FFmpeg
afc.c
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1 /*
2  * AFC 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 
23 #include "avformat.h"
24 #include "internal.h"
25 
26 typedef struct AFCDemuxContext {
27  int64_t data_end;
29 
31 {
33  AVStream *st;
34 
35  st = avformat_new_stream(s, NULL);
36  if (!st)
37  return AVERROR(ENOMEM);
40  st->codecpar->channels = 2;
42 
43  if (ff_alloc_extradata(st->codecpar, 1))
44  return AVERROR(ENOMEM);
45  st->codecpar->extradata[0] = 8 * st->codecpar->channels;
46 
47  c->data_end = avio_rb32(s->pb) + 32LL;
48  st->duration = avio_rb32(s->pb);
49  st->codecpar->sample_rate = avio_rb16(s->pb);
50  avio_skip(s->pb, 22);
51  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
52 
53  return 0;
54 }
55 
57 {
59  int64_t size;
60  int ret;
61 
62  size = FFMIN(c->data_end - avio_tell(s->pb), 18 * 128);
63  if (size <= 0)
64  return AVERROR_EOF;
65 
66  ret = av_get_packet(s->pb, pkt, size);
67  pkt->stream_index = 0;
68  return ret;
69 }
70 
72  .name = "afc",
73  .long_name = NULL_IF_CONFIG_SMALL("AFC"),
74  .priv_data_size = sizeof(AFCDemuxContext),
77  .extensions = "afc",
79 };
#define NULL
Definition: coverity.c:32
#define AVFMT_NOBINSEARCH
Format does not allow to fall back on binary search via read_timestamp.
Definition: avformat.h:473
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:4882
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3953
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:331
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:786
Format I/O context.
Definition: avformat.h:1358
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:801
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4455
static int afc_read_header(AVFormatContext *s)
Definition: afc.c:30
#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:310
ptrdiff_t size
Definition: opengl_enc.c:100
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4055
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3949
audio channel layout utility functions
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:3287
#define FFMIN(a, b)
Definition: common.h:96
#define s(width, name)
Definition: cbs_vp9.c:257
int64_t data_end
Definition: afc.c:27
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:881
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
static int afc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: afc.c:56
#define AVFMT_NOGENSEARCH
Format does not allow to fall back on generic search.
Definition: avformat.h:474
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVInputFormat ff_afc_demuxer
Definition: afc.c:71
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4063
Main libavformat public API header.
#define AVFMT_NO_BYTE_SEEK
Format does not allow seeking by bytes.
Definition: avformat.h:475
void * priv_data
Format private data.
Definition: avformat.h:1386
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3967
int channels
Audio only.
Definition: avcodec.h:4059
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int stream_index
Definition: avcodec.h:1479
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
This structure stores compressed data.
Definition: avcodec.h:1454