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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197
|
/*
* Copyright (C) 2003-2009 The Music Player Daemon Project
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_OUTPUT_PLUGIN_H
#define MPD_OUTPUT_PLUGIN_H
#include <glib.h>
#include <stdbool.h>
#include <stddef.h>
struct config_param;
struct audio_format;
struct tag;
/**
* 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 audio_format the configured audio format, or NULL if
* none is configured
* @param param the configuration section, or NULL if there is
* no configuration
* @param error location to store the error occuring, or NULL
* to ignore errors
* @return NULL on error, or an opaque pointer to the plugin's
* data
*/
void *(*init)(const struct audio_format *audio_format,
const struct config_param *param,
GError **error);
/**
* 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
* @param error location to store the error occuring, or NULL
* to ignore errors
*/
bool (*open)(void *data, struct audio_format *audio_format,
GError **error);
/**
* Close the device.
*/
void (*close)(void *data);
/**
* Display metadata for the next chunk. Optional method,
* because not all devices can display metadata.
*/
void (*send_tag)(void *data, const struct tag *tag);
/**
* Play a chunk of audio data.
*
* @param error location to store the error occuring, or NULL
* to ignore errors
* @return the number of bytes played, or 0 on error
*/
size_t (*play)(void *data, const void *chunk, size_t size,
GError **error);
/**
* Try to cancel data which may still be in the device's
* buffers.
*/
void (*cancel)(void *data);
/**
* 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.
*
* @return false on error (output will be closed then), true
* for continue to pause
*/
bool (*pause)(void *data);
/**
* The mixer plugin associated with this output plugin. This
* may be NULL if no mixer plugin is implemented. When
* created, this mixer plugin gets the same #config_param as
* this audio output device.
*/
const struct mixer_plugin *mixer_plugin;
};
static inline bool
ao_plugin_test_default_device(const struct audio_output_plugin *plugin)
{
return plugin->test_default_device != NULL
? plugin->test_default_device()
: false;
}
static inline void *
ao_plugin_init(const struct audio_output_plugin *plugin,
const struct audio_format *audio_format,
const struct config_param *param,
GError **error)
{
return plugin->init(audio_format, param, error);
}
static inline void
ao_plugin_finish(const struct audio_output_plugin *plugin, void *data)
{
plugin->finish(data);
}
static inline bool
ao_plugin_open(const struct audio_output_plugin *plugin,
void *data, struct audio_format *audio_format,
GError **error)
{
return plugin->open(data, audio_format, error);
}
static inline void
ao_plugin_close(const struct audio_output_plugin *plugin, void *data)
{
plugin->close(data);
}
static inline void
ao_plugin_send_tag(const struct audio_output_plugin *plugin,
void *data, const struct tag *tag)
{
if (plugin->send_tag != NULL)
plugin->send_tag(data, tag);
}
static inline size_t
ao_plugin_play(const struct audio_output_plugin *plugin,
void *data, const void *chunk, size_t size,
GError **error)
{
return plugin->play(data, chunk, size, error);
}
static inline void
ao_plugin_cancel(const struct audio_output_plugin *plugin, void *data)
{
if (plugin->cancel != NULL)
plugin->cancel(data);
}
static inline bool
ao_plugin_pause(const struct audio_output_plugin *plugin, void *data)
{
return plugin->pause != NULL
? plugin->pause(data)
: false;
}
#endif
|