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 (!avio_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->codecpar->width = avio_rl32(s->pb);
68  st->codecpar->height = avio_rl32(s->pb);
69  avio_skip(s->pb, 4);
70  st->codecpar->codec_tag = avio_rl32(s->pb);
72  st->codecpar->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->codecpar->codec_tag = avio_rl16(s->pb);
82  st->codecpar->channels = avio_rl16(s->pb);
83  st->codecpar->sample_rate = avio_rl16(s->pb);
84  avio_skip(s->pb, 8);
87  st->codecpar->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 (!avio_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 };
const char * s
Definition: avisynth_c.h:768
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
enum AVCodecID id
Definition: mxfenc.c:104
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:3027
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1621
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4581
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3981
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:230
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:304
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1338
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
static int nb_streams
Definition: ffprobe.c:254
int width
Video only.
Definition: avcodec.h:4047
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4214
static int lvf_read_header(AVFormatContext *s)
Definition: lvfdec.c:37
static int flags
Definition: log.c:57
#define AVERROR_EOF
End of file.
Definition: error.h:55
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:289
ptrdiff_t size
Definition: opengl_enc.c:101
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:511
static int lvf_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: lvfdec.c:104
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1633
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:726
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3977
const AVCodecTag ff_codec_wav_tags[]
Definition: riff.c:436
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1607
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:595
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:463
static int lvf_probe(AVProbeData *p)
Definition: lvfdec.c:26
const AVCodecTag ff_codec_bmp_tags[]
Definition: riff.c:32
internal header for RIFF based (de)muxers do NOT include this in end user applications ...
AVInputFormat ff_lvf_demuxer
Definition: lvfdec.c:144
Stream structure.
Definition: avformat.h:889
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
AVIOContext * pb
I/O context.
Definition: avformat.h:1380
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:487
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:471
This structure contains the data a format has to probe a file.
Definition: avformat.h:461
int sample_rate
Audio only.
Definition: avcodec.h:4091
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:473
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:710
Main libavformat public API header.
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4023
int channels
Audio only.
Definition: avcodec.h:4087
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:664
AVCodecParameters * codecpar
Definition: avformat.h:1241
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:328
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3985
int stream_index
Definition: avcodec.h:1603
#define MKTAG(a, b, c, d)
Definition: common.h:342
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1578
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1594