libavformat/svag.c

   1 /*
   2  * SVAG demuxer
   3  * Copyright (c) 2015 Paul B Mahol
   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 "avformat.h"
  23 #include "internal.h"
  24
  25 static int svag_probe(AVProbeData *p)
  26 {
  27     if (memcmp(p->buf, "Svag", 4))
  28         return 0;
  29
  30     return AVPROBE_SCORE_MAX;
  31 }
  32
  33 static int svag_read_header(AVFormatContext *s)
  34 {
  35     unsigned size, align;
  36     AVStream *st;
  37
  38     avio_skip(s->pb, 4);
  39
  40     st = avformat_new_stream(s, NULL);
  41     if (!st)
  42         return AVERROR(ENOMEM);
  43
  44     size                   = avio_rl32(s->pb);
  45     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
  46     st->codecpar->codec_id    = AV_CODEC_ID_ADPCM_PSX;
  47     st->codecpar->sample_rate = avio_rl32(s->pb);
  48     if (st->codecpar->sample_rate <= 0)
  49         return AVERROR_INVALIDDATA;
  50     st->codecpar->channels    = avio_rl32(s->pb);
  51     if (st->codecpar->channels <= 0 || st->codecpar->channels > 8)
  52         return AVERROR_INVALIDDATA;
  53     st->duration           = size / (16 * st->codecpar->channels) * 28;
  54     align                  = avio_rl32(s->pb);
  55     if (align <= 0 || align > INT_MAX / st->codecpar->channels)
  56         return AVERROR_INVALIDDATA;
  57     st->codecpar->block_align = align * st->codecpar->channels;
  58     avio_skip(s->pb, 0x800 - avio_tell(s->pb));
  59     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  60
  61     return 0;
  62 }
  63
  64 static int svag_read_packet(AVFormatContext *s, AVPacket *pkt)
  65 {
  66     AVCodecParameters *par = s->streams[0]->codecpar;
  67
  68     return av_get_packet(s->pb, pkt, par->block_align);
  69 }
  70
  71 AVInputFormat ff_svag_demuxer = {
  72     .name           = "svag",
  73     .long_name      = NULL_IF_CONFIG_SMALL("Konami PS2 SVAG"),
  74     .read_probe     = svag_probe,
  75     .read_header    = svag_read_header,
  76     .read_packet    = svag_read_packet,
  77     .extensions     = "svag",
  78 };