AudioPolicyInterface.h revision baac183f3808d7b68f184647a97bd381620415fe 
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_AUDIOPOLICY_INTERFACE_H
18#define ANDROID_AUDIOPOLICY_INTERFACE_H
19
20#include <media/AudioSystem.h>
21#include <media/AudioPolicy.h>
22#include <utils/String8.h>
23
24#include <hardware/audio_policy.h>
25
26namespace android {
27
28// ----------------------------------------------------------------------------
29
30// The AudioPolicyInterface and AudioPolicyClientInterface classes define the communication interfaces
31// between the platform specific audio policy manager and Android generic audio policy manager.
32// The platform specific audio policy manager must implement methods of the AudioPolicyInterface class.
33// This implementation makes use of the AudioPolicyClientInterface to control the activity and
34// configuration of audio input and output streams.
35//
36// The platform specific audio policy manager is in charge of the audio routing and volume control
37// policies for a given platform.
38// The main roles of this module are:
39//   - keep track of current system state (removable device connections, phone state, user requests...).
40//   System state changes and user actions are notified to audio policy manager with methods of the AudioPolicyInterface.
41//   - process getOutput() queries received when AudioTrack objects are created: Those queries
42//   return a handler on an output that has been selected, configured and opened by the audio policy manager and that
43//   must be used by the AudioTrack when registering to the AudioFlinger with the createTrack() method.
44//   When the AudioTrack object is released, a putOutput() query is received and the audio policy manager can decide
45//   to close or reconfigure the output depending on other streams using this output and current system state.
46//   - similarly process getInput() and putInput() queries received from AudioRecord objects and configure audio inputs.
47//   - process volume control requests: the stream volume is converted from an index value (received from UI) to a float value
48//   applicable to each output as a function of platform specific settings and current output route (destination device). It
49//   also make sure that streams are not muted if not allowed (e.g. camera shutter sound in some countries).
50//
51// The platform specific audio policy manager is provided as a shared library by platform vendors (as for libaudio.so)
52// and is linked with libaudioflinger.so
53
54
55//    Audio Policy Manager Interface
56class AudioPolicyInterface
57{
58
59public:
60    virtual ~AudioPolicyInterface() {}
61    //
62    // configuration functions
63    //
64
65    // indicate a change in device connection status
66    virtual status_t setDeviceConnectionState(audio_devices_t device,
67                                              audio_policy_dev_state_t state,
68                                          const char *device_address) = 0;
69    // retrieve a device connection status
70    virtual audio_policy_dev_state_t getDeviceConnectionState(audio_devices_t device,
71                                                                          const char *device_address) = 0;
72    // indicate a change in phone state. Valid phones states are defined by audio_mode_t
73    virtual void setPhoneState(audio_mode_t state) = 0;
74    // force using a specific device category for the specified usage
75    virtual void setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config) = 0;
76    // retrieve current device category forced for a given usage
77    virtual audio_policy_forced_cfg_t getForceUse(audio_policy_force_use_t usage) = 0;
78    // set a system property (e.g. camera sound always audible)
79    virtual void setSystemProperty(const char* property, const char* value) = 0;
80    // check proper initialization
81    virtual status_t initCheck() = 0;
82
83    //
84    // Audio routing query functions
85    //
86
87    // request an output appropriate for playback of the supplied stream type and parameters
88    virtual audio_io_handle_t getOutput(audio_stream_type_t stream,
89                                        uint32_t samplingRate,
90                                        audio_format_t format,
91                                        audio_channel_mask_t channelMask,
92                                        audio_output_flags_t flags,
93                                        const audio_offload_info_t *offloadInfo) = 0;
94    virtual status_t getOutputForAttr(const audio_attributes_t *attr,
95                                        audio_io_handle_t *output,
96                                        audio_session_t session,
97                                        audio_stream_type_t *stream,
98                                        uint32_t samplingRate,
99                                        audio_format_t format,
100                                        audio_channel_mask_t channelMask,
101                                        audio_output_flags_t flags,
102                                        const audio_offload_info_t *offloadInfo) = 0;
103    // indicates to the audio policy manager that the output starts being used by corresponding stream.
104    virtual status_t startOutput(audio_io_handle_t output,
105                                 audio_stream_type_t stream,
106                                 audio_session_t session) = 0;
107    // indicates to the audio policy manager that the output stops being used by corresponding stream.
108    virtual status_t stopOutput(audio_io_handle_t output,
109                                audio_stream_type_t stream,
110                                audio_session_t session) = 0;
111    // releases the output.
112    virtual void releaseOutput(audio_io_handle_t output,
113                               audio_stream_type_t stream,
114                               audio_session_t session) = 0;
115
116    // request an input appropriate for record from the supplied device with supplied parameters.
117    virtual status_t getInputForAttr(const audio_attributes_t *attr,
118                                     audio_io_handle_t *input,
119                                     audio_session_t session,
120                                     uint32_t samplingRate,
121                                     audio_format_t format,
122                                     audio_channel_mask_t channelMask,
123                                     audio_input_flags_t flags) = 0;
124    // indicates to the audio policy manager that the input starts being used.
125    virtual status_t startInput(audio_io_handle_t input,
126                                audio_session_t session) = 0;
127    // indicates to the audio policy manager that the input stops being used.
128    virtual status_t stopInput(audio_io_handle_t input,
129                               audio_session_t session) = 0;
130    // releases the input.
131    virtual void releaseInput(audio_io_handle_t input,
132                              audio_session_t session) = 0;
133
134    //
135    // volume control functions
136    //
137
138    // initialises stream volume conversion parameters by specifying volume index range.
139    virtual void initStreamVolume(audio_stream_type_t stream,
140                                      int indexMin,
141                                      int indexMax) = 0;
142
143    // sets the new stream volume at a level corresponding to the supplied index for the
144    // supplied device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
145    // setting volume for all devices
146    virtual status_t setStreamVolumeIndex(audio_stream_type_t stream,
147                                          int index,
148                                          audio_devices_t device) = 0;
149
150    // retrieve current volume index for the specified stream and the
151    // specified device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
152    // querying the volume of the active device.
153    virtual status_t getStreamVolumeIndex(audio_stream_type_t stream,
154                                          int *index,
155                                          audio_devices_t device) = 0;
156
157    // return the strategy corresponding to a given stream type
158    virtual uint32_t getStrategyForStream(audio_stream_type_t stream) = 0;
159
160    // return the enabled output devices for the given stream type
161    virtual audio_devices_t getDevicesForStream(audio_stream_type_t stream) = 0;
162
163    // Audio effect management
164    virtual audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc) = 0;
165    virtual status_t registerEffect(const effect_descriptor_t *desc,
166                                    audio_io_handle_t io,
167                                    uint32_t strategy,
168                                    int session,
169                                    int id) = 0;
170    virtual status_t unregisterEffect(int id) = 0;
171    virtual status_t setEffectEnabled(int id, bool enabled) = 0;
172
173    virtual bool isStreamActive(audio_stream_type_t stream, uint32_t inPastMs = 0) const = 0;
174    virtual bool isStreamActiveRemotely(audio_stream_type_t stream,
175                                        uint32_t inPastMs = 0) const = 0;
176    virtual bool isSourceActive(audio_source_t source) const = 0;
177
178    //dump state
179    virtual status_t    dump(int fd) = 0;
180
181    virtual bool isOffloadSupported(const audio_offload_info_t& offloadInfo) = 0;
182
183    virtual status_t listAudioPorts(audio_port_role_t role,
184                                    audio_port_type_t type,
185                                    unsigned int *num_ports,
186                                    struct audio_port *ports,
187                                    unsigned int *generation) = 0;
188    virtual status_t getAudioPort(struct audio_port *port) = 0;
189    virtual status_t createAudioPatch(const struct audio_patch *patch,
190                                       audio_patch_handle_t *handle,
191                                       uid_t uid) = 0;
192    virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
193                                          uid_t uid) = 0;
194    virtual status_t listAudioPatches(unsigned int *num_patches,
195                                      struct audio_patch *patches,
196                                      unsigned int *generation) = 0;
197    virtual status_t setAudioPortConfig(const struct audio_port_config *config) = 0;
198    virtual void clearAudioPatches(uid_t uid) = 0;
199
200    virtual status_t acquireSoundTriggerSession(audio_session_t *session,
201                                           audio_io_handle_t *ioHandle,
202                                           audio_devices_t *device) = 0;
203
204    virtual status_t releaseSoundTriggerSession(audio_session_t session) = 0;
205
206    virtual status_t registerPolicyMixes(Vector<AudioMix> mixes) = 0;
207    virtual status_t unregisterPolicyMixes(Vector<AudioMix> mixes) = 0;
208};
209
210
211// Audio Policy client Interface
212class AudioPolicyClientInterface
213{
214public:
215    virtual ~AudioPolicyClientInterface() {}
216
217    //
218    // Audio HW module functions
219    //
220
221    // loads a HW module.
222    virtual audio_module_handle_t loadHwModule(const char *name) = 0;
223
224    //
225    // Audio output Control functions
226    //
227
228    // opens an audio output with the requested parameters. The parameter values can indicate to use the default values
229    // in case the audio policy manager has no specific requirements for the output being opened.
230    // When the function returns, the parameter values reflect the actual values used by the audio hardware output stream.
231    // The audio policy manager can check if the proposed parameters are suitable or not and act accordingly.
232    virtual status_t openOutput(audio_module_handle_t module,
233                                audio_io_handle_t *output,
234                                audio_config_t *config,
235                                audio_devices_t *devices,
236                                const String8& address,
237                                uint32_t *latencyMs,
238                                audio_output_flags_t flags) = 0;
239    // creates a special output that is duplicated to the two outputs passed as arguments. The duplication is performed by
240    // a special mixer thread in the AudioFlinger.
241    virtual audio_io_handle_t openDuplicateOutput(audio_io_handle_t output1, audio_io_handle_t output2) = 0;
242    // closes the output stream
243    virtual status_t closeOutput(audio_io_handle_t output) = 0;
244    // suspends the output. When an output is suspended, the corresponding audio hardware output stream is placed in
245    // standby and the AudioTracks attached to the mixer thread are still processed but the output mix is discarded.
246    virtual status_t suspendOutput(audio_io_handle_t output) = 0;
247    // restores a suspended output.
248    virtual status_t restoreOutput(audio_io_handle_t output) = 0;
249
250    //
251    // Audio input Control functions
252    //
253
254    // opens an audio input
255    virtual status_t openInput(audio_module_handle_t module,
256                               audio_io_handle_t *input,
257                               audio_config_t *config,
258                               audio_devices_t *device,
259                               const String8& address,
260                               audio_source_t source,
261                               audio_input_flags_t flags) = 0;
262    // closes an audio input
263    virtual status_t closeInput(audio_io_handle_t input) = 0;
264    //
265    // misc control functions
266    //
267
268    // set a stream volume for a particular output. For the same user setting, a given stream type can have different volumes
269    // for each output (destination device) it is attached to.
270    virtual status_t setStreamVolume(audio_stream_type_t stream, float volume, audio_io_handle_t output, int delayMs = 0) = 0;
271
272    // invalidate a stream type, causing a reroute to an unspecified new output
273    virtual status_t invalidateStream(audio_stream_type_t stream) = 0;
274
275    // function enabling to send proprietary informations directly from audio policy manager to audio hardware interface.
276    virtual void setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs, int delayMs = 0) = 0;
277    // function enabling to receive proprietary informations directly from audio hardware interface to audio policy manager.
278    virtual String8 getParameters(audio_io_handle_t ioHandle, const String8& keys) = 0;
279
280    // request the playback of a tone on the specified stream: used for instance to replace notification sounds when playing
281    // over a telephony device during a phone call.
282    virtual status_t startTone(audio_policy_tone_t tone, audio_stream_type_t stream) = 0;
283    virtual status_t stopTone() = 0;
284
285    // set down link audio volume.
286    virtual status_t setVoiceVolume(float volume, int delayMs = 0) = 0;
287
288    // move effect to the specified output
289    virtual status_t moveEffects(int session,
290                                     audio_io_handle_t srcOutput,
291                                     audio_io_handle_t dstOutput) = 0;
292
293    /* Create a patch between several source and sink ports */
294    virtual status_t createAudioPatch(const struct audio_patch *patch,
295                                       audio_patch_handle_t *handle,
296                                       int delayMs) = 0;
297
298    /* Release a patch */
299    virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
300                                       int delayMs) = 0;
301
302    /* Set audio port configuration */
303    virtual status_t setAudioPortConfig(const struct audio_port_config *config, int delayMs) = 0;
304
305    virtual void onAudioPortListUpdate() = 0;
306
307    virtual void onAudioPatchListUpdate() = 0;
308
309    virtual audio_unique_id_t newAudioUniqueId() = 0;
310};
311
312extern "C" AudioPolicyInterface* createAudioPolicyManager(AudioPolicyClientInterface *clientInterface);
313extern "C" void destroyAudioPolicyManager(AudioPolicyInterface *interface);
314
315
316}; // namespace android
317
318#endif // ANDROID_AUDIOPOLICY_INTERFACE_H
319