libavformat/boadec.c

   1 /*
   2  * Black ops audio demuxer
   3  * Copyright (c) 2013 Michael Niedermayer
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/intreadwrite.h"
  23 #include "libavcodec/internal.h"
  24 #include "avformat.h"
  25 #include "internal.h"
  26
  27 static int probe(const AVProbeData *p)
  28 {
  29     if (p->buf_size < 2096)
  30         return 0;
  31     if (   AV_RL32(p->buf     ) != 1
  32         || AV_RL32(p->buf +  8) > 100000
  33         || AV_RL32(p->buf + 12) > 8
  34         || AV_RL32(p->buf + 16) != 2096
  35         ||!AV_RL32(p->buf + 21)
  36         || AV_RL16(p->buf + 25) != 2096
  37         || AV_RL32(p->buf + 48) % AV_RL32(p->buf + 21)
  38         )
  39         return 0;
  40     return AVPROBE_SCORE_EXTENSION;
  41 }
  42
  43
  44 static int read_header(AVFormatContext *s)
  45 {
  46     AVStream *st = avformat_new_stream(s, NULL);
  47     if (!st)
  48         return AVERROR(ENOMEM);
  49
  50     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  51     st->codecpar->codec_id = AV_CODEC_ID_ADPCM_MS;
  52
  53     avio_rl32(s->pb);
  54     avio_rl32(s->pb);
  55     st->codecpar->sample_rate = avio_rl32(s->pb);
  56     st->codecpar->channels    = avio_rl32(s->pb);
  57     if (st->codecpar->channels > FF_SANE_NB_CHANNELS || st->codecpar->channels <= 0)
  58         return AVERROR(ENOSYS);
  59     s->internal->data_offset = avio_rl32(s->pb);
  60     avio_r8(s->pb);
  61     st->codecpar->block_align = avio_rl32(s->pb);
  62     if (st->codecpar->block_align > INT_MAX / FF_SANE_NB_CHANNELS || st->codecpar->block_align <= 0)
  63         return AVERROR_INVALIDDATA;
  64     st->codecpar->block_align *= st->codecpar->channels;
  65
  66     avio_seek(s->pb, s->internal->data_offset, SEEK_SET);
  67
  68     return 0;
  69 }
  70
  71 static int read_packet(AVFormatContext *s, AVPacket *pkt)
  72 {
  73     AVStream *st = s->streams[0];
  74
  75     return av_get_packet(s->pb, pkt, st->codecpar->block_align);
  76 }
  77
  78 AVInputFormat ff_boa_demuxer = {
  79     .name           = "boa",
  80     .long_name      = NULL_IF_CONFIG_SMALL("Black Ops Audio"),
  81     .read_probe     = probe,
  82     .read_header    = read_header,
  83     .read_packet    = read_packet,
  84     .flags          = AVFMT_GENERIC_INDEX,
  85 };