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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->codecpar->width = avio_rb32(pb);
59  st->codecpar->height = avio_rb32(pb);
60  avio_skip(pb, 12);
62  st->codecpar->codec_tag = avio_rb32(pb);
64  st->codecpar->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 (avio_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:631
Bytestream IO Context.
Definition: avio.h:111
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:2944
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1597
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:4404
static av_always_inline float av_int2float(uint32_t i)
Reinterpret a 32-bit integer as a float.
Definition: intfloat.h:40
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3915
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:287
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1319
int width
Video only.
Definition: avcodec.h:3981
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:703
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1595
enum AVStreamParseType need_parsing
Definition: avformat.h:1074
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4042
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:87
#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:260
static int read_probe(AVProbeData *p)
Definition: mgsts.c:27
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3911
Only parse headers, do not repack.
Definition: avformat.h:807
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:461
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:32
internal header for RIFF based (de)muxers do NOT include this in end user applications ...
Stream structure.
Definition: avformat.h:876
AVIOContext * pb
I/O context.
Definition: avformat.h:1361
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:485
rational number numerator/denominator
Definition: rational.h:43
This structure contains the data a format has to probe a file.
Definition: avformat.h:459
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:930
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:471
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:923
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:932
int den
denominator
Definition: rational.h:45
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:660
AVCodecParameters * codecpar
Definition: avformat.h:1006
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:311
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3919
This structure stores compressed data.
Definition: avcodec.h:1554