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         API_INPUT_TELEPHONY_RX, // used for capture from telephony RX path
68     } input_type_t;
69 
70 public:
~AudioPolicyInterface()71     virtual ~AudioPolicyInterface() {}
72     //
73     // configuration functions
74     //
75 
76     // indicate a change in device connection status
77     virtual status_t setDeviceConnectionState(audio_devices_t device,
78                                               audio_policy_dev_state_t state,
79                                               const char *device_address,
80                                               const char *device_name) = 0;
81     // retrieve a device connection status
82     virtual audio_policy_dev_state_t getDeviceConnectionState(audio_devices_t device,
83                                                                           const char *device_address) = 0;
84     // indicate a change in phone state. Valid phones states are defined by audio_mode_t
85     virtual void setPhoneState(audio_mode_t state) = 0;
86     // force using a specific device category for the specified usage
87     virtual void setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config) = 0;
88     // retrieve current device category forced for a given usage
89     virtual audio_policy_forced_cfg_t getForceUse(audio_policy_force_use_t usage) = 0;
90     // set a system property (e.g. camera sound always audible)
91     virtual void setSystemProperty(const char* property, const char* value) = 0;
92     // check proper initialization
93     virtual status_t initCheck() = 0;
94 
95     //
96     // Audio routing query functions
97     //
98 
99     // request an output appropriate for playback of the supplied stream type and parameters
100     virtual audio_io_handle_t getOutput(audio_stream_type_t stream,
101                                         uint32_t samplingRate,
102                                         audio_format_t format,
103                                         audio_channel_mask_t channelMask,
104                                         audio_output_flags_t flags,
105                                         const audio_offload_info_t *offloadInfo) = 0;
106     virtual status_t getOutputForAttr(const audio_attributes_t *attr,
107                                         audio_io_handle_t *output,
108                                         audio_session_t session,
109                                         audio_stream_type_t *stream,
110                                         uid_t uid,
111                                         uint32_t samplingRate,
112                                         audio_format_t format,
113                                         audio_channel_mask_t channelMask,
114                                         audio_output_flags_t flags,
115                                         int selectedDeviceId,
116                                         const audio_offload_info_t *offloadInfo) = 0;
117     // indicates to the audio policy manager that the output starts being used by corresponding stream.
118     virtual status_t startOutput(audio_io_handle_t output,
119                                  audio_stream_type_t stream,
120                                  audio_session_t session) = 0;
121     // indicates to the audio policy manager that the output stops being used by corresponding stream.
122     virtual status_t stopOutput(audio_io_handle_t output,
123                                 audio_stream_type_t stream,
124                                 audio_session_t session) = 0;
125     // releases the output.
126     virtual void releaseOutput(audio_io_handle_t output,
127                                audio_stream_type_t stream,
128                                audio_session_t session) = 0;
129 
130     // request an input appropriate for record from the supplied device with supplied parameters.
131     virtual status_t getInputForAttr(const audio_attributes_t *attr,
132                                      audio_io_handle_t *input,
133                                      audio_session_t session,
134                                      uid_t uid,
135                                      uint32_t samplingRate,
136                                      audio_format_t format,
137                                      audio_channel_mask_t channelMask,
138                                      audio_input_flags_t flags,
139                                      audio_port_handle_t selectedDeviceId,
140                                      input_type_t *inputType) = 0;
141     // indicates to the audio policy manager that the input starts being used.
142     virtual status_t startInput(audio_io_handle_t input,
143                                 audio_session_t session) = 0;
144     // indicates to the audio policy manager that the input stops being used.
145     virtual status_t stopInput(audio_io_handle_t input,
146                                audio_session_t session) = 0;
147     // releases the input.
148     virtual void releaseInput(audio_io_handle_t input,
149                               audio_session_t session) = 0;
150 
151     //
152     // volume control functions
153     //
154 
155     // initialises stream volume conversion parameters by specifying volume index range.
156     virtual void initStreamVolume(audio_stream_type_t stream,
157                                       int indexMin,
158                                       int indexMax) = 0;
159 
160     // sets the new stream volume at a level corresponding to the supplied index for the
161     // supplied device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT_FOR_VOLUME means
162     // setting volume for all devices
163     virtual status_t setStreamVolumeIndex(audio_stream_type_t stream,
164                                           int index,
165                                           audio_devices_t device) = 0;
166 
167     // retrieve current volume index for the specified stream and the
168     // specified device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT_FOR_VOLUME means
169     // querying the volume of the active device.
170     virtual status_t getStreamVolumeIndex(audio_stream_type_t stream,
171                                           int *index,
172                                           audio_devices_t device) = 0;
173 
174     // return the strategy corresponding to a given stream type
175     virtual uint32_t getStrategyForStream(audio_stream_type_t stream) = 0;
176 
177     // return the enabled output devices for the given stream type
178     virtual audio_devices_t getDevicesForStream(audio_stream_type_t stream) = 0;
179 
180     // Audio effect management
181     virtual audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc) = 0;
182     virtual status_t registerEffect(const effect_descriptor_t *desc,
183                                     audio_io_handle_t io,
184                                     uint32_t strategy,
185                                     int session,
186                                     int id) = 0;
187     virtual status_t unregisterEffect(int id) = 0;
188     virtual status_t setEffectEnabled(int id, bool enabled) = 0;
189 
190     virtual bool isStreamActive(audio_stream_type_t stream, uint32_t inPastMs = 0) const = 0;
191     virtual bool isStreamActiveRemotely(audio_stream_type_t stream,
192                                         uint32_t inPastMs = 0) const = 0;
193     virtual bool isSourceActive(audio_source_t source) const = 0;
194 
195     //dump state
196     virtual status_t    dump(int fd) = 0;
197 
198     virtual bool isOffloadSupported(const audio_offload_info_t& offloadInfo) = 0;
199 
200     virtual status_t listAudioPorts(audio_port_role_t role,
201                                     audio_port_type_t type,
202                                     unsigned int *num_ports,
203                                     struct audio_port *ports,
204                                     unsigned int *generation) = 0;
205     virtual status_t getAudioPort(struct audio_port *port) = 0;
206     virtual status_t createAudioPatch(const struct audio_patch *patch,
207                                        audio_patch_handle_t *handle,
208                                        uid_t uid) = 0;
209     virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
210                                           uid_t uid) = 0;
211     virtual status_t listAudioPatches(unsigned int *num_patches,
212                                       struct audio_patch *patches,
213                                       unsigned int *generation) = 0;
214     virtual status_t setAudioPortConfig(const struct audio_port_config *config) = 0;
215     virtual void releaseResourcesForUid(uid_t uid) = 0;
216 
217     virtual status_t acquireSoundTriggerSession(audio_session_t *session,
218                                            audio_io_handle_t *ioHandle,
219                                            audio_devices_t *device) = 0;
220 
221     virtual status_t releaseSoundTriggerSession(audio_session_t session) = 0;
222 
223     virtual status_t registerPolicyMixes(Vector<AudioMix> mixes) = 0;
224     virtual status_t unregisterPolicyMixes(Vector<AudioMix> mixes) = 0;
225 
226     virtual status_t startAudioSource(const struct audio_port_config *source,
227                                       const audio_attributes_t *attributes,
228                                       audio_io_handle_t *handle,
229                                       uid_t uid) = 0;
230     virtual status_t stopAudioSource(audio_io_handle_t handle) = 0;
231 
232     virtual status_t setMasterMono(bool mono) = 0;
233     virtual status_t getMasterMono(bool *mono) = 0;
234 };
235 
236 
237 // Audio Policy client Interface
238 class AudioPolicyClientInterface
239 {
240 public:
~AudioPolicyClientInterface()241     virtual ~AudioPolicyClientInterface() {}
242 
243     //
244     // Audio HW module functions
245     //
246 
247     // loads a HW module.
248     virtual audio_module_handle_t loadHwModule(const char *name) = 0;
249 
250     //
251     // Audio output Control functions
252     //
253 
254     // opens an audio output with the requested parameters. The parameter values can indicate to use the default values
255     // in case the audio policy manager has no specific requirements for the output being opened.
256     // When the function returns, the parameter values reflect the actual values used by the audio hardware output stream.
257     // The audio policy manager can check if the proposed parameters are suitable or not and act accordingly.
258     virtual status_t openOutput(audio_module_handle_t module,
259                                 audio_io_handle_t *output,
260                                 audio_config_t *config,
261                                 audio_devices_t *devices,
262                                 const String8& address,
263                                 uint32_t *latencyMs,
264                                 audio_output_flags_t flags) = 0;
265     // creates a special output that is duplicated to the two outputs passed as arguments. The duplication is performed by
266     // a special mixer thread in the AudioFlinger.
267     virtual audio_io_handle_t openDuplicateOutput(audio_io_handle_t output1, audio_io_handle_t output2) = 0;
268     // closes the output stream
269     virtual status_t closeOutput(audio_io_handle_t output) = 0;
270     // suspends the output. When an output is suspended, the corresponding audio hardware output stream is placed in
271     // standby and the AudioTracks attached to the mixer thread are still processed but the output mix is discarded.
272     virtual status_t suspendOutput(audio_io_handle_t output) = 0;
273     // restores a suspended output.
274     virtual status_t restoreOutput(audio_io_handle_t output) = 0;
275 
276     //
277     // Audio input Control functions
278     //
279 
280     // opens an audio input
281     virtual status_t openInput(audio_module_handle_t module,
282                                audio_io_handle_t *input,
283                                audio_config_t *config,
284                                audio_devices_t *device,
285                                const String8& address,
286                                audio_source_t source,
287                                audio_input_flags_t flags) = 0;
288     // closes an audio input
289     virtual status_t closeInput(audio_io_handle_t input) = 0;
290     //
291     // misc control functions
292     //
293 
294     // set a stream volume for a particular output. For the same user setting, a given stream type can have different volumes
295     // for each output (destination device) it is attached to.
296     virtual status_t setStreamVolume(audio_stream_type_t stream, float volume, audio_io_handle_t output, int delayMs = 0) = 0;
297 
298     // invalidate a stream type, causing a reroute to an unspecified new output
299     virtual status_t invalidateStream(audio_stream_type_t stream) = 0;
300 
301     // function enabling to send proprietary informations directly from audio policy manager to audio hardware interface.
302     virtual void setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs, int delayMs = 0) = 0;
303     // function enabling to receive proprietary informations directly from audio hardware interface to audio policy manager.
304     virtual String8 getParameters(audio_io_handle_t ioHandle, const String8& keys) = 0;
305 
306     // request the playback of a tone on the specified stream: used for instance to replace notification sounds when playing
307     // over a telephony device during a phone call.
308     virtual status_t startTone(audio_policy_tone_t tone, audio_stream_type_t stream) = 0;
309     virtual status_t stopTone() = 0;
310 
311     // set down link audio volume.
312     virtual status_t setVoiceVolume(float volume, int delayMs = 0) = 0;
313 
314     // move effect to the specified output
315     virtual status_t moveEffects(audio_session_t session,
316                                      audio_io_handle_t srcOutput,
317                                      audio_io_handle_t dstOutput) = 0;
318 
319     /* Create a patch between several source and sink ports */
320     virtual status_t createAudioPatch(const struct audio_patch *patch,
321                                        audio_patch_handle_t *handle,
322                                        int delayMs) = 0;
323 
324     /* Release a patch */
325     virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
326                                        int delayMs) = 0;
327 
328     /* Set audio port configuration */
329     virtual status_t setAudioPortConfig(const struct audio_port_config *config, int delayMs) = 0;
330 
331     virtual void onAudioPortListUpdate() = 0;
332 
333     virtual void onAudioPatchListUpdate() = 0;
334 
335     virtual audio_unique_id_t newAudioUniqueId(audio_unique_id_use_t use) = 0;
336 
337     virtual void onDynamicPolicyMixStateUpdate(String8 regId, int32_t state) = 0;
338 
339     virtual void onRecordingConfigurationUpdate(int event, audio_session_t session,
340                     audio_source_t source,
341                     const struct audio_config_base *clientConfig,
342                     const struct audio_config_base *deviceConfig,
343                     audio_patch_handle_t patchHandle) = 0;
344 };
345 
346 extern "C" AudioPolicyInterface* createAudioPolicyManager(AudioPolicyClientInterface *clientInterface);
347 extern "C" void destroyAudioPolicyManager(AudioPolicyInterface *interface);
348 
349 
350 }; // namespace android
351 
352 #endif // ANDROID_AUDIOPOLICY_INTERFACE_H
353