libavformat/sdxdec.c

   1 /*
   2  * SDX demuxer
   3  * Copyright (c) 2017 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/avstring.h"
  23 #include "libavutil/intreadwrite.h"
  24 #include "avformat.h"
  25 #include "internal.h"
  26 #include "pcm.h"
  27
  28 static int sdx_probe(const AVProbeData *p)
  29 {
  30     if (AV_RB32(p->buf) == AV_RB32("SDX:"))
  31         return AVPROBE_SCORE_EXTENSION;
  32     return 0;
  33 }
  34
  35 static int sdx_read_header(AVFormatContext *s)
  36 {
  37     AVStream *st;
  38     int depth, length;
  39
  40     avio_skip(s->pb, 4);
  41     while (!avio_feof(s->pb)) {
  42         if (avio_r8(s->pb) == 0x1a)
  43             break;
  44     }
  45     if (avio_r8(s->pb) != 1)
  46         return AVERROR_INVALIDDATA;
  47     length = avio_r8(s->pb);
  48     avio_skip(s->pb, length);
  49     avio_skip(s->pb, 4);
  50     depth = avio_r8(s->pb);
  51
  52     st = avformat_new_stream(s, NULL);
  53     if (!st)
  54         return AVERROR(ENOMEM);
  55
  56     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  57     st->codecpar->channels = 1;
  58     st->codecpar->sample_rate = avio_rl32(s->pb);
  59     switch (depth) {
  60     case 8:
  61         st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
  62         break;
  63     case 16:
  64         st->codecpar->codec_id = AV_CODEC_ID_PCM_U16LE;
  65         break;
  66     case 24:
  67         st->codecpar->codec_id = AV_CODEC_ID_PCM_U24LE;
  68         break;
  69     case 32:
  70         st->codecpar->codec_id = AV_CODEC_ID_PCM_U32LE;
  71         break;
  72     default:
  73         return AVERROR_INVALIDDATA;
  74     }
  75     avio_skip(s->pb, 16);
  76     st->codecpar->block_align = depth / 8;
  77
  78     return 0;
  79 }
  80
  81 AVInputFormat ff_sdx_demuxer = {
  82     .name           = "sdx",
  83     .long_name      = NULL_IF_CONFIG_SMALL("Sample Dump eXchange"),
  84     .read_probe     = sdx_probe,
  85     .read_header    = sdx_read_header,
  86     .read_packet    = ff_pcm_read_packet,
  87     .read_seek      = ff_pcm_read_seek,
  88     .extensions     = "sdx",
  89     .flags          = AVFMT_GENERIC_INDEX,
  90 };