AudioPolicyInterface.h revision cf2c0210c8afbe7d0661ccbbae3835b5ce73c0bf 
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 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_in_acoustics_t acoustics,
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) = 0;
119    // indicates to the audio policy manager that the input stops being used.
120    virtual status_t stopInput(audio_io_handle_t input) = 0;
121    // releases the input.
122    virtual void releaseInput(audio_io_handle_t input) = 0;
123
124    //
125    // volume control functions
126    //
127
128    // initialises stream volume conversion parameters by specifying volume index range.
129    virtual void initStreamVolume(audio_stream_type_t stream,
130                                      int indexMin,
131                                      int indexMax) = 0;
132
133    // sets the new stream volume at a level corresponding to the supplied index for the
134    // supplied device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
135    // setting volume for all devices
136    virtual status_t setStreamVolumeIndex(audio_stream_type_t stream,
137                                          int index,
138                                          audio_devices_t device) = 0;
139
140    // retrieve current volume index for the specified stream and the
141    // specified device. By convention, specifying AUDIO_DEVICE_OUT_DEFAULT means
142    // querying the volume of the active device.
143    virtual status_t getStreamVolumeIndex(audio_stream_type_t stream,
144                                          int *index,
145                                          audio_devices_t device) = 0;
146
147    // return the strategy corresponding to a given stream type
148    virtual uint32_t getStrategyForStream(audio_stream_type_t stream) = 0;
149
150    // return the enabled output devices for the given stream type
151    virtual audio_devices_t getDevicesForStream(audio_stream_type_t stream) = 0;
152
153    // Audio effect management
154    virtual audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc) = 0;
155    virtual status_t registerEffect(const effect_descriptor_t *desc,
156                                    audio_io_handle_t io,
157                                    uint32_t strategy,
158                                    int session,
159                                    int id) = 0;
160    virtual status_t unregisterEffect(int id) = 0;
161    virtual status_t setEffectEnabled(int id, bool enabled) = 0;
162
163    virtual bool isStreamActive(audio_stream_type_t stream, uint32_t inPastMs = 0) const = 0;
164    virtual bool isStreamActiveRemotely(audio_stream_type_t stream,
165                                        uint32_t inPastMs = 0) const = 0;
166    virtual bool isSourceActive(audio_source_t source) const = 0;
167
168    //dump state
169    virtual status_t    dump(int fd) = 0;
170
171    virtual bool isOffloadSupported(const audio_offload_info_t& offloadInfo) = 0;
172
173    virtual status_t listAudioPorts(audio_port_role_t role,
174                                    audio_port_type_t type,
175                                    unsigned int *num_ports,
176                                    struct audio_port *ports,
177                                    unsigned int *generation) = 0;
178    virtual status_t getAudioPort(struct audio_port *port) = 0;
179    virtual status_t createAudioPatch(const struct audio_patch *patch,
180                                       audio_patch_handle_t *handle,
181                                       uid_t uid) = 0;
182    virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
183                                          uid_t uid) = 0;
184    virtual status_t listAudioPatches(unsigned int *num_patches,
185                                      struct audio_patch *patches,
186                                      unsigned int *generation) = 0;
187    virtual status_t setAudioPortConfig(const struct audio_port_config *config) = 0;
188    virtual void clearAudioPatches(uid_t uid) = 0;
189
190};
191
192
193// Audio Policy client Interface
194class AudioPolicyClientInterface
195{
196public:
197    virtual ~AudioPolicyClientInterface() {}
198
199    //
200    // Audio HW module functions
201    //
202
203    // loads a HW module.
204    virtual audio_module_handle_t loadHwModule(const char *name) = 0;
205
206    //
207    // Audio output Control functions
208    //
209
210    // opens an audio output with the requested parameters. The parameter values can indicate to use the default values
211    // in case the audio policy manager has no specific requirements for the output being opened.
212    // When the function returns, the parameter values reflect the actual values used by the audio hardware output stream.
213    // The audio policy manager can check if the proposed parameters are suitable or not and act accordingly.
214    virtual status_t openOutput(audio_module_handle_t module,
215                                audio_io_handle_t *output,
216                                audio_config_t *config,
217                                audio_devices_t *devices,
218                                const String8& address,
219                                uint32_t *latencyMs,
220                                audio_output_flags_t flags) = 0;
221    // creates a special output that is duplicated to the two outputs passed as arguments. The duplication is performed by
222    // a special mixer thread in the AudioFlinger.
223    virtual audio_io_handle_t openDuplicateOutput(audio_io_handle_t output1, audio_io_handle_t output2) = 0;
224    // closes the output stream
225    virtual status_t closeOutput(audio_io_handle_t output) = 0;
226    // suspends the output. When an output is suspended, the corresponding audio hardware output stream is placed in
227    // standby and the AudioTracks attached to the mixer thread are still processed but the output mix is discarded.
228    virtual status_t suspendOutput(audio_io_handle_t output) = 0;
229    // restores a suspended output.
230    virtual status_t restoreOutput(audio_io_handle_t output) = 0;
231
232    //
233    // Audio input Control functions
234    //
235
236    // opens an audio input
237    virtual status_t openInput(audio_module_handle_t module,
238                               audio_io_handle_t *input,
239                               audio_config_t *config,
240                               audio_devices_t *device,
241                               const String8& address,
242                               audio_source_t source,
243                               audio_input_flags_t flags) = 0;
244    // closes an audio input
245    virtual status_t closeInput(audio_io_handle_t input) = 0;
246    //
247    // misc control functions
248    //
249
250    // set a stream volume for a particular output. For the same user setting, a given stream type can have different volumes
251    // for each output (destination device) it is attached to.
252    virtual status_t setStreamVolume(audio_stream_type_t stream, float volume, audio_io_handle_t output, int delayMs = 0) = 0;
253
254    // invalidate a stream type, causing a reroute to an unspecified new output
255    virtual status_t invalidateStream(audio_stream_type_t stream) = 0;
256
257    // function enabling to send proprietary informations directly from audio policy manager to audio hardware interface.
258    virtual void setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs, int delayMs = 0) = 0;
259    // function enabling to receive proprietary informations directly from audio hardware interface to audio policy manager.
260    virtual String8 getParameters(audio_io_handle_t ioHandle, const String8& keys) = 0;
261
262    // request the playback of a tone on the specified stream: used for instance to replace notification sounds when playing
263    // over a telephony device during a phone call.
264    virtual status_t startTone(audio_policy_tone_t tone, audio_stream_type_t stream) = 0;
265    virtual status_t stopTone() = 0;
266
267    // set down link audio volume.
268    virtual status_t setVoiceVolume(float volume, int delayMs = 0) = 0;
269
270    // move effect to the specified output
271    virtual status_t moveEffects(int session,
272                                     audio_io_handle_t srcOutput,
273                                     audio_io_handle_t dstOutput) = 0;
274
275    /* Create a patch between several source and sink ports */
276    virtual status_t createAudioPatch(const struct audio_patch *patch,
277                                       audio_patch_handle_t *handle,
278                                       int delayMs) = 0;
279
280    /* Release a patch */
281    virtual status_t releaseAudioPatch(audio_patch_handle_t handle,
282                                       int delayMs) = 0;
283
284    /* Set audio port configuration */
285    virtual status_t setAudioPortConfig(const struct audio_port_config *config, int delayMs) = 0;
286
287    virtual void onAudioPortListUpdate() = 0;
288
289    virtual void onAudioPatchListUpdate() = 0;
290};
291
292extern "C" AudioPolicyInterface* createAudioPolicyManager(AudioPolicyClientInterface *clientInterface);
293extern "C" void destroyAudioPolicyManager(AudioPolicyInterface *interface);
294
295
296}; // namespace android
297
298#endif // ANDROID_AUDIOPOLICY_INTERFACE_H
299