0,0 → 1,119 |
/* |
* 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" |
#include "ast.h" |
|
static int ast_probe(AVProbeData *p) |
{ |
if (AV_RL32(p->buf) == MKTAG('S','T','R','M') && |
AV_RB16(p->buf + 10) && |
AV_RB16(p->buf + 12) && |
AV_RB32(p->buf + 16)) |
return AVPROBE_SCORE_MAX / 3 * 2; |
return 0; |
} |
|
static int ast_read_header(AVFormatContext *s) |
{ |
int depth; |
AVStream *st; |
|
st = avformat_new_stream(s, NULL); |
if (!st) |
return AVERROR(ENOMEM); |
|
avio_skip(s->pb, 8); |
st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
st->codec->codec_id = ff_codec_get_id(ff_codec_ast_tags, avio_rb16(s->pb)); |
|
depth = avio_rb16(s->pb); |
if (depth != 16) { |
avpriv_request_sample(s, "depth %d", depth); |
return AVERROR_INVALIDDATA; |
} |
|
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, |
.codec_tag = (const AVCodecTag* const []){ff_codec_ast_tags, 0}, |
}; |