1 /*
2  * Copyright (C) 2008 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 #ifndef ANDROID_AUDIOSYSTEM_H_
18 #define ANDROID_AUDIOSYSTEM_H_
19 
20 #include <sys/types.h>
21 
22 #include <media/AudioPolicy.h>
23 #include <media/AudioProductStrategy.h>
24 #include <media/AudioVolumeGroup.h>
25 #include <media/AudioIoDescriptor.h>
26 #include <media/IAudioFlingerClient.h>
27 #include <media/IAudioPolicyServiceClient.h>
28 #include <media/MicrophoneInfo.h>
29 #include <system/audio.h>
30 #include <system/audio_effect.h>
31 #include <system/audio_policy.h>
32 #include <utils/Errors.h>
33 #include <utils/Mutex.h>
34 #include <vector>
35 
36 namespace android {
37 
38 typedef void (*audio_error_callback)(status_t err);
39 typedef void (*dynamic_policy_callback)(int event, String8 regId, int val);
40 typedef void (*record_config_callback)(int event,
41                                        const record_client_info_t *clientInfo,
42                                        const audio_config_base_t *clientConfig,
43                                        std::vector<effect_descriptor_t> clientEffects,
44                                        const audio_config_base_t *deviceConfig,
45                                        std::vector<effect_descriptor_t> effects,
46                                        audio_patch_handle_t patchHandle,
47                                        audio_source_t source);
48 
49 class IAudioFlinger;
50 class IAudioPolicyService;
51 class String8;
52 
53 class AudioSystem
54 {
55 public:
56 
57     // FIXME Declare in binder opcode order, similarly to IAudioFlinger.h and IAudioFlinger.cpp
58 
59     /* These are static methods to control the system-wide AudioFlinger
60      * only privileged processes can have access to them
61      */
62 
63     // mute/unmute microphone
64     static status_t muteMicrophone(bool state);
65     static status_t isMicrophoneMuted(bool *state);
66 
67     // set/get master volume
68     static status_t setMasterVolume(float value);
69     static status_t getMasterVolume(float* volume);
70 
71     // mute/unmute audio outputs
72     static status_t setMasterMute(bool mute);
73     static status_t getMasterMute(bool* mute);
74 
75     // set/get stream volume on specified output
76     static status_t setStreamVolume(audio_stream_type_t stream, float value,
77                                     audio_io_handle_t output);
78     static status_t getStreamVolume(audio_stream_type_t stream, float* volume,
79                                     audio_io_handle_t output);
80 
81     // mute/unmute stream
82     static status_t setStreamMute(audio_stream_type_t stream, bool mute);
83     static status_t getStreamMute(audio_stream_type_t stream, bool* mute);
84 
85     // set audio mode in audio hardware
86     static status_t setMode(audio_mode_t mode);
87 
88     // returns true in *state if tracks are active on the specified stream or have been active
89     // in the past inPastMs milliseconds
90     static status_t isStreamActive(audio_stream_type_t stream, bool *state, uint32_t inPastMs);
91     // returns true in *state if tracks are active for what qualifies as remote playback
92     // on the specified stream or have been active in the past inPastMs milliseconds. Remote
93     // playback isn't mutually exclusive with local playback.
94     static status_t isStreamActiveRemotely(audio_stream_type_t stream, bool *state,
95             uint32_t inPastMs);
96     // returns true in *state if a recorder is currently recording with the specified source
97     static status_t isSourceActive(audio_source_t source, bool *state);
98 
99     // set/get audio hardware parameters. The function accepts a list of parameters
100     // key value pairs in the form: key1=value1;key2=value2;...
101     // Some keys are reserved for standard parameters (See AudioParameter class).
102     // The versions with audio_io_handle_t are intended for internal media framework use only.
103     static status_t setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs);
104     static String8  getParameters(audio_io_handle_t ioHandle, const String8& keys);
105     // The versions without audio_io_handle_t are intended for JNI.
106     static status_t setParameters(const String8& keyValuePairs);
107     static String8  getParameters(const String8& keys);
108 
109     static void setErrorCallback(audio_error_callback cb);
110     static void setDynPolicyCallback(dynamic_policy_callback cb);
111     static void setRecordConfigCallback(record_config_callback);
112 
113     // helper function to obtain AudioFlinger service handle
114     static const sp<IAudioFlinger> get_audio_flinger();
115 
116     static float linearToLog(int volume);
117     static int logToLinear(float volume);
118     static size_t calculateMinFrameCount(
119             uint32_t afLatencyMs, uint32_t afFrameCount, uint32_t afSampleRate,
120             uint32_t sampleRate, float speed /*, uint32_t notificationsPerBufferReq*/);
121 
122     // Returned samplingRate and frameCount output values are guaranteed
123     // to be non-zero if status == NO_ERROR
124     // FIXME This API assumes a route, and so should be deprecated.
125     static status_t getOutputSamplingRate(uint32_t* samplingRate,
126             audio_stream_type_t stream);
127     // FIXME This API assumes a route, and so should be deprecated.
128     static status_t getOutputFrameCount(size_t* frameCount,
129             audio_stream_type_t stream);
130     // FIXME This API assumes a route, and so should be deprecated.
131     static status_t getOutputLatency(uint32_t* latency,
132             audio_stream_type_t stream);
133     // returns the audio HAL sample rate
134     static status_t getSamplingRate(audio_io_handle_t ioHandle,
135                                           uint32_t* samplingRate);
136     // For output threads with a fast mixer, returns the number of frames per normal mixer buffer.
137     // For output threads without a fast mixer, or for input, this is same as getFrameCountHAL().
138     static status_t getFrameCount(audio_io_handle_t ioHandle,
139                                   size_t* frameCount);
140     // returns the audio output latency in ms. Corresponds to
141     // audio_stream_out->get_latency()
142     static status_t getLatency(audio_io_handle_t output,
143                                uint32_t* latency);
144 
145     // return status NO_ERROR implies *buffSize > 0
146     // FIXME This API assumes a route, and so should deprecated.
147     static status_t getInputBufferSize(uint32_t sampleRate, audio_format_t format,
148         audio_channel_mask_t channelMask, size_t* buffSize);
149 
150     static status_t setVoiceVolume(float volume);
151 
152     // return the number of audio frames written by AudioFlinger to audio HAL and
153     // audio dsp to DAC since the specified output has exited standby.
154     // returned status (from utils/Errors.h) can be:
155     // - NO_ERROR: successful operation, halFrames and dspFrames point to valid data
156     // - INVALID_OPERATION: Not supported on current hardware platform
157     // - BAD_VALUE: invalid parameter
158     // NOTE: this feature is not supported on all hardware platforms and it is
159     // necessary to check returned status before using the returned values.
160     static status_t getRenderPosition(audio_io_handle_t output,
161                                       uint32_t *halFrames,
162                                       uint32_t *dspFrames);
163 
164     // return the number of input frames lost by HAL implementation, or 0 if the handle is invalid
165     static uint32_t getInputFramesLost(audio_io_handle_t ioHandle);
166 
167     // Allocate a new unique ID for use as an audio session ID or I/O handle.
168     // If unable to contact AudioFlinger, returns AUDIO_UNIQUE_ID_ALLOCATE instead.
169     // FIXME If AudioFlinger were to ever exhaust the unique ID namespace,
170     //       this method could fail by returning either a reserved ID like AUDIO_UNIQUE_ID_ALLOCATE
171     //       or an unspecified existing unique ID.
172     static audio_unique_id_t newAudioUniqueId(audio_unique_id_use_t use);
173 
174     static void acquireAudioSessionId(audio_session_t audioSession, pid_t pid);
175     static void releaseAudioSessionId(audio_session_t audioSession, pid_t pid);
176 
177     // Get the HW synchronization source used for an audio session.
178     // Return a valid source or AUDIO_HW_SYNC_INVALID if an error occurs
179     // or no HW sync source is used.
180     static audio_hw_sync_t getAudioHwSyncForSession(audio_session_t sessionId);
181 
182     // Indicate JAVA services are ready (scheduling, power management ...)
183     static status_t systemReady();
184 
185     // Returns the number of frames per audio HAL buffer.
186     // Corresponds to audio_stream->get_buffer_size()/audio_stream_in_frame_size() for input.
187     // See also getFrameCount().
188     static status_t getFrameCountHAL(audio_io_handle_t ioHandle,
189                                      size_t* frameCount);
190 
191     // Events used to synchronize actions between audio sessions.
192     // For instance SYNC_EVENT_PRESENTATION_COMPLETE can be used to delay recording start until
193     // playback is complete on another audio session.
194     // See definitions in MediaSyncEvent.java
195     enum sync_event_t {
196         SYNC_EVENT_SAME = -1,             // used internally to indicate restart with same event
197         SYNC_EVENT_NONE = 0,
198         SYNC_EVENT_PRESENTATION_COMPLETE,
199 
200         //
201         // Define new events here: SYNC_EVENT_START, SYNC_EVENT_STOP, SYNC_EVENT_TIME ...
202         //
203         SYNC_EVENT_CNT,
204     };
205 
206     // Timeout for synchronous record start. Prevents from blocking the record thread forever
207     // if the trigger event is not fired.
208     static const uint32_t kSyncRecordStartTimeOutMs = 30000;
209 
210     //
211     // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
212     //
213     static status_t setDeviceConnectionState(audio_devices_t device, audio_policy_dev_state_t state,
214                                              const char *device_address, const char *device_name,
215                                              audio_format_t encodedFormat);
216     static audio_policy_dev_state_t getDeviceConnectionState(audio_devices_t device,
217                                                                 const char *device_address);
218     static status_t handleDeviceConfigChange(audio_devices_t device,
219                                              const char *device_address,
220                                              const char *device_name,
221                                              audio_format_t encodedFormat);
222     static status_t setPhoneState(audio_mode_t state);
223     static status_t setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config);
224     static audio_policy_forced_cfg_t getForceUse(audio_policy_force_use_t usage);
225 
226     static status_t getOutputForAttr(audio_attributes_t *attr,
227                                      audio_io_handle_t *output,
228                                      audio_session_t session,
229                                      audio_stream_type_t *stream,
230                                      pid_t pid,
231                                      uid_t uid,
232                                      const audio_config_t *config,
233                                      audio_output_flags_t flags,
234                                      audio_port_handle_t *selectedDeviceId,
235                                      audio_port_handle_t *portId,
236                                      std::vector<audio_io_handle_t> *secondaryOutputs);
237     static status_t startOutput(audio_port_handle_t portId);
238     static status_t stopOutput(audio_port_handle_t portId);
239     static void releaseOutput(audio_port_handle_t portId);
240 
241     // Client must successfully hand off the handle reference to AudioFlinger via createRecord(),
242     // or release it with releaseInput().
243     static status_t getInputForAttr(const audio_attributes_t *attr,
244                                     audio_io_handle_t *input,
245                                     audio_unique_id_t riid,
246                                     audio_session_t session,
247                                     pid_t pid,
248                                     uid_t uid,
249                                     const String16& opPackageName,
250                                     const audio_config_base_t *config,
251                                     audio_input_flags_t flags,
252                                     audio_port_handle_t *selectedDeviceId,
253                                     audio_port_handle_t *portId);
254 
255     static status_t startInput(audio_port_handle_t portId);
256     static status_t stopInput(audio_port_handle_t portId);
257     static void releaseInput(audio_port_handle_t portId);
258     static status_t initStreamVolume(audio_stream_type_t stream,
259                                       int indexMin,
260                                       int indexMax);
261     static status_t setStreamVolumeIndex(audio_stream_type_t stream,
262                                          int index,
263                                          audio_devices_t device);
264     static status_t getStreamVolumeIndex(audio_stream_type_t stream,
265                                          int *index,
266                                          audio_devices_t device);
267 
268     static status_t setVolumeIndexForAttributes(const audio_attributes_t &attr,
269                                                 int index,
270                                                 audio_devices_t device);
271     static status_t getVolumeIndexForAttributes(const audio_attributes_t &attr,
272                                                 int &index,
273                                                 audio_devices_t device);
274 
275     static status_t getMaxVolumeIndexForAttributes(const audio_attributes_t &attr, int &index);
276 
277     static status_t getMinVolumeIndexForAttributes(const audio_attributes_t &attr, int &index);
278 
279     static uint32_t getStrategyForStream(audio_stream_type_t stream);
280     static audio_devices_t getDevicesForStream(audio_stream_type_t stream);
281 
282     static audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc);
283     static status_t registerEffect(const effect_descriptor_t *desc,
284                                     audio_io_handle_t io,
285                                     uint32_t strategy,
286                                     audio_session_t session,
287                                     int id);
288     static status_t unregisterEffect(int id);
289     static status_t setEffectEnabled(int id, bool enabled);
290     static status_t moveEffectsToIo(const std::vector<int>& ids, audio_io_handle_t io);
291 
292     // clear stream to output mapping cache (gStreamOutputMap)
293     // and output configuration cache (gOutputs)
294     static void clearAudioConfigCache();
295 
296     static const sp<IAudioPolicyService> get_audio_policy_service();
297 
298     // helpers for android.media.AudioManager.getProperty(), see description there for meaning
299     static uint32_t getPrimaryOutputSamplingRate();
300     static size_t getPrimaryOutputFrameCount();
301 
302     static status_t setLowRamDevice(bool isLowRamDevice, int64_t totalMemory);
303 
304     static status_t setAllowedCapturePolicy(uid_t uid, audio_flags_mask_t flags);
305 
306     // Check if hw offload is possible for given format, stream type, sample rate,
307     // bit rate, duration, video and streaming or offload property is enabled
308     static bool isOffloadSupported(const audio_offload_info_t& info);
309 
310     // check presence of audio flinger service.
311     // returns NO_ERROR if binding to service succeeds, DEAD_OBJECT otherwise
312     static status_t checkAudioFlinger();
313 
314     /* List available audio ports and their attributes */
315     static status_t listAudioPorts(audio_port_role_t role,
316                                    audio_port_type_t type,
317                                    unsigned int *num_ports,
318                                    struct audio_port *ports,
319                                    unsigned int *generation);
320 
321     /* Get attributes for a given audio port */
322     static status_t getAudioPort(struct audio_port *port);
323 
324     /* Create an audio patch between several source and sink ports */
325     static status_t createAudioPatch(const struct audio_patch *patch,
326                                        audio_patch_handle_t *handle);
327 
328     /* Release an audio patch */
329     static status_t releaseAudioPatch(audio_patch_handle_t handle);
330 
331     /* List existing audio patches */
332     static status_t listAudioPatches(unsigned int *num_patches,
333                                       struct audio_patch *patches,
334                                       unsigned int *generation);
335     /* Set audio port configuration */
336     static status_t setAudioPortConfig(const struct audio_port_config *config);
337 
338 
339     static status_t acquireSoundTriggerSession(audio_session_t *session,
340                                            audio_io_handle_t *ioHandle,
341                                            audio_devices_t *device);
342     static status_t releaseSoundTriggerSession(audio_session_t session);
343 
344     static audio_mode_t getPhoneState();
345 
346     static status_t registerPolicyMixes(const Vector<AudioMix>& mixes, bool registration);
347 
348     static status_t setUidDeviceAffinities(uid_t uid, const Vector<AudioDeviceTypeAddr>& devices);
349 
350     static status_t removeUidDeviceAffinities(uid_t uid);
351 
352     static status_t startAudioSource(const struct audio_port_config *source,
353                                      const audio_attributes_t *attributes,
354                                      audio_port_handle_t *portId);
355     static status_t stopAudioSource(audio_port_handle_t portId);
356 
357     static status_t setMasterMono(bool mono);
358     static status_t getMasterMono(bool *mono);
359 
360     static status_t setMasterBalance(float balance);
361     static status_t getMasterBalance(float *balance);
362 
363     static float    getStreamVolumeDB(
364             audio_stream_type_t stream, int index, audio_devices_t device);
365 
366     static status_t getMicrophones(std::vector<media::MicrophoneInfo> *microphones);
367 
368     static status_t getHwOffloadEncodingFormatsSupportedForA2DP(
369                                     std::vector<audio_format_t> *formats);
370 
371     // numSurroundFormats holds the maximum number of formats and bool value allowed in the array.
372     // When numSurroundFormats is 0, surroundFormats and surroundFormatsEnabled will not be
373     // populated. The actual number of surround formats should be returned at numSurroundFormats.
374     static status_t getSurroundFormats(unsigned int *numSurroundFormats,
375                                        audio_format_t *surroundFormats,
376                                        bool *surroundFormatsEnabled,
377                                        bool reported);
378     static status_t setSurroundFormatEnabled(audio_format_t audioFormat, bool enabled);
379 
380     static status_t setAssistantUid(uid_t uid);
381     static status_t setA11yServicesUids(const std::vector<uid_t>& uids);
382 
383     static bool     isHapticPlaybackSupported();
384 
385     static status_t listAudioProductStrategies(AudioProductStrategyVector &strategies);
386     static status_t getProductStrategyFromAudioAttributes(const AudioAttributes &aa,
387                                                         product_strategy_t &productStrategy);
388 
389     static audio_attributes_t streamTypeToAttributes(audio_stream_type_t stream);
390     static audio_stream_type_t attributesToStreamType(const audio_attributes_t &attr);
391 
392     static status_t listAudioVolumeGroups(AudioVolumeGroupVector &groups);
393 
394     static status_t getVolumeGroupFromAudioAttributes(const AudioAttributes &aa,
395                                                       volume_group_t &volumeGroup);
396 
397     static status_t setRttEnabled(bool enabled);
398 
399     // ----------------------------------------------------------------------------
400 
401     class AudioVolumeGroupCallback : public RefBase
402     {
403     public:
404 
AudioVolumeGroupCallback()405         AudioVolumeGroupCallback() {}
~AudioVolumeGroupCallback()406         virtual ~AudioVolumeGroupCallback() {}
407 
408         virtual void onAudioVolumeGroupChanged(volume_group_t group, int flags) = 0;
409         virtual void onServiceDied() = 0;
410 
411     };
412 
413     static status_t addAudioVolumeGroupCallback(const sp<AudioVolumeGroupCallback>& callback);
414     static status_t removeAudioVolumeGroupCallback(const sp<AudioVolumeGroupCallback>& callback);
415 
416     class AudioPortCallback : public RefBase
417     {
418     public:
419 
AudioPortCallback()420                 AudioPortCallback() {}
~AudioPortCallback()421         virtual ~AudioPortCallback() {}
422 
423         virtual void onAudioPortListUpdate() = 0;
424         virtual void onAudioPatchListUpdate() = 0;
425         virtual void onServiceDied() = 0;
426 
427     };
428 
429     static status_t addAudioPortCallback(const sp<AudioPortCallback>& callback);
430     static status_t removeAudioPortCallback(const sp<AudioPortCallback>& callback);
431 
432     class AudioDeviceCallback : public RefBase
433     {
434     public:
435 
AudioDeviceCallback()436                 AudioDeviceCallback() {}
~AudioDeviceCallback()437         virtual ~AudioDeviceCallback() {}
438 
439         virtual void onAudioDeviceUpdate(audio_io_handle_t audioIo,
440                                          audio_port_handle_t deviceId) = 0;
441     };
442 
443     static status_t addAudioDeviceCallback(const wp<AudioDeviceCallback>& callback,
444                                            audio_io_handle_t audioIo,
445                                            audio_port_handle_t portId);
446     static status_t removeAudioDeviceCallback(const wp<AudioDeviceCallback>& callback,
447                                               audio_io_handle_t audioIo,
448                                               audio_port_handle_t portId);
449 
450     static audio_port_handle_t getDeviceIdForIo(audio_io_handle_t audioIo);
451 
452 private:
453 
454     class AudioFlingerClient: public IBinder::DeathRecipient, public BnAudioFlingerClient
455     {
456     public:
AudioFlingerClient()457         AudioFlingerClient() :
458             mInBuffSize(0), mInSamplingRate(0),
459             mInFormat(AUDIO_FORMAT_DEFAULT), mInChannelMask(AUDIO_CHANNEL_NONE) {
460         }
461 
462         void clearIoCache();
463         status_t getInputBufferSize(uint32_t sampleRate, audio_format_t format,
464                                     audio_channel_mask_t channelMask, size_t* buffSize);
465         sp<AudioIoDescriptor> getIoDescriptor(audio_io_handle_t ioHandle);
466 
467         // DeathRecipient
468         virtual void binderDied(const wp<IBinder>& who);
469 
470         // IAudioFlingerClient
471 
472         // indicate a change in the configuration of an output or input: keeps the cached
473         // values for output/input parameters up-to-date in client process
474         virtual void ioConfigChanged(audio_io_config_event event,
475                                      const sp<AudioIoDescriptor>& ioDesc);
476 
477 
478         status_t addAudioDeviceCallback(const wp<AudioDeviceCallback>& callback,
479                                                audio_io_handle_t audioIo,
480                                                audio_port_handle_t portId);
481         status_t removeAudioDeviceCallback(const wp<AudioDeviceCallback>& callback,
482                                            audio_io_handle_t audioIo,
483                                            audio_port_handle_t portId);
484 
485         audio_port_handle_t getDeviceIdForIo(audio_io_handle_t audioIo);
486 
487     private:
488         Mutex                               mLock;
489         DefaultKeyedVector<audio_io_handle_t, sp<AudioIoDescriptor> >   mIoDescriptors;
490 
491         std::map<audio_io_handle_t, std::map<audio_port_handle_t, wp<AudioDeviceCallback>>>
492                 mAudioDeviceCallbacks;
493         // cached values for recording getInputBufferSize() queries
494         size_t                              mInBuffSize;    // zero indicates cache is invalid
495         uint32_t                            mInSamplingRate;
496         audio_format_t                      mInFormat;
497         audio_channel_mask_t                mInChannelMask;
498         sp<AudioIoDescriptor> getIoDescriptor_l(audio_io_handle_t ioHandle);
499     };
500 
501     class AudioPolicyServiceClient: public IBinder::DeathRecipient,
502                                     public BnAudioPolicyServiceClient
503     {
504     public:
AudioPolicyServiceClient()505         AudioPolicyServiceClient() {
506         }
507 
508         int addAudioPortCallback(const sp<AudioPortCallback>& callback);
509         int removeAudioPortCallback(const sp<AudioPortCallback>& callback);
isAudioPortCbEnabled()510         bool isAudioPortCbEnabled() const { return (mAudioPortCallbacks.size() != 0); }
511 
512         int addAudioVolumeGroupCallback(const sp<AudioVolumeGroupCallback>& callback);
513         int removeAudioVolumeGroupCallback(const sp<AudioVolumeGroupCallback>& callback);
isAudioVolumeGroupCbEnabled()514         bool isAudioVolumeGroupCbEnabled() const { return (mAudioVolumeGroupCallback.size() != 0); }
515 
516         // DeathRecipient
517         virtual void binderDied(const wp<IBinder>& who);
518 
519         // IAudioPolicyServiceClient
520         virtual void onAudioPortListUpdate();
521         virtual void onAudioPatchListUpdate();
522         virtual void onAudioVolumeGroupChanged(volume_group_t group, int flags);
523         virtual void onDynamicPolicyMixStateUpdate(String8 regId, int32_t state);
524         virtual void onRecordingConfigurationUpdate(int event,
525                                                     const record_client_info_t *clientInfo,
526                                                     const audio_config_base_t *clientConfig,
527                                                     std::vector<effect_descriptor_t> clientEffects,
528                                                     const audio_config_base_t *deviceConfig,
529                                                     std::vector<effect_descriptor_t> effects,
530                                                     audio_patch_handle_t patchHandle,
531                                                     audio_source_t source);
532 
533     private:
534         Mutex                               mLock;
535         Vector <sp <AudioPortCallback> >    mAudioPortCallbacks;
536         Vector <sp <AudioVolumeGroupCallback> > mAudioVolumeGroupCallback;
537     };
538 
539     static audio_io_handle_t getOutput(audio_stream_type_t stream);
540     static const sp<AudioFlingerClient> getAudioFlingerClient();
541     static sp<AudioIoDescriptor> getIoDescriptor(audio_io_handle_t ioHandle);
542 
543     static sp<AudioFlingerClient> gAudioFlingerClient;
544     static sp<AudioPolicyServiceClient> gAudioPolicyServiceClient;
545     friend class AudioFlingerClient;
546     friend class AudioPolicyServiceClient;
547 
548     static Mutex gLock;      // protects gAudioFlinger and gAudioErrorCallback,
549     static Mutex gLockAPS;   // protects gAudioPolicyService and gAudioPolicyServiceClient
550     static sp<IAudioFlinger> gAudioFlinger;
551     static audio_error_callback gAudioErrorCallback;
552     static dynamic_policy_callback gDynPolicyCallback;
553     static record_config_callback gRecordConfigCallback;
554 
555     static size_t gInBuffSize;
556     // previous parameters for recording buffer size queries
557     static uint32_t gPrevInSamplingRate;
558     static audio_format_t gPrevInFormat;
559     static audio_channel_mask_t gPrevInChannelMask;
560 
561     static sp<IAudioPolicyService> gAudioPolicyService;
562 };
563 
564 };  // namespace android
565 
566 #endif  /*ANDROID_AUDIOSYSTEM_H_*/
567