FFmpeg
sdns.c
Go to the documentation of this file.
1 /*
2  * SDNS demuxer
3  * Copyright (c) 2023 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 "demux.h"
26 #include "internal.h"
27 
28 static int sdns_probe(const AVProbeData *p)
29 {
30  if (AV_RL32(p->buf) != MKTAG('S','D','N','S'))
31  return 0;
32  if (AV_RB32(p->buf + 8) <= 0)
33  return 0;
34  if (AV_RB32(p->buf + 12) <= 0 ||
35  AV_RB32(p->buf + 12) > 128)
36  return 0;
37  return AVPROBE_SCORE_MAX / 3;
38 }
39 
41 {
42  AVIOContext *pb = s->pb;
43  AVCodecParameters *par;
44  int channels, ret;
45  AVStream *st;
46 
47  avio_skip(pb, 8);
48 
49  st = avformat_new_stream(s, NULL);
50  if (!st)
51  return AVERROR(ENOMEM);
52 
53  par = st->codecpar;
56  par->sample_rate = avio_rb32(pb);
57  channels = avio_rb32(pb);
59  return AVERROR_INVALIDDATA;
61  if (par->sample_rate <= 0)
62  return AVERROR_INVALIDDATA;
63  par->block_align = 2048;
64  if ((ret = ff_alloc_extradata(par, 8 + 20 * ((channels + 1) / 2))) < 0)
65  return ret;
66  memset(par->extradata, 0, 28);
67  par->extradata[4] = (channels + 1) / 2;
68  for (int i = 0; i < par->extradata[4]; i++)
69  par->extradata[8 + 20 * i + 17] = FFMIN(2, channels - i * 2);
70  avpriv_set_pts_info(st, 64, 1, par->sample_rate);
71  avio_seek(pb, 0x1000, SEEK_SET);
72 
73  return 0;
74 }
75 
77 {
78  int ret;
79 
80  if (avio_feof(s->pb))
81  return AVERROR_EOF;
82  ret = av_get_packet(s->pb, pkt, 2048);
83  pkt->stream_index = 0;
84 
85  return ret;
86 }
87 
89  .name = "sdns",
90  .long_name = NULL_IF_CONFIG_SMALL("Xbox SDNS"),
91  .read_probe = sdns_probe,
92  .read_header = sdns_read_header,
93  .read_packet = sdns_read_packet,
94  .flags = AVFMT_GENERIC_INDEX,
95  .extensions = "sdns",
96 };
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:69
sdns_read_header
static int sdns_read_header(AVFormatContext *s)
Definition: sdns.c:40
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
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:47
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
ff_sdns_demuxer
const AVInputFormat ff_sdns_demuxer
Definition: sdns.c:88
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:464
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:830
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:481
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:808
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:549
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AV_CODEC_ID_XMA1
@ AV_CODEC_ID_XMA1
Definition: codec_id.h:522
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:554
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:454
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
channels
channels
Definition: aptx.h:31
AVFormatContext
Format I/O context.
Definition: avformat.h:1202
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
NULL
#define NULL
Definition: coverity.c:32
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:452
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:206
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:171
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
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:106
AV_RB32
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:96
sdns_read_packet
static int sdns_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: sdns.c:76
av_channel_layout_default
void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels)
Get the default channel layout for a given number of channels.
Definition: channel_layout.c:1033
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:245
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:178
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
demux.h
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:103
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:841
sdns_probe
static int sdns_probe(const AVProbeData *p)
Definition: sdns.c:28
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:278
avformat.h
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
channel_layout.h
AVPacket::stream_index
int stream_index
Definition: packet.h:524
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:365
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:499
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
ff_alloc_extradata
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0.
Definition: utils.c:239
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:393