FFmpeg
mods.c
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1 /*
2  * MODS demuxer
3  * Copyright (c) 2020 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 
24 #include "avformat.h"
25 #include "internal.h"
26 
27 static int mods_probe(const AVProbeData *p)
28 {
29  if (memcmp(p->buf, "MODSN3\x0a\x00", 8))
30  return 0;
31  if (AV_RB32(p->buf + 8) == 0)
32  return 0;
33  if (AV_RB32(p->buf + 12) == 0)
34  return 0;
35  if (AV_RB32(p->buf + 16) == 0)
36  return 0;
37  return AVPROBE_SCORE_MAX;
38 }
39 
41 {
42  AVIOContext *pb = s->pb;
43  AVRational fps;
44  int64_t pos;
45 
47  if (!st)
48  return AVERROR(ENOMEM);
49 
50  avio_skip(pb, 8);
51 
52  st->nb_frames = avio_rl32(pb);
55  st->codecpar->width = avio_rl32(pb);
56  st->codecpar->height = avio_rl32(pb);
57 
58  fps.num = avio_rl32(pb);
59  fps.den = 0x1000000;
60  avpriv_set_pts_info(st, 64, fps.den, fps.num);
61 
62  avio_skip(pb, 16);
63 
64  pos = avio_rl32(pb) + 4;
65  avio_seek(pb, pos, SEEK_SET);
66  pos = avio_rl32(pb);
67  avio_seek(pb, pos, SEEK_SET);
68 
69  return 0;
70 }
71 
73 {
74  AVIOContext *pb = s->pb;
75  unsigned size;
76  int64_t pos;
77  int ret;
78 
79  if (avio_feof(pb))
80  return AVERROR_EOF;
81 
82  pos = avio_tell(pb);
83  size = avio_rl32(pb) >> 14;
84  ret = av_get_packet(pb, pkt, size);
85  pkt->pos = pos;
86  pkt->stream_index = 0;
87  pkt->flags |= AV_PKT_FLAG_KEY;
88 
89  return ret;
90 }
91 
93  .name = "mods",
94  .long_name = NULL_IF_CONFIG_SMALL("MobiClip MODS"),
95  .read_probe = mods_probe,
96  .read_header = mods_read_header,
97  .read_packet = mods_read_packet,
98  .extensions = "mods",
99  .flags = AVFMT_GENERIC_INDEX,
100 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
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:4868
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int num
Numerator.
Definition: rational.h:59
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
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1355
int width
Video only.
Definition: codec_par.h:126
static int mods_read_header(AVFormatContext *s)
Definition: mods.c:40
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4449
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:91
static int mods_probe(const AVProbeData *p)
Definition: mods.c:27
#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
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
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:401
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
static int mods_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mods.c:72
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
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:880
AVIOContext * pb
I/O context.
Definition: avformat.h:1397
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
Rational number (pair of numerator and denominator).
Definition: rational.h:58
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
Main libavformat public API header.
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:931
int den
Denominator.
Definition: rational.h:60
AVInputFormat ff_mods_demuxer
Definition: mods.c:92
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:1027
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
This structure stores compressed data.
Definition: packet.h:340