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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 
26 namespace 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
56 class AudioPolicyInterface
57 {
58 
59 public:
60     typedef enum {
61         API_INPUT_INVALID = -1,
62         API_INPUT_LEGACY  = 0,// e.g. audio recording from a microphone
63         API_INPUT_MIX_CAPTURE,// used for "remote submix", capture of the media to play it remotely
64         API_INPUT_MIX_EXT_POLICY_REROUTE,// used for platform audio rerouting, where mixes are
65                                          // handled by external and dynamically installed
66                                          // policies which reroute audio mixes
67     } input_type_t;
68 
69 public:
~AudioPolicyInterface()70     virtual ~AudioPolicyInterface() {}
71     //
72     // configuration functions
73     //
74 
75     // indicate a change in device connection status
76     virtual status_t setDeviceConnectionState(audio_devices_t device,
77                                               audio_policy_dev_state_t state,
78                                           const char *device_address) = 0;
79     // retrieve a device connection status
80     virtual audio_policy_dev_state_t getDeviceConnectionState(audio_devices_t device,
81                                                                           const char *device_address) = 0;
82     // indicate a change in phone state. Valid phones states are defined by audio_mode_t
83     virtual void setPhoneState(audio_mode_t state) = 0;
84     // force using a specific device category for the specified usage
85     virtual void setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config) = 0;
86     // retrieve current device category forced for a given usage
87     virtual audio_policy_forced_cfg_t getForceUse(audio_policy_force_use_t usage) = 0;
88     // set a system property (e.g. camera sound always audible)
89     virtual void setSystemProperty(const char* property, const char* value) = 0;
90     // check proper initialization
91     virtual status_t initCheck() = 0;
92 
93     //
94     // Audio routing query functions
95     //
96 
97     // request an output appropriate for playback of the supplied stream type and parameters
98     virtual audio_io_handle_t getOutput(audio_stream_type_t stream,
99                                         uint32_t samplingRate,
100                                         audio_format_t format,
101                                         audio_channel_mask_t channelMask,
102                                         audio_output_flags_t flags,
103                                         const audio_offload_info_t *offloadInfo) = 0;
104     virtual status_t getOutputForAttr(const audio_attributes_t *attr,
105                                         audio_io_handle_t *output,
106                                         audio_session_t session,
107                                         audio_stream_type_t *stream,
108                                         uint32_t samplingRate,
109                                         audio_format_t format,
110                                         audio_channel_mask_t channelMask,
111                                         audio_output_flags_t flags,
112                                         const audio_offload_info_t *offloadInfo) = 0;
113     // indicates to the audio policy manager that the output starts being used by corresponding stream.
114     virtual status_t startOutput(audio_io_handle_t output,
115                                  audio_stream_type_t stream,
116                                  audio_session_t session) = 0;
117     // indicates to the audio policy manager that the output stops being used by corresponding stream.
118     virtual status_t stopOutput(audio_io_handle_t output,
119                                 audio_stream_type_t stream,
120                                 audio_session_t session) = 0;
121     // releases the output.
122     virtual void releaseOutput(audio_io_handle_t output,
123                                audio_stream_type_t stream,
124                                audio_session_t session) = 0;
125 
126     // request an input appropriate for record from the supplied device with supplied parameters.
127     virtual status_t getInputForAttr(const audio_attributes_t *attr,
128                                      audio_io_handle_t *input,
129                                      audio_session_t session,
130                                      uint32_t samplingRate,
131                                      audio_format_t format,
132                                      audio_channel_mask_t channelMask,
133                                      audio_input_flags_t flags,
134                                      input_type_t *inputType) = 0;
135     // indicates to the audio policy manager that the input starts being used.
136     virtual status_t startInput(audio_io_handle_t input,
137                                 audio_session_t session) = 0;
138     // indicates to the audio policy manager that the input stops being used.
139     virtual status_t stopInput(audio_io_handle_t input,
140                                audio_session_t session) = 0;
141     // releases the input.
142     virtual void releaseInput(audio_io_handle_t input,
143                               audio_session_t session) = 0;
144 
145     //
146     // volume control functions
147     //
148 
149     // initialises stream volume conversion parameters by specifying volume index range.
150     virtual void initStreamVolume(audio_stream_type_t stream,
151                                       int indexMin,
152                                       int indexMax) = 0;
153 
154     // sets the new stream volume at a level corresponding to the supplied index for the
155     // supplied device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
156     // setting volume for all devices
157     virtual status_t setStreamVolumeIndex(audio_stream_type_t stream,
158                                           int index,
159                                           audio_devices_t device) = 0;
160 
161     // retrieve current volume index for the specified stream and the
162     // specified device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
163     // querying the volume of the active device.
164     virtual status_t getStreamVolumeIndex(audio_stream_type_t stream,
165                                           int *index,
166                                           audio_devices_t device) = 0;
167 
168     // return the strategy corresponding to a given stream type
169     virtual uint32_t getStrategyForStream(audio_stream_type_t stream) = 0;
170 
171     // return the enabled output devices for the given stream type
172     virtual audio_devices_t getDevicesForStream(audio_stream_type_t stream) = 0;
173 
174     // Audio effect management
175     virtual audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc) = 0;
176     virtual status_t registerEffect(const effect_descriptor_t *desc,
177                                     audio_io_handle_t io,
178                                     uint32_t strategy,
179                                     int session,
180                                     int id) = 0;
181     virtual status_t unregisterEffect(int id) = 0;
182     virtual status_t setEffectEnabled(int id, bool enabled) = 0;
183 
184     virtual bool isStreamActive(audio_stream_type_t stream, uint32_t inPastMs = 0) const = 0;
185     virtual bool isStreamActiveRemotely(audio_stream_type_t stream,
186                                         uint32_t inPastMs = 0) const = 0;
187     virtual bool isSourceActive(audio_source_t source) const = 0;
188 
189     //dump state
190     virtual status_t    dump(int fd) = 0;
191 
192     virtual bool isOffloadSupported(const audio_offload_info_t& offloadInfo) = 0;
193 
194     virtual status_t listAudioPorts(audio_port_role_t role,
195                                     audio_port_type_t type,
196                                     unsigned int *num_ports,
197                                     struct audio_port *ports,
198                                     unsigned int *generation) = 0;
199     virtual status_t getAudioPort(struct audio_port *port) = 0;
200     virtual status_t createAudioPatch(const struct audio_patch *patch,
201                                        audio_patch_handle_t *handle,
202                                        uid_t uid) = 0;
203     virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
204                                           uid_t uid) = 0;
205     virtual status_t listAudioPatches(unsigned int *num_patches,
206                                       struct audio_patch *patches,
207                                       unsigned int *generation) = 0;
208     virtual status_t setAudioPortConfig(const struct audio_port_config *config) = 0;
209     virtual void clearAudioPatches(uid_t uid) = 0;
210 
211     virtual status_t acquireSoundTriggerSession(audio_session_t *session,
212                                            audio_io_handle_t *ioHandle,
213                                            audio_devices_t *device) = 0;
214 
215     virtual status_t releaseSoundTriggerSession(audio_session_t session) = 0;
216 
217     virtual status_t registerPolicyMixes(Vector<AudioMix> mixes) = 0;
218     virtual status_t unregisterPolicyMixes(Vector<AudioMix> mixes) = 0;
219 };
220 
221 
222 // Audio Policy client Interface
223 class AudioPolicyClientInterface
224 {
225 public:
~AudioPolicyClientInterface()226     virtual ~AudioPolicyClientInterface() {}
227 
228     //
229     // Audio HW module functions
230     //
231 
232     // loads a HW module.
233     virtual audio_module_handle_t loadHwModule(const char *name) = 0;
234 
235     //
236     // Audio output Control functions
237     //
238 
239     // opens an audio output with the requested parameters. The parameter values can indicate to use the default values
240     // in case the audio policy manager has no specific requirements for the output being opened.
241     // When the function returns, the parameter values reflect the actual values used by the audio hardware output stream.
242     // The audio policy manager can check if the proposed parameters are suitable or not and act accordingly.
243     virtual status_t openOutput(audio_module_handle_t module,
244                                 audio_io_handle_t *output,
245                                 audio_config_t *config,
246                                 audio_devices_t *devices,
247                                 const String8& address,
248                                 uint32_t *latencyMs,
249                                 audio_output_flags_t flags) = 0;
250     // creates a special output that is duplicated to the two outputs passed as arguments. The duplication is performed by
251     // a special mixer thread in the AudioFlinger.
252     virtual audio_io_handle_t openDuplicateOutput(audio_io_handle_t output1, audio_io_handle_t output2) = 0;
253     // closes the output stream
254     virtual status_t closeOutput(audio_io_handle_t output) = 0;
255     // suspends the output. When an output is suspended, the corresponding audio hardware output stream is placed in
256     // standby and the AudioTracks attached to the mixer thread are still processed but the output mix is discarded.
257     virtual status_t suspendOutput(audio_io_handle_t output) = 0;
258     // restores a suspended output.
259     virtual status_t restoreOutput(audio_io_handle_t output) = 0;
260 
261     //
262     // Audio input Control functions
263     //
264 
265     // opens an audio input
266     virtual status_t openInput(audio_module_handle_t module,
267                                audio_io_handle_t *input,
268                                audio_config_t *config,
269                                audio_devices_t *device,
270                                const String8& address,
271                                audio_source_t source,
272                                audio_input_flags_t flags) = 0;
273     // closes an audio input
274     virtual status_t closeInput(audio_io_handle_t input) = 0;
275     //
276     // misc control functions
277     //
278 
279     // set a stream volume for a particular output. For the same user setting, a given stream type can have different volumes
280     // for each output (destination device) it is attached to.
281     virtual status_t setStreamVolume(audio_stream_type_t stream, float volume, audio_io_handle_t output, int delayMs = 0) = 0;
282 
283     // invalidate a stream type, causing a reroute to an unspecified new output
284     virtual status_t invalidateStream(audio_stream_type_t stream) = 0;
285 
286     // function enabling to send proprietary informations directly from audio policy manager to audio hardware interface.
287     virtual void setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs, int delayMs = 0) = 0;
288     // function enabling to receive proprietary informations directly from audio hardware interface to audio policy manager.
289     virtual String8 getParameters(audio_io_handle_t ioHandle, const String8& keys) = 0;
290 
291     // request the playback of a tone on the specified stream: used for instance to replace notification sounds when playing
292     // over a telephony device during a phone call.
293     virtual status_t startTone(audio_policy_tone_t tone, audio_stream_type_t stream) = 0;
294     virtual status_t stopTone() = 0;
295 
296     // set down link audio volume.
297     virtual status_t setVoiceVolume(float volume, int delayMs = 0) = 0;
298 
299     // move effect to the specified output
300     virtual status_t moveEffects(int session,
301                                      audio_io_handle_t srcOutput,
302                                      audio_io_handle_t dstOutput) = 0;
303 
304     /* Create a patch between several source and sink ports */
305     virtual status_t createAudioPatch(const struct audio_patch *patch,
306                                        audio_patch_handle_t *handle,
307                                        int delayMs) = 0;
308 
309     /* Release a patch */
310     virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
311                                        int delayMs) = 0;
312 
313     /* Set audio port configuration */
314     virtual status_t setAudioPortConfig(const struct audio_port_config *config, int delayMs) = 0;
315 
316     virtual void onAudioPortListUpdate() = 0;
317 
318     virtual void onAudioPatchListUpdate() = 0;
319 
320     virtual audio_unique_id_t newAudioUniqueId() = 0;
321 };
322 
323 extern "C" AudioPolicyInterface* createAudioPolicyManager(AudioPolicyClientInterface *clientInterface);
324 extern "C" void destroyAudioPolicyManager(AudioPolicyInterface *interface);
325 
326 
327 }; // namespace android
328 
329 #endif // ANDROID_AUDIOPOLICY_INTERFACE_H
330