FFmpeg
lvfdec.c
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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(const 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 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:3131
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1497
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:4892
#define avpriv_request_sample(...)
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3957
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:246
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1358
static int nb_streams
Definition: ffprobe.c:280
int width
Video only.
Definition: avcodec.h:4023
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4465
static int lvf_read_header(AVFormatContext *s)
Definition: lvfdec.c:37
#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:310
ptrdiff_t size
Definition: opengl_enc.c:100
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
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:1509
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:772
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3953
const AVCodecTag ff_codec_wav_tags[]
Definition: riff.c:494
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1483
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:641
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
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
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:881
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:468
static int lvf_probe(const AVProbeData *p)
Definition: lvfdec.c:26
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:456
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
#define flags(name, subs,...)
Definition: cbs_av1.c:561
int sample_rate
Audio only.
Definition: avcodec.h:4067
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:756
Main libavformat public API header.
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:3999
int channels
Audio only.
Definition: avcodec.h:4063
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3961
int stream_index
Definition: avcodec.h:1479
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define MKTAG(a, b, c, d)
Definition: common.h:366
enum AVCodecID id
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1454
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1470