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 "libavcodec/bytestream.h"
22#include "avformat.h"
23#include "internal.h"
24#include "oggdec.h"
25
26static 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->codec->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
96const struct ogg_codec ff_skeleton_codec = {
97    .magic = "fishead",
98    .magicsize = 8,
99    .header = skeleton_header,
100    .nb_header = 0,
101};
102