yading@11: /*
yading@11:  * MD STUDIO audio demuxer
yading@11:  *
yading@11:  * Copyright (c) 2009 Benjamin Larsson
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 "libavutil/channel_layout.h"
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "avformat.h"
yading@11: #include "pcm.h"
yading@11: 
yading@11: #define AT1_SU_SIZE     212
yading@11: 
yading@11: static int aea_read_probe(AVProbeData *p)
yading@11: {
yading@11:     if (p->buf_size <= 2048+212)
yading@11:         return 0;
yading@11: 
yading@11:     /* Magic is '00 08 00 00' in Little Endian*/
yading@11:     if (AV_RL32(p->buf)==0x800) {
yading@11:         int bsm_s, bsm_e, inb_s, inb_e, ch;
yading@11:         ch    = p->buf[264];
yading@11:         bsm_s = p->buf[2048];
yading@11:         inb_s = p->buf[2048+1];
yading@11:         inb_e = p->buf[2048+210];
yading@11:         bsm_e = p->buf[2048+211];
yading@11: 
yading@11:         if (ch != 1 && ch != 2)
yading@11:             return 0;
yading@11: 
yading@11:         /* Check so that the redundant bsm bytes and info bytes are valid
yading@11:          * the block size mode bytes have to be the same
yading@11:          * the info bytes have to be the same
yading@11:          */
yading@11:         if (bsm_s == bsm_e && inb_s == inb_e)
yading@11:             return AVPROBE_SCORE_MAX / 4 + 1;
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int aea_read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVStream *st = avformat_new_stream(s, NULL);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     /* Parse the amount of channels and skip to pos 2048(0x800) */
yading@11:     avio_skip(s->pb, 264);
yading@11:     st->codec->channels = avio_r8(s->pb);
yading@11:     avio_skip(s->pb, 1783);
yading@11: 
yading@11: 
yading@11:     st->codec->codec_type     = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->codec_id       = AV_CODEC_ID_ATRAC1;
yading@11:     st->codec->sample_rate    = 44100;
yading@11:     st->codec->bit_rate       = 292000;
yading@11: 
yading@11:     if (st->codec->channels != 1 && st->codec->channels != 2) {
yading@11:         av_log(s,AV_LOG_ERROR,"Channels %d not supported!\n",st->codec->channels);
yading@11:         return -1;
yading@11:     }
yading@11: 
yading@11:     st->codec->channel_layout = (st->codec->channels == 1) ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
yading@11: 
yading@11:     st->codec->block_align = AT1_SU_SIZE * st->codec->channels;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int aea_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     int ret = av_get_packet(s->pb, pkt, s->streams[0]->codec->block_align);
yading@11: 
yading@11:     pkt->stream_index = 0;
yading@11:     if (ret <= 0)
yading@11:         return AVERROR(EIO);
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_aea_demuxer = {
yading@11:     .name           = "aea",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("MD STUDIO audio"),
yading@11:     .read_probe     = aea_read_probe,
yading@11:     .read_header    = aea_read_header,
yading@11:     .read_packet    = aea_read_packet,
yading@11:     .read_seek      = ff_pcm_read_seek,
yading@11:     .flags          = AVFMT_GENERIC_INDEX,
yading@11:     .extensions     = "aea",
yading@11: };