yading@11: /*
yading@11:  * CRYO APC audio format demuxer
yading@11:  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include <string.h>
yading@11: 
yading@11: #include "libavutil/channel_layout.h"
yading@11: #include "avformat.h"
yading@11: 
yading@11: static int apc_probe(AVProbeData *p)
yading@11: {
yading@11:     if (!strncmp(p->buf, "CRYO_APC", 8))
yading@11:         return AVPROBE_SCORE_MAX;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int apc_read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     AVStream *st;
yading@11: 
yading@11:     avio_rl32(pb); /* CRYO */
yading@11:     avio_rl32(pb); /* _APC */
yading@11:     avio_rl32(pb); /* 1.20 */
yading@11: 
yading@11:     st = avformat_new_stream(s, NULL);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->codec_id = AV_CODEC_ID_ADPCM_IMA_APC;
yading@11: 
yading@11:     avio_rl32(pb); /* number of samples */
yading@11:     st->codec->sample_rate = avio_rl32(pb);
yading@11: 
yading@11:     st->codec->extradata_size = 2 * 4;
yading@11:     st->codec->extradata = av_malloc(st->codec->extradata_size +
yading@11:                                      FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:     if (!st->codec->extradata)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     /* initial predictor values for adpcm decoder */
yading@11:     avio_read(pb, st->codec->extradata, 2 * 4);
yading@11: 
yading@11:     if (avio_rl32(pb)) {
yading@11:         st->codec->channels       = 2;
yading@11:         st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
yading@11:     } else {
yading@11:         st->codec->channels       = 1;
yading@11:         st->codec->channel_layout = AV_CH_LAYOUT_MONO;
yading@11:     }
yading@11: 
yading@11:     st->codec->bits_per_coded_sample = 4;
yading@11:     st->codec->bit_rate = st->codec->bits_per_coded_sample * st->codec->channels
yading@11:                           * st->codec->sample_rate;
yading@11:     st->codec->block_align = 1;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: #define MAX_READ_SIZE 4096
yading@11: 
yading@11: static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0)
yading@11:         return AVERROR(EIO);
yading@11:     pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
yading@11:     pkt->stream_index = 0;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_apc_demuxer = {
yading@11:     .name           = "apc",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("CRYO APC"),
yading@11:     .read_probe     = apc_probe,
yading@11:     .read_header    = apc_read_header,
yading@11:     .read_packet    = apc_read_packet,
yading@11: };