AudioSystem.h revision e33054eb968cbf8ccaee1b0ff0301403902deed6 
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 <utils/RefBase.h>
21#include <utils/threads.h>
22#include <media/IAudioFlinger.h>
23
24#include <system/audio.h>
25#include <system/audio_policy.h>
26
27/* XXX: Should be include by all the users instead */
28#include <media/AudioParameter.h>
29
30namespace android {
31
32typedef void (*audio_error_callback)(status_t err);
33
34class IAudioPolicyService;
35class String8;
36
37class AudioSystem
38{
39public:
40
41    /* These are static methods to control the system-wide AudioFlinger
42     * only privileged processes can have access to them
43     */
44
45    // mute/unmute microphone
46    static status_t muteMicrophone(bool state);
47    static status_t isMicrophoneMuted(bool *state);
48
49    // set/get master volume
50    static status_t setMasterVolume(float value);
51    static status_t getMasterVolume(float* volume);
52
53    // mute/unmute audio outputs
54    static status_t setMasterMute(bool mute);
55    static status_t getMasterMute(bool* mute);
56
57    // set/get stream volume on specified output
58    static status_t setStreamVolume(audio_stream_type_t stream, float value,
59                                    audio_io_handle_t output);
60    static status_t getStreamVolume(audio_stream_type_t stream, float* volume,
61                                    audio_io_handle_t output);
62
63    // mute/unmute stream
64    static status_t setStreamMute(audio_stream_type_t stream, bool mute);
65    static status_t getStreamMute(audio_stream_type_t stream, bool* mute);
66
67    // set audio mode in audio hardware
68    static status_t setMode(audio_mode_t mode);
69
70    // returns true in *state if tracks are active on the specified stream or has been active
71    // in the past inPastMs milliseconds
72    static status_t isStreamActive(audio_stream_type_t stream, bool *state, uint32_t inPastMs = 0);
73    // returns true in *state if a recorder is currently recording with the specified source
74    static status_t isSourceActive(audio_source_t source, bool *state);
75
76    // set/get audio hardware parameters. The function accepts a list of parameters
77    // key value pairs in the form: key1=value1;key2=value2;...
78    // Some keys are reserved for standard parameters (See AudioParameter class).
79    static status_t setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs);
80    static String8  getParameters(audio_io_handle_t ioHandle, const String8& keys);
81
82    static void setErrorCallback(audio_error_callback cb);
83
84    // helper function to obtain AudioFlinger service handle
85    static const sp<IAudioFlinger>& get_audio_flinger();
86
87    static float linearToLog(int volume);
88    static int logToLinear(float volume);
89
90    static status_t getOutputSamplingRate(uint32_t* samplingRate,
91            audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
92    static status_t getOutputFrameCount(size_t* frameCount,
93            audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
94    static status_t getOutputLatency(uint32_t* latency,
95            audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
96    static status_t getSamplingRate(audio_io_handle_t output,
97                                          audio_stream_type_t streamType,
98                                          uint32_t* samplingRate);
99    // returns the number of frames per audio HAL write buffer. Corresponds to
100    // audio_stream->get_buffer_size()/audio_stream_frame_size()
101    static status_t getFrameCount(audio_io_handle_t output,
102                                  audio_stream_type_t stream,
103                                  size_t* frameCount);
104    // returns the audio output stream latency in ms. Corresponds to
105    // audio_stream_out->get_latency()
106    static status_t getLatency(audio_io_handle_t output,
107                               audio_stream_type_t stream,
108                               uint32_t* latency);
109
110    static bool routedToA2dpOutput(audio_stream_type_t streamType);
111
112    static status_t getInputBufferSize(uint32_t sampleRate, audio_format_t format,
113        audio_channel_mask_t channelMask, size_t* buffSize);
114
115    static status_t setVoiceVolume(float volume);
116
117    // return the number of audio frames written by AudioFlinger to audio HAL and
118    // audio dsp to DAC since the output on which the specified stream is playing
119    // has exited standby.
120    // returned status (from utils/Errors.h) can be:
121    // - NO_ERROR: successful operation, halFrames and dspFrames point to valid data
122    // - INVALID_OPERATION: Not supported on current hardware platform
123    // - BAD_VALUE: invalid parameter
124    // NOTE: this feature is not supported on all hardware platforms and it is
125    // necessary to check returned status before using the returned values.
126    static status_t getRenderPosition(size_t *halFrames, size_t *dspFrames,
127            audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
128
129    // return the number of input frames lost by HAL implementation, or 0 if the handle is invalid
130    static size_t getInputFramesLost(audio_io_handle_t ioHandle);
131
132    static int newAudioSessionId();
133    static void acquireAudioSessionId(int audioSession);
134    static void releaseAudioSessionId(int audioSession);
135
136    // types of io configuration change events received with ioConfigChanged()
137    enum io_config_event {
138        OUTPUT_OPENED,
139        OUTPUT_CLOSED,
140        OUTPUT_CONFIG_CHANGED,
141        INPUT_OPENED,
142        INPUT_CLOSED,
143        INPUT_CONFIG_CHANGED,
144        STREAM_CONFIG_CHANGED,
145        NUM_CONFIG_EVENTS
146    };
147
148    // audio output descriptor used to cache output configurations in client process to avoid
149    // frequent calls through IAudioFlinger
150    class OutputDescriptor {
151    public:
152        OutputDescriptor()
153        : samplingRate(0), format(AUDIO_FORMAT_DEFAULT), channels(0), frameCount(0), latency(0)  {}
154
155        uint32_t samplingRate;
156        int32_t format;
157        int32_t channels;
158        size_t frameCount;
159        uint32_t latency;
160    };
161
162    // Events used to synchronize actions between audio sessions.
163    // For instance SYNC_EVENT_PRESENTATION_COMPLETE can be used to delay recording start until
164    // playback is complete on another audio session.
165    // See definitions in MediaSyncEvent.java
166    enum sync_event_t {
167        SYNC_EVENT_SAME = -1,             // used internally to indicate restart with same event
168        SYNC_EVENT_NONE = 0,
169        SYNC_EVENT_PRESENTATION_COMPLETE,
170
171        //
172        // Define new events here: SYNC_EVENT_START, SYNC_EVENT_STOP, SYNC_EVENT_TIME ...
173        //
174        SYNC_EVENT_CNT,
175    };
176
177    // Timeout for synchronous record start. Prevents from blocking the record thread forever
178    // if the trigger event is not fired.
179    static const uint32_t kSyncRecordStartTimeOutMs = 30000;
180
181    //
182    // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
183    //
184    static status_t setDeviceConnectionState(audio_devices_t device, audio_policy_dev_state_t state,
185                                                const char *device_address);
186    static audio_policy_dev_state_t getDeviceConnectionState(audio_devices_t device,
187                                                                const char *device_address);
188    static status_t setPhoneState(audio_mode_t state);
189    static status_t setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config);
190    static audio_policy_forced_cfg_t getForceUse(audio_policy_force_use_t usage);
191    static audio_io_handle_t getOutput(audio_stream_type_t stream,
192                                        uint32_t samplingRate = 0,
193                                        audio_format_t format = AUDIO_FORMAT_DEFAULT,
194                                        audio_channel_mask_t channelMask = AUDIO_CHANNEL_OUT_STEREO,
195                                        audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE);
196    static status_t startOutput(audio_io_handle_t output,
197                                audio_stream_type_t stream,
198                                int session = 0);
199    static status_t stopOutput(audio_io_handle_t output,
200                               audio_stream_type_t stream,
201                               int session = 0);
202    static void releaseOutput(audio_io_handle_t output);
203    static audio_io_handle_t getInput(audio_source_t inputSource,
204                                    uint32_t samplingRate = 0,
205                                    audio_format_t format = AUDIO_FORMAT_DEFAULT,
206                                    audio_channel_mask_t channelMask = AUDIO_CHANNEL_IN_MONO,
207                                    int sessionId = 0);
208    static status_t startInput(audio_io_handle_t input);
209    static status_t stopInput(audio_io_handle_t input);
210    static void releaseInput(audio_io_handle_t input);
211    static status_t initStreamVolume(audio_stream_type_t stream,
212                                      int indexMin,
213                                      int indexMax);
214    static status_t setStreamVolumeIndex(audio_stream_type_t stream,
215                                         int index,
216                                         audio_devices_t device);
217    static status_t getStreamVolumeIndex(audio_stream_type_t stream,
218                                         int *index,
219                                         audio_devices_t device);
220
221    static uint32_t getStrategyForStream(audio_stream_type_t stream);
222    static audio_devices_t getDevicesForStream(audio_stream_type_t stream);
223
224    static audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc);
225    static status_t registerEffect(const effect_descriptor_t *desc,
226                                    audio_io_handle_t io,
227                                    uint32_t strategy,
228                                    int session,
229                                    int id);
230    static status_t unregisterEffect(int id);
231    static status_t setEffectEnabled(int id, bool enabled);
232
233    // clear stream to output mapping cache (gStreamOutputMap)
234    // and output configuration cache (gOutputs)
235    static void clearAudioConfigCache();
236
237    static const sp<IAudioPolicyService>& get_audio_policy_service();
238
239    // helpers for android.media.AudioManager.getProperty(), see description there for meaning
240    static uint32_t getPrimaryOutputSamplingRate();
241    static size_t getPrimaryOutputFrameCount();
242
243    // ----------------------------------------------------------------------------
244
245private:
246
247    class AudioFlingerClient: public IBinder::DeathRecipient, public BnAudioFlingerClient
248    {
249    public:
250        AudioFlingerClient() {
251        }
252
253        // DeathRecipient
254        virtual void binderDied(const wp<IBinder>& who);
255
256        // IAudioFlingerClient
257
258        // indicate a change in the configuration of an output or input: keeps the cached
259        // values for output/input parameters up-to-date in client process
260        virtual void ioConfigChanged(int event, audio_io_handle_t ioHandle, const void *param2);
261    };
262
263    class AudioPolicyServiceClient: public IBinder::DeathRecipient
264    {
265    public:
266        AudioPolicyServiceClient() {
267        }
268
269        // DeathRecipient
270        virtual void binderDied(const wp<IBinder>& who);
271    };
272
273    static sp<AudioFlingerClient> gAudioFlingerClient;
274    static sp<AudioPolicyServiceClient> gAudioPolicyServiceClient;
275    friend class AudioFlingerClient;
276    friend class AudioPolicyServiceClient;
277
278    static Mutex gLock;
279    static sp<IAudioFlinger> gAudioFlinger;
280    static audio_error_callback gAudioErrorCallback;
281
282    static size_t gInBuffSize;
283    // previous parameters for recording buffer size queries
284    static uint32_t gPrevInSamplingRate;
285    static audio_format_t gPrevInFormat;
286    static audio_channel_mask_t gPrevInChannelMask;
287
288    static sp<IAudioPolicyService> gAudioPolicyService;
289
290    // mapping between stream types and outputs
291    static DefaultKeyedVector<audio_stream_type_t, audio_io_handle_t> gStreamOutputMap;
292    // list of output descriptors containing cached parameters
293    // (sampling rate, framecount, channel count...)
294    static DefaultKeyedVector<audio_io_handle_t, OutputDescriptor *> gOutputs;
295};
296
297};  // namespace android
298
299#endif  /*ANDROID_AUDIOSYSTEM_H_*/
300