libavformat/epafdec.c

   1 /*
   2  * Ensoniq Paris Audio File demuxer
   3  * Copyright (c) 2012 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/intreadwrite.h"
  23 #include "libavcodec/internal.h"
  24 #include "avformat.h"
  25 #include "demux.h"
  26 #include "internal.h"
  27 #include "pcm.h"
  28
  29 static int epaf_probe(const AVProbeData *p)
  30 {
  31     if (((AV_RL32(p->buf) == MKTAG('f','a','p',' ') &&
  32           AV_RL32(p->buf + 8) == 1) ||
  33          (AV_RL32(p->buf) == MKTAG(' ','p','a','f') &&
  34           AV_RN32(p->buf + 8) == 0)) &&
  35        !AV_RN32(p->buf +  4) && AV_RN32(p->buf + 12) &&
  36         AV_RN32(p->buf + 20))
  37         return AVPROBE_SCORE_MAX / 4 * 3;
  38     return 0;
  39 }
  40
  41 static int epaf_read_header(AVFormatContext *s)
  42 {
  43     int le, sample_rate, codec, channels;
  44     AVStream *st;
  45
  46     avio_skip(s->pb, 4);
  47     if (avio_rl32(s->pb))
  48         return AVERROR_INVALIDDATA;
  49
  50     le = avio_rl32(s->pb);
  51     if (le && le != 1)
  52         return AVERROR_INVALIDDATA;
  53
  54     if (le) {
  55         sample_rate = avio_rl32(s->pb);
  56         codec       = avio_rl32(s->pb);
  57         channels    = avio_rl32(s->pb);
  58     } else {
  59         sample_rate = avio_rb32(s->pb);
  60         codec       = avio_rb32(s->pb);
  61         channels    = avio_rb32(s->pb);
  62     }
  63
  64     if (channels <= 0 || channels > FF_SANE_NB_CHANNELS || sample_rate <= 0)
  65         return AVERROR_INVALIDDATA;
  66
  67     st = avformat_new_stream(s, NULL);
  68     if (!st)
  69         return AVERROR(ENOMEM);
  70
  71     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
  72     st->codecpar->ch_layout.nb_channels = channels;
  73     st->codecpar->sample_rate = sample_rate;
  74     switch (codec) {
  75     case 0:
  76         st->codecpar->codec_id = le ? AV_CODEC_ID_PCM_S16LE : AV_CODEC_ID_PCM_S16BE;
  77         break;
  78     case 2:
  79         st->codecpar->codec_id = AV_CODEC_ID_PCM_S8;
  80         break;
  81     case 1:
  82         avpriv_request_sample(s, "24-bit Paris PCM format");
  83     default:
  84         return AVERROR_INVALIDDATA;
  85     }
  86
  87     st->codecpar->bits_per_coded_sample = av_get_bits_per_sample(st->codecpar->codec_id);
  88     st->codecpar->block_align = st->codecpar->bits_per_coded_sample *
  89                                 st->codecpar->ch_layout.nb_channels / 8;
  90
  91     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  92
  93     if (avio_skip(s->pb, 2024) < 0)
  94         return AVERROR_INVALIDDATA;
  95     return 0;
  96 }
  97
  98 const FFInputFormat ff_epaf_demuxer = {
  99     .p.name         = "epaf",
 100     .p.long_name    = NULL_IF_CONFIG_SMALL("Ensoniq Paris Audio File"),
 101     .p.extensions   = "paf,fap",
 102     .p.flags        = AVFMT_GENERIC_INDEX,
 103     .read_probe     = epaf_probe,
 104     .read_header    = epaf_read_header,
 105     .read_packet    = ff_pcm_read_packet,
 106     .read_seek      = ff_pcm_read_seek,
 107 };