AudioPolicyInterface.h revision e1715a465a29db625da9d0ea365edf371e39e201 
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    // indicates to the audio policy manager that the output starts being used by corresponding stream.
94    virtual status_t startOutput(audio_io_handle_t output,
95                                 audio_stream_type_t stream,
96                                 int session = 0) = 0;
97    // indicates to the audio policy manager that the output stops being used by corresponding stream.
98    virtual status_t stopOutput(audio_io_handle_t output,
99                                audio_stream_type_t stream,
100                                int session = 0) = 0;
101    // releases the output.
102    virtual void releaseOutput(audio_io_handle_t output) = 0;
103
104    // request an input appropriate for record from the supplied device with supplied parameters.
105    virtual audio_io_handle_t getInput(audio_source_t inputSource,
106                                    uint32_t samplingRate,
107                                    audio_format_t format,
108                                    audio_channel_mask_t channelMask,
109                                    audio_in_acoustics_t acoustics) = 0;
110    // indicates to the audio policy manager that the input starts being used.
111    virtual status_t startInput(audio_io_handle_t input) = 0;
112    // indicates to the audio policy manager that the input stops being used.
113    virtual status_t stopInput(audio_io_handle_t input) = 0;
114    // releases the input.
115    virtual void releaseInput(audio_io_handle_t input) = 0;
116
117    //
118    // volume control functions
119    //
120
121    // initialises stream volume conversion parameters by specifying volume index range.
122    virtual void initStreamVolume(audio_stream_type_t stream,
123                                      int indexMin,
124                                      int indexMax) = 0;
125
126    // sets the new stream volume at a level corresponding to the supplied index for the
127    // supplied device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
128    // setting volume for all devices
129    virtual status_t setStreamVolumeIndex(audio_stream_type_t stream,
130                                          int index,
131                                          audio_devices_t device) = 0;
132
133    // retrieve current volume index for the specified stream and the
134    // specified device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
135    // querying the volume of the active device.
136    virtual status_t getStreamVolumeIndex(audio_stream_type_t stream,
137                                          int *index,
138                                          audio_devices_t device) = 0;
139
140    // return the strategy corresponding to a given stream type
141    virtual uint32_t getStrategyForStream(audio_stream_type_t stream) = 0;
142
143    // return the enabled output devices for the given stream type
144    virtual audio_devices_t getDevicesForStream(audio_stream_type_t stream) = 0;
145
146    // Audio effect management
147    virtual audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc) = 0;
148    virtual status_t registerEffect(const effect_descriptor_t *desc,
149                                    audio_io_handle_t io,
150                                    uint32_t strategy,
151                                    int session,
152                                    int id) = 0;
153    virtual status_t unregisterEffect(int id) = 0;
154    virtual status_t setEffectEnabled(int id, bool enabled) = 0;
155
156    virtual bool isStreamActive(audio_stream_type_t stream, uint32_t inPastMs = 0) const = 0;
157    virtual bool isStreamActiveRemotely(audio_stream_type_t stream,
158                                        uint32_t inPastMs = 0) const = 0;
159    virtual bool isSourceActive(audio_source_t source) const = 0;
160
161    //dump state
162    virtual status_t    dump(int fd) = 0;
163
164    virtual bool isOffloadSupported(const audio_offload_info_t& offloadInfo) = 0;
165
166    virtual status_t listAudioPorts(audio_port_role_t role,
167                                    audio_port_type_t type,
168                                    unsigned int *num_ports,
169                                    struct audio_port *ports,
170                                    unsigned int *generation) = 0;
171    virtual status_t getAudioPort(struct audio_port *port) = 0;
172    virtual status_t createAudioPatch(const struct audio_patch *patch,
173                                       audio_patch_handle_t *handle,
174                                       uid_t uid) = 0;
175    virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
176                                          uid_t uid) = 0;
177    virtual status_t listAudioPatches(unsigned int *num_patches,
178                                      struct audio_patch *patches,
179                                      unsigned int *generation) = 0;
180    virtual status_t setAudioPortConfig(const struct audio_port_config *config) = 0;
181    virtual void clearAudioPatches(uid_t uid) = 0;
182
183};
184
185
186// Audio Policy client Interface
187class AudioPolicyClientInterface
188{
189public:
190    virtual ~AudioPolicyClientInterface() {}
191
192    //
193    // Audio HW module functions
194    //
195
196    // loads a HW module.
197    virtual audio_module_handle_t loadHwModule(const char *name) = 0;
198
199    //
200    // Audio output Control functions
201    //
202
203    // opens an audio output with the requested parameters. The parameter values can indicate to use the default values
204    // in case the audio policy manager has no specific requirements for the output being opened.
205    // When the function returns, the parameter values reflect the actual values used by the audio hardware output stream.
206    // The audio policy manager can check if the proposed parameters are suitable or not and act accordingly.
207    virtual audio_io_handle_t openOutput(audio_module_handle_t module,
208                                         audio_devices_t *pDevices,
209                                         uint32_t *pSamplingRate,
210                                         audio_format_t *pFormat,
211                                         audio_channel_mask_t *pChannelMask,
212                                         uint32_t *pLatencyMs,
213                                         audio_output_flags_t flags,
214                                         const audio_offload_info_t *offloadInfo = NULL) = 0;
215    // creates a special output that is duplicated to the two outputs passed as arguments. The duplication is performed by
216    // a special mixer thread in the AudioFlinger.
217    virtual audio_io_handle_t openDuplicateOutput(audio_io_handle_t output1, audio_io_handle_t output2) = 0;
218    // closes the output stream
219    virtual status_t closeOutput(audio_io_handle_t output) = 0;
220    // suspends the output. When an output is suspended, the corresponding audio hardware output stream is placed in
221    // standby and the AudioTracks attached to the mixer thread are still processed but the output mix is discarded.
222    virtual status_t suspendOutput(audio_io_handle_t output) = 0;
223    // restores a suspended output.
224    virtual status_t restoreOutput(audio_io_handle_t output) = 0;
225
226    //
227    // Audio input Control functions
228    //
229
230    // opens an audio input
231    virtual audio_io_handle_t openInput(audio_module_handle_t module,
232                                        audio_devices_t *pDevices,
233                                        uint32_t *pSamplingRate,
234                                        audio_format_t *pFormat,
235                                        audio_channel_mask_t *pChannelMask) = 0;
236    // closes an audio input
237    virtual status_t closeInput(audio_io_handle_t input) = 0;
238    //
239    // misc control functions
240    //
241
242    // set a stream volume for a particular output. For the same user setting, a given stream type can have different volumes
243    // for each output (destination device) it is attached to.
244    virtual status_t setStreamVolume(audio_stream_type_t stream, float volume, audio_io_handle_t output, int delayMs = 0) = 0;
245
246    // invalidate a stream type, causing a reroute to an unspecified new output
247    virtual status_t invalidateStream(audio_stream_type_t stream) = 0;
248
249    // function enabling to send proprietary informations directly from audio policy manager to audio hardware interface.
250    virtual void setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs, int delayMs = 0) = 0;
251    // function enabling to receive proprietary informations directly from audio hardware interface to audio policy manager.
252    virtual String8 getParameters(audio_io_handle_t ioHandle, const String8& keys) = 0;
253
254    // request the playback of a tone on the specified stream: used for instance to replace notification sounds when playing
255    // over a telephony device during a phone call.
256    virtual status_t startTone(audio_policy_tone_t tone, audio_stream_type_t stream) = 0;
257    virtual status_t stopTone() = 0;
258
259    // set down link audio volume.
260    virtual status_t setVoiceVolume(float volume, int delayMs = 0) = 0;
261
262    // move effect to the specified output
263    virtual status_t moveEffects(int session,
264                                     audio_io_handle_t srcOutput,
265                                     audio_io_handle_t dstOutput) = 0;
266
267    /* Create a patch between several source and sink ports */
268    virtual status_t createAudioPatch(const struct audio_patch *patch,
269                                       audio_patch_handle_t *handle,
270                                       int delayMs) = 0;
271
272    /* Release a patch */
273    virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
274                                       int delayMs) = 0;
275
276    /* Set audio port configuration */
277    virtual status_t setAudioPortConfig(const struct audio_port_config *config, int delayMs) = 0;
278
279    virtual void onAudioPortListUpdate() = 0;
280
281    virtual void onAudioPatchListUpdate() = 0;
282};
283
284extern "C" AudioPolicyInterface* createAudioPolicyManager(AudioPolicyClientInterface *clientInterface);
285extern "C" void destroyAudioPolicyManager(AudioPolicyInterface *interface);
286
287
288}; // namespace android
289
290#endif // ANDROID_AUDIOPOLICY_INTERFACE_H
291