1 /*
2 * ALSA input and output
3 * Copyright (c) 2007 Luca Abeni ( lucabe72 email it )
4 * Copyright (c) 2007 Benoit Fouet ( benoit fouet free fr )
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file
25 * ALSA input and output: definitions and structures
26 * @author Luca Abeni ( lucabe72 email it )
27 * @author Benoit Fouet ( benoit fouet free fr )
28 */
29
30 #ifndef AVDEVICE_ALSA_H
31 #define AVDEVICE_ALSA_H
32
33 #include <alsa/asoundlib.h>
38
39 /* XXX: we make the assumption that the soundcard accepts this format */
40 /* XXX: find better solution with "preinit" method, needed also in
41 other formats */
42 #define DEFAULT_CODEC_ID AV_NE(AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE)
43
45
46 #define ALSA_BUFFER_SIZE_MAX 131072
47
52 int period_size;
///< preferred size for reads and writes, in frames
54 int channels;
///< number of channels set by user
60 int64_t
timestamp;
///< current timestamp, without latency applied.
62
63 /**
64 * Open an ALSA PCM.
65 *
66 * @param s media file handle
67 * @param mode either SND_PCM_STREAM_CAPTURE or SND_PCM_STREAM_PLAYBACK
68 * @param sample_rate in: requested sample rate;
69 * out: actually selected sample rate
70 * @param channels number of channels
71 * @param codec_id in: requested AVCodecID or AV_CODEC_ID_NONE;
72 * out: actually selected AVCodecID, changed only if
73 * AV_CODEC_ID_NONE was requested
74 *
75 * @return 0 if OK, AVERROR_xxx on error
76 */
81
82 /**
83 * Close the ALSA PCM.
84 *
85 * @param s1 media file handle
86 *
87 * @return 0
88 */
90
91 /**
92 * Try to recover from ALSA buffer underrun.
93 *
94 * @param s1 media file handle
95 * @param err error code reported by the previous ALSA call
96 *
97 * @return 0 if OK, AVERROR_xxx on error
98 */
101
104
107
108 #endif /* AVDEVICE_ALSA_H */
int64_t timestamp
current timestamp, without latency applied.
Opaque type representing a time filter state.
void(* reorder_func)(const void *, void *, int)
Main libavdevice API header.
av_warn_unused_result int ff_alsa_open(AVFormatContext *s, snd_pcm_stream_t mode, unsigned int *sample_rate, int channels, enum AVCodecID *codec_id)
Open an ALSA PCM.
AVCodecID
Identify the syntax and semantics of the bitstream.
av_warn_unused_result int ff_alsa_extend_reorder_buf(AlsaData *s, int size)
av_warn_unused_result int ff_alsa_get_device_list(AVDeviceInfoList *device_list, snd_pcm_stream_t stream_type)
av_warn_unused_result int ff_alsa_xrun_recover(AVFormatContext *s1, int err)
Try to recover from ALSA buffer underrun.
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
void(* ff_reorder_func)(const void *, void *, int)
int channels
number of channels set by user
int ff_alsa_close(AVFormatContext *s1)
Close the ALSA PCM.
Describe the class of an AVClass context structure.
int period_size
preferred size for reads and writes, in frames
#define av_warn_unused_result
int frame_size
bytes per sample * channels
int sample_rate
sample rate set by user
int reorder_buf_size
in frames
mode
Use these values in ebur128_init (or'ed).