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 "demux.h"
  24 #include "internal.h"
  25
  26 static int svag_probe(const AVProbeData *p)
  27 {
  28     if (memcmp(p->buf, "Svag", 4))
  29         return 0;
  30
  31     return AVPROBE_SCORE_MAX;
  32 }
  33
  34 static int svag_read_header(AVFormatContext *s)
  35 {
  36     unsigned size, align;
  37     AVStream *st;
  38
  39     avio_skip(s->pb, 4);
  40
  41     st = avformat_new_stream(s, NULL);
  42     if (!st)
  43         return AVERROR(ENOMEM);
  44
  45     size                   = avio_rl32(s->pb);
  46     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
  47     st->codecpar->codec_id    = AV_CODEC_ID_ADPCM_PSX;
  48     st->codecpar->sample_rate = avio_rl32(s->pb);
  49     if (st->codecpar->sample_rate <= 0)
  50         return AVERROR_INVALIDDATA;
  51     st->codecpar->ch_layout.nb_channels = avio_rl32(s->pb);
  52     if (st->codecpar->ch_layout.nb_channels <= 0 ||
  53         st->codecpar->ch_layout.nb_channels > 8)
  54         return AVERROR_INVALIDDATA;
  55     st->duration           = size / (16 * st->codecpar->ch_layout.nb_channels) * 28;
  56     align                  = avio_rl32(s->pb);
  57     if (align <= 0 || align > INT_MAX / st->codecpar->ch_layout.nb_channels)
  58         return AVERROR_INVALIDDATA;
  59     st->codecpar->block_align = align * st->codecpar->ch_layout.nb_channels;
  60     avio_skip(s->pb, 0x800 - avio_tell(s->pb));
  61     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  62
  63     return 0;
  64 }
  65
  66 static int svag_read_packet(AVFormatContext *s, AVPacket *pkt)
  67 {
  68     AVCodecParameters *par = s->streams[0]->codecpar;
  69
  70     return av_get_packet(s->pb, pkt, par->block_align);
  71 }
  72
  73 const FFInputFormat ff_svag_demuxer = {
  74     .p.name         = "svag",
  75     .p.long_name    = NULL_IF_CONFIG_SMALL("Konami PS2 SVAG"),
  76     .p.extensions   = "svag",
  77     .read_probe     = svag_probe,
  78     .read_header    = svag_read_header,
  79     .read_packet    = svag_read_packet,
  80 };