/* * EXIF metadata parser * Copyright (c) 2013 Thilo Borgmann * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * EXIF metadata parser * @author Thilo Borgmann */ #include "exif.h" #include "tiff_common.h" #define EXIF_TAG_NAME_LENGTH 32 struct exif_tag { char name[EXIF_TAG_NAME_LENGTH]; uint16_t id; }; static const struct exif_tag tag_list[] = { // JEITA CP-3451 EXIF specification: {"GPSVersionID", 0x00}, // <- Table 12 GPS Attribute Information {"GPSLatitudeRef", 0x01}, {"GPSLatitude", 0x02}, {"GPSLongitudeRef", 0x03}, {"GPSLongitude", 0x04}, {"GPSAltitudeRef", 0x05}, {"GPSAltitude", 0x06}, {"GPSTimeStamp", 0x07}, {"GPSSatellites", 0x08}, {"GPSStatus", 0x09}, {"GPSMeasureMode", 0x0A}, {"GPSDOP", 0x0B}, {"GPSSpeedRef", 0x0C}, {"GPSSpeed", 0x0D}, {"GPSTrackRef", 0x0E}, {"GPSTrack", 0x0F}, {"GPSImgDirectionRef", 0x10}, {"GPSImgDirection", 0x11}, {"GPSMapDatum", 0x12}, {"GPSDestLatitudeRef", 0x13}, {"GPSDestLatitude", 0x14}, {"GPSDestLongitudeRef", 0x15}, {"GPSDestLongitude", 0x16}, {"GPSDestBearingRef", 0x17}, {"GPSDestBearing", 0x18}, {"GPSDestDistanceRef", 0x19}, {"GPSDestDistance", 0x1A}, {"GPSProcessingMethod", 0x1B}, {"GPSAreaInformation", 0x1C}, {"GPSDateStamp", 0x1D}, {"GPSDifferential", 0x1E}, {"ImageWidth", 0x100}, // <- Table 3 TIFF Rev. 6.0 Attribute Information Used in Exif {"ImageLength", 0x101}, {"BitsPerSample", 0x102}, {"Compression", 0x103}, {"PhotometricInterpretation", 0x106}, {"Orientation", 0x112}, {"SamplesPerPixel", 0x115}, {"PlanarConfiguration", 0x11C}, {"YCbCrSubSampling", 0x212}, {"YCbCrPositioning", 0x213}, {"XResolution", 0x11A}, {"YResolution", 0x11B}, {"ResolutionUnit", 0x128}, {"StripOffsets", 0x111}, {"RowsPerStrip", 0x116}, {"StripByteCounts", 0x117}, {"JPEGInterchangeFormat", 0x201}, {"JPEGInterchangeFormatLength",0x202}, {"TransferFunction", 0x12D}, {"WhitePoint", 0x13E}, {"PrimaryChromaticities", 0x13F}, {"YCbCrCoefficients", 0x211}, {"ReferenceBlackWhite", 0x214}, {"DateTime", 0x132}, {"ImageDescription", 0x10E}, {"Make", 0x10F}, {"Model", 0x110}, {"Software", 0x131}, {"Artist", 0x13B}, {"Copyright", 0x8298}, {"ExifVersion", 0x9000}, // <- Table 4 Exif IFD Attribute Information (1) {"FlashpixVersion", 0xA000}, {"ColorSpace", 0xA001}, {"ComponentsConfiguration", 0x9101}, {"CompressedBitsPerPixel", 0x9102}, {"PixelXDimension", 0xA002}, {"PixelYDimension", 0xA003}, {"MakerNote", 0x927C}, {"UserComment", 0x9286}, {"RelatedSoundFile", 0xA004}, {"DateTimeOriginal", 0x9003}, {"DateTimeDigitized", 0x9004}, {"SubSecTime", 0x9290}, {"SubSecTimeOriginal", 0x9291}, {"SubSecTimeDigitized", 0x9292}, {"ImageUniqueID", 0xA420}, {"ExposureTime", 0x829A}, // <- Table 5 Exif IFD Attribute Information (2) {"FNumber", 0x829D}, {"ExposureProgram", 0x8822}, {"SpectralSensitivity", 0x8824}, {"ISOSpeedRatings", 0x8827}, {"OECF", 0x8828}, {"ShutterSpeedValue", 0x9201}, {"ApertureValue", 0x9202}, {"BrightnessValue", 0x9203}, {"ExposureBiasValue", 0x9204}, {"MaxApertureValue", 0x9205}, {"SubjectDistance", 0x9206}, {"MeteringMode", 0x9207}, {"LightSource", 0x9208}, {"Flash", 0x9209}, {"FocalLength", 0x920A}, {"SubjectArea", 0x9214}, {"FlashEnergy", 0xA20B}, {"SpatialFrequencyResponse", 0xA20C}, {"FocalPlaneXResolution", 0xA20E}, {"FocalPlaneYResolution", 0xA20F}, {"FocalPlaneResolutionUnit", 0xA210}, {"SubjectLocation", 0xA214}, {"ExposureIndex", 0xA215}, {"SensingMethod", 0xA217}, {"FileSource", 0xA300}, {"SceneType", 0xA301}, {"CFAPattern", 0xA302}, {"CustomRendered", 0xA401}, {"ExposureMode", 0xA402}, {"WhiteBalance", 0xA403}, {"DigitalZoomRatio", 0xA404}, {"FocalLengthIn35mmFilm", 0xA405}, {"SceneCaptureType", 0xA406}, {"GainControl", 0xA407}, {"Contrast", 0xA408}, {"Saturation", 0xA409}, {"Sharpness", 0xA40A}, {"DeviceSettingDescription", 0xA40B}, {"SubjectDistanceRange", 0xA40C} // {"InteroperabilityIndex", 0x1}, // <- Table 13 Interoperability IFD Attribute Information }; static const char *exif_get_tag_name(uint16_t id) { int i; for (i = 0; i < FF_ARRAY_ELEMS(tag_list); i++) { if (tag_list[i].id == id) return tag_list[i].name; } return NULL; } static int exif_add_metadata(void *logctx, int count, int type, const char *name, const char *sep, GetByteContext *gb, int le, AVDictionary **metadata) { switch(type) { case 0: av_log(logctx, AV_LOG_WARNING, "Invalid TIFF tag type 0 found for %s with size %d\n", name, count); return 0; case TIFF_DOUBLE : return ff_tadd_doubles_metadata(count, name, sep, gb, le, metadata); case TIFF_SSHORT : return ff_tadd_shorts_metadata(count, name, sep, gb, le, 1, metadata); case TIFF_SHORT : return ff_tadd_shorts_metadata(count, name, sep, gb, le, 0, metadata); case TIFF_SBYTE : return ff_tadd_bytes_metadata(count, name, sep, gb, le, 1, metadata); case TIFF_BYTE : case TIFF_UNDEFINED: return ff_tadd_bytes_metadata(count, name, sep, gb, le, 0, metadata); case TIFF_STRING : return ff_tadd_string_metadata(count, name, gb, le, metadata); case TIFF_SRATIONAL: case TIFF_RATIONAL : return ff_tadd_rational_metadata(count, name, sep, gb, le, metadata); case TIFF_SLONG : case TIFF_LONG : return ff_tadd_long_metadata(count, name, sep, gb, le, metadata); default: avpriv_request_sample(logctx, "TIFF tag type (%u)", type); return 0; }; } static int exif_decode_tag(void *logctx, GetByteContext *gbytes, int le, int depth, AVDictionary **metadata) { int ret, cur_pos; unsigned id, count; enum TiffTypes type; if (depth > 2) { return 0; } ff_tread_tag(gbytes, le, &id, &type, &count, &cur_pos); if (!bytestream2_tell(gbytes)) { bytestream2_seek(gbytes, cur_pos, SEEK_SET); return 0; } // read count values and add it metadata // store metadata or proceed with next IFD ret = ff_tis_ifd(id); if (ret) { ret = ff_exif_decode_ifd(logctx, gbytes, le, depth + 1, metadata); } else { const char *name = exif_get_tag_name(id); char buf[7]; if (!name) { name = buf; snprintf(buf, sizeof(buf), "0x%04X", id); } ret = exif_add_metadata(logctx, count, type, name, NULL, gbytes, le, metadata); } bytestream2_seek(gbytes, cur_pos, SEEK_SET); return ret; } int ff_exif_decode_ifd(void *logctx, GetByteContext *gbytes, int le, int depth, AVDictionary **metadata) { int i, ret; int entries; entries = ff_tget_short(gbytes, le); if (bytestream2_get_bytes_left(gbytes) < entries * 12) { return AVERROR_INVALIDDATA; } for (i = 0; i < entries; i++) { if ((ret = exif_decode_tag(logctx, gbytes, le, depth, metadata)) < 0) { return ret; } } // return next IDF offset or 0x000000000 or a value < 0 for failure return ff_tget_long(gbytes, le); } int avpriv_exif_decode_ifd(void *logctx, const uint8_t *buf, int size, int le, int depth, AVDictionary **metadata) { GetByteContext gb; bytestream2_init(&gb, buf, size); return ff_exif_decode_ifd(logctx, &gb, le, depth, metadata); }