AudioSystem.h revision 58f30210ea540b6ce5aa6a46330cd3499483cb97 
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, int output);
59    static status_t getStreamVolume(audio_stream_type_t stream, float* volume, int 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 has been active
69    // in the past inPastMs milliseconds
70    static status_t isStreamActive(audio_stream_type_t stream, bool *state, uint32_t inPastMs = 0);
71
72    // set/get audio hardware parameters. The function accepts a list of parameters
73    // key value pairs in the form: key1=value1;key2=value2;...
74    // Some keys are reserved for standard parameters (See AudioParameter class).
75    static status_t setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs);
76    static String8  getParameters(audio_io_handle_t ioHandle, const String8& keys);
77
78    static void setErrorCallback(audio_error_callback cb);
79
80    // helper function to obtain AudioFlinger service handle
81    static const sp<IAudioFlinger>& get_audio_flinger();
82
83    static float linearToLog(int volume);
84    static int logToLinear(float volume);
85
86    static status_t getOutputSamplingRate(int* samplingRate, audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
87    static status_t getOutputFrameCount(int* frameCount, audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
88    static status_t getOutputLatency(uint32_t* latency, audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
89
90    // DEPRECATED
91    static status_t getOutputSamplingRate(int* samplingRate, int stream = AUDIO_STREAM_DEFAULT);
92
93    // DEPRECATED
94    static status_t getOutputFrameCount(int* frameCount, int stream = AUDIO_STREAM_DEFAULT);
95
96    static bool routedToA2dpOutput(audio_stream_type_t streamType);
97
98    static status_t getInputBufferSize(uint32_t sampleRate, audio_format_t format, int channelCount,
99        size_t* buffSize);
100
101    static status_t setVoiceVolume(float volume);
102
103    // return the number of audio frames written by AudioFlinger to audio HAL and
104    // audio dsp to DAC since the output on which the specified stream is playing
105    // has exited standby.
106    // returned status (from utils/Errors.h) can be:
107    // - NO_ERROR: successful operation, halFrames and dspFrames point to valid data
108    // - INVALID_OPERATION: Not supported on current hardware platform
109    // - BAD_VALUE: invalid parameter
110    // NOTE: this feature is not supported on all hardware platforms and it is
111    // necessary to check returned status before using the returned values.
112    static status_t getRenderPosition(uint32_t *halFrames, uint32_t *dspFrames, audio_stream_type_t stream = AUDIO_STREAM_DEFAULT);
113
114    static unsigned int  getInputFramesLost(audio_io_handle_t ioHandle);
115
116    static int newAudioSessionId();
117    static void acquireAudioSessionId(int audioSession);
118    static void releaseAudioSessionId(int audioSession);
119
120    // types of io configuration change events received with ioConfigChanged()
121    enum io_config_event {
122        OUTPUT_OPENED,
123        OUTPUT_CLOSED,
124        OUTPUT_CONFIG_CHANGED,
125        INPUT_OPENED,
126        INPUT_CLOSED,
127        INPUT_CONFIG_CHANGED,
128        STREAM_CONFIG_CHANGED,
129        NUM_CONFIG_EVENTS
130    };
131
132    // audio output descritor used to cache output configurations in client process to avoid frequent calls
133    // through IAudioFlinger
134    class OutputDescriptor {
135    public:
136        OutputDescriptor()
137        : samplingRate(0), format(AUDIO_FORMAT_DEFAULT), channels(0), frameCount(0), latency(0)  {}
138
139        uint32_t samplingRate;
140        int32_t format;
141        int32_t channels;
142        size_t frameCount;
143        uint32_t latency;
144    };
145
146    //
147    // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
148    //
149    static status_t setDeviceConnectionState(audio_devices_t device, audio_policy_dev_state_t state, const char *device_address);
150    static audio_policy_dev_state_t getDeviceConnectionState(audio_devices_t device, const char *device_address);
151    static status_t setPhoneState(audio_mode_t state);
152    static status_t setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config);
153    static audio_policy_forced_cfg_t getForceUse(audio_policy_force_use_t usage);
154    static audio_io_handle_t getOutput(audio_stream_type_t stream,
155                                        uint32_t samplingRate = 0,
156                                        audio_format_t format = AUDIO_FORMAT_DEFAULT,
157                                        uint32_t channels = AUDIO_CHANNEL_OUT_STEREO,
158                                        audio_policy_output_flags_t flags = AUDIO_POLICY_OUTPUT_FLAG_INDIRECT);
159    static status_t startOutput(audio_io_handle_t output,
160                                audio_stream_type_t stream,
161                                int session = 0);
162    static status_t stopOutput(audio_io_handle_t output,
163                               audio_stream_type_t stream,
164                               int session = 0);
165    static void releaseOutput(audio_io_handle_t output);
166    static audio_io_handle_t getInput(int inputSource,
167                                    uint32_t samplingRate = 0,
168                                    audio_format_t format = AUDIO_FORMAT_DEFAULT,
169                                    uint32_t channels = AUDIO_CHANNEL_IN_MONO,
170                                    audio_in_acoustics_t acoustics = (audio_in_acoustics_t)0,
171                                    int sessionId = 0);
172    static status_t startInput(audio_io_handle_t input);
173    static status_t stopInput(audio_io_handle_t input);
174    static void releaseInput(audio_io_handle_t input);
175    static status_t initStreamVolume(audio_stream_type_t stream,
176                                      int indexMin,
177                                      int indexMax);
178    static status_t setStreamVolumeIndex(audio_stream_type_t stream,
179                                         int index,
180                                         audio_devices_t device);
181    static status_t getStreamVolumeIndex(audio_stream_type_t stream,
182                                         int *index,
183                                         audio_devices_t device);
184
185    static uint32_t getStrategyForStream(audio_stream_type_t stream);
186    static uint32_t getDevicesForStream(audio_stream_type_t stream);
187
188    static audio_io_handle_t getOutputForEffect(effect_descriptor_t *desc);
189    static status_t registerEffect(effect_descriptor_t *desc,
190                                    audio_io_handle_t io,
191                                    uint32_t strategy,
192                                    int session,
193                                    int id);
194    static status_t unregisterEffect(int id);
195    static status_t setEffectEnabled(int id, bool enabled);
196
197    // clear stream to output mapping cache (gStreamOutputMap)
198    // and output configuration cache (gOutputs)
199    static void clearAudioConfigCache();
200
201    static const sp<IAudioPolicyService>& get_audio_policy_service();
202
203    // ----------------------------------------------------------------------------
204
205private:
206
207    class AudioFlingerClient: public IBinder::DeathRecipient, public BnAudioFlingerClient
208    {
209    public:
210        AudioFlingerClient() {
211        }
212
213        // DeathRecipient
214        virtual void binderDied(const wp<IBinder>& who);
215
216        // IAudioFlingerClient
217
218        // indicate a change in the configuration of an output or input: keeps the cached
219        // values for output/input parameters upto date in client process
220        virtual void ioConfigChanged(int event, int ioHandle, void *param2);
221    };
222
223    class AudioPolicyServiceClient: public IBinder::DeathRecipient
224    {
225    public:
226        AudioPolicyServiceClient() {
227        }
228
229        // DeathRecipient
230        virtual void binderDied(const wp<IBinder>& who);
231    };
232
233    static sp<AudioFlingerClient> gAudioFlingerClient;
234    static sp<AudioPolicyServiceClient> gAudioPolicyServiceClient;
235    friend class AudioFlingerClient;
236    friend class AudioPolicyServiceClient;
237
238    static Mutex gLock;
239    static sp<IAudioFlinger> gAudioFlinger;
240    static audio_error_callback gAudioErrorCallback;
241
242    static size_t gInBuffSize;
243    // previous parameters for recording buffer size queries
244    static uint32_t gPrevInSamplingRate;
245    static audio_format_t gPrevInFormat;
246    static int gPrevInChannelCount;
247
248    static sp<IAudioPolicyService> gAudioPolicyService;
249
250    // mapping between stream types and outputs
251    static DefaultKeyedVector<int, audio_io_handle_t> gStreamOutputMap;
252    // list of output descriptors containing cached parameters
253    // (sampling rate, framecount, channel count...)
254    static DefaultKeyedVector<audio_io_handle_t, OutputDescriptor *> gOutputs;
255};
256
257};  // namespace android
258
259#endif  /*ANDROID_AUDIOSYSTEM_H_*/
260