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vag.c
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1 /*
2  * VAG demuxer
3  * Copyright (c) 2015 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 
23 #include "avformat.h"
24 #include "internal.h"
25 
26 static int vag_probe(AVProbeData *p)
27 {
28  if (memcmp(p->buf, "VAGp\0\0\0", 7))
29  return 0;
30 
31  return AVPROBE_SCORE_MAX;
32 }
33 
35 {
36  AVStream *st;
37 
38  st = avformat_new_stream(s, NULL);
39  if (!st)
40  return AVERROR(ENOMEM);
41 
42  avio_skip(s->pb, 4);
45  st->codec->channels = 1 + (avio_rb32(s->pb) == 0x00000004);
46  avio_skip(s->pb, 4);
47  if (st->codec->channels > 1) {
48  st->duration = avio_rb32(s->pb);
49  } else {
50  st->duration = avio_rb32(s->pb) / 16 * 28;
51  }
52  st->codec->sample_rate = avio_rb32(s->pb);
53  if (st->codec->sample_rate <= 0)
54  return AVERROR_INVALIDDATA;
55  avio_seek(s->pb, 0x1000, SEEK_SET);
56  if (avio_rl32(s->pb) == MKTAG('V','A','G','p')) {
57  st->codec->block_align = 0x1000 * st->codec->channels;
58  avio_seek(s->pb, 0, SEEK_SET);
59  st->duration = st->duration / 16 * 28;
60  } else {
61  st->codec->block_align = 16 * st->codec->channels;
62  avio_seek(s->pb, st->codec->channels > 1 ? 0x80 : 0x30, SEEK_SET);
63  }
64  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
65 
66  return 0;
67 }
68 
70 {
71  AVCodecContext *codec = s->streams[0]->codec;
72 
73  return av_get_packet(s->pb, pkt, codec->block_align);
74 }
75 
77  .name = "vag",
78  .long_name = NULL_IF_CONFIG_SMALL("Sony PS2 VAG"),
79  .read_probe = vag_probe,
80  .read_header = vag_read_header,
81  .read_packet = vag_read_packet,
82  .extensions = "vag",
83 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
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:4149
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:208
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:282
static AVPacket pkt
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:2324
Format I/O context.
Definition: avformat.h:1314
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:698
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3805
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1382
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:252
static int vag_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: vag.c:69
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:667
#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
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:896
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:462
AVInputFormat ff_vag_demuxer
Definition: vag.c:76
audio channel layout utility functions
static int vag_probe(AVProbeData *p)
Definition: vag.c:26
Stream structure.
Definition: avformat.h:877
static int vag_read_header(AVFormatContext *s)
Definition: vag.c:34
enum AVMediaType codec_type
Definition: avcodec.h:1540
enum AVCodecID codec_id
Definition: avcodec.h:1549
int sample_rate
samples per second
Definition: avcodec.h:2287
AVIOContext * pb
I/O context.
Definition: avformat.h:1356
main external API structure.
Definition: avcodec.h:1532
This structure contains the data a format has to probe a file.
Definition: avformat.h:460
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:936
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:472
Main libavformat public API header.
int channels
number of audio channels
Definition: avcodec.h:2288
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:661
#define MKTAG(a, b, c, d)
Definition: common.h:342
This structure stores compressed data.
Definition: avcodec.h:1444