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 {
32  AFCDemuxContext *c = s->priv_data;
33  AVStream *st;
34  int ret;
35 
36  st = avformat_new_stream(s, NULL);
37  if (!st)
38  return AVERROR(ENOMEM);
41  st->codecpar->channels = 2;
43 
44  if ((ret = ff_alloc_extradata(st->codecpar, 1)) < 0)
45  return ret;
46  st->codecpar->extradata[0] = 8 * st->codecpar->channels;
47 
48  c->data_end = avio_rb32(s->pb) + 32LL;
49  st->duration = avio_rb32(s->pb);
50  st->codecpar->sample_rate = avio_rb16(s->pb);
51  avio_skip(s->pb, 22);
52  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
53 
54  return 0;
55 }
56 
58 {
59  AFCDemuxContext *c = s->priv_data;
60  int64_t size;
61  int ret;
62 
63  size = FFMIN(c->data_end - avio_tell(s->pb), 18 * 128);
64  if (size <= 0)
65  return AVERROR_EOF;
66 
67  ret = av_get_packet(s->pb, pkt, size);
68  pkt->stream_index = 0;
69  return ret;
70 }
71 
73  .name = "afc",
74  .long_name = NULL_IF_CONFIG_SMALL("AFC"),
75  .priv_data_size = sizeof(AFCDemuxContext),
78  .extensions = "afc",
80 };
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
AVFMT_NO_BYTE_SEEK
#define AVFMT_NO_BYTE_SEEK
Format does not allow seeking by bytes.
Definition: avformat.h:470
afc_read_packet
static int afc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: afc.c:57
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:4372
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
AVFMT_NOBINSEARCH
#define AVFMT_NOBINSEARCH
Format does not allow to fall back on binary search via read_timestamp.
Definition: avformat.h:468
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:875
AV_CH_LAYOUT_STEREO
#define AV_CH_LAYOUT_STEREO
Definition: channel_layout.h:91
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:764
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:616
s
#define s(width, name)
Definition: cbs_vp9.c:257
AV_CODEC_ID_ADPCM_AFC
@ AV_CODEC_ID_ADPCM_AFC
Definition: codec_id.h:382
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:621
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
ff_afc_demuxer
const AVInputFormat ff_afc_demuxer
Definition: afc.c:72
AVFormatContext
Format I/O context.
Definition: avformat.h:1106
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:979
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
NULL
#define NULL
Definition: coverity.c:32
AFCDemuxContext::data_end
int64_t data_end
Definition: afc.c:27
c
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
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
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:117
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:4797
size
int size
Definition: twinvq_data.h:10344
FFMIN
#define FFMIN(a, b)
Definition: common.h:105
AFCDemuxContext
Definition: afc.c:26
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:280
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:832
avio_rb16
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:749
avformat.h
channel_layout.h
AVFMT_NOGENSEARCH
#define AVFMT_NOGENSEARCH
Format does not allow to fall back on generic search.
Definition: avformat.h:469
AVPacket::stream_index
int stream_index
Definition: packet.h:367
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:327
afc_read_header
static int afc_read_header(AVFormatContext *s)
Definition: afc.c:30
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:342
AVCodecParameters::channel_layout
uint64_t channel_layout
Audio only.
Definition: codec_par.h:162
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
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:3261