FFmpeg: libavformat/luodatdec.c Source File

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 
48  static int dat_read_header(AVFormatContext *s)
49 {
50  s->ctx_flags |= AVFMTCTX_NOHEADER;
51 
52  avio_seek(s->pb, 0x2000, SEEK_SET);
53 
54  return 0;
55 }
56 
57  static int dat_read_packet(AVFormatContext *s, AVPacket *pkt)
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) {
90  AVStream *st = avformat_new_stream(s, NULL);
91 
92  if (!st)
93  return AVERROR(ENOMEM);
94 
95  st->id = stream_id;
96  st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
97  st->codecpar->codec_id = AV_CODEC_ID_H264;
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 
118  const AVInputFormat ff_luodat_demuxer = {
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 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVERROR
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: options.c:237
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:57
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:456
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:429
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:465
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:697
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:505
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:482
pts
static int64_t pts
Definition: transcode_aac.c:654
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:790
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:656
width
#define width
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:256
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:661
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:455
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:127
key
const char * key
Definition: hwcontext_opencl.c:174
AV_CODEC_ID_H264
@ AV_CODEC_ID_H264
Definition: codec_id.h:77
AVFormatContext
Format I/O context.
Definition: avformat.h:1213
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1108
NULL
#define NULL
Definition: coverity.c:32
AVFMTCTX_NOHEADER
#define AVFMTCTX_NOHEADER
signal that no header is present (streams are added dynamically)
Definition: avformat.h:1164
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:453
index
int index
Definition: gxfenc.c:89
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:759
AVIOContext
Bytestream IO Context.
Definition: avio.h:162
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
MKBETAG
#define MKBETAG(a, b, c, d)
Definition: macros.h:56
height
#define height
dat_read_packet
static int dat_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: luodatdec.c:57
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:380
ff_luodat_demuxer
const AVInputFormat ff_luodat_demuxer
Definition: luodatdec.c:118
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:367
avio_internal.h
AVCodecParameters::height
int height
Definition: codec_par.h:128
av_get_packet
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:102
AVStream::id
int id
Format-specific stream ID.
Definition: avformat.h:962
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:948
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:260
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
AVPacket::stream_index
int stream_index
Definition: packet.h:376
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:347
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:61
AVPacket
This structure stores compressed data.
Definition: packet.h:351
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:394
avio_rl64
uint64_t avio_rl64(AVIOContext *s)
Definition: aviobuf.c:767
dat_probe
static int dat_probe(const AVProbeData *p)
Definition: luodatdec.c:28
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:375
dat_read_header
static int dat_read_header(AVFormatContext *s)
Definition: luodatdec.c:48
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