libavformat/acm.c

   1 /*
   2  * ACM 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 "libavutil/intreadwrite.h"
  23 #include "avformat.h"
  24 #include "demux.h"
  25 #include "rawdec.h"
  26 #include "internal.h"
  27
  28 static int acm_probe(const AVProbeData *p)
  29 {
  30     if (AV_RB32(p->buf) != 0x97280301)
  31         return 0;
  32
  33     return AVPROBE_SCORE_MAX / 3 * 2;
  34 }
  35
  36 static int acm_read_header(AVFormatContext *s)
  37 {
  38     AVStream *st;
  39     int ret;
  40
  41     st = avformat_new_stream(s, NULL);
  42     if (!st)
  43         return AVERROR(ENOMEM);
  44
  45     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  46     st->codecpar->codec_id   = AV_CODEC_ID_INTERPLAY_ACM;
  47
  48     ret = ff_get_extradata(s, st->codecpar, s->pb, 14);
  49     if (ret < 0)
  50         return ret;
  51
  52     st->codecpar->ch_layout.nb_channels = AV_RL16(st->codecpar->extradata +  8);
  53     st->codecpar->sample_rate = AV_RL16(st->codecpar->extradata + 10);
  54     if (st->codecpar->ch_layout.nb_channels <= 0 || st->codecpar->sample_rate <= 0)
  55         return AVERROR_INVALIDDATA;
  56     st->start_time         = 0;
  57     st->duration           = AV_RL32(st->codecpar->extradata +  4) / st->codecpar->ch_layout.nb_channels;
  58     ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL_RAW;
  59     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  60
  61     return 0;
  62 }
  63
  64 const FFInputFormat ff_acm_demuxer = {
  65     .p.name         = "acm",
  66     .p.long_name    = NULL_IF_CONFIG_SMALL("Interplay ACM"),
  67     .p.flags        = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS,
  68     .p.extensions   = "acm",
  69     .p.priv_class   = &ff_raw_demuxer_class,
  70     .read_probe     = acm_probe,
  71     .read_header    = acm_read_header,
  72     .read_packet    = ff_raw_read_partial_packet,
  73     .raw_codec_id   = AV_CODEC_ID_INTERPLAY_ACM,
  74     .priv_data_size = sizeof(FFRawDemuxerContext),
  75 };