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