3 * Copyright (c) 2013 Thilo Borgmann <thilo.borgmann _at_ mail.de>
5 * This file is part of FFmpeg.
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.
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.
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
24 * EXIF metadata parser
25 * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>
31 static const char *exif_get_tag_name(uint16_t id)
35 for (i = 0; i < FF_ARRAY_ELEMS(tag_list); i++) {
36 if (tag_list[i].id == id)
37 return tag_list[i].name;
44 static int exif_add_metadata(AVCodecContext *avctx, int count, int type,
45 const char *name, const char *sep,
46 GetByteContext *gb, int le,
47 AVDictionary **metadata)
50 case TIFF_DOUBLE : return ff_tadd_doubles_metadata(count, name, sep, gb, le, metadata);
51 case TIFF_SHORT : return ff_tadd_shorts_metadata(count, name, sep, gb, le, metadata);
54 case TIFF_STRING : return ff_tadd_string_metadata(count, name, gb, le, metadata);
56 case TIFF_RATIONAL : return ff_tadd_rational_metadata(count, name, sep, gb, le, metadata);
58 case TIFF_LONG : return ff_tadd_long_metadata(count, name, sep, gb, le, metadata);
60 avpriv_request_sample(avctx, "TIFF tag type (%u)", type);
66 static int exif_decode_tag(AVCodecContext *avctx, GetByteContext *gbytes, int le,
67 int depth, AVDictionary **metadata)
77 ff_tread_tag(gbytes, le, &id, &type, &count, &cur_pos);
79 // read count values and add it metadata
80 // store metadata or proceed with next IFD
83 ret = ff_exif_decode_ifd(avctx, gbytes, le, depth + 1, metadata);
85 const char *name = exif_get_tag_name(id);
86 char *use_name = (char*) name;
89 use_name = av_malloc(7);
91 return AVERROR(ENOMEM);
93 snprintf(use_name, 7, "0x%04X", id);
96 ret = exif_add_metadata(avctx, count, type, use_name, NULL,
97 gbytes, le, metadata);
104 bytestream2_seek(gbytes, cur_pos, SEEK_SET);
110 int ff_exif_decode_ifd(AVCodecContext *avctx, GetByteContext *gbytes, int le,
111 int depth, AVDictionary **metadata)
116 entries = ff_tget_short(gbytes, le);
118 if (bytestream2_get_bytes_left(gbytes) < entries * 12) {
119 return AVERROR_INVALIDDATA;
122 for (i = 0; i < entries; i++) {
123 if ((ret = exif_decode_tag(avctx, gbytes, le, depth, metadata)) < 0) {
128 // return next IDF offset or 0x000000000 or a value < 0 for failure
129 return ff_tget_long(gbytes, le);