1 /*
2 * EXIF metadata parser
3 * Copyright (c) 2013 Thilo Borgmann <thilo.borgmann _at_ mail.de>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * EXIF metadata parser
25 * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>
26 */
27
28 #include "exif.h"
29 #include "tiff_common.h"
30
31 #define EXIF_TAG_NAME_LENGTH 32
32
33 struct exif_tag {
34 char name[EXIF_TAG_NAME_LENGTH];
35 uint16_t id;
36 };
37
38 static const struct exif_tag tag_list[] = { // JEITA CP-3451 EXIF specification:
39 {"GPSVersionID", 0x00}, // <- Table 12 GPS Attribute Information
40 {"GPSLatitudeRef", 0x01},
41 {"GPSLatitude", 0x02},
42 {"GPSLongitudeRef", 0x03},
43 {"GPSLongitude", 0x04},
44 {"GPSAltitudeRef", 0x05},
45 {"GPSAltitude", 0x06},
46 {"GPSTimeStamp", 0x07},
47 {"GPSSatellites", 0x08},
48 {"GPSStatus", 0x09},
49 {"GPSMeasureMode", 0x0A},
50 {"GPSDOP", 0x0B},
51 {"GPSSpeedRef", 0x0C},
52 {"GPSSpeed", 0x0D},
53 {"GPSTrackRef", 0x0E},
54 {"GPSTrack", 0x0F},
55 {"GPSImgDirectionRef", 0x10},
56 {"GPSImgDirection", 0x11},
57 {"GPSMapDatum", 0x12},
58 {"GPSDestLatitudeRef", 0x13},
59 {"GPSDestLatitude", 0x14},
60 {"GPSDestLongitudeRef", 0x15},
61 {"GPSDestLongitude", 0x16},
62 {"GPSDestBearingRef", 0x17},
63 {"GPSDestBearing", 0x18},
64 {"GPSDestDistanceRef", 0x19},
65 {"GPSDestDistance", 0x1A},
66 {"GPSProcessingMethod", 0x1B},
67 {"GPSAreaInformation", 0x1C},
68 {"GPSDateStamp", 0x1D},
69 {"GPSDifferential", 0x1E},
70 {"ImageWidth", 0x100}, // <- Table 3 TIFF Rev. 6.0 Attribute Information Used in Exif
71 {"ImageLength", 0x101},
72 {"BitsPerSample", 0x102},
73 {"Compression", 0x103},
74 {"PhotometricInterpretation", 0x106},
75 {"Orientation", 0x112},
76 {"SamplesPerPixel", 0x115},
77 {"PlanarConfiguration", 0x11C},
78 {"YCbCrSubSampling", 0x212},
79 {"YCbCrPositioning", 0x213},
80 {"XResolution", 0x11A},
81 {"YResolution", 0x11B},
82 {"ResolutionUnit", 0x128},
83 {"StripOffsets", 0x111},
84 {"RowsPerStrip", 0x116},
85 {"StripByteCounts", 0x117},
86 {"JPEGInterchangeFormat", 0x201},
87 {"JPEGInterchangeFormatLength",0x202},
88 {"TransferFunction", 0x12D},
89 {"WhitePoint", 0x13E},
90 {"PrimaryChromaticities", 0x13F},
91 {"YCbCrCoefficients", 0x211},
92 {"ReferenceBlackWhite", 0x214},
93 {"DateTime", 0x132},
94 {"ImageDescription", 0x10E},
95 {"Make", 0x10F},
96 {"Model", 0x110},
97 {"Software", 0x131},
98 {"Artist", 0x13B},
99 {"Copyright", 0x8298},
100 {"ExifVersion", 0x9000}, // <- Table 4 Exif IFD Attribute Information (1)
101 {"FlashpixVersion", 0xA000},
102 {"ColorSpace", 0xA001},
103 {"ComponentsConfiguration", 0x9101},
104 {"CompressedBitsPerPixel", 0x9102},
105 {"PixelXDimension", 0xA002},
106 {"PixelYDimension", 0xA003},
107 {"MakerNote", 0x927C},
108 {"UserComment", 0x9286},
109 {"RelatedSoundFile", 0xA004},
110 {"DateTimeOriginal", 0x9003},
111 {"DateTimeDigitized", 0x9004},
112 {"SubSecTime", 0x9290},
113 {"SubSecTimeOriginal", 0x9291},
114 {"SubSecTimeDigitized", 0x9292},
115 {"ImageUniqueID", 0xA420},
116 {"ExposureTime", 0x829A}, // <- Table 5 Exif IFD Attribute Information (2)
117 {"FNumber", 0x829D},
118 {"ExposureProgram", 0x8822},
119 {"SpectralSensitivity", 0x8824},
120 {"ISOSpeedRatings", 0x8827},
121 {"OECF", 0x8828},
122 {"ShutterSpeedValue", 0x9201},
123 {"ApertureValue", 0x9202},
124 {"BrightnessValue", 0x9203},
125 {"ExposureBiasValue", 0x9204},
126 {"MaxApertureValue", 0x9205},
127 {"SubjectDistance", 0x9206},
128 {"MeteringMode", 0x9207},
129 {"LightSource", 0x9208},
130 {"Flash", 0x9209},
131 {"FocalLength", 0x920A},
132 {"SubjectArea", 0x9214},
133 {"FlashEnergy", 0xA20B},
134 {"SpatialFrequencyResponse", 0xA20C},
135 {"FocalPlaneXResolution", 0xA20E},
136 {"FocalPlaneYResolution", 0xA20F},
137 {"FocalPlaneResolutionUnit", 0xA210},
138 {"SubjectLocation", 0xA214},
139 {"ExposureIndex", 0xA215},
140 {"SensingMethod", 0xA217},
141 {"FileSource", 0xA300},
142 {"SceneType", 0xA301},
143 {"CFAPattern", 0xA302},
144 {"CustomRendered", 0xA401},
145 {"ExposureMode", 0xA402},
146 {"WhiteBalance", 0xA403},
147 {"DigitalZoomRatio", 0xA404},
148 {"FocalLengthIn35mmFilm", 0xA405},
149 {"SceneCaptureType", 0xA406},
150 {"GainControl", 0xA407},
151 {"Contrast", 0xA408},
152 {"Saturation", 0xA409},
153 {"Sharpness", 0xA40A},
154 {"DeviceSettingDescription", 0xA40B},
155 {"SubjectDistanceRange", 0xA40C}
156 // {"InteroperabilityIndex", 0x1}, // <- Table 13 Interoperability IFD Attribute Information
157 };
158
exif_get_tag_name(uint16_t id)159 static const char *exif_get_tag_name(uint16_t id)
160 {
161 int i;
162
163 for (i = 0; i < FF_ARRAY_ELEMS(tag_list); i++) {
164 if (tag_list[i].id == id)
165 return tag_list[i].name;
166 }
167
168 return NULL;
169 }
170
171
exif_add_metadata(void * logctx,int count,int type,const char * name,const char * sep,GetByteContext * gb,int le,AVDictionary ** metadata)172 static int exif_add_metadata(void *logctx, int count, int type,
173 const char *name, const char *sep,
174 GetByteContext *gb, int le,
175 AVDictionary **metadata)
176 {
177 switch(type) {
178 case 0:
179 av_log(logctx, AV_LOG_WARNING,
180 "Invalid TIFF tag type 0 found for %s with size %d\n",
181 name, count);
182 return 0;
183 case TIFF_DOUBLE : return ff_tadd_doubles_metadata(count, name, sep, gb, le, metadata);
184 case TIFF_SSHORT : return ff_tadd_shorts_metadata(count, name, sep, gb, le, 1, metadata);
185 case TIFF_SHORT : return ff_tadd_shorts_metadata(count, name, sep, gb, le, 0, metadata);
186 case TIFF_SBYTE : return ff_tadd_bytes_metadata(count, name, sep, gb, le, 1, metadata);
187 case TIFF_BYTE :
188 case TIFF_UNDEFINED: return ff_tadd_bytes_metadata(count, name, sep, gb, le, 0, metadata);
189 case TIFF_STRING : return ff_tadd_string_metadata(count, name, gb, le, metadata);
190 case TIFF_SRATIONAL:
191 case TIFF_RATIONAL : return ff_tadd_rational_metadata(count, name, sep, gb, le, metadata);
192 case TIFF_SLONG :
193 case TIFF_LONG : return ff_tadd_long_metadata(count, name, sep, gb, le, metadata);
194 default:
195 avpriv_request_sample(logctx, "TIFF tag type (%u)", type);
196 return 0;
197 };
198 }
199
200
exif_decode_tag(void * logctx,GetByteContext * gbytes,int le,int depth,AVDictionary ** metadata)201 static int exif_decode_tag(void *logctx, GetByteContext *gbytes, int le,
202 int depth, AVDictionary **metadata)
203 {
204 int ret, cur_pos;
205 unsigned id, count;
206 enum TiffTypes type;
207
208 if (depth > 2) {
209 return 0;
210 }
211
212 ff_tread_tag(gbytes, le, &id, &type, &count, &cur_pos);
213
214 if (!bytestream2_tell(gbytes)) {
215 bytestream2_seek(gbytes, cur_pos, SEEK_SET);
216 return 0;
217 }
218
219 // read count values and add it metadata
220 // store metadata or proceed with next IFD
221 ret = ff_tis_ifd(id);
222 if (ret) {
223 ret = ff_exif_decode_ifd(logctx, gbytes, le, depth + 1, metadata);
224 } else {
225 const char *name = exif_get_tag_name(id);
226 char buf[7];
227
228 if (!name) {
229 name = buf;
230 snprintf(buf, sizeof(buf), "0x%04X", id);
231 }
232
233 ret = exif_add_metadata(logctx, count, type, name, NULL,
234 gbytes, le, metadata);
235 }
236
237 bytestream2_seek(gbytes, cur_pos, SEEK_SET);
238
239 return ret;
240 }
241
242
ff_exif_decode_ifd(void * logctx,GetByteContext * gbytes,int le,int depth,AVDictionary ** metadata)243 int ff_exif_decode_ifd(void *logctx, GetByteContext *gbytes,
244 int le, int depth, AVDictionary **metadata)
245 {
246 int i, ret;
247 int entries;
248
249 entries = ff_tget_short(gbytes, le);
250
251 if (bytestream2_get_bytes_left(gbytes) < entries * 12) {
252 return AVERROR_INVALIDDATA;
253 }
254
255 for (i = 0; i < entries; i++) {
256 if ((ret = exif_decode_tag(logctx, gbytes, le, depth, metadata)) < 0) {
257 return ret;
258 }
259 }
260
261 // return next IDF offset or 0x000000000 or a value < 0 for failure
262 return ff_tget_long(gbytes, le);
263 }
264
avpriv_exif_decode_ifd(void * logctx,const uint8_t * buf,int size,int le,int depth,AVDictionary ** metadata)265 int avpriv_exif_decode_ifd(void *logctx, const uint8_t *buf, int size,
266 int le, int depth, AVDictionary **metadata)
267 {
268 GetByteContext gb;
269
270 bytestream2_init(&gb, buf, size);
271
272 return ff_exif_decode_ifd(logctx, &gb, le, depth, metadata);
273 }
274