blob: 3290b3b7bca0e15b678d9c7519dc3c4548f77220
1 | /* |
2 | * Metadata demuxer |
3 | * Copyright (c) 2010 Anton Khirnov |
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 | #include "libavutil/mathematics.h" |
23 | #include "avformat.h" |
24 | #include "ffmeta.h" |
25 | #include "internal.h" |
26 | #include "libavutil/dict.h" |
27 | |
28 | static int probe(AVProbeData *p) |
29 | { |
30 | if(!memcmp(p->buf, ID_STRING, strlen(ID_STRING))) |
31 | return AVPROBE_SCORE_MAX; |
32 | return 0; |
33 | } |
34 | |
35 | static void get_line(AVIOContext *s, uint8_t *buf, int size) |
36 | { |
37 | do { |
38 | uint8_t c; |
39 | int i = 0; |
40 | |
41 | while ((c = avio_r8(s))) { |
42 | if (c == '\\') { |
43 | if (i < size - 1) |
44 | buf[i++] = c; |
45 | c = avio_r8(s); |
46 | } else if (c == '\n') |
47 | break; |
48 | |
49 | if (i < size - 1) |
50 | buf[i++] = c; |
51 | } |
52 | buf[i] = 0; |
53 | } while (!avio_feof(s) && (buf[0] == ';' || buf[0] == '#' || buf[0] == 0)); |
54 | } |
55 | |
56 | static AVChapter *read_chapter(AVFormatContext *s) |
57 | { |
58 | uint8_t line[256]; |
59 | int64_t start, end; |
60 | AVRational tb = {1, 1e9}; |
61 | |
62 | get_line(s->pb, line, sizeof(line)); |
63 | |
64 | if (sscanf(line, "TIMEBASE=%d/%d", &tb.num, &tb.den)) |
65 | get_line(s->pb, line, sizeof(line)); |
66 | if (!sscanf(line, "START=%"SCNd64, &start)) { |
67 | av_log(s, AV_LOG_ERROR, "Expected chapter start timestamp, found %s.\n", line); |
68 | start = (s->nb_chapters && s->chapters[s->nb_chapters - 1]->end != AV_NOPTS_VALUE) ? |
69 | s->chapters[s->nb_chapters - 1]->end : 0; |
70 | } else |
71 | get_line(s->pb, line, sizeof(line)); |
72 | |
73 | if (!sscanf(line, "END=%"SCNd64, &end)) { |
74 | av_log(s, AV_LOG_ERROR, "Expected chapter end timestamp, found %s.\n", line); |
75 | end = AV_NOPTS_VALUE; |
76 | } |
77 | |
78 | return avpriv_new_chapter(s, s->nb_chapters, tb, start, end, NULL); |
79 | } |
80 | |
81 | static uint8_t *unescape(const uint8_t *buf, int size) |
82 | { |
83 | uint8_t *ret = av_malloc(size + 1); |
84 | uint8_t *p1 = ret; |
85 | const uint8_t *p2 = buf; |
86 | |
87 | if (!ret) |
88 | return NULL; |
89 | |
90 | while (p2 < buf + size) { |
91 | if (*p2 == '\\') |
92 | p2++; |
93 | *p1++ = *p2++; |
94 | } |
95 | *p1 = 0; |
96 | return ret; |
97 | } |
98 | |
99 | static int read_tag(const uint8_t *line, AVDictionary **m) |
100 | { |
101 | uint8_t *key, *value; |
102 | const uint8_t *p = line; |
103 | |
104 | /* find first not escaped '=' */ |
105 | while (1) { |
106 | if (*p == '=') |
107 | break; |
108 | else if (*p == '\\') |
109 | p++; |
110 | |
111 | if (*p++) |
112 | continue; |
113 | |
114 | return 0; |
115 | } |
116 | |
117 | if (!(key = unescape(line, p - line))) |
118 | return AVERROR(ENOMEM); |
119 | if (!(value = unescape(p + 1, strlen(p + 1)))) { |
120 | av_free(key); |
121 | return AVERROR(ENOMEM); |
122 | } |
123 | |
124 | av_dict_set(m, key, value, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL); |
125 | return 0; |
126 | } |
127 | |
128 | static int read_header(AVFormatContext *s) |
129 | { |
130 | AVDictionary **m = &s->metadata; |
131 | uint8_t line[1024]; |
132 | |
133 | while(!avio_feof(s->pb)) { |
134 | get_line(s->pb, line, sizeof(line)); |
135 | |
136 | if (!memcmp(line, ID_STREAM, strlen(ID_STREAM))) { |
137 | AVStream *st = avformat_new_stream(s, NULL); |
138 | |
139 | if (!st) |
140 | return AVERROR(ENOMEM); |
141 | |
142 | st->codecpar->codec_type = AVMEDIA_TYPE_DATA; |
143 | st->codecpar->codec_id = AV_CODEC_ID_FFMETADATA; |
144 | |
145 | m = &st->metadata; |
146 | } else if (!memcmp(line, ID_CHAPTER, strlen(ID_CHAPTER))) { |
147 | AVChapter *ch = read_chapter(s); |
148 | |
149 | if (!ch) |
150 | return AVERROR(ENOMEM); |
151 | |
152 | m = &ch->metadata; |
153 | } else |
154 | read_tag(line, m); |
155 | } |
156 | |
157 | s->start_time = 0; |
158 | if (s->nb_chapters) |
159 | s->duration = av_rescale_q(s->chapters[s->nb_chapters - 1]->end, |
160 | s->chapters[s->nb_chapters - 1]->time_base, |
161 | AV_TIME_BASE_Q); |
162 | |
163 | return 0; |
164 | } |
165 | |
166 | static int read_packet(AVFormatContext *s, AVPacket *pkt) |
167 | { |
168 | return AVERROR_EOF; |
169 | } |
170 | |
171 | AVInputFormat ff_ffmetadata_demuxer = { |
172 | .name = "ffmetadata", |
173 | .long_name = NULL_IF_CONFIG_SMALL("FFmpeg metadata in text"), |
174 | .read_probe = probe, |
175 | .read_header = read_header, |
176 | .read_packet = read_packet, |
177 | }; |
178 |