AudioSystem.h revision 5f972c031d4061f4f037c9fda1ea4bd9b6a756cd 
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    // The versions with audio_io_handle_t are intended for internal media framework use only.
83    static status_t setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs);
84    static String8  getParameters(audio_io_handle_t ioHandle, const String8& keys);
85    // The versions without audio_io_handle_t are intended for JNI.
86    static status_t setParameters(const String8& keyValuePairs);
87    static String8  getParameters(const String8& keys);
88
89    static void setErrorCallback(audio_error_callback cb);
90
91    // helper function to obtain AudioFlinger service handle
92    static const sp<IAudioFlinger>& get_audio_flinger();
93
94    static float linearToLog(int volume);
95    static int logToLinear(float volume);
96
97    // Returned samplingRate and frameCount output values are guaranteed
98    // to be non-zero if status == NO_ERROR
99    static status_t getOutputSamplingRate(uint32_t* samplingRate,
100            audio_stream_type_t stream);
101    static status_t getOutputFrameCount(size_t* frameCount,
102            audio_stream_type_t stream);
103    static status_t getOutputLatency(uint32_t* latency,
104            audio_stream_type_t stream);
105    static status_t getSamplingRate(audio_io_handle_t output,
106                                          audio_stream_type_t streamType,
107                                          uint32_t* samplingRate);
108    // returns the number of frames per audio HAL write buffer. Corresponds to
109    // audio_stream->get_buffer_size()/audio_stream_frame_size()
110    static status_t getFrameCount(audio_io_handle_t output,
111                                  audio_stream_type_t stream,
112                                  size_t* frameCount);
113    // returns the audio output stream latency in ms. Corresponds to
114    // audio_stream_out->get_latency()
115    static status_t getLatency(audio_io_handle_t output,
116                               audio_stream_type_t stream,
117                               uint32_t* latency);
118
119    static bool routedToA2dpOutput(audio_stream_type_t streamType);
120
121    static status_t getInputBufferSize(uint32_t sampleRate, audio_format_t format,
122        audio_channel_mask_t channelMask, size_t* buffSize);
123
124    static status_t setVoiceVolume(float volume);
125
126    // return the number of audio frames written by AudioFlinger to audio HAL and
127    // audio dsp to DAC since the output on which the specified stream is playing
128    // has exited standby.
129    // returned status (from utils/Errors.h) can be:
130    // - NO_ERROR: successful operation, halFrames and dspFrames point to valid data
131    // - INVALID_OPERATION: Not supported on current hardware platform
132    // - BAD_VALUE: invalid parameter
133    // NOTE: this feature is not supported on all hardware platforms and it is
134    // necessary to check returned status before using the returned values.
135    static status_t getRenderPosition(audio_io_handle_t output,
136                                      size_t *halFrames,
137                                      size_t *dspFrames,
138                                      audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
139
140    // return the number of input frames lost by HAL implementation, or 0 if the handle is invalid
141    static uint32_t getInputFramesLost(audio_io_handle_t ioHandle);
142
143    static int newAudioSessionId();
144    static void acquireAudioSessionId(int audioSession);
145    static void releaseAudioSessionId(int audioSession);
146
147    // types of io configuration change events received with ioConfigChanged()
148    enum io_config_event {
149        OUTPUT_OPENED,
150        OUTPUT_CLOSED,
151        OUTPUT_CONFIG_CHANGED,
152        INPUT_OPENED,
153        INPUT_CLOSED,
154        INPUT_CONFIG_CHANGED,
155        STREAM_CONFIG_CHANGED,
156        NUM_CONFIG_EVENTS
157    };
158
159    // audio output descriptor used to cache output configurations in client process to avoid
160    // frequent calls through IAudioFlinger
161    class OutputDescriptor {
162    public:
163        OutputDescriptor()
164        : samplingRate(0), format(AUDIO_FORMAT_DEFAULT), channelMask(0), frameCount(0), latency(0)
165            {}
166
167        uint32_t samplingRate;
168        audio_format_t format;
169        audio_channel_mask_t channelMask;
170        size_t frameCount;
171        uint32_t latency;
172    };
173
174    // Events used to synchronize actions between audio sessions.
175    // For instance SYNC_EVENT_PRESENTATION_COMPLETE can be used to delay recording start until
176    // playback is complete on another audio session.
177    // See definitions in MediaSyncEvent.java
178    enum sync_event_t {
179        SYNC_EVENT_SAME = -1,             // used internally to indicate restart with same event
180        SYNC_EVENT_NONE = 0,
181        SYNC_EVENT_PRESENTATION_COMPLETE,
182
183        //
184        // Define new events here: SYNC_EVENT_START, SYNC_EVENT_STOP, SYNC_EVENT_TIME ...
185        //
186        SYNC_EVENT_CNT,
187    };
188
189    // Timeout for synchronous record start. Prevents from blocking the record thread forever
190    // if the trigger event is not fired.
191    static const uint32_t kSyncRecordStartTimeOutMs = 30000;
192
193    //
194    // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
195    //
196    static status_t setDeviceConnectionState(audio_devices_t device, audio_policy_dev_state_t state,
197                                                const char *device_address);
198    static audio_policy_dev_state_t getDeviceConnectionState(audio_devices_t device,
199                                                                const char *device_address);
200    static status_t setPhoneState(audio_mode_t state);
201    static status_t setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config);
202    static audio_policy_forced_cfg_t getForceUse(audio_policy_force_use_t usage);
203    static audio_io_handle_t getOutput(audio_stream_type_t stream,
204                                        uint32_t samplingRate = 0,
205                                        audio_format_t format = AUDIO_FORMAT_DEFAULT,
206                                        audio_channel_mask_t channelMask = AUDIO_CHANNEL_OUT_STEREO,
207                                        audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
208                                        const audio_offload_info_t *offloadInfo = NULL);
209    static status_t startOutput(audio_io_handle_t output,
210                                audio_stream_type_t stream,
211                                int session);
212    static status_t stopOutput(audio_io_handle_t output,
213                               audio_stream_type_t stream,
214                               int session);
215    static void releaseOutput(audio_io_handle_t output);
216    static audio_io_handle_t getInput(audio_source_t inputSource,
217                                    uint32_t samplingRate,
218                                    audio_format_t format,
219                                    audio_channel_mask_t channelMask,
220                                    int sessionId);
221    static status_t startInput(audio_io_handle_t input);
222    static status_t stopInput(audio_io_handle_t input);
223    static void releaseInput(audio_io_handle_t input);
224    static status_t initStreamVolume(audio_stream_type_t stream,
225                                      int indexMin,
226                                      int indexMax);
227    static status_t setStreamVolumeIndex(audio_stream_type_t stream,
228                                         int index,
229                                         audio_devices_t device);
230    static status_t getStreamVolumeIndex(audio_stream_type_t stream,
231                                         int *index,
232                                         audio_devices_t device);
233
234    static uint32_t getStrategyForStream(audio_stream_type_t stream);
235    static audio_devices_t getDevicesForStream(audio_stream_type_t stream);
236
237    static audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc);
238    static status_t registerEffect(const effect_descriptor_t *desc,
239                                    audio_io_handle_t io,
240                                    uint32_t strategy,
241                                    int session,
242                                    int id);
243    static status_t unregisterEffect(int id);
244    static status_t setEffectEnabled(int id, bool enabled);
245
246    // clear stream to output mapping cache (gStreamOutputMap)
247    // and output configuration cache (gOutputs)
248    static void clearAudioConfigCache();
249
250    static const sp<IAudioPolicyService>& get_audio_policy_service();
251
252    // helpers for android.media.AudioManager.getProperty(), see description there for meaning
253    static uint32_t getPrimaryOutputSamplingRate();
254    static size_t getPrimaryOutputFrameCount();
255
256    static status_t setLowRamDevice(bool isLowRamDevice);
257
258    // Check if hw offload is possible for given format, stream type, sample rate,
259    // bit rate, duration, video and streaming or offload property is enabled
260    static bool isOffloadSupported(const audio_offload_info_t& info);
261
262    // check presence of audio flinger service.
263    // returns NO_ERROR if binding to service succeeds, DEAD_OBJECT otherwise
264    static status_t checkAudioFlinger();
265    // ----------------------------------------------------------------------------
266
267private:
268
269    class AudioFlingerClient: public IBinder::DeathRecipient, public BnAudioFlingerClient
270    {
271    public:
272        AudioFlingerClient() {
273        }
274
275        // DeathRecipient
276        virtual void binderDied(const wp<IBinder>& who);
277
278        // IAudioFlingerClient
279
280        // indicate a change in the configuration of an output or input: keeps the cached
281        // values for output/input parameters up-to-date in client process
282        virtual void ioConfigChanged(int event, audio_io_handle_t ioHandle, const void *param2);
283    };
284
285    class AudioPolicyServiceClient: public IBinder::DeathRecipient
286    {
287    public:
288        AudioPolicyServiceClient() {
289        }
290
291        // DeathRecipient
292        virtual void binderDied(const wp<IBinder>& who);
293    };
294
295    static sp<AudioFlingerClient> gAudioFlingerClient;
296    static sp<AudioPolicyServiceClient> gAudioPolicyServiceClient;
297    friend class AudioFlingerClient;
298    friend class AudioPolicyServiceClient;
299
300    static Mutex gLock;
301    static sp<IAudioFlinger> gAudioFlinger;
302    static audio_error_callback gAudioErrorCallback;
303
304    static size_t gInBuffSize;
305    // previous parameters for recording buffer size queries
306    static uint32_t gPrevInSamplingRate;
307    static audio_format_t gPrevInFormat;
308    static audio_channel_mask_t gPrevInChannelMask;
309
310    static sp<IAudioPolicyService> gAudioPolicyService;
311
312    // mapping between stream types and outputs
313    static DefaultKeyedVector<audio_stream_type_t, audio_io_handle_t> gStreamOutputMap;
314    // list of output descriptors containing cached parameters
315    // (sampling rate, framecount, channel count...)
316    static DefaultKeyedVector<audio_io_handle_t, OutputDescriptor *> gOutputs;
317};
318
319};  // namespace android
320
321#endif  /*ANDROID_AUDIOSYSTEM_H_*/
322