release/src/router/ffmpeg/libavformat/aea.c

   1 /*
   2  * MD STUDIO audio demuxer
   3  *
   4  * Copyright (c) 2009 Benjamin Larsson
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "avformat.h"
  24 #include "raw.h"
  25 #include "libavutil/intreadwrite.h"
  26
  27 #define AT1_SU_SIZE     212
  28
  29 static int aea_read_probe(AVProbeData *p)
  30 {
  31     if (p->buf_size <= 2048+212)
  32         return 0;
  33
  34     /* Magic is '00 08 00 00' in Little Endian*/
  35     if (AV_RL32(p->buf)==0x800) {
  36         int bsm_s, bsm_e, inb_s, inb_e, ch;
  37         ch    = p->buf[264];
  38         bsm_s = p->buf[2048];
  39         inb_s = p->buf[2048+1];
  40         inb_e = p->buf[2048+210];
  41         bsm_e = p->buf[2048+211];
  42
  43         if (ch != 1 && ch != 2)
  44             return 0;
  45
  46         /* Check so that the redundant bsm bytes and info bytes are valid
  47          * the block size mode bytes have to be the same
  48          * the info bytes have to be the same
  49          */
  50         if (bsm_s == bsm_e && inb_s == inb_e)
  51             return AVPROBE_SCORE_MAX / 4 + 1;
  52     }
  53     return 0;
  54 }
  55
  56 static int aea_read_header(AVFormatContext *s,
  57                            AVFormatParameters *ap)
  58 {
  59     AVStream *st = av_new_stream(s, 0);
  60     if (!st)
  61         return AVERROR(ENOMEM);
  62
  63     /* Parse the amount of channels and skip to pos 2048(0x800) */
  64     url_fskip(s->pb, 264);
  65     st->codec->channels = get_byte(s->pb);
  66     url_fskip(s->pb, 1783);
  67
  68
  69     st->codec->codec_type     = AVMEDIA_TYPE_AUDIO;
  70     st->codec->codec_id       = CODEC_ID_ATRAC1;
  71     st->codec->sample_rate    = 44100;
  72     st->codec->bit_rate       = 292000;
  73
  74     if (st->codec->channels != 1 && st->codec->channels != 2) {
  75         av_log(s,AV_LOG_ERROR,"Channels %d not supported!\n",st->codec->channels);
  76         return -1;
  77     }
  78
  79     st->codec->channel_layout = (st->codec->channels == 1) ? CH_LAYOUT_MONO : CH_LAYOUT_STEREO;
  80
  81     st->codec->block_align = AT1_SU_SIZE * st->codec->channels;
  82     return 0;
  83 }
  84
  85 static int aea_read_packet(AVFormatContext *s, AVPacket *pkt)
  86 {
  87     int ret = av_get_packet(s->pb, pkt, s->streams[0]->codec->block_align);
  88
  89     pkt->stream_index = 0;
  90     if (ret <= 0)
  91         return AVERROR(EIO);
  92
  93     return ret;
  94 }
  95
  96 AVInputFormat aea_demuxer = {
  97     "aea",
  98     NULL_IF_CONFIG_SMALL("MD STUDIO audio"),
  99     0,
 100     aea_read_probe,
 101     aea_read_header,
 102     aea_read_packet,
 103     0,
 104     pcm_read_seek,
 105     .flags= AVFMT_GENERIC_INDEX,
 106     .extensions = "aea",
 107 };
 108