FFmpeg  4.4.5
svs.c
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1 /*
2  * SVS 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 
23 #include "libavutil/intreadwrite.h"
24 #include "avformat.h"
25 #include "internal.h"
26 
27 static int svs_probe(const AVProbeData *p)
28 {
29  if (p->buf_size < 32)
30  return 0;
31 
32  if (memcmp(p->buf, "SVS\00", 4))
33  return 0;
34 
35  if (AV_RL32(p->buf + 16) == 0)
36  return 0;
37 
38  return AVPROBE_SCORE_MAX / 3;
39 }
40 
42 {
43  AVStream *st;
44  uint32_t pitch;
45 
46  st = avformat_new_stream(s, NULL);
47  if (!st)
48  return AVERROR(ENOMEM);
49 
50  avio_skip(s->pb, 16);
51  pitch = avio_rl32(s->pb);
52  avio_skip(s->pb, 12);
53 
54  s->internal->data_offset = avio_tell(s->pb);
58  st->codecpar->channels = 2;
59  st->codecpar->sample_rate = av_rescale_rnd(pitch, 48000, 4096, AV_ROUND_INF);
60  st->codecpar->block_align = 32;
61  st->start_time = 0;
62  if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
64  avio_size(s->pb) - 32);
65 
66  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
67 
68  return 0;
69 }
70 
72 {
73  int ret;
74 
75  if (avio_feof(s->pb))
76  return AVERROR_EOF;
77 
78  ret = av_get_packet(s->pb, pkt, 32 * 256);
79  if (ret != 32 * 256) {
80  if (ret < 0)
81  return ret;
83  }
84  pkt->stream_index = 0;
85 
86  return ret;
87 }
88 
90  .name = "svs",
91  .long_name = NULL_IF_CONFIG_SMALL("Square SVS"),
92  .read_probe = svs_probe,
93  .read_header = svs_read_header,
94  .read_packet = svs_read_packet,
95  .extensions = "svs",
96 };
Main libavformat public API header.
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
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:310
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:342
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:337
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:750
#define AV_RL32
Definition: intreadwrite.h:146
#define s(width, name)
Definition: cbs_vp9.c:257
audio channel layout utility functions
#define NULL
Definition: coverity.c:32
#define AV_CH_LAYOUT_STEREO
@ AV_CODEC_ID_ADPCM_PSX
Definition: codec_id.h:391
int av_get_audio_frame_duration2(AVCodecParameters *par, int frame_bytes)
This function is the same as av_get_audio_frame_duration(), except it works with AVCodecParameters in...
Definition: utils.c:871
#define AV_PKT_FLAG_CORRUPT
The packet content is corrupted.
Definition: packet.h:411
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4509
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define AVERROR(e)
Definition: error.h:43
int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd)
Rescale a 64-bit integer with specified rounding.
Definition: mathematics.c:58
@ AV_ROUND_INF
Round away from zero.
Definition: mathematics.h:81
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
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:4945
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
uint64_t channel_layout
Audio only.
Definition: codec_par.h:162
int channels
Audio only.
Definition: codec_par.h:166
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
int block_align
Audio only.
Definition: codec_par.h:177
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int sample_rate
Audio only.
Definition: codec_par.h:170
Format I/O context.
Definition: avformat.h:1232
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
This structure stores compressed data.
Definition: packet.h:346
int stream_index
Definition: packet.h:371
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:375
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:922
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:912
static int svs_read_header(AVFormatContext *s)
Definition: svs.c:41
static int svs_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: svs.c:71
static int svs_probe(const AVProbeData *p)
Definition: svs.c:27
AVInputFormat ff_svs_demuxer
Definition: svs.c:89
AVPacket * pkt
Definition: movenc.c:59