FFmpeg
luodatdec.c
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1 /*
2  * CCTV DAT demuxer
3  *
4  * Copyright (c) 2020 Paul B Mahol
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "libavutil/intreadwrite.h"
24 #include "avio_internal.h"
25 #include "avformat.h"
26 #include "internal.h"
27 
28 static int dat_probe(const AVProbeData *p)
29 {
30  if (p->buf_size < 0x2080)
31  return 0;
32 
33  if (memcmp(p->buf, "luo ", 4))
34  return 0;
35 
36  if (memcmp(p->buf + 0x1ffc, " oulliu ", 8))
37  return 0;
38 
39  if (!AV_RL32(p->buf + 0x2004))
40  return 0;
41 
42  if (memcmp(p->buf + 0x207c, " uil", 4))
43  return 0;
44 
45  return AVPROBE_SCORE_MAX;
46 }
47 
49 {
51 
52  avio_seek(s->pb, 0x2000, SEEK_SET);
53 
54  return 0;
55 }
56 
58 {
59  AVIOContext *pb = s->pb;
60  int index, ret, key, stream_id, stream_index, width, height, fps, pkt_size;
61  int64_t pts, pos = avio_tell(pb);
62 
63  if (avio_feof(pb))
64  return AVERROR_EOF;
65 
66  if (avio_rb32(pb) != MKBETAG('l', 'i', 'u', ' '))
67  return AVERROR_INVALIDDATA;
68  stream_id = avio_rl32(pb);
69  width = avio_rl32(pb);
70  height = avio_rl32(pb);
71  fps = avio_rl32(pb);
72  avio_skip(pb, 16);
73  key = avio_rl32(pb) == 1;
74  avio_skip(pb, 4);
75  index = avio_rl32(pb);
76  avio_skip(pb, 4);
77  pts = avio_rl64(pb);
78  pkt_size = avio_rl32(pb);
79  avio_skip(pb, 64);
80 
81  if (pkt_size == 0)
82  return AVERROR_EOF;
83 
84  for (stream_index = 0; stream_index < s->nb_streams; stream_index++) {
85  if (s->streams[stream_index]->id == stream_id)
86  break;
87  }
88 
89  if (stream_index == s->nb_streams) {
91 
92  if (!st)
93  return AVERROR(ENOMEM);
94 
95  st->id = stream_id;
98  st->codecpar->width = width;
99  st->codecpar->height = height;
100  avpriv_set_pts_info(st, 64, 1, fps);
101  }
102 
103  if (index >= s->nb_streams)
104  av_log(s, AV_LOG_WARNING, "Stream index out of range.\n");
105 
106  ret = av_get_packet(pb, pkt, pkt_size);
107  if (ret < 0)
108  return ret;
109  pkt->pos = pos;
110  pkt->pts = pts;
111  pkt->stream_index = stream_index;
112  if (key)
113  pkt->flags |= AV_PKT_FLAG_KEY;
114 
115  return ret;
116 }
117 
119  .name = "luodat",
120  .long_name = NULL_IF_CONFIG_SMALL("Video CCTV DAT"),
121  .read_probe = dat_probe,
122  .read_header = dat_read_header,
123  .read_packet = dat_read_packet,
124  .extensions = "dat",
125  .flags = AVFMT_GENERIC_INDEX,
126 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:383
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:4871
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:341
const char * key
static AVPacket pkt
int ctx_flags
Flags signalling stream properties.
Definition: avformat.h:1288
static int dat_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: luodatdec.c:57
static int dat_read_header(AVFormatContext *s)
Definition: luodatdec.c:48
Format I/O context.
Definition: avformat.h:1239
int width
Video only.
Definition: codec_par.h:126
#define AVFMTCTX_NOHEADER
signal that no header is present (streams are added dynamically)
Definition: avformat.h:1183
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:783
int id
Format-specific stream ID.
Definition: avformat.h:887
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4453
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1307
#define height
#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:305
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
#define av_log(a,...)
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:401
static int dat_probe(const AVProbeData *p)
Definition: luodatdec.c:28
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:752
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
unsigned int pos
Definition: spdifenc.c:410
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:369
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1295
#define width
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:880
AVIOContext * pb
I/O context.
Definition: avformat.h:1281
int index
Definition: gxfenc.c:89
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
AVInputFormat ff_luodat_demuxer
Definition: luodatdec.c:118
static int64_t pts
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
Main libavformat public API header.
#define MKBETAG(a, b, c, d)
Definition: common.h:406
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:652
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1045
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:368
int stream_index
Definition: packet.h:365
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
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:91
This structure stores compressed data.
Definition: packet.h:340
uint64_t avio_rl64(AVIOContext *s)
Definition: aviobuf.c:760
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:356