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 
40  st = avformat_new_stream(s1, NULL);
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;
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)) {
70  av_packet_unref(pkt);
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 
93  ff_sndio_close(s);
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 };
#define NULL
Definition: coverity.c:32
AVOption.
Definition: opt.h:246
static const AVOption options[]
Definition: sndio_dec.c:98
int channels
Definition: sndio.h:41
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
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:4943
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:4036
int size
Definition: avcodec.h:1534
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
static int audio_read_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: sndio_dec.c:59
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1353
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:72
enum AVCodecID codec_id
Definition: sndio.h:34
#define av_cold
Definition: attributes.h:82
AVOptions.
int sample_rate
Definition: sndio.h:42
static const AVClass sndio_demuxer_class
Definition: sndio_dec.c:104
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4524
uint8_t * data
Definition: avcodec.h:1533
#define AVERROR_EOF
End of file.
Definition: error.h:55
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
channels
Definition: aptx.h:33
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
AVInputFormat ff_sndio_demuxer
Definition: sndio_dec.c:112
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
char * url
input or output URL.
Definition: avformat.h:1449
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:4032
common internal API header
int bps
Definition: sndio.h:38
static av_cold int audio_read_close(AVFormatContext *s1)
Definition: sndio_dec.c:89
#define s(width, name)
Definition: cbs_vp9.c:257
int ff_sndio_close(SndioData *s)
Definition: sndio.c:112
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
int64_t av_gettime(void)
Get the current time in microseconds.
Definition: time.c:39
Stream structure.
Definition: avformat.h:876
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
sample_rate
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:600
int buffer_size
Definition: sndio.h:39
Describe the class of an AVClass context structure.
Definition: log.h:67
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:277
av_cold int ff_sndio_open(AVFormatContext *s1, int is_output, const char *audio_device)
Definition: sndio.c:36
#define s1
Definition: regdef.h:38
#define flags(name, subs,...)
Definition: cbs_av1.c:564
int64_t hwpos
Definition: sndio.h:35
int64_t softpos
Definition: sndio.h:36
struct sio_hdl * hdl
Definition: sndio.h:33
int sample_rate
Audio only.
Definition: avcodec.h:4146
Main libavformat public API header.
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:458
void * priv_data
Format private data.
Definition: avformat.h:1381
int channels
Audio only.
Definition: avcodec.h:4142
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:650
static av_cold int audio_read_header(AVFormatContext *s1)
Definition: sndio_dec.c:34
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1023
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:1510
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1526