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Initial commit of the MD studio demuxer, not hooked up yet

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Originally committed as revision 19812 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Benjamin Larsson 2009-09-10 18:48:12 +00:00
parent dbb0f96f0f
commit d0b57c6f85
1 changed files with 110 additions and 0 deletions
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libavformat/aea.c Normal file
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/*
* MD STUDIO audio demuxer
*
* Copyright (c) 2009 Benjamin Larsson
*
* 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
*/
/**
* @file libavformat/aea.c
*/
#include "avformat.h"
#include "raw.h"
#include "libavutil/intreadwrite.h"
#define AT1_SU_SIZE 212
static int aea_read_probe(AVProbeData *p)
{
if (p->buf_size <= 2048+212)
return 0;
/* Magic is '00 08 00 00' in Little Endian*/
if(AV_RL32(p->buf)==0x800) {
int bsm_s, bsm_e, inb_s, inb_e;
bsm_s = p->buf[2048];
inb_s = p->buf[2048+1];
inb_e = p->buf[2048+210];
bsm_e = p->buf[2048+211];
/* Check so that the redundant bsm bytes and info bytes are valid
* the block size mode bytes have to be the same
* the info bytes have to be the same
* the block size mode and info byte can't be the same
*/
if (bsm_s == bsm_e && inb_s == inb_e && bsm_s != inb_s)
return AVPROBE_SCORE_MAX/2;
}
return 0;
}
static int aea_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
AVStream *st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
/* Parse the amount of channels and skip to pos 2048(0x800) */
url_fskip(s->pb, 264);
st->codec->channels = get_byte(s->pb);
url_fskip(s->pb, 1783);
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_ATRAC1;
st->codec->sample_rate = 44100;
st->codec->bit_rate = 292000;
if (st->codec->channels != 1 && st->codec->channels != 2) {
av_log(s,AV_LOG_ERROR,"Channels %d not supported!\n",st->codec->channels);
return -1;
}
st->codec->channel_layout = (st->codec->channels==1) ? CH_LAYOUT_MONO : CH_LAYOUT_STEREO;
st->codec->block_align = AT1_SU_SIZE * st->codec->channels;
return 0;
}
static int aea_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret = av_get_packet(s->pb, pkt, s->streams[0]->codec->block_align);
pkt->stream_index = 0;
if (ret <= 0)
return AVERROR(EIO);
return ret;
}
AVInputFormat aea_demuxer = {
"aea",
NULL_IF_CONFIG_SMALL("MD STUDIO audio"),
0,
aea_read_probe,
aea_read_header,
aea_read_packet,
0,
pcm_read_seek,
.flags= AVFMT_GENERIC_INDEX,
.extensions = "aea",
};