1 /*
2 * Copyright (C) 2010 David Conrad
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "libavutil/intreadwrite.h"
22 #include "avformat.h"
23 #include "internal.h"
24 #include "oggdec.h"
25
skeleton_header(AVFormatContext * s,int idx)26 static int skeleton_header(AVFormatContext *s, int idx)
27 {
28 struct ogg *ogg = s->priv_data;
29 struct ogg_stream *os = ogg->streams + idx;
30 AVStream *st = s->streams[idx];
31 uint8_t *buf = os->buf + os->pstart;
32 int version_major, version_minor;
33 int64_t start_num, start_den;
34 uint64_t start_granule;
35 int target_idx, start_time;
36
37 st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
38
39 if ((os->flags & OGG_FLAG_EOS) && os->psize == 0)
40 return 1;
41
42 if (os->psize < 8)
43 return -1;
44
45 if (!strncmp(buf, "fishead", 8)) {
46 if (os->psize < 64)
47 return -1;
48
49 version_major = AV_RL16(buf+8);
50 version_minor = AV_RL16(buf+10);
51
52 if (version_major != 3 && version_major != 4) {
53 av_log(s, AV_LOG_WARNING, "Unknown skeleton version %d.%d\n",
54 version_major, version_minor);
55 return -1;
56 }
57
58 // This is the overall start time. We use it for the start time of
59 // of the skeleton stream since if left unset lavf assumes 0,
60 // which we don't want since skeleton is timeless
61 // FIXME: the real meaning of this field is "start playback at
62 // this time which can be in the middle of a packet
63 start_num = AV_RL64(buf+12);
64 start_den = AV_RL64(buf+20);
65
66 if (start_den > 0 && start_num > 0) {
67 int base_den;
68 av_reduce(&start_time, &base_den, start_num, start_den, INT_MAX);
69 avpriv_set_pts_info(st, 64, 1, base_den);
70 os->lastpts =
71 st->start_time = start_time;
72 }
73 } else if (!strncmp(buf, "fisbone", 8)) {
74 if (os->psize < 52)
75 return -1;
76
77 target_idx = ogg_find_stream(ogg, AV_RL32(buf+12));
78 start_granule = AV_RL64(buf+36);
79 if (target_idx < 0) {
80 av_log(s, AV_LOG_WARNING, "Serial number in fisbone doesn't match any stream\n");
81 return 1;
82 }
83 os = ogg->streams + target_idx;
84 if (os->start_granule != OGG_NOGRANULE_VALUE) {
85 av_log(s, AV_LOG_WARNING, "Multiple fisbone for the same stream\n");
86 return 1;
87 }
88 if (start_granule != OGG_NOGRANULE_VALUE) {
89 os->start_granule = start_granule;
90 }
91 }
92
93 return 1;
94 }
95
96 const struct ogg_codec ff_skeleton_codec = {
97 .magic = "fishead",
98 .magicsize = 8,
99 .header = skeleton_header,
100 .nb_header = 0,
101 };
102