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>
34 #include "config.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.
63
64 /**
65 * Open an ALSA PCM.
66 *
67 * @param s media file handle
68 * @param mode either SND_PCM_STREAM_CAPTURE or SND_PCM_STREAM_PLAYBACK
69 * @param sample_rate in: requested sample rate;
70 * out: actually selected sample rate
71 * @param channels number of channels
72 * @param codec_id in: requested AVCodecID or AV_CODEC_ID_NONE;
73 * out: actually selected AVCodecID, changed only if
74 * AV_CODEC_ID_NONE was requested
75 *
76 * @return 0 if OK, AVERROR_xxx on error
77 */
82
83 /**
84 * Close the ALSA PCM.
85 *
86 * @param s1 media file handle
87 *
88 * @return 0
89 */
91
92 /**
93 * Try to recover from ALSA buffer underrun.
94 *
95 * @param s1 media file handle
96 * @param err error code reported by the previous ALSA call
97 *
98 * @return 0 if OK, AVERROR_xxx on error
99 */
102
105
108
109 #endif /* AVDEVICE_ALSA_H */