AudioSystem.h revision 6a5e79733c760d7555aacec53c8bd21e8516c0a1 
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 <hardware/audio_effect.h>
21#include <media/IAudioFlingerClient.h>
22#include <system/audio.h>
23#include <system/audio_policy.h>
24#include <utils/Errors.h>
25#include <utils/Mutex.h>
26
27namespace android {
28
29typedef void (*audio_error_callback)(status_t err);
30
31class IAudioFlinger;
32class IAudioPolicyService;
33class String8;
34
35class AudioSystem
36{
37public:
38
39    /* These are static methods to control the system-wide AudioFlinger
40     * only privileged processes can have access to them
41     */
42
43    // mute/unmute microphone
44    static status_t muteMicrophone(bool state);
45    static status_t isMicrophoneMuted(bool *state);
46
47    // set/get master volume
48    static status_t setMasterVolume(float value);
49    static status_t getMasterVolume(float* volume);
50
51    // mute/unmute audio outputs
52    static status_t setMasterMute(bool mute);
53    static status_t getMasterMute(bool* mute);
54
55    // set/get stream volume on specified output
56    static status_t setStreamVolume(audio_stream_type_t stream, float value,
57                                    audio_io_handle_t output);
58    static status_t getStreamVolume(audio_stream_type_t stream, float* volume,
59                                    audio_io_handle_t output);
60
61    // mute/unmute stream
62    static status_t setStreamMute(audio_stream_type_t stream, bool mute);
63    static status_t getStreamMute(audio_stream_type_t stream, bool* mute);
64
65    // set audio mode in audio hardware
66    static status_t setMode(audio_mode_t mode);
67
68    // returns true in *state if tracks are active on the specified stream or have been active
69    // in the past inPastMs milliseconds
70    static status_t isStreamActive(audio_stream_type_t stream, bool *state, uint32_t inPastMs);
71    // returns true in *state if tracks are active for what qualifies as remote playback
72    // on the specified stream or have been active in the past inPastMs milliseconds. Remote
73    // playback isn't mutually exclusive with local playback.
74    static status_t isStreamActiveRemotely(audio_stream_type_t stream, bool *state,
75            uint32_t inPastMs);
76    // returns true in *state if a recorder is currently recording with the specified source
77    static status_t isSourceActive(audio_source_t source, bool *state);
78
79    // set/get audio hardware parameters. The function accepts a list of parameters
80    // key value pairs in the form: key1=value1;key2=value2;...
81    // Some keys are reserved for standard parameters (See AudioParameter class).
82    static status_t setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs);
83    static String8  getParameters(audio_io_handle_t ioHandle, const String8& keys);
84
85    static void setErrorCallback(audio_error_callback cb);
86
87    // helper function to obtain AudioFlinger service handle
88    static const sp<IAudioFlinger>& get_audio_flinger();
89
90    static float linearToLog(int volume);
91    static int logToLinear(float volume);
92
93    static status_t getOutputSamplingRate(uint32_t* samplingRate,
94            audio_stream_type_t stream);
95    static status_t getOutputFrameCount(size_t* frameCount,
96            audio_stream_type_t stream);
97    static status_t getOutputLatency(uint32_t* latency,
98            audio_stream_type_t stream);
99    static status_t getSamplingRate(audio_io_handle_t output,
100                                          audio_stream_type_t streamType,
101                                          uint32_t* samplingRate);
102    // returns the number of frames per audio HAL write buffer. Corresponds to
103    // audio_stream->get_buffer_size()/audio_stream_frame_size()
104    static status_t getFrameCount(audio_io_handle_t output,
105                                  audio_stream_type_t stream,
106                                  size_t* frameCount);
107    // returns the audio output stream latency in ms. Corresponds to
108    // audio_stream_out->get_latency()
109    static status_t getLatency(audio_io_handle_t output,
110                               audio_stream_type_t stream,
111                               uint32_t* latency);
112
113    static bool routedToA2dpOutput(audio_stream_type_t streamType);
114
115    static status_t getInputBufferSize(uint32_t sampleRate, audio_format_t format,
116        audio_channel_mask_t channelMask, size_t* buffSize);
117
118    static status_t setVoiceVolume(float volume);
119
120    // return the number of audio frames written by AudioFlinger to audio HAL and
121    // audio dsp to DAC since the output on which the specified stream is playing
122    // has exited standby.
123    // returned status (from utils/Errors.h) can be:
124    // - NO_ERROR: successful operation, halFrames and dspFrames point to valid data
125    // - INVALID_OPERATION: Not supported on current hardware platform
126    // - BAD_VALUE: invalid parameter
127    // NOTE: this feature is not supported on all hardware platforms and it is
128    // necessary to check returned status before using the returned values.
129    static status_t getRenderPosition(audio_io_handle_t output,
130                                      size_t *halFrames,
131                                      size_t *dspFrames,
132                                      audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
133
134    // return the number of input frames lost by HAL implementation, or 0 if the handle is invalid
135    static size_t getInputFramesLost(audio_io_handle_t ioHandle);
136
137    static int newAudioSessionId();
138    static void acquireAudioSessionId(int audioSession);
139    static void releaseAudioSessionId(int audioSession);
140
141    // types of io configuration change events received with ioConfigChanged()
142    enum io_config_event {
143        OUTPUT_OPENED,
144        OUTPUT_CLOSED,
145        OUTPUT_CONFIG_CHANGED,
146        INPUT_OPENED,
147        INPUT_CLOSED,
148        INPUT_CONFIG_CHANGED,
149        STREAM_CONFIG_CHANGED,
150        NUM_CONFIG_EVENTS
151    };
152
153    // audio output descriptor used to cache output configurations in client process to avoid
154    // frequent calls through IAudioFlinger
155    class OutputDescriptor {
156    public:
157        OutputDescriptor()
158        : samplingRate(0), format(AUDIO_FORMAT_DEFAULT), channelMask(0), frameCount(0), latency(0)
159            {}
160
161        uint32_t samplingRate;
162        audio_format_t format;
163        audio_channel_mask_t channelMask;
164        size_t frameCount;
165        uint32_t latency;
166    };
167
168    // Events used to synchronize actions between audio sessions.
169    // For instance SYNC_EVENT_PRESENTATION_COMPLETE can be used to delay recording start until
170    // playback is complete on another audio session.
171    // See definitions in MediaSyncEvent.java
172    enum sync_event_t {
173        SYNC_EVENT_SAME = -1,             // used internally to indicate restart with same event
174        SYNC_EVENT_NONE = 0,
175        SYNC_EVENT_PRESENTATION_COMPLETE,
176
177        //
178        // Define new events here: SYNC_EVENT_START, SYNC_EVENT_STOP, SYNC_EVENT_TIME ...
179        //
180        SYNC_EVENT_CNT,
181    };
182
183    // Timeout for synchronous record start. Prevents from blocking the record thread forever
184    // if the trigger event is not fired.
185    static const uint32_t kSyncRecordStartTimeOutMs = 30000;
186
187    //
188    // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
189    //
190    static status_t setDeviceConnectionState(audio_devices_t device, audio_policy_dev_state_t state,
191                                                const char *device_address);
192    static audio_policy_dev_state_t getDeviceConnectionState(audio_devices_t device,
193                                                                const char *device_address);
194    static status_t setPhoneState(audio_mode_t state);
195    static status_t setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config);
196    static audio_policy_forced_cfg_t getForceUse(audio_policy_force_use_t usage);
197    static audio_io_handle_t getOutput(audio_stream_type_t stream,
198                                        uint32_t samplingRate = 0,
199                                        audio_format_t format = AUDIO_FORMAT_DEFAULT,
200                                        audio_channel_mask_t channelMask = AUDIO_CHANNEL_OUT_STEREO,
201                                        audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
202                                        const audio_offload_info_t *offloadInfo = NULL);
203    static status_t startOutput(audio_io_handle_t output,
204                                audio_stream_type_t stream,
205                                int session);
206    static status_t stopOutput(audio_io_handle_t output,
207                               audio_stream_type_t stream,
208                               int session);
209    static void releaseOutput(audio_io_handle_t output);
210    static audio_io_handle_t getInput(audio_source_t inputSource,
211                                    uint32_t samplingRate,
212                                    audio_format_t format,
213                                    audio_channel_mask_t channelMask,
214                                    int sessionId);
215    static status_t startInput(audio_io_handle_t input);
216    static status_t stopInput(audio_io_handle_t input);
217    static void releaseInput(audio_io_handle_t input);
218    static status_t initStreamVolume(audio_stream_type_t stream,
219                                      int indexMin,
220                                      int indexMax);
221    static status_t setStreamVolumeIndex(audio_stream_type_t stream,
222                                         int index,
223                                         audio_devices_t device);
224    static status_t getStreamVolumeIndex(audio_stream_type_t stream,
225                                         int *index,
226                                         audio_devices_t device);
227
228    static uint32_t getStrategyForStream(audio_stream_type_t stream);
229    static audio_devices_t getDevicesForStream(audio_stream_type_t stream);
230
231    static audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc);
232    static status_t registerEffect(const effect_descriptor_t *desc,
233                                    audio_io_handle_t io,
234                                    uint32_t strategy,
235                                    int session,
236                                    int id);
237    static status_t unregisterEffect(int id);
238    static status_t setEffectEnabled(int id, bool enabled);
239
240    // clear stream to output mapping cache (gStreamOutputMap)
241    // and output configuration cache (gOutputs)
242    static void clearAudioConfigCache();
243
244    static const sp<IAudioPolicyService>& get_audio_policy_service();
245
246    // helpers for android.media.AudioManager.getProperty(), see description there for meaning
247    static uint32_t getPrimaryOutputSamplingRate();
248    static size_t getPrimaryOutputFrameCount();
249
250    static status_t setLowRamDevice(bool isLowRamDevice);
251
252    // Check if hw offload is possible for given format, stream type, sample rate,
253    // bit rate, duration, video and streaming or offload property is enabled
254    static bool isOffloadSupported(const audio_offload_info_t& info);
255
256    // check presence of audio flinger service.
257    // returns NO_ERROR if binding to service succeeds, DEAD_OBJECT otherwise
258    static status_t checkAudioFlinger();
259    // ----------------------------------------------------------------------------
260
261private:
262
263    class AudioFlingerClient: public IBinder::DeathRecipient, public BnAudioFlingerClient
264    {
265    public:
266        AudioFlingerClient() {
267        }
268
269        // DeathRecipient
270        virtual void binderDied(const wp<IBinder>& who);
271
272        // IAudioFlingerClient
273
274        // indicate a change in the configuration of an output or input: keeps the cached
275        // values for output/input parameters up-to-date in client process
276        virtual void ioConfigChanged(int event, audio_io_handle_t ioHandle, const void *param2);
277    };
278
279    class AudioPolicyServiceClient: public IBinder::DeathRecipient
280    {
281    public:
282        AudioPolicyServiceClient() {
283        }
284
285        // DeathRecipient
286        virtual void binderDied(const wp<IBinder>& who);
287    };
288
289    static sp<AudioFlingerClient> gAudioFlingerClient;
290    static sp<AudioPolicyServiceClient> gAudioPolicyServiceClient;
291    friend class AudioFlingerClient;
292    friend class AudioPolicyServiceClient;
293
294    static Mutex gLock;
295    static sp<IAudioFlinger> gAudioFlinger;
296    static audio_error_callback gAudioErrorCallback;
297
298    static size_t gInBuffSize;
299    // previous parameters for recording buffer size queries
300    static uint32_t gPrevInSamplingRate;
301    static audio_format_t gPrevInFormat;
302    static audio_channel_mask_t gPrevInChannelMask;
303
304    static sp<IAudioPolicyService> gAudioPolicyService;
305
306    // mapping between stream types and outputs
307    static DefaultKeyedVector<audio_stream_type_t, audio_io_handle_t> gStreamOutputMap;
308    // list of output descriptors containing cached parameters
309    // (sampling rate, framecount, channel count...)
310    static DefaultKeyedVector<audio_io_handle_t, OutputDescriptor *> gOutputs;
311};
312
313};  // namespace android
314
315#endif  /*ANDROID_AUDIOSYSTEM_H_*/
316