122 lines
3.4 KiB
C
122 lines
3.4 KiB
C
/*
|
|
* AST demuxer
|
|
* Copyright (c) 2012 Paul B Mahol
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg 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.
|
|
*
|
|
* FFmpeg 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 FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "libavutil/channel_layout.h"
|
|
#include "libavutil/intreadwrite.h"
|
|
#include "avformat.h"
|
|
#include "internal.h"
|
|
|
|
static int ast_probe(AVProbeData *p)
|
|
{
|
|
if (AV_RL32(p->buf) == MKTAG('S', 'T', 'R', 'M'))
|
|
return AVPROBE_SCORE_MAX / 2;
|
|
return 0;
|
|
}
|
|
|
|
static int ast_read_header(AVFormatContext *s)
|
|
{
|
|
int codec, depth;
|
|
AVStream *st;
|
|
|
|
st = avformat_new_stream(s, NULL);
|
|
if (!st)
|
|
return AVERROR(ENOMEM);
|
|
|
|
avio_skip(s->pb, 8);
|
|
codec = avio_rb16(s->pb);
|
|
switch (codec) {
|
|
case 1:
|
|
st->codec->codec_id = AV_CODEC_ID_PCM_S16BE_PLANAR;
|
|
break;
|
|
default:
|
|
av_log(s, AV_LOG_ERROR, "unsupported codec %d\n", codec);
|
|
}
|
|
|
|
depth = avio_rb16(s->pb);
|
|
if (depth != 16) {
|
|
av_log_ask_for_sample(s, "unsupported depth %d\n", depth);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
|
|
st->codec->channels = avio_rb16(s->pb);
|
|
if (!st->codec->channels)
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
if (st->codec->channels == 2)
|
|
st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
|
|
else if (st->codec->channels == 4)
|
|
st->codec->channel_layout = AV_CH_LAYOUT_4POINT0;
|
|
|
|
avio_skip(s->pb, 2);
|
|
st->codec->sample_rate = avio_rb32(s->pb);
|
|
if (st->codec->sample_rate <= 0)
|
|
return AVERROR_INVALIDDATA;
|
|
st->start_time = 0;
|
|
st->duration = avio_rb32(s->pb);
|
|
avio_skip(s->pb, 40);
|
|
avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ast_read_packet(AVFormatContext *s, AVPacket *pkt)
|
|
{
|
|
uint32_t type, size;
|
|
int64_t pos;
|
|
int ret;
|
|
|
|
if (url_feof(s->pb))
|
|
return AVERROR_EOF;
|
|
|
|
pos = avio_tell(s->pb);
|
|
type = avio_rl32(s->pb);
|
|
size = avio_rb32(s->pb);
|
|
if (size > INT_MAX / s->streams[0]->codec->channels)
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
size *= s->streams[0]->codec->channels;
|
|
if ((ret = avio_skip(s->pb, 24)) < 0) // padding
|
|
return ret;
|
|
|
|
if (type == MKTAG('B','L','C','K')) {
|
|
ret = av_get_packet(s->pb, pkt, size);
|
|
pkt->stream_index = 0;
|
|
pkt->pos = pos;
|
|
} else {
|
|
av_log(s, AV_LOG_ERROR, "unknown chunk %x\n", type);
|
|
avio_skip(s->pb, size);
|
|
ret = AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
AVInputFormat ff_ast_demuxer = {
|
|
.name = "ast",
|
|
.long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),
|
|
.read_probe = ast_probe,
|
|
.read_header = ast_read_header,
|
|
.read_packet = ast_read_packet,
|
|
.extensions = "ast",
|
|
.flags = AVFMT_GENERIC_INDEX,
|
|
};
|