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/*
* CRYO APC audio format demuxer
* Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
*
* 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 <string.h>
#include "libavutil/channel_layout.h"
#include "avformat.h"
static int apc_probe(AVProbeData *p)
{
if (!strncmp(p->buf, "CRYO_APC", 8))
return AVPROBE_SCORE_MAX;
return 0;
}
static int apc_read_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
AVStream *st;
avio_rl32(pb); /* CRYO */
avio_rl32(pb); /* _APC */
avio_rl32(pb); /* 1.20 */
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = AV_CODEC_ID_ADPCM_IMA_APC;
avio_rl32(pb); /* number of samples */
st->codec->sample_rate = avio_rl32(pb);
st->codec->extradata_size = 2 * 4;
st->codec->extradata = av_malloc(st->codec->extradata_size +
FF_INPUT_BUFFER_PADDING_SIZE);
if (!st->codec->extradata)
return AVERROR(ENOMEM);
/* initial predictor values for adpcm decoder */
avio_read(pb, st->codec->extradata, 2 * 4);
if (avio_rl32(pb)) {
st->codec->channels = 2;
st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
} else {
st->codec->channels = 1;
st->codec->channel_layout = AV_CH_LAYOUT_MONO;
}
st->codec->bits_per_coded_sample = 4;
st->codec->bit_rate = st->codec->bits_per_coded_sample * st->codec->channels
* st->codec->sample_rate;
st->codec->block_align = 1;
return 0;
}
#define MAX_READ_SIZE 4096
static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
{
if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0)
return AVERROR(EIO);
pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
pkt->stream_index = 0;
return 0;
}
AVInputFormat ff_apc_demuxer = {
.name = "apc",
.long_name = NULL_IF_CONFIG_SMALL("CRYO APC"),
.read_probe = apc_probe,
.read_header = apc_read_header,
.read_packet = apc_read_packet,
};
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