FFmpeg
oss_enc.c
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1 /*
2  * Linux audio grab interface
3  * Copyright (c) 2000, 2001 Fabrice Bellard
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 "config.h"
23 
24 #if HAVE_UNISTD_H
25 #include <unistd.h>
26 #endif
27 #include <fcntl.h>
28 #include <sys/ioctl.h>
29 #include <sys/soundcard.h>
30 
31 #include "libavutil/internal.h"
32 
33 #include "libavcodec/avcodec.h"
34 
35 #include "avdevice.h"
36 #include "libavformat/internal.h"
37 
38 #include "oss.h"
39 
41 {
42  OSSAudioData *s = s1->priv_data;
43  AVStream *st;
44  int ret;
45 
46  st = s1->streams[0];
48  s->channels = st->codecpar->channels;
49  ret = ff_oss_audio_open(s1, 1, s1->url);
50  if (ret < 0) {
51  return AVERROR(EIO);
52  } else {
53  return 0;
54  }
55 }
56 
58 {
59  OSSAudioData *s = s1->priv_data;
60  int len, ret;
61  int size= pkt->size;
62  uint8_t *buf= pkt->data;
63 
64  while (size > 0) {
65  len = FFMIN(OSS_AUDIO_BLOCK_SIZE - s->buffer_ptr, size);
66  memcpy(s->buffer + s->buffer_ptr, buf, len);
67  s->buffer_ptr += len;
68  if (s->buffer_ptr >= OSS_AUDIO_BLOCK_SIZE) {
69  for(;;) {
70  ret = write(s->fd, s->buffer, OSS_AUDIO_BLOCK_SIZE);
71  if (ret > 0)
72  break;
73  if (ret < 0 && (errno != EAGAIN && errno != EINTR))
74  return AVERROR(EIO);
75  }
76  s->buffer_ptr = 0;
77  }
78  buf += len;
79  size -= len;
80  }
81  return 0;
82 }
83 
85 {
86  OSSAudioData *s = s1->priv_data;
87 
89  return 0;
90 }
91 
92 static const AVClass oss_muxer_class = {
93  .class_name = "OSS outdev",
94  .item_name = av_default_item_name,
95  .version = LIBAVUTIL_VERSION_INT,
97 };
98 
100  .name = "oss",
101  .long_name = NULL_IF_CONFIG_SMALL("OSS (Open Sound System) playback"),
102  .priv_data_size = sizeof(OSSAudioData),
103  /* XXX: we make the assumption that the soundcard accepts this format */
104  /* XXX: find better solution with "preinit" method, needed also in
105  other formats */
107  .video_codec = AV_CODEC_ID_NONE,
108  .write_header = audio_write_header,
109  .write_packet = audio_write_packet,
110  .write_trailer = audio_write_trailer,
111  .flags = AVFMT_NOFILE,
112  .priv_class = &oss_muxer_class,
113 };
static int audio_write_trailer(AVFormatContext *s1)
Definition: oss_enc.c:84
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
int size
Definition: avcodec.h:1534
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
AVOutputFormat ff_oss_muxer
Definition: oss_enc.c:99
static AVPacket pkt
uint8_t buffer[OSS_AUDIO_BLOCK_SIZE]
Definition: oss.h:36
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
uint8_t
#define AV_NE(be, le)
Definition: common.h:50
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1421
int channels
Definition: oss.h:32
uint8_t * data
Definition: avcodec.h:1533
#define OSS_AUDIO_BLOCK_SIZE
Definition: oss.h:26
ptrdiff_t size
Definition: opengl_enc.c:100
int ff_oss_audio_open(AVFormatContext *s1, int is_output, const char *audio_device)
Definition: oss.c:40
Main libavdevice API header.
#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
common internal API header
#define FFMIN(a, b)
Definition: common.h:96
const char * name
Definition: avformat.h:500
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:876
Libavcodec external API header.
int fd
Definition: oss.h:30
Describe the class of an AVClass context structure.
Definition: log.h:67
static int audio_write_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: oss_enc.c:57
#define s1
Definition: regdef.h:38
int buffer_ptr
Definition: oss.h:37
int sample_rate
Audio only.
Definition: avcodec.h:4146
static int audio_write_header(AVFormatContext *s1)
Definition: oss_enc.c:40
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:458
int ff_oss_audio_close(OSSAudioData *s)
Definition: oss.c:135
int len
void * priv_data
Format private data.
Definition: avformat.h:1381
int channels
Audio only.
Definition: avcodec.h:4142
static const AVClass oss_muxer_class
Definition: oss_enc.c:92
int sample_rate
Definition: oss.h:31
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