audio_policy.h revision 114c2fd2d3d953763edb4372324c993bd66cbe91
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 18#ifndef ANDROID_AUDIO_POLICY_INTERFACE_H 19#define ANDROID_AUDIO_POLICY_INTERFACE_H 20 21#include <stdint.h> 22#include <sys/cdefs.h> 23#include <sys/types.h> 24 25#include <hardware/hardware.h> 26 27#include <system/audio.h> 28#include <system/audio_policy.h> 29 30__BEGIN_DECLS 31 32/** 33 * The id of this module 34 */ 35#define AUDIO_POLICY_HARDWARE_MODULE_ID "audio_policy" 36 37/** 38 * Name of the audio devices to open 39 */ 40#define AUDIO_POLICY_INTERFACE "policy" 41 42/* ---------------------------------------------------------------------------- */ 43 44/* 45 * The audio_policy and audio_policy_service_ops structs define the 46 * communication interfaces between the platform specific audio policy manager 47 * and Android generic audio policy manager. 48 * The platform specific audio policy manager must implement methods of the 49 * audio_policy struct. 50 * This implementation makes use of the audio_policy_service_ops to control 51 * the activity and configuration of audio input and output streams. 52 * 53 * The platform specific audio policy manager is in charge of the audio 54 * routing and volume control policies for a given platform. 55 * The main roles of this module are: 56 * - keep track of current system state (removable device connections, phone 57 * state, user requests...). 58 * System state changes and user actions are notified to audio policy 59 * manager with methods of the audio_policy. 60 * 61 * - process get_output() queries received when AudioTrack objects are 62 * created: Those queries return a handler on an output that has been 63 * selected, configured and opened by the audio policy manager and that 64 * must be used by the AudioTrack when registering to the AudioFlinger 65 * with the createTrack() method. 66 * When the AudioTrack object is released, a release_output() query 67 * is received and the audio policy manager can decide to close or 68 * reconfigure the output depending on other streams using this output and 69 * current system state. 70 * 71 * - similarly process get_input() and release_input() queries received from 72 * AudioRecord objects and configure audio inputs. 73 * - process volume control requests: the stream volume is converted from 74 * an index value (received from UI) to a float value applicable to each 75 * output as a function of platform specific settings and current output 76 * route (destination device). It also make sure that streams are not 77 * muted if not allowed (e.g. camera shutter sound in some countries). 78 */ 79 80/* XXX: this should be defined OUTSIDE of frameworks/base */ 81struct effect_descriptor_s; 82 83struct audio_policy { 84 /* 85 * configuration functions 86 */ 87 88 /* indicate a change in device connection status */ 89 int (*set_device_connection_state)(struct audio_policy *pol, 90 audio_devices_t device, 91 audio_policy_dev_state_t state, 92 const char *device_address); 93 94 /* retrieve a device connection status */ 95 audio_policy_dev_state_t (*get_device_connection_state)( 96 const struct audio_policy *pol, 97 audio_devices_t device, 98 const char *device_address); 99 100 /* indicate a change in phone state. Valid phones states are defined 101 * by audio_mode_t */ 102 void (*set_phone_state)(struct audio_policy *pol, audio_mode_t state); 103 104 /* deprecated, never called (was "indicate a change in ringer mode") */ 105 void (*set_ringer_mode)(struct audio_policy *pol, uint32_t mode, 106 uint32_t mask); 107 108 /* force using a specific device category for the specified usage */ 109 void (*set_force_use)(struct audio_policy *pol, 110 audio_policy_force_use_t usage, 111 audio_policy_forced_cfg_t config); 112 113 /* retrieve current device category forced for a given usage */ 114 audio_policy_forced_cfg_t (*get_force_use)(const struct audio_policy *pol, 115 audio_policy_force_use_t usage); 116 117 /* if can_mute is true, then audio streams that are marked ENFORCED_AUDIBLE 118 * can still be muted. */ 119 void (*set_can_mute_enforced_audible)(struct audio_policy *pol, 120 bool can_mute); 121 122 /* check proper initialization */ 123 int (*init_check)(const struct audio_policy *pol); 124 125 /* 126 * Audio routing query functions 127 */ 128 129 /* request an output appriate for playback of the supplied stream type and 130 * parameters */ 131 audio_io_handle_t (*get_output)(struct audio_policy *pol, 132 audio_stream_type_t stream, 133 uint32_t samplingRate, 134 audio_format_t format, 135 uint32_t channels, 136 audio_policy_output_flags_t flags); 137 138 /* indicates to the audio policy manager that the output starts being used 139 * by corresponding stream. */ 140 int (*start_output)(struct audio_policy *pol, 141 audio_io_handle_t output, 142 audio_stream_type_t stream, 143 int session); 144 145 /* indicates to the audio policy manager that the output stops being used 146 * by corresponding stream. */ 147 int (*stop_output)(struct audio_policy *pol, 148 audio_io_handle_t output, 149 audio_stream_type_t stream, 150 int session); 151 152 /* releases the output. */ 153 void (*release_output)(struct audio_policy *pol, audio_io_handle_t output); 154 155 /* request an input appriate for record from the supplied device with 156 * supplied parameters. */ 157 audio_io_handle_t (*get_input)(struct audio_policy *pol, int inputSource, 158 uint32_t samplingRate, 159 audio_format_t format, 160 uint32_t channels, 161 audio_in_acoustics_t acoustics); 162 163 /* indicates to the audio policy manager that the input starts being used */ 164 int (*start_input)(struct audio_policy *pol, audio_io_handle_t input); 165 166 /* indicates to the audio policy manager that the input stops being used. */ 167 int (*stop_input)(struct audio_policy *pol, audio_io_handle_t input); 168 169 /* releases the input. */ 170 void (*release_input)(struct audio_policy *pol, audio_io_handle_t input); 171 172 /* 173 * volume control functions 174 */ 175 176 /* initialises stream volume conversion parameters by specifying volume 177 * index range. The index range for each stream is defined by AudioService. */ 178 void (*init_stream_volume)(struct audio_policy *pol, 179 audio_stream_type_t stream, 180 int index_min, 181 int index_max); 182 183 /* sets the new stream volume at a level corresponding to the supplied 184 * index. The index is within the range specified by init_stream_volume() */ 185 int (*set_stream_volume_index)(struct audio_policy *pol, 186 audio_stream_type_t stream, 187 int index); 188 189 /* retrieve current volume index for the specified stream */ 190 int (*get_stream_volume_index)(const struct audio_policy *pol, 191 audio_stream_type_t stream, 192 int *index); 193 194 /* sets the new stream volume at a level corresponding to the supplied 195 * index for the specified device. 196 * The index is within the range specified by init_stream_volume() */ 197 int (*set_stream_volume_index_for_device)(struct audio_policy *pol, 198 audio_stream_type_t stream, 199 int index, 200 audio_devices_t device); 201 202 /* retrieve current volume index for the specified stream for the specified device */ 203 int (*get_stream_volume_index_for_device)(const struct audio_policy *pol, 204 audio_stream_type_t stream, 205 int *index, 206 audio_devices_t device); 207 208 /* return the strategy corresponding to a given stream type */ 209 uint32_t (*get_strategy_for_stream)(const struct audio_policy *pol, 210 audio_stream_type_t stream); 211 212 /* return the enabled output devices for the given stream type */ 213 uint32_t (*get_devices_for_stream)(const struct audio_policy *pol, 214 audio_stream_type_t stream); 215 216 /* Audio effect management */ 217 audio_io_handle_t (*get_output_for_effect)(struct audio_policy *pol, 218 struct effect_descriptor_s *desc); 219 220 int (*register_effect)(struct audio_policy *pol, 221 struct effect_descriptor_s *desc, 222 audio_io_handle_t output, 223 uint32_t strategy, 224 int session, 225 int id); 226 227 int (*unregister_effect)(struct audio_policy *pol, int id); 228 229 int (*set_effect_enabled)(struct audio_policy *pol, int id, bool enabled); 230 231 bool (*is_stream_active)(const struct audio_policy *pol, 232 audio_stream_type_t stream, 233 uint32_t in_past_ms); 234 235 /* dump state */ 236 int (*dump)(const struct audio_policy *pol, int fd); 237}; 238 239struct audio_policy_service_ops { 240 /* 241 * Audio output Control functions 242 */ 243 244 /* Opens an audio output with the requested parameters. 245 * 246 * The parameter values can indicate to use the default values in case the 247 * audio policy manager has no specific requirements for the output being 248 * opened. 249 * 250 * When the function returns, the parameter values reflect the actual 251 * values used by the audio hardware output stream. 252 * 253 * The audio policy manager can check if the proposed parameters are 254 * suitable or not and act accordingly. 255 */ 256 audio_io_handle_t (*open_output)(void *service, 257 uint32_t *pDevices, 258 uint32_t *pSamplingRate, 259 audio_format_t *pFormat, 260 uint32_t *pChannels, 261 uint32_t *pLatencyMs, 262 audio_policy_output_flags_t flags); 263 264 /* creates a special output that is duplicated to the two outputs passed as 265 * arguments. The duplication is performed by 266 * a special mixer thread in the AudioFlinger. 267 */ 268 audio_io_handle_t (*open_duplicate_output)(void *service, 269 audio_io_handle_t output1, 270 audio_io_handle_t output2); 271 272 /* closes the output stream */ 273 int (*close_output)(void *service, audio_io_handle_t output); 274 275 /* suspends the output. 276 * 277 * When an output is suspended, the corresponding audio hardware output 278 * stream is placed in standby and the AudioTracks attached to the mixer 279 * thread are still processed but the output mix is discarded. 280 */ 281 int (*suspend_output)(void *service, audio_io_handle_t output); 282 283 /* restores a suspended output. */ 284 int (*restore_output)(void *service, audio_io_handle_t output); 285 286 /* */ 287 /* Audio input Control functions */ 288 /* */ 289 290 /* opens an audio input */ 291 audio_io_handle_t (*open_input)(void *service, 292 uint32_t *pDevices, 293 uint32_t *pSamplingRate, 294 audio_format_t *pFormat, 295 uint32_t *pChannels, 296 audio_in_acoustics_t acoustics); 297 298 /* closes an audio input */ 299 int (*close_input)(void *service, audio_io_handle_t input); 300 301 /* */ 302 /* misc control functions */ 303 /* */ 304 305 /* set a stream volume for a particular output. 306 * 307 * For the same user setting, a given stream type can have different 308 * volumes for each output (destination device) it is attached to. 309 */ 310 int (*set_stream_volume)(void *service, 311 audio_stream_type_t stream, 312 float volume, 313 audio_io_handle_t output, 314 int delay_ms); 315 316 /* reroute a given stream type to the specified output */ 317 int (*set_stream_output)(void *service, 318 audio_stream_type_t stream, 319 audio_io_handle_t output); 320 321 /* function enabling to send proprietary informations directly from audio 322 * policy manager to audio hardware interface. */ 323 void (*set_parameters)(void *service, 324 audio_io_handle_t io_handle, 325 const char *kv_pairs, 326 int delay_ms); 327 328 /* function enabling to receive proprietary informations directly from 329 * audio hardware interface to audio policy manager. 330 * 331 * Returns a pointer to a heap allocated string. The caller is responsible 332 * for freeing the memory for it. 333 */ 334 335 char * (*get_parameters)(void *service, audio_io_handle_t io_handle, 336 const char *keys); 337 338 /* request the playback of a tone on the specified stream. 339 * used for instance to replace notification sounds when playing over a 340 * telephony device during a phone call. 341 */ 342 int (*start_tone)(void *service, 343 audio_policy_tone_t tone, 344 audio_stream_type_t stream); 345 346 int (*stop_tone)(void *service); 347 348 /* set down link audio volume. */ 349 int (*set_voice_volume)(void *service, 350 float volume, 351 int delay_ms); 352 353 /* move effect to the specified output */ 354 int (*move_effects)(void *service, 355 int session, 356 audio_io_handle_t src_output, 357 audio_io_handle_t dst_output); 358}; 359 360/**********************************************************************/ 361 362/** 363 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM 364 * and the fields of this data structure must begin with hw_module_t 365 * followed by module specific information. 366 */ 367typedef struct audio_policy_module { 368 struct hw_module_t common; 369} audio_policy_module_t; 370 371struct audio_policy_device { 372 struct hw_device_t common; 373 374 int (*create_audio_policy)(const struct audio_policy_device *device, 375 struct audio_policy_service_ops *aps_ops, 376 void *service, 377 struct audio_policy **ap); 378 379 int (*destroy_audio_policy)(const struct audio_policy_device *device, 380 struct audio_policy *ap); 381}; 382 383/** convenience API for opening and closing a supported device */ 384 385static inline int audio_policy_dev_open(const hw_module_t* module, 386 struct audio_policy_device** device) 387{ 388 return module->methods->open(module, AUDIO_POLICY_INTERFACE, 389 (hw_device_t**)device); 390} 391 392static inline int audio_policy_dev_close(struct audio_policy_device* device) 393{ 394 return device->common.close(&device->common); 395} 396 397 398__END_DECLS 399 400#endif // ANDROID_AUDIO_POLICY_INTERFACE_H 401