/* * EXIF metadata parser * Copyright (c) 2013 Thilo Borgmann <thilo.borgmann _at_ mail.de> * * 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 <thilo.borgmann _at_ mail.de> */ #include "exif.h" 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); }