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

Generated on Tue Jun 26 19:43:36 2007 for EXIF library (libexif) Internals by  doxygen 1.4.7