mgsts.c
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1 /*
2  * Metar Gear Solid: The Twin Snakes 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 "libavutil/intfloat.h"
24 #include "avformat.h"
25 #include "riff.h"
26 
27 static int read_probe(AVProbeData *p)
28 {
29  if (AV_RB32(p->buf ) != 0x000E ||
30  AV_RB32(p->buf + 4) != 0x0050 ||
31  AV_RB32(p->buf + 12) != 0x0034)
32  return 0;
33  return AVPROBE_SCORE_MAX;
34 }
35 
37 {
38  AVIOContext *pb = s->pb;
39  AVStream *st;
40  AVRational fps;
41  uint32_t chunk_size;
42 
43  avio_skip(pb, 4);
44  chunk_size = avio_rb32(pb);
45  if (chunk_size != 80)
46  return AVERROR(EIO);
47  avio_skip(pb, 20);
48 
49  st = avformat_new_stream(s, 0);
50  if (!st)
51  return AVERROR(ENOMEM);
52 
54  st->start_time = 0;
55  st->nb_frames =
56  st->duration = avio_rb32(pb);
57  fps = av_d2q(av_int2float(avio_rb32(pb)), INT_MAX);
58  st->codec->width = avio_rb32(pb);
59  st->codec->height = avio_rb32(pb);
60  avio_skip(pb, 12);
62  st->codec->codec_tag = avio_rb32(pb);
64  st->codec->codec_tag);
65  avpriv_set_pts_info(st, 64, fps.den, fps.num);
66  avio_skip(pb, 20);
67 
68  return 0;
69 }
70 
72 {
73  AVIOContext *pb = s->pb;
74  uint32_t chunk_size, payload_size;
75  int ret;
76 
77  if (url_feof(pb))
78  return AVERROR_EOF;
79 
80  avio_skip(pb, 4);
81  chunk_size = avio_rb32(pb);
82  avio_skip(pb, 4);
83  payload_size = avio_rb32(pb);
84 
85  if (chunk_size < payload_size + 16)
86  return AVERROR(EIO);
87 
88  ret = av_get_packet(pb, pkt, payload_size);
89  if (ret < 0)
90  return ret;
91 
92  pkt->pos -= 16;
93  pkt->duration = 1;
94  avio_skip(pb, chunk_size - (ret + 16));
95 
96  return ret;
97 }
98 
100  .name = "mgsts",
101  .long_name = NULL_IF_CONFIG_SMALL("Metal Gear Solid: The Twin Snakes"),
102  .read_probe = read_probe,
103  .read_header = read_header,
104  .read_packet = read_packet,
105  .flags = AVFMT_GENERIC_INDEX,
106 };
const char * s
Definition: avisynth_c.h:668
Bytestream IO Context.
Definition: avio.h:68
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
int64_t pos
byte position in stream, -1 if unknown
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.
static av_always_inline float av_int2float(uint32_t i)
Reinterpret a 32-bit integer as a float.
Definition: intfloat.h:40
int num
numerator
Definition: rational.h:44
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:256
Format I/O context.
Definition: avformat.h:944
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:610
#define AV_RB32
static AVPacket pkt
Definition: demuxing.c:56
enum AVStreamParseType need_parsing
Definition: avformat.h:811
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
#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.
int duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
static int read_probe(AVProbeData *p)
Definition: mgsts.c:27
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Only parse headers, do not repack.
Definition: avformat.h:583
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:662
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:336
static int read_header(AVFormatContext *s)
Definition: mgsts.c:36
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
const AVCodecTag ff_codec_bmp_tags[]
Definition: riff.c:35
ret
Definition: avfilter.c:821
int width
picture width / height.
internal header for RIFF based (de)muxers do NOT include this in end user applications ...
int url_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:280
Stream structure.
Definition: avformat.h:643
enum AVMediaType codec_type
enum AVCodecID codec_id
AVIOContext * pb
I/O context.
Definition: avformat.h:977
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> (&#39;D&#39;<<24) + (&#39;C&#39;<<16) + (&#39;B&#39;<<8) + &#39;A&#39;).
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:353
rational number numerator/denominator
Definition: rational.h:43
This structure contains the data a format has to probe a file.
Definition: avformat.h:334
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFilterBuffer 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.Buffer references ownership and permissions
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mgsts.c:71
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:696
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:340
AVInputFormat ff_mgsts_demuxer
Definition: mgsts.c:99
Main libavformat public API header.
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:689
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:698
int den
denominator
Definition: rational.h:45
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:461
This structure stores compressed data.