blob: 07ce1741c26429889db821980ebfbc25657ab04c
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 | |
30 | |
31 | static const char *exif_get_tag_name(uint16_t id) |
32 | { |
33 | int i; |
34 | |
35 | for (i = 0; i < FF_ARRAY_ELEMS(tag_list); i++) { |
36 | if (tag_list[i].id == id) |
37 | return tag_list[i].name; |
38 | } |
39 | |
40 | return NULL; |
41 | } |
42 | |
43 | |
44 | static int exif_add_metadata(void *logctx, int count, int type, |
45 | const char *name, const char *sep, |
46 | GetByteContext *gb, int le, |
47 | AVDictionary **metadata) |
48 | { |
49 | switch(type) { |
50 | case 0: |
51 | av_log(logctx, AV_LOG_WARNING, |
52 | "Invalid TIFF tag type 0 found for %s with size %d\n", |
53 | name, count); |
54 | return 0; |
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); |
59 | case TIFF_BYTE : |
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); |
62 | case TIFF_SRATIONAL: |
63 | case TIFF_RATIONAL : return ff_tadd_rational_metadata(count, name, sep, gb, le, metadata); |
64 | case TIFF_SLONG : |
65 | case TIFF_LONG : return ff_tadd_long_metadata(count, name, sep, gb, le, metadata); |
66 | default: |
67 | avpriv_request_sample(logctx, "TIFF tag type (%u)", type); |
68 | return 0; |
69 | }; |
70 | } |
71 | |
72 | |
73 | static int exif_decode_tag(void *logctx, GetByteContext *gbytes, int le, |
74 | int depth, AVDictionary **metadata) |
75 | { |
76 | int ret, cur_pos; |
77 | unsigned id, count; |
78 | enum TiffTypes type; |
79 | |
80 | if (depth > 2) { |
81 | return 0; |
82 | } |
83 | |
84 | ff_tread_tag(gbytes, le, &id, &type, &count, &cur_pos); |
85 | |
86 | if (!bytestream2_tell(gbytes)) { |
87 | bytestream2_seek(gbytes, cur_pos, SEEK_SET); |
88 | return 0; |
89 | } |
90 | |
91 | // read count values and add it metadata |
92 | // store metadata or proceed with next IFD |
93 | ret = ff_tis_ifd(id); |
94 | if (ret) { |
95 | ret = avpriv_exif_decode_ifd(logctx, gbytes, le, depth + 1, metadata); |
96 | } else { |
97 | const char *name = exif_get_tag_name(id); |
98 | char *use_name = (char*) name; |
99 | |
100 | if (!use_name) { |
101 | use_name = av_malloc(7); |
102 | if (!use_name) { |
103 | return AVERROR(ENOMEM); |
104 | } |
105 | snprintf(use_name, 7, "0x%04X", id); |
106 | } |
107 | |
108 | ret = exif_add_metadata(logctx, count, type, use_name, NULL, |
109 | gbytes, le, metadata); |
110 | |
111 | if (!name) { |
112 | av_freep(&use_name); |
113 | } |
114 | } |
115 | |
116 | bytestream2_seek(gbytes, cur_pos, SEEK_SET); |
117 | |
118 | return ret; |
119 | } |
120 | |
121 | |
122 | int avpriv_exif_decode_ifd(void *logctx, GetByteContext *gbytes, int le, |
123 | int depth, AVDictionary **metadata) |
124 | { |
125 | int i, ret; |
126 | int entries; |
127 | |
128 | entries = ff_tget_short(gbytes, le); |
129 | |
130 | if (bytestream2_get_bytes_left(gbytes) < entries * 12) { |
131 | return AVERROR_INVALIDDATA; |
132 | } |
133 | |
134 | for (i = 0; i < entries; i++) { |
135 | if ((ret = exif_decode_tag(logctx, gbytes, le, depth, metadata)) < 0) { |
136 | return ret; |
137 | } |
138 | } |
139 | |
140 | // return next IDF offset or 0x000000000 or a value < 0 for failure |
141 | return ff_tget_long(gbytes, le); |
142 | } |
143 |