Blame view

ffmpeg-4.2.2/libavformat/acm.c 2.43 KB
aac5773f   hucm   功能基本完成,接口待打磨
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
  /*
   * ACM demuxer
   * Copyright (c) 2015 Paul B Mahol
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "libavutil/intreadwrite.h"
  #include "avformat.h"
  #include "rawdec.h"
  #include "internal.h"
  
  static int acm_probe(const AVProbeData *p)
  {
      if (AV_RB32(p->buf) != 0x97280301)
          return 0;
  
      return AVPROBE_SCORE_MAX / 3 * 2;
  }
  
  static int acm_read_header(AVFormatContext *s)
  {
      AVStream *st;
      int ret;
  
      st = avformat_new_stream(s, NULL);
      if (!st)
          return AVERROR(ENOMEM);
  
      st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
      st->codecpar->codec_id   = AV_CODEC_ID_INTERPLAY_ACM;
  
      ret = ff_get_extradata(s, st->codecpar, s->pb, 14);
      if (ret < 0)
          return ret;
  
      st->codecpar->channels    = AV_RL16(st->codecpar->extradata +  8);
      st->codecpar->sample_rate = AV_RL16(st->codecpar->extradata + 10);
      if (st->codecpar->channels <= 0 || st->codecpar->sample_rate <= 0)
          return AVERROR_INVALIDDATA;
      st->start_time         = 0;
      st->duration           = AV_RL32(st->codecpar->extradata +  4) / st->codecpar->channels;
      st->need_parsing       = AVSTREAM_PARSE_FULL_RAW;
      avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  
      return 0;
  }
  
  FF_RAW_DEMUXER_CLASS(acm)
  AVInputFormat ff_acm_demuxer = {
      .name           = "acm",
      .long_name      = NULL_IF_CONFIG_SMALL("Interplay ACM"),
      .read_probe     = acm_probe,
      .read_header    = acm_read_header,
      .read_packet    = ff_raw_read_partial_packet,
      .flags          = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS,
      .extensions     = "acm",
      .raw_codec_id   = AV_CODEC_ID_INTERPLAY_ACM,
      .priv_data_size = sizeof(FFRawDemuxerContext),
      .priv_class     = &acm_demuxer_class,
  };