1/*
2 * Copyright (C) 2009 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_AUDIOPOLICYINTERFACE_H
18#define ANDROID_AUDIOPOLICYINTERFACE_H
19
20#include <media/AudioSystem.h>
21#include <media/ToneGenerator.h>
22#include <utils/String8.h>
23
24#include <hardware_legacy/AudioSystemLegacy.h>
25
26namespace android_audio_legacy {
27    using android::Vector;
28    using android::String8;
29    using android::ToneGenerator;
30
31// ----------------------------------------------------------------------------
32
33// The AudioPolicyInterface and AudioPolicyClientInterface classes define the communication interfaces
34// between the platform specific audio policy manager and Android generic audio policy manager.
35// The platform specific audio policy manager must implement methods of the AudioPolicyInterface class.
36// This implementation makes use of the AudioPolicyClientInterface to control the activity and
37// configuration of audio input and output streams.
38//
39// The platform specific audio policy manager is in charge of the audio routing and volume control
40// policies for a given platform.
41// The main roles of this module are:
42//   - keep track of current system state (removable device connections, phone state, user requests...).
43//   System state changes and user actions are notified to audio policy manager with methods of the AudioPolicyInterface.
44//   - process getOutput() queries received when AudioTrack objects are created: Those queries
45//   return a handler on an output that has been selected, configured and opened by the audio policy manager and that
46//   must be used by the AudioTrack when registering to the AudioFlinger with the createTrack() method.
47//   When the AudioTrack object is released, a putOutput() query is received and the audio policy manager can decide
48//   to close or reconfigure the output depending on other streams using this output and current system state.
49//   - similarly process getInput() and putInput() queries received from AudioRecord objects and configure audio inputs.
50//   - process volume control requests: the stream volume is converted from an index value (received from UI) to a float value
51//   applicable to each output as a function of platform specific settings and current output route (destination device). It
52//   also make sure that streams are not muted if not allowed (e.g. camera shutter sound in some countries).
53//
54// The platform specific audio policy manager is provided as a shared library by platform vendors (as for libaudio.so)
55// and is linked with libaudioflinger.so
56
57
58//    Audio Policy Manager Interface
59class AudioPolicyInterface
60{
61
62public:
63    virtual ~AudioPolicyInterface() {}
64    //
65    // configuration functions
66    //
67
68    // indicate a change in device connection status
69    virtual status_t setDeviceConnectionState(AudioSystem::audio_devices device,
70                                          AudioSystem::device_connection_state state,
71                                          const char *device_address) = 0;
72    // retrieve a device connection status
73    virtual AudioSystem::device_connection_state getDeviceConnectionState(AudioSystem::audio_devices device,
74                                                                          const char *device_address) = 0;
75    // indicate a change in phone state. Valid phones states are defined by AudioSystem::audio_mode
76    virtual void setPhoneState(int state) = 0;
77    // force using a specific device category for the specified usage
78    virtual void setForceUse(AudioSystem::force_use usage, AudioSystem::forced_config config) = 0;
79    // retrieve current device category forced for a given usage
80    virtual AudioSystem::forced_config getForceUse(AudioSystem::force_use usage) = 0;
81    // set a system property (e.g. camera sound always audible)
82    virtual void setSystemProperty(const char* property, const char* value) = 0;
83    // check proper initialization
84    virtual status_t initCheck() = 0;
85
86    //
87    // Audio routing query functions
88    //
89
90    // request an output appropriate for playback of the supplied stream type and parameters
91    virtual audio_io_handle_t getOutput(AudioSystem::stream_type stream,
92                                        uint32_t samplingRate = 0,
93                                        uint32_t format = AudioSystem::FORMAT_DEFAULT,
94                                        uint32_t channels = 0,
95                                        AudioSystem::output_flags flags = AudioSystem::OUTPUT_FLAG_INDIRECT) = 0;
96    // indicates to the audio policy manager that the output starts being used by corresponding stream.
97    virtual status_t startOutput(audio_io_handle_t output,
98                                 AudioSystem::stream_type stream,
99                                 int session = 0) = 0;
100    // indicates to the audio policy manager that the output stops being used by corresponding stream.
101    virtual status_t stopOutput(audio_io_handle_t output,
102                                AudioSystem::stream_type stream,
103                                int session = 0) = 0;
104    // releases the output.
105    virtual void releaseOutput(audio_io_handle_t output) = 0;
106
107    // request an input appropriate for record from the supplied device with supplied parameters.
108    virtual audio_io_handle_t getInput(int inputSource,
109                                    uint32_t samplingRate = 0,
110                                    uint32_t Format = AudioSystem::FORMAT_DEFAULT,
111                                    uint32_t channels = 0,
112                                    AudioSystem::audio_in_acoustics acoustics = (AudioSystem::audio_in_acoustics)0) = 0;
113    // indicates to the audio policy manager that the input starts being used.
114    virtual status_t startInput(audio_io_handle_t input) = 0;
115    // indicates to the audio policy manager that the input stops being used.
116    virtual status_t stopInput(audio_io_handle_t input) = 0;
117    // releases the input.
118    virtual void releaseInput(audio_io_handle_t input) = 0;
119
120    //
121    // volume control functions
122    //
123
124    // initialises stream volume conversion parameters by specifying volume index range.
125    virtual void initStreamVolume(AudioSystem::stream_type stream,
126                                      int indexMin,
127                                      int indexMax) = 0;
128
129    // sets the new stream volume at a level corresponding to the supplied index for the
130    // supplied device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
131    // setting volume for all devices
132    virtual status_t setStreamVolumeIndex(AudioSystem::stream_type stream,
133                                          int index,
134                                          audio_devices_t device) = 0;
135
136    // retrieve current volume index for the specified stream and the
137    // specified device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
138    // querying the volume of the active device.
139    virtual status_t getStreamVolumeIndex(AudioSystem::stream_type stream,
140                                          int *index,
141                                          audio_devices_t device) = 0;
142
143    // return the strategy corresponding to a given stream type
144    virtual uint32_t getStrategyForStream(AudioSystem::stream_type stream) = 0;
145
146    // return the enabled output devices for the given stream type
147    virtual audio_devices_t getDevicesForStream(AudioSystem::stream_type stream) = 0;
148
149    // Audio effect management
150    virtual audio_io_handle_t getOutputForEffect(effect_descriptor_t *desc) = 0;
151    virtual status_t registerEffect(effect_descriptor_t *desc,
152                                    audio_io_handle_t io,
153                                    uint32_t strategy,
154                                    int session,
155                                    int id) = 0;
156    virtual status_t unregisterEffect(int id) = 0;
157    virtual status_t setEffectEnabled(int id, bool enabled) = 0;
158
159    virtual bool isStreamActive(int stream, uint32_t inPastMs = 0) const = 0;
160
161    //dump state
162    virtual status_t    dump(int fd) = 0;
163};
164
165
166// Audio Policy client Interface
167class AudioPolicyClientInterface
168{
169public:
170    virtual ~AudioPolicyClientInterface() {}
171
172    //
173    // Audio HW module functions
174    //
175
176    // loads a HW module.
177    virtual audio_module_handle_t loadHwModule(const char *name) = 0;
178
179    //
180    // Audio output Control functions
181    //
182
183    // opens an audio output with the requested parameters. The parameter values can indicate to use the default values
184    // in case the audio policy manager has no specific requirements for the output being opened.
185    // When the function returns, the parameter values reflect the actual values used by the audio hardware output stream.
186    // The audio policy manager can check if the proposed parameters are suitable or not and act accordingly.
187    virtual audio_io_handle_t openOutput(audio_module_handle_t module,
188                                         audio_devices_t *pDevices,
189                                         uint32_t *pSamplingRate,
190                                         audio_format_t *pFormat,
191                                         audio_channel_mask_t *pChannelMask,
192                                         uint32_t *pLatencyMs,
193                                         audio_output_flags_t flags) = 0;
194    // creates a special output that is duplicated to the two outputs passed as arguments. The duplication is performed by
195    // a special mixer thread in the AudioFlinger.
196    virtual audio_io_handle_t openDuplicateOutput(audio_io_handle_t output1, audio_io_handle_t output2) = 0;
197    // closes the output stream
198    virtual status_t closeOutput(audio_io_handle_t output) = 0;
199    // suspends the output. When an output is suspended, the corresponding audio hardware output stream is placed in
200    // standby and the AudioTracks attached to the mixer thread are still processed but the output mix is discarded.
201    virtual status_t suspendOutput(audio_io_handle_t output) = 0;
202    // restores a suspended output.
203    virtual status_t restoreOutput(audio_io_handle_t output) = 0;
204
205    //
206    // Audio input Control functions
207    //
208
209    // opens an audio input
210    virtual audio_io_handle_t openInput(audio_module_handle_t module,
211                                        audio_devices_t *pDevices,
212                                        uint32_t *pSamplingRate,
213                                        audio_format_t *pFormat,
214                                        audio_channel_mask_t *pChannelMask) = 0;
215    // closes an audio input
216    virtual status_t closeInput(audio_io_handle_t input) = 0;
217    //
218    // misc control functions
219    //
220
221    // set a stream volume for a particular output. For the same user setting, a given stream type can have different volumes
222    // for each output (destination device) it is attached to.
223    virtual status_t setStreamVolume(AudioSystem::stream_type stream, float volume, audio_io_handle_t output, int delayMs = 0) = 0;
224
225    // FIXME ignores output, should be renamed to invalidateStreamOuput(stream)
226    // reroute a given stream type to the specified output
227    virtual status_t setStreamOutput(AudioSystem::stream_type stream, audio_io_handle_t output) = 0;
228
229    // function enabling to send proprietary informations directly from audio policy manager to audio hardware interface.
230    virtual void setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs, int delayMs = 0) = 0;
231    // function enabling to receive proprietary informations directly from audio hardware interface to audio policy manager.
232    virtual String8 getParameters(audio_io_handle_t ioHandle, const String8& keys) = 0;
233
234    // request the playback of a tone on the specified stream: used for instance to replace notification sounds when playing
235    // over a telephony device during a phone call.
236    virtual status_t startTone(ToneGenerator::tone_type tone, AudioSystem::stream_type stream) = 0;
237    virtual status_t stopTone() = 0;
238
239    // set down link audio volume.
240    virtual status_t setVoiceVolume(float volume, int delayMs = 0) = 0;
241
242    // move effect to the specified output
243    virtual status_t moveEffects(int session,
244                                     audio_io_handle_t srcOutput,
245                                     audio_io_handle_t dstOutput) = 0;
246
247};
248
249extern "C" AudioPolicyInterface* createAudioPolicyManager(AudioPolicyClientInterface *clientInterface);
250extern "C" void destroyAudioPolicyManager(AudioPolicyInterface *interface);
251
252
253}; // namespace android
254
255#endif // ANDROID_AUDIOPOLICYINTERFACE_H
256