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 "demux.h"
  26 #include "internal.h"
  27
  28 static int probe(const AVProbeData *p)
  29 {
  30     if (p->buf_size < 2096)
  31         return 0;
  32     if (   AV_RL32(p->buf     ) != 1
  33         || AV_RL32(p->buf +  8) > 100000
  34         || AV_RL32(p->buf + 12) > 8
  35         || AV_RL32(p->buf + 16) != 2096
  36         ||!AV_RL32(p->buf + 21)
  37         || AV_RL16(p->buf + 25) != 2096
  38         || AV_RL32(p->buf + 48) % AV_RL32(p->buf + 21)
  39         )
  40         return 0;
  41     return AVPROBE_SCORE_EXTENSION;
  42 }
  43
  44
  45 static int read_header(AVFormatContext *s)
  46 {
  47     AVStream *st = avformat_new_stream(s, NULL);
  48     uint32_t data_offset;
  49
  50     if (!st)
  51         return AVERROR(ENOMEM);
  52
  53     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  54     st->codecpar->codec_id = AV_CODEC_ID_ADPCM_MS;
  55
  56     avio_rl32(s->pb);
  57     avio_rl32(s->pb);
  58     st->codecpar->sample_rate = avio_rl32(s->pb);
  59     st->codecpar->ch_layout.nb_channels    = avio_rl32(s->pb);
  60     if (st->codecpar->ch_layout.nb_channels > FF_SANE_NB_CHANNELS ||
  61         st->codecpar->ch_layout.nb_channels <= 0)
  62         return AVERROR(ENOSYS);
  63     ffformatcontext(s)->data_offset = data_offset = avio_rl32(s->pb);
  64     avio_r8(s->pb);
  65     st->codecpar->block_align = avio_rl32(s->pb);
  66     if (st->codecpar->block_align > INT_MAX / FF_SANE_NB_CHANNELS || st->codecpar->block_align <= 0)
  67         return AVERROR_INVALIDDATA;
  68     st->codecpar->block_align *= st->codecpar->ch_layout.nb_channels;
  69
  70     avio_seek(s->pb, data_offset, SEEK_SET);
  71
  72     return 0;
  73 }
  74
  75 static int read_packet(AVFormatContext *s, AVPacket *pkt)
  76 {
  77     AVStream *st = s->streams[0];
  78
  79     return av_get_packet(s->pb, pkt, st->codecpar->block_align);
  80 }
  81
  82 const FFInputFormat ff_boa_demuxer = {
  83     .p.name         = "boa",
  84     .p.long_name    = NULL_IF_CONFIG_SMALL("Black Ops Audio"),
  85     .p.flags        = AVFMT_GENERIC_INDEX,
  86     .read_probe     = probe,
  87     .read_header    = read_header,
  88     .read_packet    = read_packet,
  89 };