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
)
51 av_log(avctx
, AV_LOG_WARNING
,
52 "Invalid TIFF tag type 0 found for %s with size %d\n",
55 case TIFF_DOUBLE
: return ff_tadd_doubles_metadata(count
, name
, sep
, gb
, le
, metadata
);
56 case TIFF_SSHORT
: return ff_tadd_shorts_metadata(count
, name
, sep
, gb
, le
, 1, metadata
);
57 case TIFF_SHORT
: return ff_tadd_shorts_metadata(count
, name
, sep
, gb
, le
, 0, metadata
);
58 case TIFF_SBYTE
: return ff_tadd_bytes_metadata(count
, name
, sep
, gb
, le
, 1, metadata
);
60 case TIFF_UNDEFINED
: return ff_tadd_bytes_metadata(count
, name
, sep
, gb
, le
, 0, metadata
);
61 case TIFF_STRING
: return ff_tadd_string_metadata(count
, name
, gb
, le
, metadata
);
63 case TIFF_RATIONAL
: return ff_tadd_rational_metadata(count
, name
, sep
, gb
, le
, metadata
);
65 case TIFF_LONG
: return ff_tadd_long_metadata(count
, name
, sep
, gb
, le
, metadata
);
67 avpriv_request_sample(avctx
, "TIFF tag type (%u)", type
);
73 static int exif_decode_tag(AVCodecContext
*avctx
, GetByteContext
*gbytes
, int le
,
74 int depth
, AVDictionary
**metadata
)
84 ff_tread_tag(gbytes
, le
, &id
, &type
, &count
, &cur_pos
);
86 if (!bytestream2_tell(gbytes
)) {
87 bytestream2_seek(gbytes
, cur_pos
, SEEK_SET
);
91 // read count values and add it metadata
92 // store metadata or proceed with next IFD
95 ret
= avpriv_exif_decode_ifd(avctx
, gbytes
, le
, depth
+ 1, metadata
);
97 const char *name
= exif_get_tag_name(id
);
98 char *use_name
= (char*) name
;
101 use_name
= av_malloc(7);
103 return AVERROR(ENOMEM
);
105 snprintf(use_name
, 7, "0x%04X", id
);
108 ret
= exif_add_metadata(avctx
, count
, type
, use_name
, NULL
,
109 gbytes
, le
, metadata
);
116 bytestream2_seek(gbytes
, cur_pos
, SEEK_SET
);
122 int avpriv_exif_decode_ifd(AVCodecContext
*avctx
, GetByteContext
*gbytes
, int le
,
123 int depth
, AVDictionary
**metadata
)
128 entries
= ff_tget_short(gbytes
, le
);
130 if (bytestream2_get_bytes_left(gbytes
) < entries
* 12) {
131 return AVERROR_INVALIDDATA
;
134 for (i
= 0; i
< entries
; i
++) {
135 if ((ret
= exif_decode_tag(avctx
, gbytes
, le
, depth
, metadata
)) < 0) {
140 // return next IDF offset or 0x000000000 or a value < 0 for failure
141 return ff_tget_long(gbytes
, le
);