FFmpeg/libavformat/oggparseskeleton.c
Luca Barbato d1f05dd183 ogg: calculate the start position once all the headers are parsed
The fisbone packets can be muxed in any order as long the last one
comes before the first data packet.
2012-09-24 22:35:29 +02:00

96 lines
3.1 KiB
C

/*
* Copyright (C) 2010 David Conrad
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavcodec/bytestream.h"
#include "avformat.h"
#include "internal.h"
#include "oggdec.h"
static int skeleton_header(AVFormatContext *s, int idx)
{
struct ogg *ogg = s->priv_data;
struct ogg_stream *os = ogg->streams + idx;
AVStream *st = s->streams[idx];
uint8_t *buf = os->buf + os->pstart;
int version_major, version_minor;
int64_t start_num, start_den;
uint64_t start_granule;
int target_idx, start_time;
strcpy(st->codec->codec_name, "skeleton");
st->codec->codec_type = AVMEDIA_TYPE_DATA;
if (os->psize < 8)
return -1;
if (!strncmp(buf, "fishead", 8)) {
if (os->psize < 64)
return -1;
version_major = AV_RL16(buf+8);
version_minor = AV_RL16(buf+10);
if (version_major != 3) {
av_log(s, AV_LOG_WARNING, "Unknown skeleton version %d.%d\n",
version_major, version_minor);
return -1;
}
// This is the overall start time. We use it for the start time of
// of the skeleton stream since if left unset lavf assumes 0,
// which we don't want since skeleton is timeless
// FIXME: the real meaning of this field is "start playback at
// this time which can be in the middle of a packet
start_num = AV_RL64(buf+12);
start_den = AV_RL64(buf+20);
if (start_den) {
int base_den;
av_reduce(&start_time, &base_den, start_num, start_den, INT_MAX);
avpriv_set_pts_info(st, 64, 1, base_den);
os->lastpts =
st->start_time = start_time;
}
} else if (!strncmp(buf, "fisbone", 8)) {
if (os->psize < 52)
return -1;
target_idx = ogg_find_stream(ogg, AV_RL32(buf+12));
start_granule = AV_RL64(buf+36);
if (os->start_granule != OGG_NOGRANULE_VALUE) {
av_log_missing_feature(s, "multiple fisbone for the "
"same stream\n", 0);
return 1;
}
if (target_idx >= 0 && start_granule != OGG_NOGRANULE_VALUE) {
os->start_granule = start_granule;
}
}
return 1;
}
const struct ogg_codec ff_skeleton_codec = {
.magic = "fishead",
.magicsize = 8,
.header = skeleton_header,
.nb_header = 0,
};