libavformat/derf.c

   1 /*
   2  * DERF demuxer
   3  * Copyright (c) 2020 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 "libavutil/channel_layout.h"
  23 #include "libavutil/intreadwrite.h"
  24 #include "avformat.h"
  25 #include "demux.h"
  26 #include "internal.h"
  27 #include "pcm.h"
  28
  29 static int derf_probe(const AVProbeData *p)
  30 {
  31     if (AV_RL32(p->buf) != MKTAG('D','E','R','F'))
  32         return 0;
  33     if (AV_RL32(p->buf+4) != 1 && AV_RL32(p->buf+4) != 2)
  34         return 0;
  35
  36     return AVPROBE_SCORE_MAX / 3 * 2;
  37 }
  38
  39 static int derf_read_header(AVFormatContext *s)
  40 {
  41     unsigned data_size;
  42     int channels;
  43     AVIOContext *pb = s->pb;
  44     AVCodecParameters *par;
  45     AVStream *st;
  46
  47     avio_skip(pb, 4);
  48
  49     st = avformat_new_stream(s, NULL);
  50     if (!st)
  51         return AVERROR(ENOMEM);
  52
  53     par              = st->codecpar;
  54     par->codec_type  = AVMEDIA_TYPE_AUDIO;
  55     par->codec_id    = AV_CODEC_ID_DERF_DPCM;
  56     par->format      = AV_SAMPLE_FMT_S16;
  57     channels         = avio_rl32(pb);
  58     if (channels != 1 && channels != 2)
  59         return AVERROR_INVALIDDATA;
  60     av_channel_layout_default(&par->ch_layout, channels);
  61     data_size = avio_rl32(pb);
  62     st->duration = data_size / channels;
  63     par->sample_rate = 22050;
  64     par->block_align = 1;
  65
  66     avpriv_set_pts_info(st, 64, 1, par->sample_rate);
  67
  68     return 0;
  69 }
  70
  71 const FFInputFormat ff_derf_demuxer = {
  72     .p.name         = "derf",
  73     .p.long_name    = NULL_IF_CONFIG_SMALL("Xilam DERF"),
  74     .p.extensions   = "adp",
  75     .read_probe     = derf_probe,
  76     .read_header    = derf_read_header,
  77     .read_packet    = ff_pcm_read_packet,
  78     .read_seek      = ff_pcm_read_seek,
  79 };