1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
/* the Music Player Daemon (MPD)
* Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
* Copyright (C) 2008 Max Kellermann <max@duempel.org>
* This project's homepage is: http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef MPD_OUTPUT_API_H
#define MPD_OUTPUT_API_H
#include "../config.h"
#include "audio_format.h"
#include "tag.h"
#include "conf.h"
#include <stdbool.h>
#define DISABLED_AUDIO_OUTPUT_PLUGIN(plugin) const struct audio_output_plugin plugin;
struct audio_output;
/**
* A plugin which controls an audio output device.
*/
struct audio_output_plugin {
/**
* the plugin's name
*/
const char *name;
/**
* Test if this plugin can provide a default output, in case
* none has been configured. This method is optional.
*/
bool (*test_default_device)(void);
/**
* Configure and initialize the device, but do not open it
* yet.
*
* @param ao an opaque pointer to the audio_output structure
* @param audio_format the configured audio format, or NULL if
* none is configured
* @param param the configuration section, or NULL if there is
* no configuration
* @return NULL on error, or an opaque pointer to the plugin's
* data
*/
void *(*init)(struct audio_output *ao,
const struct audio_format *audio_format,
const struct config_param *param);
/**
* Free resources allocated by this device.
*/
void (*finish)(void *data);
/**
* Really open the device.
* @param audio_format the audio format in which data is going
* to be delivered; may be modified by the plugin
*/
bool (*open)(void *data, struct audio_format *audio_format);
/**
* Play a chunk of audio data.
*/
bool (*play)(void *data, const char *playChunk, size_t size);
/**
* Pause the device. If supported, it may perform a special
* action, which keeps the device open, but does not play
* anything. Output plugins like "shout" might want to play
* silence during pause, so their clients won't be
* disconnected. Plugins which do not support pausing will
* simply be closed, and have to be reopened when unpaused.
*/
void (*pause)(void *data);
/**
* Try to cancel data which may still be in the device's
* buffers.
*/
void (*cancel)(void *data);
/**
* Close the device.
*/
void (*close)(void *data);
/**
* Control the device. Usualy used for implementing
* set and get mixer levels
*/
bool (*control)(void *data, int cmd, void *arg);
/**
* Display metadata for the next chunk. Optional method,
* because not all devices can display metadata.
*/
void (*send_tag)(void *data, const struct tag *tag);
};
enum audio_output_command {
AO_COMMAND_NONE = 0,
AO_COMMAND_OPEN,
AO_COMMAND_CLOSE,
AO_COMMAND_PLAY,
AO_COMMAND_PAUSE,
AO_COMMAND_CANCEL,
AO_COMMAND_SEND_TAG,
AO_COMMAND_KILL
};
enum audio_control_command {
AC_MIXER_GETVOL = 0,
AC_MIXER_SETVOL,
AC_MIXER_CONFIGURE,
};
struct audio_output;
const char *audio_output_get_name(const struct audio_output *ao);
void audio_output_closed(struct audio_output *ao);
/**
* Returns true if there is a command pending.
*/
bool audio_output_is_pending(const struct audio_output *ao);
#endif
|
