FFmpeg
sndio_dec.c
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1 /*
2  * sndio play and grab interface
3  * Copyright (c) 2010 Jacob Meuser
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 <stdint.h>
23 #include <sndio.h>
24 
25 #include "libavutil/internal.h"
26 #include "libavutil/opt.h"
27 #include "libavutil/time.h"
28 
29 #include "libavformat/avformat.h"
30 #include "libavformat/internal.h"
31 
32 #include "libavdevice/sndio.h"
33 
35 {
36  SndioData *s = s1->priv_data;
37  AVStream *st;
38  int ret;
39 
41  if (!st)
42  return AVERROR(ENOMEM);
43 
44  ret = ff_sndio_open(s1, 0, s1->url);
45  if (ret < 0)
46  return ret;
47 
48  /* take real parameters */
50  st->codecpar->codec_id = s->codec_id;
51  st->codecpar->sample_rate = s->sample_rate;
52  st->codecpar->channels = s->channels;
53 
54  avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
55 
56  return 0;
57 }
58 
60 {
61  SndioData *s = s1->priv_data;
62  int64_t bdelay, cur_time;
63  int ret;
64 
65  if ((ret = av_new_packet(pkt, s->buffer_size)) < 0)
66  return ret;
67 
68  ret = sio_read(s->hdl, pkt->data, pkt->size);
69  if (ret == 0 || sio_eof(s->hdl)) {
71  return AVERROR_EOF;
72  }
73 
74  pkt->size = ret;
75  s->softpos += ret;
76 
77  /* compute pts of the start of the packet */
78  cur_time = av_gettime();
79 
80  bdelay = ret + s->hwpos - s->softpos;
81 
82  /* convert to pts */
83  pkt->pts = cur_time - ((bdelay * 1000000) /
84  (s->bps * s->channels * s->sample_rate));
85 
86  return 0;
87 }
88 
90 {
91  SndioData *s = s1->priv_data;
92 
94 
95  return 0;
96 }
97 
98 static const AVOption options[] = {
99  { "sample_rate", "", offsetof(SndioData, sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
100  { "channels", "", offsetof(SndioData, channels), AV_OPT_TYPE_INT, {.i64 = 2}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
101  { NULL },
102 };
103 
104 static const AVClass sndio_demuxer_class = {
105  .class_name = "sndio indev",
106  .item_name = av_default_item_name,
107  .option = options,
108  .version = LIBAVUTIL_VERSION_INT,
110 };
111 
113  .name = "sndio",
114  .long_name = NULL_IF_CONFIG_SMALL("sndio audio capture"),
115  .priv_data_size = sizeof(SndioData),
119  .flags = AVFMT_NOFILE,
120  .priv_class = &sndio_demuxer_class,
121 };
audio_read_close
static av_cold int audio_read_close(AVFormatContext *s1)
Definition: sndio_dec.c:89
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:417
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
opt.h
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:724
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:57
ff_sndio_open
av_cold int ff_sndio_open(AVFormatContext *s1, int is_output, const char *audio_device)
Definition: sndio.c:36
AVPacket::data
uint8_t * data
Definition: packet.h:373
AVOption
AVOption.
Definition: opt.h:247
sndio.h
sample_rate
sample_rate
Definition: ffmpeg_filter.c:156
sndio_demuxer_class
static const AVClass sndio_demuxer_class
Definition: sndio_dec.c:104
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:141
AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT
@ AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT
Definition: log.h:43
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:638
av_cold
#define av_cold
Definition: attributes.h:90
s
#define s(width, name)
Definition: cbs_vp9.c:257
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:99
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:643
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
s1
#define s1
Definition: regdef.h:38
ff_sndio_demuxer
const AVInputFormat ff_sndio_demuxer
Definition: sndio_dec.c:112
channels
channels
Definition: aptx.h:33
AVFormatContext
Format I/O context.
Definition: avformat.h:1109
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1004
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
time.h
SndioData
Definition: sndio.h:31
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
AVPacket::size
int size
Definition: packet.h:374
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
AVFMT_NOFILE
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:463
ff_sndio_close
int ff_sndio_close(SndioData *s)
Definition: sndio.c:112
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:366
internal.h
AV_OPT_FLAG_DECODING_PARAM
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:278
audio_read_header
static av_cold int audio_read_header(AVFormatContext *s1)
Definition: sndio_dec.c:34
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:857
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
avformat.h
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:224
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: utils.c:1146
av_gettime
int64_t av_gettime(void)
Get the current time in microseconds.
Definition: time.c:39
options
static const AVOption options[]
Definition: sndio_dec.c:98
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:350
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
audio_read_packet
static int audio_read_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: sndio_dec.c:59