AudioEffect.h revision e360f0f6cad290f69e07fd3a20dcf11a1dbc4160
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_AUDIOEFFECT_H
18#define ANDROID_AUDIOEFFECT_H
19
20#include <stdint.h>
21#include <sys/types.h>
22
23#include <media/IAudioFlinger.h>
24#include <media/IAudioPolicyService.h>
25#include <media/IEffect.h>
26#include <media/IEffectClient.h>
27#include <hardware/audio_effect.h>
28#include <media/AudioSystem.h>
29
30#include <utils/RefBase.h>
31#include <utils/Errors.h>
32#include <binder/IInterface.h>
33
34
35namespace android {
36
37// ----------------------------------------------------------------------------
38
39class effect_param_cblk_t;
40
41// ----------------------------------------------------------------------------
42
43class AudioEffect : public RefBase
44{
45public:
46
47    /*
48     *  Static methods for effects enumeration.
49     */
50
51    /*
52     * Returns the number of effects available. This method together
53     * with queryEffect() is used to enumerate all effects:
54     * The enumeration sequence is:
55     *      queryNumberEffects(&num_effects);
56     *      for (i = 0; i < num_effects; i++)
57     *          queryEffect(i,...);
58     *
59     * Parameters:
60     *      numEffects:    address where the number of effects should be returned.
61     *
62     * Returned status (from utils/Errors.h) can be:
63     *      NO_ERROR   successful operation.
64     *      PERMISSION_DENIED could not get AudioFlinger interface
65     *      NO_INIT    effect library failed to initialize
66     *      BAD_VALUE  invalid numEffects pointer
67     *
68     * Returned value
69     *   *numEffects:     updated with number of effects available
70     */
71    static status_t queryNumberEffects(uint32_t *numEffects);
72
73    /*
74     * Returns an effect descriptor during effect
75     * enumeration.
76     *
77     * Parameters:
78     *      index:      index of the queried effect.
79     *      descriptor: address where the effect descriptor should be returned.
80     *
81     * Returned status (from utils/Errors.h) can be:
82     *      NO_ERROR        successful operation.
83     *      PERMISSION_DENIED could not get AudioFlinger interface
84     *      NO_INIT         effect library failed to initialize
85     *      BAD_VALUE       invalid descriptor pointer or index
86     *      INVALID_OPERATION  effect list has changed since last execution of queryNumberEffects()
87     *
88     * Returned value
89     *   *descriptor:     updated with effect descriptor
90     */
91    static status_t queryEffect(uint32_t index, effect_descriptor_t *descriptor);
92
93
94    /*
95     * Returns the descriptor for the specified effect uuid.
96     *
97     * Parameters:
98     *      uuid:       pointer to effect uuid.
99     *      descriptor: address where the effect descriptor should be returned.
100     *
101     * Returned status (from utils/Errors.h) can be:
102     *      NO_ERROR        successful operation.
103     *      PERMISSION_DENIED could not get AudioFlinger interface
104     *      NO_INIT         effect library failed to initialize
105     *      BAD_VALUE       invalid uuid or descriptor pointers
106     *      NAME_NOT_FOUND  no effect with this uuid found
107     *
108     * Returned value
109     *   *descriptor updated with effect descriptor
110     */
111    static status_t getEffectDescriptor(const effect_uuid_t *uuid,
112                                        effect_descriptor_t *descriptor) /*const*/;
113
114
115    /*
116     * Returns a list of descriptors corresponding to the pre processings enabled by default
117     * on an AudioRecord with the supplied audio session ID.
118     *
119     * Parameters:
120     *      audioSession:  audio session ID.
121     *      descriptors: address where the effect descriptors should be returned.
122     *      count: as input, the maximum number of descriptor than should be returned
123     *             as output, the number of descriptor returned if status is NO_ERROR or the actual
124     *             number of enabled pre processings if status is NO_MEMORY
125     *
126     * Returned status (from utils/Errors.h) can be:
127     *      NO_ERROR        successful operation.
128     *      NO_MEMORY       the number of descriptor to return is more than the maximum number
129     *                      indicated by count.
130     *      PERMISSION_DENIED could not get AudioFlinger interface
131     *      NO_INIT         effect library failed to initialize
132     *      BAD_VALUE       invalid audio session or descriptor pointers
133     *
134     * Returned value
135     *   *descriptor updated with descriptors of pre processings enabled by default
136     *   *count      number of descriptors returned if returned status is NO_ERROR.
137     *               total number of pre processing enabled by default if returned status is
138     *               NO_MEMORY. This happens if the count passed as input is less than the number
139     *               of descriptors to return.
140     *               *count is limited to kMaxPreProcessing on return.
141     */
142    static status_t queryDefaultPreProcessing(int audioSession,
143                                              effect_descriptor_t *descriptors,
144                                              uint32_t *count);
145
146    /*
147     * Events used by callback function (effect_callback_t).
148     */
149    enum event_type {
150        EVENT_CONTROL_STATUS_CHANGED = 0,
151        EVENT_ENABLE_STATUS_CHANGED = 1,
152        EVENT_PARAMETER_CHANGED = 2,
153        EVENT_ERROR = 3
154    };
155
156    /* Callback function notifying client application of a change in effect engine state or
157     * configuration.
158     * An effect engine can be shared by several applications but only one has the control
159     * of the engine activity and configuration at a time.
160     * The EVENT_CONTROL_STATUS_CHANGED event is received when an application loses or
161     * retrieves the control of the effect engine. Loss of control happens
162     * if another application requests the use of the engine by creating an AudioEffect for
163     * the same effect type but with a higher priority. Control is returned when the
164     * application having the control deletes its AudioEffect object.
165     * The EVENT_ENABLE_STATUS_CHANGED event is received by all applications not having the
166     * control of the effect engine when the effect is enabled or disabled.
167     * The EVENT_PARAMETER_CHANGED event is received by all applications not having the
168     * control of the effect engine when an effect parameter is changed.
169     * The EVENT_ERROR event is received when the media server process dies.
170     *
171     * Parameters:
172     *
173     * event:   type of event notified (see enum AudioEffect::event_type).
174     * user:    Pointer to context for use by the callback receiver.
175     * info:    Pointer to optional parameter according to event type:
176     *  - EVENT_CONTROL_STATUS_CHANGED:  boolean indicating if control is granted (true)
177     *  or stolen (false).
178     *  - EVENT_ENABLE_STATUS_CHANGED: boolean indicating if effect is now enabled (true)
179     *  or disabled (false).
180     *  - EVENT_PARAMETER_CHANGED: pointer to a effect_param_t structure.
181     *  - EVENT_ERROR:  status_t indicating the error (DEAD_OBJECT when media server dies).
182     */
183
184    typedef void (*effect_callback_t)(int32_t event, void* user, void *info);
185
186
187    /* Constructor.
188     * AudioEffect is the base class for creating and controlling an effect engine from
189     * the application process. Creating an AudioEffect object will create the effect engine
190     * in the AudioFlinger if no engine of the specified type exists. If one exists, this engine
191     * will be used. The application creating the AudioEffect object (or a derived class like
192     * Reverb for instance) will either receive control of the effect engine or not, depending
193     * on the priority parameter. If priority is higher than the priority used by the current
194     * effect engine owner, the control will be transfered to the new application. Otherwise
195     * control will remain to the previous application. In this case, the new application will be
196     * notified of changes in effect engine state or control ownership by the effect callback.
197     * After creating the AudioEffect, the application must call the initCheck() method and
198     * check the creation status before trying to control the effect engine (see initCheck()).
199     * If the effect is to be applied to an AudioTrack or MediaPlayer only the application
200     * must specify the audio session ID corresponding to this player.
201     */
202
203    /* Simple Constructor.
204     */
205    AudioEffect();
206
207
208    /* Constructor.
209     *
210     * Parameters:
211     *
212     * type:  type of effect created: can be null if uuid is specified. This corresponds to
213     *        the OpenSL ES interface implemented by this effect.
214     * uuid:  Uuid of effect created: can be null if type is specified. This uuid corresponds to
215     *        a particular implementation of an effect type.
216     * priority:    requested priority for effect control: the priority level corresponds to the
217     *      value of priority parameter: negative values indicate lower priorities, positive values
218     *      higher priorities, 0 being the normal priority.
219     * cbf:         optional callback function (see effect_callback_t)
220     * user:        pointer to context for use by the callback receiver.
221     * sessionID:   audio session this effect is associated to. If 0, the effect will be global to
222     *      the output mix. If not 0, the effect will be applied to all players
223     *      (AudioTrack or MediaPLayer) within the same audio session.
224     * io:  HAL audio output or input stream to which this effect must be attached. Leave at 0 for
225     *      automatic output selection by AudioFlinger.
226     */
227
228    AudioEffect(const effect_uuid_t *type,
229                const effect_uuid_t *uuid = NULL,
230                  int32_t priority = 0,
231                  effect_callback_t cbf = NULL,
232                  void* user = NULL,
233                  int sessionId = 0,
234                  audio_io_handle_t io = 0
235                  );
236
237    /* Constructor.
238     *      Same as above but with type and uuid specified by character strings
239     */
240    AudioEffect(const char *typeStr,
241                    const char *uuidStr = NULL,
242                    int32_t priority = 0,
243                    effect_callback_t cbf = NULL,
244                    void* user = NULL,
245                    int sessionId = 0,
246                    audio_io_handle_t io = 0
247                    );
248
249    /* Terminates the AudioEffect and unregisters it from AudioFlinger.
250     * The effect engine is also destroyed if this AudioEffect was the last controlling
251     * the engine.
252     */
253                        ~AudioEffect();
254
255    /* Initialize an uninitialized AudioEffect.
256    * Returned status (from utils/Errors.h) can be:
257    *  - NO_ERROR or ALREADY_EXISTS: successful initialization
258    *  - INVALID_OPERATION: AudioEffect is already initialized
259    *  - BAD_VALUE: invalid parameter
260    *  - NO_INIT: audio flinger or audio hardware not initialized
261    * */
262            status_t    set(const effect_uuid_t *type,
263                            const effect_uuid_t *uuid = NULL,
264                            int32_t priority = 0,
265                            effect_callback_t cbf = NULL,
266                            void* user = NULL,
267                            int sessionId = 0,
268                            audio_io_handle_t io = 0
269                            );
270
271    /* Result of constructing the AudioEffect. This must be checked
272     * before using any AudioEffect API.
273     * initCheck() can return:
274     *  - NO_ERROR:    the effect engine is successfully created and the application has control.
275     *  - ALREADY_EXISTS: the effect engine is successfully created but the application does not
276     *              have control.
277     *  - NO_INIT:     the effect creation failed.
278     *
279     */
280            status_t    initCheck() const;
281
282
283    /* Returns the unique effect Id for the controlled effect engine. This ID is unique
284     * system wide and is used for instance in the case of auxiliary effects to attach
285     * the effect to an AudioTrack or MediaPlayer.
286     *
287     */
288            int32_t     id() const { return mId; }
289
290    /* Returns a descriptor for the effect (see effect_descriptor_t in audio_effect.h).
291     */
292            effect_descriptor_t descriptor() const;
293
294    /* Returns effect control priority of this AudioEffect object.
295     */
296            int32_t     priority() const { return mPriority; }
297
298
299    /* Enables or disables the effect engine.
300     *
301     * Parameters:
302     *  enabled: requested enable state.
303     *
304     * Returned status (from utils/Errors.h) can be:
305     *  - NO_ERROR: successful operation
306     *  - INVALID_OPERATION: the application does not have control of the effect engine or the
307     *  effect is already in the requested state.
308     */
309    virtual status_t    setEnabled(bool enabled);
310            bool        getEnabled() const;
311
312    /* Sets a parameter value.
313     *
314     * Parameters:
315     *      param:  pointer to effect_param_t structure containing the parameter
316     *          and its value (See audio_effect.h).
317     * Returned status (from utils/Errors.h) can be:
318     *  - NO_ERROR: successful operation.
319     *  - INVALID_OPERATION: the application does not have control of the effect engine.
320     *  - BAD_VALUE: invalid parameter identifier or value.
321     *  - DEAD_OBJECT: the effect engine has been deleted.
322     */
323     virtual status_t   setParameter(effect_param_t *param);
324
325    /* Prepare a new parameter value that will be set by next call to
326     * setParameterCommit(). This method can be used to set multiple parameters
327     * in a synchronous manner or to avoid multiple binder calls for each
328     * parameter.
329     *
330     * Parameters:
331     *      param:  pointer to effect_param_t structure containing the parameter
332     *          and its value (See audio_effect.h).
333     *
334     * Returned status (from utils/Errors.h) can be:
335     *  - NO_ERROR: successful operation.
336     *  - INVALID_OPERATION: the application does not have control of the effect engine.
337     *  - NO_MEMORY: no more space available in shared memory used for deferred parameter
338     *  setting.
339     */
340     virtual status_t   setParameterDeferred(effect_param_t *param);
341
342     /* Commit all parameter values previously prepared by setParameterDeferred().
343      *
344      * Parameters:
345      *     none
346      *
347      * Returned status (from utils/Errors.h) can be:
348      *  - NO_ERROR: successful operation.
349      *  - INVALID_OPERATION: No new parameter values ready for commit.
350      *  - BAD_VALUE: invalid parameter identifier or value: there is no indication
351      *     as to which of the parameters caused this error.
352      *  - DEAD_OBJECT: the effect engine has been deleted.
353      */
354     virtual status_t   setParameterCommit();
355
356    /* Gets a parameter value.
357     *
358     * Parameters:
359     *      param:  pointer to effect_param_t structure containing the parameter
360     *          and the returned value (See audio_effect.h).
361     *
362     * Returned status (from utils/Errors.h) can be:
363     *  - NO_ERROR: successful operation.
364     *  - INVALID_OPERATION: the AudioEffect was not successfully initialized.
365     *  - BAD_VALUE: invalid parameter identifier.
366     *  - DEAD_OBJECT: the effect engine has been deleted.
367     */
368     virtual status_t   getParameter(effect_param_t *param);
369
370     /* Sends a command and receives a response to/from effect engine.
371      *     See audio_effect.h for details on effect command() function, valid command codes
372      *     and formats.
373      */
374     virtual status_t command(uint32_t cmdCode,
375                              uint32_t cmdSize,
376                              void *cmdData,
377                              uint32_t *replySize,
378                              void *replyData);
379
380
381     /*
382      * Utility functions.
383      */
384
385     /* Converts the string passed as first argument to the effect_uuid_t
386      * pointed to by second argument
387      */
388     static status_t stringToGuid(const char *str, effect_uuid_t *guid);
389     /* Converts the effect_uuid_t pointed to by first argument to the
390      * string passed as second argument
391      */
392     static status_t guidToString(const effect_uuid_t *guid, char *str, size_t maxLen);
393
394     // kMaxPreProcessing is a reasonable value for the maximum number of preprocessing effects
395     // that can be applied simultaneously.
396     static const uint32_t kMaxPreProcessing = 10;
397
398protected:
399     bool                    mEnabled;           // enable state
400     int32_t                 mSessionId;         // audio session ID
401     int32_t                 mPriority;          // priority for effect control
402     status_t                mStatus;            // effect status
403     effect_callback_t       mCbf;               // callback function for status, control and
404                                                 // parameter changes notifications
405     void*                   mUserData;          // client context for callback function
406     effect_descriptor_t     mDescriptor;        // effect descriptor
407     int32_t                 mId;                // system wide unique effect engine instance ID
408     Mutex                   mLock;               // Mutex for mEnabled access
409
410     // IEffectClient
411     virtual void controlStatusChanged(bool controlGranted);
412     virtual void enableStatusChanged(bool enabled);
413     virtual void commandExecuted(uint32_t cmdCode,
414             uint32_t cmdSize,
415             void *pCmdData,
416             uint32_t replySize,
417             void *pReplyData);
418
419private:
420
421     // Implements the IEffectClient interface
422    class EffectClient : public android::BnEffectClient,  public android::IBinder::DeathRecipient
423    {
424    public:
425
426        EffectClient(AudioEffect *effect) : mEffect(effect){}
427
428        // IEffectClient
429        virtual void controlStatusChanged(bool controlGranted) {
430            mEffect->controlStatusChanged(controlGranted);
431        }
432        virtual void enableStatusChanged(bool enabled) {
433            mEffect->enableStatusChanged(enabled);
434        }
435        virtual void commandExecuted(uint32_t cmdCode,
436                                     uint32_t cmdSize,
437                                     void *pCmdData,
438                                     uint32_t replySize,
439                                     void *pReplyData) {
440            mEffect->commandExecuted(cmdCode, cmdSize, pCmdData, replySize, pReplyData);
441        }
442
443        // IBinder::DeathRecipient
444        virtual void binderDied(const wp<IBinder>& who) {mEffect->binderDied();}
445
446    private:
447        AudioEffect *mEffect;
448    };
449
450    void binderDied();
451
452    sp<IEffect>             mIEffect;           // IEffect binder interface
453    sp<EffectClient>        mIEffectClient;     // IEffectClient implementation
454    sp<IMemory>             mCblkMemory;        // shared memory for deferred parameter setting
455    effect_param_cblk_t*    mCblk;              // control block for deferred parameter setting
456};
457
458
459}; // namespace android
460
461#endif // ANDROID_AUDIOEFFECT_H
462