
00491                 /* The pointer to IFD_GPS is in IFD_0. */
00492                 if (data->ifd[EXIF_IFD_GPS]->count)
00493                         n_ptr++;
00494 
00495                 break;
00496         case EXIF_IFD_1:
00497                 if (data->size)
00498                         n_thumb = 2;
00499                 break;
00500         case EXIF_IFD_EXIF:
00501                 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
00502                         n_ptr++;
00503         default:
00504                 break;
00505         }
00506 
00507         /*
00508          * Allocate enough memory for all entries
00509          * and the number of entries.
00510          */
00511         *ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
00512         *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00513         if (!*d) {
00514                 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
00515                 return;
00516         }
00517 
00518         /* Save the number of entries */
00519         exif_set_short (*d + 6 + offset, data->priv->order,
00520                         (ExifShort) (ifd->count + n_ptr + n_thumb));
00521         offset += 2;
00522 
00523         /* Save each entry */
00524         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00525                   "Saving %i entries (IFD '%s', offset: %i)...",
00526                   ifd->count, exif_ifd_get_name (i), offset);
00527         for (j = 0; j < ifd->count; j++)
00528                 exif_data_save_data_entry (data, ifd->entries[j], d, ds, offset + 12 * j);
00529 
00530         offset += 12 * ifd->count;
00531 
00532         /* Now save special entries. */
00533         switch (i) {
00534         case EXIF_IFD_0:
00535 
00536                 /*
00537                  * The pointer to IFD_EXIF is in IFD_0.
00538                  * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
00539                  * therefore, if IFD_INTEROPERABILITY is not empty, we need
00540                  * IFD_EXIF even if latter is empty.
00541                  */
00542                 if (data->ifd[EXIF_IFD_EXIF]->count ||
00543                     data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
00544                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00545                                         EXIF_TAG_EXIF_IFD_POINTER);
00546                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00547                                         EXIF_FORMAT_LONG);
00548                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00549                                         1);
00550                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00551                                         *ds - 6);
00552                         exif_data_save_data_content (data,
00553                                                      data->ifd[EXIF_IFD_EXIF], d, ds, *ds - 6);
00554                         offset += 12;
00555                 }
00556 
00557                 /* The pointer to IFD_GPS is in IFD_0, too. */
00558                 if (data->ifd[EXIF_IFD_GPS]->count) {
00559                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00560                                         EXIF_TAG_GPS_INFO_IFD_POINTER);
00561                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00562                                         EXIF_FORMAT_LONG);
00563                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00564                                         1);
00565                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00566                                         *ds - 6);
00567                         exif_data_save_data_content (data,
00568                                                      data->ifd[EXIF_IFD_GPS], d, ds, *ds - 6);
00569                         offset += 12;
00570                 }
00571 
00572                 break;
00573         case EXIF_IFD_EXIF:
00574 
00575                 /*
00576                  * The pointer to IFD_INTEROPERABILITY is in IFD_EXIF.
00577                  * See note above.
00578                  */
00579                 if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
00580                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00581                                         EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
00582                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00583                                         EXIF_FORMAT_LONG);
00584                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00585                                         1);
00586                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00587                                         *ds - 6);
00588                         exif_data_save_data_content (data,
00589                                                      data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds,
00590                                                      *ds - 6);
00591                         offset += 12;
00592                 }
00593 
00594                 break;
00595         case EXIF_IFD_1:
00596 
00597                 /*
00598                  * Information about the thumbnail (if any) is saved in
00599                  * IFD_1.
00600                  */
00601                 if (data->size) {
00602 
00603                         /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
00604                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00605                                         EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
00606                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00607                                         EXIF_FORMAT_LONG);
00608                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00609                                         1);
00610                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00611                                         *ds - 6);
00612                         *ds += data->size;
00613                         *d = exif_mem_realloc (data->priv->mem, *d, *ds);
00614                         if (!*d) {
00615                                 EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData",
00616                                                     *ds);
00617                                 return;
00618                         }
00619                         memcpy (*d + *ds - data->size, data->data, data->size);
00620                         offset += 12;
00621 
00622                         /* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
00623                         exif_set_short (*d + 6 + offset + 0, data->priv->order,
00624                                         EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
00625                         exif_set_short (*d + 6 + offset + 2, data->priv->order,
00626                                         EXIF_FORMAT_LONG);
00627                         exif_set_long  (*d + 6 + offset + 4, data->priv->order,
00628                                         1);
00629                         exif_set_long  (*d + 6 + offset + 8, data->priv->order,
00630                                         data->size);
00631                         offset += 12;
00632                 }
00633 
00634                 break;
00635         default:
00636                 break;
00637         }
00638 
00639         /* Sort the directory according to TIFF specification */
00640         qsort (*d + 6 + offset - (ifd->count + n_ptr + n_thumb) * 12,
00641                (ifd->count + n_ptr + n_thumb), 12,
00642                (data->priv->order == EXIF_BYTE_ORDER_INTEL) ? cmp_func_intel : cmp_func_motorola);
00643 
00644         /* Correctly terminate the directory */
00645         if (i == EXIF_IFD_0 && (data->ifd[EXIF_IFD_1]->count ||
00646                                 data->size)) {
00647 
00648                 /*
00649                  * We are saving IFD 0. Tell where IFD 1 starts and save
00650                  * IFD 1.
00651                  */
00652                 exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
00653                 exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
00654                                              *ds - 6);
00655         } else
00656                 exif_set_long (*d + 6 + offset, data->priv->order, 0);
00657 }
00658 
00659 typedef enum {
00660         EXIF_DATA_TYPE_MAKER_NOTE_NONE          = 0,
00661         EXIF_DATA_TYPE_MAKER_NOTE_CANON         = 1,
00662         EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS       = 2,
00663         EXIF_DATA_TYPE_MAKER_NOTE_PENTAX        = 3
00664 } ExifDataTypeMakerNote;
00665 
00666 static ExifDataTypeMakerNote
00667 exif_data_get_type_maker_note (ExifData *d)
00668 {
00669         ExifEntry *e, *em;
00670         char value[1024];
00671 
00672         if (!d) 
00673                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00674         
00675         e = exif_data_get_entry (d, EXIF_TAG_MAKER_NOTE);
00676         if (!e) 
00677                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00678 
00679         /* Olympus & Nikon */
00680         if ((e->size >= 5) && (!memcmp (e->data, "OLYMP", 5) ||
00681                                !memcmp (e->data, "Nikon", 5)))
00682                 return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
00683 
00684         em = exif_data_get_entry (d, EXIF_TAG_MAKE);
00685         if (!em) 
00686                 return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00687 
00688         /* Canon */
00689         if (!strcmp (exif_entry_get_value (em, value, sizeof (value)), "Canon"))
00690                 return EXIF_DATA_TYPE_MAKER_NOTE_CANON;
00691 
00692         /* Pentax & some variant of Nikon */
00693         if ((e->size >= 2) && (e->data[0] == 0x00) && (e->data[1] == 0x1b)) {
00694                 if (!strncasecmp (
00695                             exif_entry_get_value (em, value, sizeof(value)),
00696                             "Nikon", 5))
00697                         return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
00698                 else
00699                         return EXIF_DATA_TYPE_MAKER_NOTE_PENTAX;
00700         }
00701 
00702         return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
00703 }
00704 
00705 #define LOG_TOO_SMALL \
00706 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData", \
00707                 _("Size of data too small to allow for EXIF data."));
00708 
00709 void
00710 exif_data_load_data (ExifData *data, const unsigned char *d_orig,
00711                      unsigned int ds_orig)
00712 {
00713         unsigned int l;
00714         ExifLong offset;
00715         ExifShort n;
00716         const unsigned char *d = d_orig;
00717         unsigned int ds = ds_orig, len;
00718 
00719         if (!data || !data->priv || !d || !ds) 
00720                 return;
00721 
00722         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00723                   "Parsing %i byte(s) EXIF data...\n", ds);
00724 
00725         /*
00726          * It can be that the data starts with the EXIF header. If it does
00727          * not, search the EXIF marker.
00728          */
00729         if (ds < 6) {
00730                 LOG_TOO_SMALL;
00731                 return;
00732         }
00733         if (!memcmp (d, ExifHeader, 6)) {
00734                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00735                           "Found EXIF header.");
00736         } else {
00737                 while (1) {
00738                         while ((d[0] == 0xff) && ds) {
00739                                 d++;
00740                                 ds--;
00741                         }
00742 
00743                         /* JPEG_MARKER_SOI */
00744                         if (d[0] == JPEG_MARKER_SOI) {
00745                                 d++;
00746                                 ds--;
00747                                 continue;
00748                         }
00749 
00750                         /* JPEG_MARKER_APP0 */
00751                         if (d[0] == JPEG_MARKER_APP0) {
00752                                 d++;
00753                                 ds--;
00754                                 l = (d[0] << 8) | d[1];
00755                                 if (l > ds)
00756                                         return;
00757                                 d += l;
00758                                 ds -= l;
00759                                 continue;
00760                         }
00761 
00762                         /* JPEG_MARKER_APP1 */
00763                         if (d[0] == JPEG_MARKER_APP1)
00764                                 break;
00765 
00766                         /* Unknown marker or data. Give up. */
00767                         exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00768                                   "ExifData", _("EXIF marker not found."));
00769                         return;
00770                 }
00771                 d++;
00772                 ds--;
00773                 if (ds < 2) {
00774                         LOG_TOO_SMALL;
00775                         return;
00776                 }
00777                 len = (d[0] << 8) | d[1];
00778                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00779                           "We have to deal with %i byte(s) of EXIF data.",
00780                           len);
00781                 d += 2;
00782                 ds -= 2;
00783         }
00784 
00785         /*
00786          * Verify the exif header
00787          * (offset 2, length 6).
00788          */
00789         if (ds < 6) {
00790                 LOG_TOO_SMALL;
00791                 return;
00792         }
00793         if (memcmp (d, ExifHeader, 6)) {
00794                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00795                           "ExifData", _("EXIF header not found."));
00796                 return;
00797         }
00798 
00799         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00800                   "Found EXIF header.");
00801 
00802         /* Byte order (offset 6, length 2) */
00803         if (ds < 14)
00804                 return;
00805         if (!memcmp (d + 6, "II", 2))
00806                 data->priv->order = EXIF_BYTE_ORDER_INTEL;
00807         else if (!memcmp (d + 6, "MM", 2))
00808                 data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
00809         else {
00810                 exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00811                           "ExifData", _("Unknown encoding."));
00812                 return;
00813         }
00814 
00815         /* Fixed value */
00816         if (exif_get_short (d + 8, data->priv->order) != 0x002a)
00817                 return;
00818 
00819         /* IFD 0 offset */
00820         offset = exif_get_long (d + 10, data->priv->order);
00821         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", 
00822                   "IFD 0 at %i.", (int) offset);
00823 
00824         /* Parse the actual exif data (usually offset 14 from start) */
00825         exif_data_load_data_content (data, EXIF_IFD_0, d + 6, ds - 6, offset, 0);
00826 
00827         /* IFD 1 offset */
00828         if (offset + 6 + 2 > ds) {
00829                 return;
00830         }
00831         n = exif_get_short (d + 6 + offset, data->priv->order);
00832         if (offset + 6 + 2 + 12 * n + 4 > ds) {
00833                 return;
00834         }
00835         offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
00836         if (offset) {
00837                 exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00838                           "IFD 1 at %i.", (int) offset);
00839 
00840                 /* Sanity check. */
00841                 if (offset > ds - 6) {
00842                         exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
00843                                   "ExifData", "Bogus offset of IFD1.");
00844                 } else {
00845                         exif_data_load_data_content (data, EXIF_IFD_1, d + 6, ds - 6, offset, 0);
00846                 }
00847         }
00848 
00849         /*
00850          * If we got an EXIF_TAG_MAKER_NOTE, try to interpret it. Some
00851          * cameras use pointers in the maker note tag that point to the
00852          * space between IFDs. Here is the only place where we have access
00853          * to that data.
00854          */
00855         switch (exif_data_get_type_maker_note (data)) {
00856         case EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS:
00857                 data->priv->md = exif_mnote_data_olympus_new (data->priv->mem);
00858                 break;
00859         case EXIF_DATA_TYPE_MAKER_NOTE_PENTAX:
00860                 data->priv->md = exif_mnote_data_pentax_new (data->priv->mem);
00861                 break;
00862         case EXIF_DATA_TYPE_MAKER_NOTE_CANON:
00863                 data->priv->md = exif_mnote_data_canon_new (data->priv->mem);
00864                 break;
00865         default:
00866                 break;
00867         }
00868 
00869         /* 
00870          * If we are able to interpret the maker note, do so.
00871          */
00872         if (data->priv->md) {
00873                 exif_mnote_data_log (data->priv->md, data->priv->log);
00874                 exif_mnote_data_set_byte_order (data->priv->md,
00875                                                 data->priv->order);
00876                 exif_mnote_data_set_offset (data->priv->md,
00877                                             data->priv->offset_mnote);
00878                 exif_mnote_data_load (data->priv->md, d, ds);
00879         }
00880 
00881         if (data->priv->options & EXIF_DATA_OPTION_FOLLOW_SPECIFICATION)
00882                 exif_data_fix (data);
00883 }
00884 
00885 void
00886 exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
00887 {
00888         if (!data || !d || !ds)
00889                 return;
00890 
00891         /* Header */
00892         *ds = 14;
00893         *d = exif_data_alloc (data, *ds);
00894         if (!*d) 
00895                 return;
00896         memcpy (*d, ExifHeader, 6);
00897 
00898         /* Order (offset 6) */
00899         if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
00900                 memcpy (*d + 6, "II", 2);
00901         } else {
00902                 memcpy (*d + 6, "MM", 2);
00903         }
00904 
00905         /* Fixed value (2 bytes, offset 8) */
00906         exif_set_short (*d + 8, data->priv->order, 0x002a);
00907 
00908         /*
00909          * IFD 0 offset (4 bytes, offset 10).
00910          * We will start 8 bytes after the
00911          * EXIF header (2 bytes for order, another 2 for the test, and
00912          * 4 bytes for the IFD 0 offset make 8 bytes together).
00913          */
00914         exif_set_long (*d + 10, data->priv->order, 8);
00915 
00916         /* Now save IFD 0. IFD 1 will be saved automatically. */
00917         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00918                   "Saving IFDs...");
00919         exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds,
00920                                      *ds - 6);
00921         exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
00922                   "Saved %i byte(s) EXIF data.", *ds);
00923 }
00924 
00925 ExifData *
00926 exif_data_new_from_file (const char *path)
00927 {
00928         ExifData *edata;
00929         ExifLoader *loader;
00930 
00931         loader = exif_loader_new ();
00932         exif_loader_write_file (loader, path);
00933         edata = exif_loader_get_data (loader);
00934         exif_loader_unref (loader);
00935 
00936         return (edata);
00937 }
00938 
00939 void
00940 exif_data_ref (ExifData *data)
00941 {
00942         if (!data)
00943                 return;
00944 
00945         data->priv->ref_count++;
00946 }
00947 
00948 void
00949 exif_data_unref (ExifData *data)
00950 {
00951         if (!data) 
00952                 return;
00953 
00954         data->priv->ref_count--;
00955         if (!data->priv->ref_count) 
00956                 exif_data_free (data);
00957 }
00958 
00959 void
00960 exif_data_free (ExifData *data)
00961 {
00962         unsigned int i;
00963         ExifMem *mem = (data && data->priv) ? data->priv->mem : NULL;
00964 
00965         if (!data) 
00966                 return;
00967 
00968         for (i = 0; i < EXIF_IFD_COUNT; i++) {
00969                 if (data->ifd[i]) {
00970                         exif_content_unref (data->ifd[i]);
00971                         data->ifd[i] = NULL;
00972                 }
00973         }
00974 
00975         if (data->data) {
00976                 exif_mem_free (mem, data->data);
00977                 data->data = NULL;
00978         }
00979 
00980         if (data->priv) {
00981                 if (data->priv->log) {
00982                         exif_log_unref (data->priv->log);
00983                         data->priv->log = NULL;
00984                 }
00985                 if (data->priv->md) {
00986                         exif_mnote_data_unref (data->priv->md);
00987                         data->priv->md = NULL;
00988                 }
00989                 exif_mem_free (mem, data->priv);
00990                 exif_mem_free (mem, data);
00991         }
00992 
00993         exif_mem_unref (mem);
00994 }
00995 
00996 void
00997 exif_data_dump (ExifData *data)
00998 {
00999         unsigned int i;
01000 
01001         if (!data)
01002                 return;
01003 
01004         for (i = 0; i < EXIF_IFD_COUNT; i++) {
01005                 if (data->ifd[i] && data->ifd[i]->count) {
01006                         printf ("Dumping IFD '%s'...\n",
01007                                 exif_ifd_get_name (i));
01008                         exif_content_dump (data->ifd[i], 0);
01009                 }
01010         }
01011 
01012         if (data->data) {
01013                 printf ("%i byte(s) thumbnail data available.", data->size);
01014                 if (data->size >= 4) {
01015                         printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
01016                                 data->data[0], data->data[1],
01017                                 data->data[data->size - 2],
01018                                 data->data[data->size - 1]);
01019                 }
01020         }
01021 }
01022 
01023 ExifByteOrder
01024 exif_data_get_byte_order (ExifData *data)
01025 {
01026         if (!data)
01027                 return (0);
01028 
01029         return (data->priv->order);
01030 }
01031 
01032 void
01033 exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
01034                            void *user_data)
01035 {
01036         unsigned int i;
01037 
01038         if (!data || !func)
01039                 return;
01040 
01041         for (i = 0; i < EXIF_IFD_COUNT; i++)
01042                 func (data->ifd[i], user_data);
01043 }
01044 
01045 typedef struct _ByteOrderChangeData ByteOrderChangeData;
01046 struct _ByteOrderChangeData {
01047         ExifByteOrder old, new;
01048 };
01049 
01050 static void
01051 entry_set_byte_order (ExifEntry *e, void *data)
01052 {
01053         ByteOrderChangeData *d = data;
01054 
01055         if (!e)
01056                 return;
01057 
01058         exif_array_set_byte_order (e->format, e->data, e->components, d->old, d->new);
01059 }
01060 
01061 static void
01062 content_set_byte_order (ExifContent *content, void *data)
01063 {
01064         exif_content_foreach_entry (content, entry_set_byte_order, data);
01065 }
01066 
01067 void
01068 exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
01069 {
01070         ByteOrderChangeData d;
01071 
01072         if (!data || (order == data->priv->order))
01073                 return;
01074 
01075         d.old = data->priv->order;
01076         d.new = order;
01077         exif_data_foreach_content (data, content_set_byte_order, &d);
01078         data->priv->order = order;
01079         if (data->priv->md)
01080                 exif_mnote_data_set_byte_order (data->priv->md, order);
01081 }
01082 
01083 void
01084 exif_data_log (ExifData *data, ExifLog *log)
01085 {
01086         unsigned int i;
01087 
01088         if (!data || !data->priv) 
01089                 return;
01090         exif_log_unref (data->priv->log);
01091         data->priv->log = log;
01092         exif_log_ref (log);
01093 
01094         for (i = 0; i < EXIF_IFD_COUNT; i++)
01095                 exif_content_log (data->ifd[i], log);
01096 }
01097 
01098 /* Used internally within libexif */
01099 ExifLog *exif_data_get_log (ExifData *);
01100 ExifLog *
01101 exif_data_get_log (ExifData *data)
01102 {
01103         if (!data || !data->priv) 
01104                 return NULL;
01105         return data->priv->log;
01106 }
01107 
01108 static struct {
01109         ExifDataOption option;
01110         const char *name;
01111         const char *description;
01112 } exif_data_option[] = {
01113         {EXIF_DATA_OPTION_IGNORE_UNKNOWN_TAGS, N_("Ignore unknown tags"),
01114          N_("Ignore unknown tags when loading EXIF data.")},
01115         {EXIF_DATA_OPTION_FOLLOW_SPECIFICATION, N_("Follow specification"),
01116          N_("Add, correct and remove entries to get EXIF data that follows "
01117             "the specification.")},
01118         {0, NULL, NULL}
01119 };
01120 
01121 const char *
01122 exif_data_option_get_name (ExifDataOption o)
01123 {
01124         unsigned int i;
01125 
01126         for (i = 0; exif_data_option[i].name; i++)
01127                 if (exif_data_option[i].option == o) 
01128                         break;
01129         return _(exif_data_option[i].name);
01130 }
01131 
01132 const char *
01133 exif_data_option_get_description (ExifDataOption o)
01134 {
01135         unsigned int i;
01136 
01137         for (i = 0; exif_data_option[i].description; i++)
01138                 if (exif_data_option[i].option == o) 
01139                         break;
01140         return _(exif_data_option[i].description);
01141 }
01142 
01143 void
01144 exif_data_set_option (ExifData *d, ExifDataOption o)
01145 {
01146         if (!d) 
01147                 return;
01148 
01149         d->priv->options |= o;
01150 }
01151 
01152 void
01153 exif_data_unset_option (ExifData *d, ExifDataOption o)
01154 {
01155         if (!d) 
01156                 return;
01157 
01158         d->priv->options &= ~o;
01159 }
01160 
01161 static void
01162 fix_func (ExifContent *c, void *data)
01163 {
01164         switch (exif_content_get_ifd (c)) {
01165         case EXIF_IFD_1:
01166                 if (c->parent->data)
01167                         exif_content_fix (c);
01168                 else {
01169                         exif_log (c->parent->priv->log, EXIF_LOG_CODE_DEBUG, "exif-data",
01170                                   "No thumbnail but entries on thumbnail. These entries have been "
01171                                   "removed.");
01172                         while (c->count)
01173                                 exif_content_remove_entry (c, c->entries[c->count - 1]);
01174                 }
01175                 break;
01176         default:
01177                 exif_content_fix (c);
01178         }
01179 }
01180 
01181 void
01182 exif_data_fix (ExifData *d)
01183 {
01184         exif_data_foreach_content (d, fix_func, NULL);
01185 }
01186 
01187 void
01188 exif_data_set_data_type (ExifData *d, ExifDataType dt)
01189 {
01190         if (!d || !d->priv) 
01191                 return;
01192 
01193         d->priv->data_type = dt;
01194 }
01195 
01196 ExifDataType
01197 exif_data_get_data_type (ExifData *d)
01198 {
01199         return (d && d->priv) ? d->priv->data_type : EXIF_DATA_TYPE_COUNT;
01200 }

Generated on Fri Feb 8 18:51:32 2008 for EXIF library (libexif) Internals by  doxygen 1.5.1