FFmpeg
svag.c
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1 /*
2  * SVAG 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 
22 #include "avformat.h"
23 #include "internal.h"
24 
25 static int svag_probe(const AVProbeData *p)
26 {
27  if (memcmp(p->buf, "Svag", 4))
28  return 0;
29 
30  return AVPROBE_SCORE_MAX;
31 }
32 
34 {
35  unsigned size, align;
36  AVStream *st;
37 
38  avio_skip(s->pb, 4);
39 
40  st = avformat_new_stream(s, NULL);
41  if (!st)
42  return AVERROR(ENOMEM);
43 
44  size = avio_rl32(s->pb);
47  st->codecpar->sample_rate = avio_rl32(s->pb);
48  if (st->codecpar->sample_rate <= 0)
49  return AVERROR_INVALIDDATA;
50  st->codecpar->channels = avio_rl32(s->pb);
51  if (st->codecpar->channels <= 0 || st->codecpar->channels > 8)
52  return AVERROR_INVALIDDATA;
53  st->duration = size / (16 * st->codecpar->channels) * 28;
54  align = avio_rl32(s->pb);
55  if (align <= 0 || align > INT_MAX / st->codecpar->channels)
56  return AVERROR_INVALIDDATA;
58  avio_skip(s->pb, 0x800 - avio_tell(s->pb));
59  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
60 
61  return 0;
62 }
63 
65 {
66  AVCodecParameters *par = s->streams[0]->codecpar;
67 
68  return av_get_packet(s->pb, pkt, par->block_align);
69 }
70 
72  .name = "svag",
73  .long_name = NULL_IF_CONFIG_SMALL("Konami PS2 SVAG"),
74  .read_probe = svag_probe,
75  .read_header = svag_read_header,
76  .read_packet = svag_read_packet,
77  .extensions = "svag",
78 };
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: utils.c:4480
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3953
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3949
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
AVCodecParameters::channels
int channels
Audio only.
Definition: avcodec.h:4063
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
svag_probe
static int svag_probe(const AVProbeData *p)
Definition: svag.c:25
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:919
AVInputFormat
Definition: avformat.h:640
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVFormatContext
Format I/O context.
Definition: avformat.h:1342
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1017
NULL
#define NULL
Definition: coverity.c:32
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: avcodec.h:4067
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:769
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:188
avpriv_set_pts_info
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:4910
size
int size
Definition: twinvq_data.h:11134
AVCodecParameters::block_align
int block_align
Audio only.
Definition: avcodec.h:4074
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:313
AVStream
Stream structure.
Definition: avformat.h:870
align
const AVS_VideoInfo int align
Definition: avisynth_c.h:887
avformat.h
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
ff_svag_demuxer
AVInputFormat ff_svag_demuxer
Definition: svag.c:71
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:331
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3957
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1454
svag_read_header
static int svag_read_header(AVFormatContext *s)
Definition: svag.c:33
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
AV_CODEC_ID_ADPCM_PSX
@ AV_CODEC_ID_ADPCM_PSX
Definition: avcodec.h:540
svag_read_packet
static int svag_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: svag.c:64