AudioPolicyInterface.h revision caf7f48a0ef558689d39aafd187c1571ff4128b4 
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
25namespace 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
55class AudioPolicyInterface
56{
57
58public:
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 status_t getOutputForAttr(const audio_attributes_t *attr,
94                                        audio_io_handle_t *output,
95                                        audio_session_t session,
96                                        audio_stream_type_t *stream,
97                                        uint32_t samplingRate,
98                                        audio_format_t format,
99                                        audio_channel_mask_t channelMask,
100                                        audio_output_flags_t flags,
101                                        const audio_offload_info_t *offloadInfo) = 0;
102    // indicates to the audio policy manager that the output starts being used by corresponding stream.
103    virtual status_t startOutput(audio_io_handle_t output,
104                                 audio_stream_type_t stream,
105                                 audio_session_t session) = 0;
106    // indicates to the audio policy manager that the output stops being used by corresponding stream.
107    virtual status_t stopOutput(audio_io_handle_t output,
108                                audio_stream_type_t stream,
109                                audio_session_t session) = 0;
110    // releases the output.
111    virtual void releaseOutput(audio_io_handle_t output,
112                               audio_stream_type_t stream,
113                               audio_session_t session) = 0;
114
115    // request an input appropriate for record from the supplied device with supplied parameters.
116    virtual status_t getInputForAttr(const audio_attributes_t *attr,
117                                     audio_io_handle_t *input,
118                                     audio_session_t session,
119                                     uint32_t samplingRate,
120                                     audio_format_t format,
121                                     audio_channel_mask_t channelMask,
122                                     audio_input_flags_t flags) = 0;
123    // indicates to the audio policy manager that the input starts being used.
124    virtual status_t startInput(audio_io_handle_t input,
125                                audio_session_t session) = 0;
126    // indicates to the audio policy manager that the input stops being used.
127    virtual status_t stopInput(audio_io_handle_t input,
128                               audio_session_t session) = 0;
129    // releases the input.
130    virtual void releaseInput(audio_io_handle_t input,
131                              audio_session_t session) = 0;
132
133    //
134    // volume control functions
135    //
136
137    // initialises stream volume conversion parameters by specifying volume index range.
138    virtual void initStreamVolume(audio_stream_type_t stream,
139                                      int indexMin,
140                                      int indexMax) = 0;
141
142    // sets the new stream volume at a level corresponding to the supplied index for the
143    // supplied device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
144    // setting volume for all devices
145    virtual status_t setStreamVolumeIndex(audio_stream_type_t stream,
146                                          int index,
147                                          audio_devices_t device) = 0;
148
149    // retrieve current volume index for the specified stream and the
150    // specified device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
151    // querying the volume of the active device.
152    virtual status_t getStreamVolumeIndex(audio_stream_type_t stream,
153                                          int *index,
154                                          audio_devices_t device) = 0;
155
156    // return the strategy corresponding to a given stream type
157    virtual uint32_t getStrategyForStream(audio_stream_type_t stream) = 0;
158
159    // return the enabled output devices for the given stream type
160    virtual audio_devices_t getDevicesForStream(audio_stream_type_t stream) = 0;
161
162    // Audio effect management
163    virtual audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc) = 0;
164    virtual status_t registerEffect(const effect_descriptor_t *desc,
165                                    audio_io_handle_t io,
166                                    uint32_t strategy,
167                                    int session,
168                                    int id) = 0;
169    virtual status_t unregisterEffect(int id) = 0;
170    virtual status_t setEffectEnabled(int id, bool enabled) = 0;
171
172    virtual bool isStreamActive(audio_stream_type_t stream, uint32_t inPastMs = 0) const = 0;
173    virtual bool isStreamActiveRemotely(audio_stream_type_t stream,
174                                        uint32_t inPastMs = 0) const = 0;
175    virtual bool isSourceActive(audio_source_t source) const = 0;
176
177    //dump state
178    virtual status_t    dump(int fd) = 0;
179
180    virtual bool isOffloadSupported(const audio_offload_info_t& offloadInfo) = 0;
181
182    virtual status_t listAudioPorts(audio_port_role_t role,
183                                    audio_port_type_t type,
184                                    unsigned int *num_ports,
185                                    struct audio_port *ports,
186                                    unsigned int *generation) = 0;
187    virtual status_t getAudioPort(struct audio_port *port) = 0;
188    virtual status_t createAudioPatch(const struct audio_patch *patch,
189                                       audio_patch_handle_t *handle,
190                                       uid_t uid) = 0;
191    virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
192                                          uid_t uid) = 0;
193    virtual status_t listAudioPatches(unsigned int *num_patches,
194                                      struct audio_patch *patches,
195                                      unsigned int *generation) = 0;
196    virtual status_t setAudioPortConfig(const struct audio_port_config *config) = 0;
197    virtual void clearAudioPatches(uid_t uid) = 0;
198
199    virtual status_t acquireSoundTriggerSession(audio_session_t *session,
200                                           audio_io_handle_t *ioHandle,
201                                           audio_devices_t *device) = 0;
202
203    virtual status_t releaseSoundTriggerSession(audio_session_t session) = 0;
204};
205
206
207// Audio Policy client Interface
208class AudioPolicyClientInterface
209{
210public:
211    virtual ~AudioPolicyClientInterface() {}
212
213    //
214    // Audio HW module functions
215    //
216
217    // loads a HW module.
218    virtual audio_module_handle_t loadHwModule(const char *name) = 0;
219
220    //
221    // Audio output Control functions
222    //
223
224    // opens an audio output with the requested parameters. The parameter values can indicate to use the default values
225    // in case the audio policy manager has no specific requirements for the output being opened.
226    // When the function returns, the parameter values reflect the actual values used by the audio hardware output stream.
227    // The audio policy manager can check if the proposed parameters are suitable or not and act accordingly.
228    virtual status_t openOutput(audio_module_handle_t module,
229                                audio_io_handle_t *output,
230                                audio_config_t *config,
231                                audio_devices_t *devices,
232                                const String8& address,
233                                uint32_t *latencyMs,
234                                audio_output_flags_t flags) = 0;
235    // creates a special output that is duplicated to the two outputs passed as arguments. The duplication is performed by
236    // a special mixer thread in the AudioFlinger.
237    virtual audio_io_handle_t openDuplicateOutput(audio_io_handle_t output1, audio_io_handle_t output2) = 0;
238    // closes the output stream
239    virtual status_t closeOutput(audio_io_handle_t output) = 0;
240    // suspends the output. When an output is suspended, the corresponding audio hardware output stream is placed in
241    // standby and the AudioTracks attached to the mixer thread are still processed but the output mix is discarded.
242    virtual status_t suspendOutput(audio_io_handle_t output) = 0;
243    // restores a suspended output.
244    virtual status_t restoreOutput(audio_io_handle_t output) = 0;
245
246    //
247    // Audio input Control functions
248    //
249
250    // opens an audio input
251    virtual status_t openInput(audio_module_handle_t module,
252                               audio_io_handle_t *input,
253                               audio_config_t *config,
254                               audio_devices_t *device,
255                               const String8& address,
256                               audio_source_t source,
257                               audio_input_flags_t flags) = 0;
258    // closes an audio input
259    virtual status_t closeInput(audio_io_handle_t input) = 0;
260    //
261    // misc control functions
262    //
263
264    // set a stream volume for a particular output. For the same user setting, a given stream type can have different volumes
265    // for each output (destination device) it is attached to.
266    virtual status_t setStreamVolume(audio_stream_type_t stream, float volume, audio_io_handle_t output, int delayMs = 0) = 0;
267
268    // invalidate a stream type, causing a reroute to an unspecified new output
269    virtual status_t invalidateStream(audio_stream_type_t stream) = 0;
270
271    // function enabling to send proprietary informations directly from audio policy manager to audio hardware interface.
272    virtual void setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs, int delayMs = 0) = 0;
273    // function enabling to receive proprietary informations directly from audio hardware interface to audio policy manager.
274    virtual String8 getParameters(audio_io_handle_t ioHandle, const String8& keys) = 0;
275
276    // request the playback of a tone on the specified stream: used for instance to replace notification sounds when playing
277    // over a telephony device during a phone call.
278    virtual status_t startTone(audio_policy_tone_t tone, audio_stream_type_t stream) = 0;
279    virtual status_t stopTone() = 0;
280
281    // set down link audio volume.
282    virtual status_t setVoiceVolume(float volume, int delayMs = 0) = 0;
283
284    // move effect to the specified output
285    virtual status_t moveEffects(int session,
286                                     audio_io_handle_t srcOutput,
287                                     audio_io_handle_t dstOutput) = 0;
288
289    /* Create a patch between several source and sink ports */
290    virtual status_t createAudioPatch(const struct audio_patch *patch,
291                                       audio_patch_handle_t *handle,
292                                       int delayMs) = 0;
293
294    /* Release a patch */
295    virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
296                                       int delayMs) = 0;
297
298    /* Set audio port configuration */
299    virtual status_t setAudioPortConfig(const struct audio_port_config *config, int delayMs) = 0;
300
301    virtual void onAudioPortListUpdate() = 0;
302
303    virtual void onAudioPatchListUpdate() = 0;
304
305    virtual audio_unique_id_t newAudioUniqueId() = 0;
306};
307
308extern "C" AudioPolicyInterface* createAudioPolicyManager(AudioPolicyClientInterface *clientInterface);
309extern "C" void destroyAudioPolicyManager(AudioPolicyInterface *interface);
310
311
312}; // namespace android
313
314#endif // ANDROID_AUDIOPOLICY_INTERFACE_H
315