0,0 → 1,94 |
/* |
* 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" |
#include "internal.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); |
|
if (ff_alloc_extradata(st->codec, 2 * 4)) |
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, |
}; |