FFmpeg: libavformat/dsfdec.c Source File

FFmpeg
dsfdec.c
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1 /*
2  * DSD Stream File (DSF) demuxer
3  * Copyright (c) 2014 Peter Ross
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 "internal.h"
25 #include "id3v2.h"
26 
27  typedef struct {
28   uint64_t data_end;
29 } DSFContext;
30 
31  static int dsf_probe(AVProbeData *p)
32 {
33  if (p->buf_size < 12 || memcmp(p->buf, "DSD ", 4) || AV_RL64(p->buf + 4) != 28)
34  return 0;
35  return AVPROBE_SCORE_MAX;
36 }
37 
38  static const uint64_t dsf_channel_layout[] = {
39  0,
40  AV_CH_LAYOUT_MONO,
41  AV_CH_LAYOUT_STEREO,
42  AV_CH_LAYOUT_SURROUND,
43  AV_CH_LAYOUT_QUAD,
44  AV_CH_LAYOUT_4POINT0,
45  AV_CH_LAYOUT_5POINT0_BACK,
46  AV_CH_LAYOUT_5POINT1_BACK,
47 };
48 
49  static void read_id3(AVFormatContext *s, uint64_t id3pos)
50 {
51  ID3v2ExtraMeta *id3v2_extra_meta = NULL;
52  if (avio_seek(s->pb, id3pos, SEEK_SET) < 0)
53  return;
54 
55  ff_id3v2_read(s, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta, 0);
56  if (id3v2_extra_meta)
57  ff_id3v2_parse_apic(s, &id3v2_extra_meta);
58  ff_id3v2_free_extra_meta(&id3v2_extra_meta);
59 }
60 
61  static int dsf_read_header(AVFormatContext *s)
62 {
63  DSFContext *dsf = s->priv_data;
64  AVIOContext *pb = s->pb;
65  AVStream *st;
66  uint64_t id3pos;
67  unsigned int channel_type;
68 
69  avio_skip(pb, 4);
70  if (avio_rl64(pb) != 28)
71  return AVERROR_INVALIDDATA;
72 
73  /* create primary stream before any id3 coverart streams */
74  st = avformat_new_stream(s, NULL);
75  if (!st)
76  return AVERROR(ENOMEM);
77 
78  avio_skip(pb, 8);
79  id3pos = avio_rl64(pb);
80  if (pb->seekable) {
81  read_id3(s, id3pos);
82  avio_seek(pb, 28, SEEK_SET);
83  }
84 
85  /* fmt chunk */
86 
87  if (avio_rl32(pb) != MKTAG('f', 'm', 't', ' ') || avio_rl64(pb) != 52)
88  return AVERROR_INVALIDDATA;
89 
90  if (avio_rl32(pb) != 1) {
91  avpriv_request_sample(s, "unknown format version");
92  return AVERROR_INVALIDDATA;
93  }
94 
95  if (avio_rl32(pb)) {
96  avpriv_request_sample(s, "unknown format id");
97  return AVERROR_INVALIDDATA;
98  }
99 
100  channel_type = avio_rl32(pb);
101  if (channel_type < FF_ARRAY_ELEMS(dsf_channel_layout))
102  st->codec->channel_layout = dsf_channel_layout[channel_type];
103  if (!st->codec->channel_layout)
104  avpriv_request_sample(s, "channel type %i", channel_type);
105 
106  st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
107  st->codec->channels = avio_rl32(pb);
108  st->codec->sample_rate = avio_rl32(pb) / 8;
109 
110  switch(avio_rl32(pb)) {
111  case 1: st->codec->codec_id = AV_CODEC_ID_DSD_LSBF_PLANAR; break;
112  case 8: st->codec->codec_id = AV_CODEC_ID_DSD_MSBF_PLANAR; break;
113  default:
114  avpriv_request_sample(s, "unknown most significant bit");
115  return AVERROR_INVALIDDATA;
116  }
117 
118  avio_skip(pb, 8);
119  st->codec->block_align = avio_rl32(pb);
120  if (st->codec->block_align > INT_MAX / st->codec->channels) {
121  avpriv_request_sample(s, "block_align overflow");
122  return AVERROR_INVALIDDATA;
123  }
124  st->codec->block_align *= st->codec->channels;
125  avio_skip(pb, 4);
126 
127  /* data chunk */
128 
129  dsf->data_end = avio_tell(pb);
130  if (avio_rl32(pb) != MKTAG('d', 'a', 't', 'a'))
131  return AVERROR_INVALIDDATA;
132  dsf->data_end += avio_rl64(pb);
133 
134  return 0;
135 }
136 
137  static int dsf_read_packet(AVFormatContext *s, AVPacket *pkt)
138 {
139  DSFContext *dsf = s->priv_data;
140  AVIOContext *pb = s->pb;
141  AVStream *st = s->streams[0];
142  int64_t pos = avio_tell(pb);
143 
144  if (pos >= dsf->data_end)
145  return AVERROR_EOF;
146 
147  pkt->stream_index = 0;
148  return av_get_packet(pb, pkt, FFMIN(dsf->data_end - pos, st->codec->block_align));
149 }
150 
151  AVInputFormat ff_dsf_demuxer = {
152  .name = "dsf",
153  .long_name = NULL_IF_CONFIG_SMALL("DSD Stream File (DSF)"),
154  .priv_data_size = sizeof(DSFContext),
155  .read_probe = dsf_probe,
156  .read_header = dsf_read_header,
157  .read_packet = dsf_read_packet,
158  .flags = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK,
159 };
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