FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
lvfdec.c
Go to the documentation of this file.
1 /*
2  * LVF 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 "avformat.h"
24 #include "riff.h"
25 
26 static int lvf_probe(AVProbeData *p)
27 {
28  if (AV_RL32(p->buf) != MKTAG('L', 'V', 'F', 'F'))
29  return 0;
30 
31  if (!AV_RL32(p->buf + 16) || AV_RL32(p->buf + 16) > 256)
32  return AVPROBE_SCORE_MAX / 8;
33 
35 }
36 
38 {
39  AVStream *st;
40  int64_t next_offset;
41  unsigned size, nb_streams, id;
42 
43  avio_skip(s->pb, 16);
44  nb_streams = avio_rl32(s->pb);
45  if (!nb_streams)
46  return AVERROR_INVALIDDATA;
47  if (nb_streams > 2) {
48  avpriv_request_sample(s, "%d streams", nb_streams);
49  return AVERROR_PATCHWELCOME;
50  }
51 
52  avio_skip(s->pb, 1012);
53 
54  while (!url_feof(s->pb)) {
55  id = avio_rl32(s->pb);
56  size = avio_rl32(s->pb);
57  next_offset = avio_tell(s->pb) + size;
58 
59  switch (id) {
60  case MKTAG('0', '0', 'f', 'm'):
61  st = avformat_new_stream(s, 0);
62  if (!st)
63  return AVERROR(ENOMEM);
64 
66  avio_skip(s->pb, 4);
67  st->codec->width = avio_rl32(s->pb);
68  st->codec->height = avio_rl32(s->pb);
69  avio_skip(s->pb, 4);
70  st->codec->codec_tag = avio_rl32(s->pb);
72  st->codec->codec_tag);
73  avpriv_set_pts_info(st, 32, 1, 1000);
74  break;
75  case MKTAG('0', '1', 'f', 'm'):
76  st = avformat_new_stream(s, 0);
77  if (!st)
78  return AVERROR(ENOMEM);
79 
81  st->codec->codec_tag = avio_rl16(s->pb);
82  st->codec->channels = avio_rl16(s->pb);
83  st->codec->sample_rate = avio_rl16(s->pb);
84  avio_skip(s->pb, 8);
87  st->codec->codec_tag);
88  avpriv_set_pts_info(st, 32, 1, 1000);
89  break;
90  case 0:
91  avio_seek(s->pb, 2048 + 8, SEEK_SET);
92  return 0;
93  default:
94  avpriv_request_sample(s, "id %d", id);
95  return AVERROR_PATCHWELCOME;
96  }
97 
98  avio_seek(s->pb, next_offset, SEEK_SET);
99  }
100 
101  return AVERROR_EOF;
102 }
103 
105 {
106  unsigned size, flags, timestamp, id;
107  int64_t pos;
108  int ret, is_video = 0;
109 
110  pos = avio_tell(s->pb);
111  while (!url_feof(s->pb)) {
112  id = avio_rl32(s->pb);
113  size = avio_rl32(s->pb);
114 
115  if (size == 0xFFFFFFFFu)
116  return AVERROR_EOF;
117 
118  switch (id) {
119  case MKTAG('0', '0', 'd', 'c'):
120  is_video = 1;
121  case MKTAG('0', '1', 'w', 'b'):
122  if (size < 8)
123  return AVERROR_INVALIDDATA;
124  timestamp = avio_rl32(s->pb);
125  flags = avio_rl32(s->pb);
126  ret = av_get_packet(s->pb, pkt, size - 8);
127  if (flags & (1 << 12))
128  pkt->flags |= AV_PKT_FLAG_KEY;
129  pkt->stream_index = is_video ? 0 : 1;
130  pkt->pts = timestamp;
131  pkt->pos = pos;
132  return ret;
133  default:
134  ret = avio_skip(s->pb, size);
135  }
136 
137  if (ret < 0)
138  return ret;
139  }
140 
141  return AVERROR_EOF;
142 }
143 
145  .name = "lvf",
146  .long_name = NULL_IF_CONFIG_SMALL("LVF"),
147  .read_probe = lvf_probe,
148  .read_header = lvf_read_header,
149  .read_packet = lvf_read_packet,
150  .extensions = "lvf",
151  .flags = AVFMT_GENERIC_INDEX,
152 };