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1 /*
2  * Copyright (C) 2011 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 
18 #ifndef ANDROID_AUDIO_EFFECT_H
19 #define ANDROID_AUDIO_EFFECT_H
20 
21 #include <errno.h>
22 #include <stdint.h>
23 #include <strings.h>
24 #include <sys/cdefs.h>
25 #include <sys/types.h>
26 
27 #include <cutils/bitops.h>
28 
29 #include <system/audio.h>
30 
31 
32 __BEGIN_DECLS
33 
34 
35 /////////////////////////////////////////////////
36 //      Common Definitions
37 /////////////////////////////////////////////////
38 
39 //
40 //--- Effect descriptor structure effect_descriptor_t
41 //
42 
43 // Unique effect ID (can be generated from the following site:
44 //  http://www.itu.int/ITU-T/asn1/uuid.html)
45 // This format is used for both "type" and "uuid" fields of the effect descriptor structure.
46 // - When used for effect type and the engine is implementing and effect corresponding to a standard
47 // OpenSL ES interface, this ID must be the one defined in OpenSLES_IID.h for that interface.
48 // - When used as uuid, it should be a unique UUID for this particular implementation.
49 typedef struct effect_uuid_s {
50     uint32_t timeLow;
51     uint16_t timeMid;
52     uint16_t timeHiAndVersion;
53     uint16_t clockSeq;
54     uint8_t node[6];
55 } effect_uuid_t;
56 
57 // Maximum length of character strings in structures defines by this API.
58 #define EFFECT_STRING_LEN_MAX 64
59 
60 // NULL UUID definition (matches SL_IID_NULL_)
61 #define EFFECT_UUID_INITIALIZER { 0xec7178ec, 0xe5e1, 0x4432, 0xa3f4, \
62                                   { 0x46, 0x57, 0xe6, 0x79, 0x52, 0x10 } }
63 static const effect_uuid_t EFFECT_UUID_NULL_ = EFFECT_UUID_INITIALIZER;
64 static const effect_uuid_t * const EFFECT_UUID_NULL = &EFFECT_UUID_NULL_;
65 static const char * const EFFECT_UUID_NULL_STR = "ec7178ec-e5e1-4432-a3f4-4657e6795210";
66 
67 
68 // The effect descriptor contains necessary information to facilitate the enumeration of the effect
69 // engines present in a library.
70 typedef struct effect_descriptor_s {
71     effect_uuid_t type;     // UUID of to the OpenSL ES interface implemented by this effect
72     effect_uuid_t uuid;     // UUID for this particular implementation
73     uint32_t apiVersion;    // Version of the effect control API implemented
74     uint32_t flags;         // effect engine capabilities/requirements flags (see below)
75     uint16_t cpuLoad;       // CPU load indication (see below)
76     uint16_t memoryUsage;   // Data Memory usage (see below)
77     char    name[EFFECT_STRING_LEN_MAX];   // human readable effect name
78     char    implementor[EFFECT_STRING_LEN_MAX];    // human readable effect implementor name
79 } effect_descriptor_t;
80 
81 // CPU load and memory usage indication: each effect implementation must provide an indication of
82 // its CPU and memory usage for the audio effect framework to limit the number of effects
83 // instantiated at a given time on a given platform.
84 // The CPU load is expressed in 0.1 MIPS units as estimated on an ARM9E core (ARMv5TE) with 0 WS.
85 // The memory usage is expressed in KB and includes only dynamically allocated memory
86 
87 // Definitions for flags field of effect descriptor.
88 //  +---------------------------+-----------+-----------------------------------
89 //  | description               | bits      | values
90 //  +---------------------------+-----------+-----------------------------------
91 //  | connection mode           | 0..2      | 0 insert: after track process
92 //  |                           |           | 1 auxiliary: connect to track auxiliary
93 //  |                           |           |  output and use send level
94 //  |                           |           | 2 replace: replaces track process function;
95 //  |                           |           |   must implement SRC, volume and mono to stereo.
96 //  |                           |           | 3 pre processing: applied below audio HAL on input
97 //  |                           |           | 4 post processing: applied below audio HAL on output
98 //  |                           |           | 5 - 7 reserved
99 //  +---------------------------+-----------+-----------------------------------
100 //  | insertion preference      | 3..5      | 0 none
101 //  |                           |           | 1 first of the chain
102 //  |                           |           | 2 last of the chain
103 //  |                           |           | 3 exclusive (only effect in the insert chain)
104 //  |                           |           | 4..7 reserved
105 //  +---------------------------+-----------+-----------------------------------
106 //  | Volume management         | 6..8      | 0 none
107 //  |                           |           | 1 implements volume control
108 //  |                           |           | 2 requires volume indication
109 //  |                           |           | 4 reserved
110 //  +---------------------------+-----------+-----------------------------------
111 //  | Device indication         | 9..11     | 0 none
112 //  |                           |           | 1 requires device updates
113 //  |                           |           | 2, 4 reserved
114 //  +---------------------------+-----------+-----------------------------------
115 //  | Sample input mode         | 12..13    | 1 direct: process() function or EFFECT_CMD_SET_CONFIG
116 //  |                           |           |   command must specify a buffer descriptor
117 //  |                           |           | 2 provider: process() function uses the
118 //  |                           |           |   bufferProvider indicated by the
119 //  |                           |           |   EFFECT_CMD_SET_CONFIG command to request input.
120 //  |                           |           |   buffers.
121 //  |                           |           | 3 both: both input modes are supported
122 //  +---------------------------+-----------+-----------------------------------
123 //  | Sample output mode        | 14..15    | 1 direct: process() function or EFFECT_CMD_SET_CONFIG
124 //  |                           |           |   command must specify a buffer descriptor
125 //  |                           |           | 2 provider: process() function uses the
126 //  |                           |           |   bufferProvider indicated by the
127 //  |                           |           |   EFFECT_CMD_SET_CONFIG command to request output
128 //  |                           |           |   buffers.
129 //  |                           |           | 3 both: both output modes are supported
130 //  +---------------------------+-----------+-----------------------------------
131 //  | Hardware acceleration     | 16..17    | 0 No hardware acceleration
132 //  |                           |           | 1 non tunneled hw acceleration: the process() function
133 //  |                           |           |   reads the samples, send them to HW accelerated
134 //  |                           |           |   effect processor, reads back the processed samples
135 //  |                           |           |   and returns them to the output buffer.
136 //  |                           |           | 2 tunneled hw acceleration: the process() function is
137 //  |                           |           |   transparent. The effect interface is only used to
138 //  |                           |           |   control the effect engine. This mode is relevant for
139 //  |                           |           |   global effects actually applied by the audio
140 //  |                           |           |   hardware on the output stream.
141 //  +---------------------------+-----------+-----------------------------------
142 //  | Audio Mode indication     | 18..19    | 0 none
143 //  |                           |           | 1 requires audio mode updates
144 //  |                           |           | 2..3 reserved
145 //  +---------------------------+-----------+-----------------------------------
146 //  | Audio source indication   | 20..21    | 0 none
147 //  |                           |           | 1 requires audio source updates
148 //  |                           |           | 2..3 reserved
149 //  +---------------------------+-----------+-----------------------------------
150 //  | Effect offload supported  | 22        | 0 The effect cannot be offloaded to an audio DSP
151 //  |                           |           | 1 The effect can be offloaded to an audio DSP
152 //  +---------------------------+-----------+-----------------------------------
153 //  | Process function not      | 23        | 0 The effect implements a process function.
154 //  | implemented               |           | 1 The effect does not implement a process function:
155 //  |                           |           |   enabling the effect has no impact on latency or
156 //  |                           |           |   CPU load.
157 //  |                           |           |   Effect implementations setting this flag do not have
158 //  |                           |           |   to implement a process function.
159 //  +---------------------------+-----------+-----------------------------------
160 
161 // Insert mode
162 #define EFFECT_FLAG_TYPE_SHIFT          0
163 #define EFFECT_FLAG_TYPE_SIZE           3
164 #define EFFECT_FLAG_TYPE_MASK           (((1 << EFFECT_FLAG_TYPE_SIZE) -1) \
165                                             << EFFECT_FLAG_TYPE_SHIFT)
166 #define EFFECT_FLAG_TYPE_INSERT         (0 << EFFECT_FLAG_TYPE_SHIFT)
167 #define EFFECT_FLAG_TYPE_AUXILIARY      (1 << EFFECT_FLAG_TYPE_SHIFT)
168 #define EFFECT_FLAG_TYPE_REPLACE        (2 << EFFECT_FLAG_TYPE_SHIFT)
169 #define EFFECT_FLAG_TYPE_PRE_PROC       (3 << EFFECT_FLAG_TYPE_SHIFT)
170 #define EFFECT_FLAG_TYPE_POST_PROC      (4 << EFFECT_FLAG_TYPE_SHIFT)
171 
172 // Insert preference
173 #define EFFECT_FLAG_INSERT_SHIFT        (EFFECT_FLAG_TYPE_SHIFT + EFFECT_FLAG_TYPE_SIZE)
174 #define EFFECT_FLAG_INSERT_SIZE         3
175 #define EFFECT_FLAG_INSERT_MASK         (((1 << EFFECT_FLAG_INSERT_SIZE) -1) \
176                                             << EFFECT_FLAG_INSERT_SHIFT)
177 #define EFFECT_FLAG_INSERT_ANY          (0 << EFFECT_FLAG_INSERT_SHIFT)
178 #define EFFECT_FLAG_INSERT_FIRST        (1 << EFFECT_FLAG_INSERT_SHIFT)
179 #define EFFECT_FLAG_INSERT_LAST         (2 << EFFECT_FLAG_INSERT_SHIFT)
180 #define EFFECT_FLAG_INSERT_EXCLUSIVE    (3 << EFFECT_FLAG_INSERT_SHIFT)
181 
182 
183 // Volume control
184 #define EFFECT_FLAG_VOLUME_SHIFT        (EFFECT_FLAG_INSERT_SHIFT + EFFECT_FLAG_INSERT_SIZE)
185 #define EFFECT_FLAG_VOLUME_SIZE         3
186 #define EFFECT_FLAG_VOLUME_MASK         (((1 << EFFECT_FLAG_VOLUME_SIZE) -1) \
187                                             << EFFECT_FLAG_VOLUME_SHIFT)
188 #define EFFECT_FLAG_VOLUME_CTRL         (1 << EFFECT_FLAG_VOLUME_SHIFT)
189 #define EFFECT_FLAG_VOLUME_IND          (2 << EFFECT_FLAG_VOLUME_SHIFT)
190 #define EFFECT_FLAG_VOLUME_NONE         (0 << EFFECT_FLAG_VOLUME_SHIFT)
191 
192 // Device indication
193 #define EFFECT_FLAG_DEVICE_SHIFT        (EFFECT_FLAG_VOLUME_SHIFT + EFFECT_FLAG_VOLUME_SIZE)
194 #define EFFECT_FLAG_DEVICE_SIZE         3
195 #define EFFECT_FLAG_DEVICE_MASK         (((1 << EFFECT_FLAG_DEVICE_SIZE) -1) \
196                                             << EFFECT_FLAG_DEVICE_SHIFT)
197 #define EFFECT_FLAG_DEVICE_IND          (1 << EFFECT_FLAG_DEVICE_SHIFT)
198 #define EFFECT_FLAG_DEVICE_NONE         (0 << EFFECT_FLAG_DEVICE_SHIFT)
199 
200 // Sample input modes
201 #define EFFECT_FLAG_INPUT_SHIFT         (EFFECT_FLAG_DEVICE_SHIFT + EFFECT_FLAG_DEVICE_SIZE)
202 #define EFFECT_FLAG_INPUT_SIZE          2
203 #define EFFECT_FLAG_INPUT_MASK          (((1 << EFFECT_FLAG_INPUT_SIZE) -1) \
204                                             << EFFECT_FLAG_INPUT_SHIFT)
205 #define EFFECT_FLAG_INPUT_DIRECT        (1 << EFFECT_FLAG_INPUT_SHIFT)
206 #define EFFECT_FLAG_INPUT_PROVIDER      (2 << EFFECT_FLAG_INPUT_SHIFT)
207 #define EFFECT_FLAG_INPUT_BOTH          (3 << EFFECT_FLAG_INPUT_SHIFT)
208 
209 // Sample output modes
210 #define EFFECT_FLAG_OUTPUT_SHIFT        (EFFECT_FLAG_INPUT_SHIFT + EFFECT_FLAG_INPUT_SIZE)
211 #define EFFECT_FLAG_OUTPUT_SIZE         2
212 #define EFFECT_FLAG_OUTPUT_MASK         (((1 << EFFECT_FLAG_OUTPUT_SIZE) -1) \
213                                             << EFFECT_FLAG_OUTPUT_SHIFT)
214 #define EFFECT_FLAG_OUTPUT_DIRECT       (1 << EFFECT_FLAG_OUTPUT_SHIFT)
215 #define EFFECT_FLAG_OUTPUT_PROVIDER     (2 << EFFECT_FLAG_OUTPUT_SHIFT)
216 #define EFFECT_FLAG_OUTPUT_BOTH         (3 << EFFECT_FLAG_OUTPUT_SHIFT)
217 
218 // Hardware acceleration mode
219 #define EFFECT_FLAG_HW_ACC_SHIFT        (EFFECT_FLAG_OUTPUT_SHIFT + EFFECT_FLAG_OUTPUT_SIZE)
220 #define EFFECT_FLAG_HW_ACC_SIZE         2
221 #define EFFECT_FLAG_HW_ACC_MASK         (((1 << EFFECT_FLAG_HW_ACC_SIZE) -1) \
222                                             << EFFECT_FLAG_HW_ACC_SHIFT)
223 #define EFFECT_FLAG_HW_ACC_SIMPLE       (1 << EFFECT_FLAG_HW_ACC_SHIFT)
224 #define EFFECT_FLAG_HW_ACC_TUNNEL       (2 << EFFECT_FLAG_HW_ACC_SHIFT)
225 
226 // Audio mode indication
227 #define EFFECT_FLAG_AUDIO_MODE_SHIFT    (EFFECT_FLAG_HW_ACC_SHIFT + EFFECT_FLAG_HW_ACC_SIZE)
228 #define EFFECT_FLAG_AUDIO_MODE_SIZE     2
229 #define EFFECT_FLAG_AUDIO_MODE_MASK     (((1 << EFFECT_FLAG_AUDIO_MODE_SIZE) -1) \
230                                             << EFFECT_FLAG_AUDIO_MODE_SHIFT)
231 #define EFFECT_FLAG_AUDIO_MODE_IND      (1 << EFFECT_FLAG_AUDIO_MODE_SHIFT)
232 #define EFFECT_FLAG_AUDIO_MODE_NONE     (0 << EFFECT_FLAG_AUDIO_MODE_SHIFT)
233 
234 // Audio source indication
235 #define EFFECT_FLAG_AUDIO_SOURCE_SHIFT  (EFFECT_FLAG_AUDIO_MODE_SHIFT + EFFECT_FLAG_AUDIO_MODE_SIZE)
236 #define EFFECT_FLAG_AUDIO_SOURCE_SIZE   2
237 #define EFFECT_FLAG_AUDIO_SOURCE_MASK   (((1 << EFFECT_FLAG_AUDIO_SOURCE_SIZE) -1) \
238                                           << EFFECT_FLAG_AUDIO_SOURCE_SHIFT)
239 #define EFFECT_FLAG_AUDIO_SOURCE_IND    (1 << EFFECT_FLAG_AUDIO_SOURCE_SHIFT)
240 #define EFFECT_FLAG_AUDIO_SOURCE_NONE   (0 << EFFECT_FLAG_AUDIO_SOURCE_SHIFT)
241 
242 // Effect offload indication
243 #define EFFECT_FLAG_OFFLOAD_SHIFT       (EFFECT_FLAG_AUDIO_SOURCE_SHIFT + \
244                                                     EFFECT_FLAG_AUDIO_SOURCE_SIZE)
245 #define EFFECT_FLAG_OFFLOAD_SIZE        1
246 #define EFFECT_FLAG_OFFLOAD_MASK        (((1 << EFFECT_FLAG_OFFLOAD_SIZE) -1) \
247                                           << EFFECT_FLAG_OFFLOAD_SHIFT)
248 #define EFFECT_FLAG_OFFLOAD_SUPPORTED   (1 << EFFECT_FLAG_OFFLOAD_SHIFT)
249 
250 // Effect has no process indication
251 #define EFFECT_FLAG_NO_PROCESS_SHIFT       (EFFECT_FLAG_OFFLOAD_SHIFT + \
252                                                     EFFECT_FLAG_OFFLOAD_SIZE)
253 #define EFFECT_FLAG_NO_PROCESS_SIZE        1
254 #define EFFECT_FLAG_NO_PROCESS_MASK        (((1 << EFFECT_FLAG_NO_PROCESS_SIZE) -1) \
255                                           << EFFECT_FLAG_NO_PROCESS_SHIFT)
256 #define EFFECT_FLAG_NO_PROCESS          (1 << EFFECT_FLAG_NO_PROCESS_SHIFT)
257 
258 #define EFFECT_MAKE_API_VERSION(M, m)  (((M)<<16) | ((m) & 0xFFFF))
259 #define EFFECT_API_VERSION_MAJOR(v)    ((v)>>16)
260 #define EFFECT_API_VERSION_MINOR(v)    ((m) & 0xFFFF)
261 
262 
263 
264 /////////////////////////////////////////////////
265 //      Effect control interface
266 /////////////////////////////////////////////////
267 
268 // Effect control interface version 2.0
269 #define EFFECT_CONTROL_API_VERSION EFFECT_MAKE_API_VERSION(2,0)
270 
271 // Effect control interface structure: effect_interface_s
272 // The effect control interface is exposed by each effect engine implementation. It consists of
273 // a set of functions controlling the configuration, activation and process of the engine.
274 // The functions are grouped in a structure of type effect_interface_s.
275 //
276 // Effect control interface handle: effect_handle_t
277 // The effect_handle_t serves two purposes regarding the implementation of the effect engine:
278 // - 1 it is the address of a pointer to an effect_interface_s structure where the functions
279 // of the effect control API for a particular effect are located.
280 // - 2 it is the address of the context of a particular effect instance.
281 // A typical implementation in the effect library would define a structure as follows:
282 // struct effect_module_s {
283 //        const struct effect_interface_s *itfe;
284 //        effect_config_t config;
285 //        effect_context_t context;
286 // }
287 // The implementation of EffectCreate() function would then allocate a structure of this
288 // type and return its address as effect_handle_t
289 typedef struct effect_interface_s **effect_handle_t;
290 
291 
292 // Forward definition of type audio_buffer_t
293 typedef struct audio_buffer_s audio_buffer_t;
294 
295 
296 
297 
298 
299 
300 // Effect control interface definition
301 struct effect_interface_s {
302     ////////////////////////////////////////////////////////////////////////////////
303     //
304     //    Function:       process
305     //
306     //    Description:    Effect process function. Takes input samples as specified
307     //          (count and location) in input buffer descriptor and output processed
308     //          samples as specified in output buffer descriptor. If the buffer descriptor
309     //          is not specified the function must use either the buffer or the
310     //          buffer provider function installed by the EFFECT_CMD_SET_CONFIG command.
311     //          The effect framework will call the process() function after the EFFECT_CMD_ENABLE
312     //          command is received and until the EFFECT_CMD_DISABLE is received. When the engine
313     //          receives the EFFECT_CMD_DISABLE command it should turn off the effect gracefully
314     //          and when done indicate that it is OK to stop calling the process() function by
315     //          returning the -ENODATA status.
316     //
317     //    NOTE: the process() function implementation should be "real-time safe" that is
318     //      it should not perform blocking calls: malloc/free, sleep, read/write/open/close,
319     //      pthread_cond_wait/pthread_mutex_lock...
320     //
321     //    Input:
322     //          self:       handle to the effect interface this function
323     //              is called on.
324     //          inBuffer:   buffer descriptor indicating where to read samples to process.
325     //              If NULL, use the configuration passed by EFFECT_CMD_SET_CONFIG command.
326     //
327     //          outBuffer:   buffer descriptor indicating where to write processed samples.
328     //              If NULL, use the configuration passed by EFFECT_CMD_SET_CONFIG command.
329     //
330     //    Output:
331     //        returned value:    0 successful operation
332     //                          -ENODATA the engine has finished the disable phase and the framework
333     //                                  can stop calling process()
334     //                          -EINVAL invalid interface handle or
335     //                                  invalid input/output buffer description
336     ////////////////////////////////////////////////////////////////////////////////
337     int32_t (*process)(effect_handle_t self,
338                        audio_buffer_t *inBuffer,
339                        audio_buffer_t *outBuffer);
340     ////////////////////////////////////////////////////////////////////////////////
341     //
342     //    Function:       command
343     //
344     //    Description:    Send a command and receive a response to/from effect engine.
345     //
346     //    Input:
347     //          self:       handle to the effect interface this function
348     //              is called on.
349     //          cmdCode:    command code: the command can be a standardized command defined in
350     //              effect_command_e (see below) or a proprietary command.
351     //          cmdSize:    size of command in bytes
352     //          pCmdData:   pointer to command data
353     //          pReplyData: pointer to reply data
354     //
355     //    Input/Output:
356     //          replySize: maximum size of reply data as input
357     //                      actual size of reply data as output
358     //
359     //    Output:
360     //          returned value: 0       successful operation
361     //                          -EINVAL invalid interface handle or
362     //                                  invalid command/reply size or format according to
363     //                                  command code
364     //              The return code should be restricted to indicate problems related to this API
365     //              specification. Status related to the execution of a particular command should be
366     //              indicated as part of the reply field.
367     //
368     //          *pReplyData updated with command response
369     //
370     ////////////////////////////////////////////////////////////////////////////////
371     int32_t (*command)(effect_handle_t self,
372                        uint32_t cmdCode,
373                        uint32_t cmdSize,
374                        void *pCmdData,
375                        uint32_t *replySize,
376                        void *pReplyData);
377     ////////////////////////////////////////////////////////////////////////////////
378     //
379     //    Function:        get_descriptor
380     //
381     //    Description:    Returns the effect descriptor
382     //
383     //    Input:
384     //          self:       handle to the effect interface this function
385     //              is called on.
386     //
387     //    Input/Output:
388     //          pDescriptor:    address where to return the effect descriptor.
389     //
390     //    Output:
391     //        returned value:    0          successful operation.
392     //                          -EINVAL     invalid interface handle or invalid pDescriptor
393     //        *pDescriptor:     updated with the effect descriptor.
394     //
395     ////////////////////////////////////////////////////////////////////////////////
396     int32_t (*get_descriptor)(effect_handle_t self,
397                               effect_descriptor_t *pDescriptor);
398     ////////////////////////////////////////////////////////////////////////////////
399     //
400     //    Function:       process_reverse
401     //
402     //    Description:    Process reverse stream function. This function is used to pass
403     //          a reference stream to the effect engine. If the engine does not need a reference
404     //          stream, this function pointer can be set to NULL.
405     //          This function would typically implemented by an Echo Canceler.
406     //
407     //    Input:
408     //          self:       handle to the effect interface this function
409     //              is called on.
410     //          inBuffer:   buffer descriptor indicating where to read samples to process.
411     //              If NULL, use the configuration passed by EFFECT_CMD_SET_CONFIG_REVERSE command.
412     //
413     //          outBuffer:   buffer descriptor indicating where to write processed samples.
414     //              If NULL, use the configuration passed by EFFECT_CMD_SET_CONFIG_REVERSE command.
415     //              If the buffer and buffer provider in the configuration received by
416     //              EFFECT_CMD_SET_CONFIG_REVERSE are also NULL, do not return modified reverse
417     //              stream data
418     //
419     //    Output:
420     //        returned value:    0 successful operation
421     //                          -ENODATA the engine has finished the disable phase and the framework
422     //                                  can stop calling process_reverse()
423     //                          -EINVAL invalid interface handle or
424     //                                  invalid input/output buffer description
425     ////////////////////////////////////////////////////////////////////////////////
426     int32_t (*process_reverse)(effect_handle_t self,
427                                audio_buffer_t *inBuffer,
428                                audio_buffer_t *outBuffer);
429 };
430 
431 
432 //
433 //--- Standardized command codes for command() function
434 //
435 enum effect_command_e {
436    EFFECT_CMD_INIT,                 // initialize effect engine
437    EFFECT_CMD_SET_CONFIG,           // configure effect engine (see effect_config_t)
438    EFFECT_CMD_RESET,                // reset effect engine
439    EFFECT_CMD_ENABLE,               // enable effect process
440    EFFECT_CMD_DISABLE,              // disable effect process
441    EFFECT_CMD_SET_PARAM,            // set parameter immediately (see effect_param_t)
442    EFFECT_CMD_SET_PARAM_DEFERRED,   // set parameter deferred
443    EFFECT_CMD_SET_PARAM_COMMIT,     // commit previous set parameter deferred
444    EFFECT_CMD_GET_PARAM,            // get parameter
445    EFFECT_CMD_SET_DEVICE,           // set audio device (see audio.h, audio_devices_t)
446    EFFECT_CMD_SET_VOLUME,           // set volume
447    EFFECT_CMD_SET_AUDIO_MODE,       // set the audio mode (normal, ring, ...)
448    EFFECT_CMD_SET_CONFIG_REVERSE,   // configure effect engine reverse stream(see effect_config_t)
449    EFFECT_CMD_SET_INPUT_DEVICE,     // set capture device (see audio.h, audio_devices_t)
450    EFFECT_CMD_GET_CONFIG,           // read effect engine configuration
451    EFFECT_CMD_GET_CONFIG_REVERSE,   // read configure effect engine reverse stream configuration
452    EFFECT_CMD_GET_FEATURE_SUPPORTED_CONFIGS,// get all supported configurations for a feature.
453    EFFECT_CMD_GET_FEATURE_CONFIG,   // get current feature configuration
454    EFFECT_CMD_SET_FEATURE_CONFIG,   // set current feature configuration
455    EFFECT_CMD_SET_AUDIO_SOURCE,     // set the audio source (see audio.h, audio_source_t)
456    EFFECT_CMD_OFFLOAD,              // set if effect thread is an offload one,
457                                     // send the ioHandle of the effect thread
458    EFFECT_CMD_FIRST_PROPRIETARY = 0x10000 // first proprietary command code
459 };
460 
461 //==================================================================================================
462 // command: EFFECT_CMD_INIT
463 //--------------------------------------------------------------------------------------------------
464 // description:
465 //  Initialize effect engine: All configurations return to default
466 //--------------------------------------------------------------------------------------------------
467 // command format:
468 //  size: 0
469 //  data: N/A
470 //--------------------------------------------------------------------------------------------------
471 // reply format:
472 //  size: sizeof(int)
473 //  data: status
474 //==================================================================================================
475 // command: EFFECT_CMD_SET_CONFIG
476 //--------------------------------------------------------------------------------------------------
477 // description:
478 //  Apply new audio parameters configurations for input and output buffers
479 //--------------------------------------------------------------------------------------------------
480 // command format:
481 //  size: sizeof(effect_config_t)
482 //  data: effect_config_t
483 //--------------------------------------------------------------------------------------------------
484 // reply format:
485 //  size: sizeof(int)
486 //  data: status
487 //==================================================================================================
488 // command: EFFECT_CMD_RESET
489 //--------------------------------------------------------------------------------------------------
490 // description:
491 //  Reset the effect engine. Keep configuration but resets state and buffer content
492 //--------------------------------------------------------------------------------------------------
493 // command format:
494 //  size: 0
495 //  data: N/A
496 //--------------------------------------------------------------------------------------------------
497 // reply format:
498 //  size: 0
499 //  data: N/A
500 //==================================================================================================
501 // command: EFFECT_CMD_ENABLE
502 //--------------------------------------------------------------------------------------------------
503 // description:
504 //  Enable the process. Called by the framework before the first call to process()
505 //--------------------------------------------------------------------------------------------------
506 // command format:
507 //  size: 0
508 //  data: N/A
509 //--------------------------------------------------------------------------------------------------
510 // reply format:
511 //  size: sizeof(int)
512 //  data: status
513 //==================================================================================================
514 // command: EFFECT_CMD_DISABLE
515 //--------------------------------------------------------------------------------------------------
516 // description:
517 //  Disable the process. Called by the framework after the last call to process()
518 //--------------------------------------------------------------------------------------------------
519 // command format:
520 //  size: 0
521 //  data: N/A
522 //--------------------------------------------------------------------------------------------------
523 // reply format:
524 //  size: sizeof(int)
525 //  data: status
526 //==================================================================================================
527 // command: EFFECT_CMD_SET_PARAM
528 //--------------------------------------------------------------------------------------------------
529 // description:
530 //  Set a parameter and apply it immediately
531 //--------------------------------------------------------------------------------------------------
532 // command format:
533 //  size: sizeof(effect_param_t) + size of param and value
534 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset
535 //--------------------------------------------------------------------------------------------------
536 // reply format:
537 //  size: sizeof(int)
538 //  data: status
539 //==================================================================================================
540 // command: EFFECT_CMD_SET_PARAM_DEFERRED
541 //--------------------------------------------------------------------------------------------------
542 // description:
543 //  Set a parameter but apply it only when receiving EFFECT_CMD_SET_PARAM_COMMIT command
544 //--------------------------------------------------------------------------------------------------
545 // command format:
546 //  size: sizeof(effect_param_t) + size of param and value
547 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset
548 //--------------------------------------------------------------------------------------------------
549 // reply format:
550 //  size: 0
551 //  data: N/A
552 //==================================================================================================
553 // command: EFFECT_CMD_SET_PARAM_COMMIT
554 //--------------------------------------------------------------------------------------------------
555 // description:
556 //  Apply all previously received EFFECT_CMD_SET_PARAM_DEFERRED commands
557 //--------------------------------------------------------------------------------------------------
558 // command format:
559 //  size: 0
560 //  data: N/A
561 //--------------------------------------------------------------------------------------------------
562 // reply format:
563 //  size: sizeof(int)
564 //  data: status
565 //==================================================================================================
566 // command: EFFECT_CMD_GET_PARAM
567 //--------------------------------------------------------------------------------------------------
568 // description:
569 //  Get a parameter value
570 //--------------------------------------------------------------------------------------------------
571 // command format:
572 //  size: sizeof(effect_param_t) + size of param
573 //  data: effect_param_t + param
574 //--------------------------------------------------------------------------------------------------
575 // reply format:
576 //  size: sizeof(effect_param_t) + size of param and value
577 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset
578 //==================================================================================================
579 // command: EFFECT_CMD_SET_DEVICE
580 //--------------------------------------------------------------------------------------------------
581 // description:
582 //  Set the rendering device the audio output path is connected to. See audio.h, audio_devices_t
583 //  for device values.
584 //  The effect implementation must set EFFECT_FLAG_DEVICE_IND flag in its descriptor to receive this
585 //  command when the device changes
586 //--------------------------------------------------------------------------------------------------
587 // command format:
588 //  size: sizeof(uint32_t)
589 //  data: uint32_t
590 //--------------------------------------------------------------------------------------------------
591 // reply format:
592 //  size: 0
593 //  data: N/A
594 //==================================================================================================
595 // command: EFFECT_CMD_SET_VOLUME
596 //--------------------------------------------------------------------------------------------------
597 // description:
598 //  Set and get volume. Used by audio framework to delegate volume control to effect engine.
599 //  The effect implementation must set EFFECT_FLAG_VOLUME_IND or EFFECT_FLAG_VOLUME_CTRL flag in
600 //  its descriptor to receive this command before every call to process() function
601 //  If EFFECT_FLAG_VOLUME_CTRL flag is set in the effect descriptor, the effect engine must return
602 //  the volume that should be applied before the effect is processed. The overall volume (the volume
603 //  actually applied by the effect engine multiplied by the returned value) should match the value
604 //  indicated in the command.
605 //--------------------------------------------------------------------------------------------------
606 // command format:
607 //  size: n * sizeof(uint32_t)
608 //  data: volume for each channel defined in effect_config_t for output buffer expressed in
609 //      8.24 fixed point format
610 //--------------------------------------------------------------------------------------------------
611 // reply format:
612 //  size: n * sizeof(uint32_t) / 0
613 //  data: - if EFFECT_FLAG_VOLUME_CTRL is set in effect descriptor:
614 //              volume for each channel defined in effect_config_t for output buffer expressed in
615 //              8.24 fixed point format
616 //        - if EFFECT_FLAG_VOLUME_CTRL is not set in effect descriptor:
617 //              N/A
618 //  It is legal to receive a null pointer as pReplyData in which case the effect framework has
619 //  delegated volume control to another effect
620 //==================================================================================================
621 // command: EFFECT_CMD_SET_AUDIO_MODE
622 //--------------------------------------------------------------------------------------------------
623 // description:
624 //  Set the audio mode. The effect implementation must set EFFECT_FLAG_AUDIO_MODE_IND flag in its
625 //  descriptor to receive this command when the audio mode changes.
626 //--------------------------------------------------------------------------------------------------
627 // command format:
628 //  size: sizeof(uint32_t)
629 //  data: audio_mode_t
630 //--------------------------------------------------------------------------------------------------
631 // reply format:
632 //  size: 0
633 //  data: N/A
634 //==================================================================================================
635 // command: EFFECT_CMD_SET_CONFIG_REVERSE
636 //--------------------------------------------------------------------------------------------------
637 // description:
638 //  Apply new audio parameters configurations for input and output buffers of reverse stream.
639 //  An example of reverse stream is the echo reference supplied to an Acoustic Echo Canceler.
640 //--------------------------------------------------------------------------------------------------
641 // command format:
642 //  size: sizeof(effect_config_t)
643 //  data: effect_config_t
644 //--------------------------------------------------------------------------------------------------
645 // reply format:
646 //  size: sizeof(int)
647 //  data: status
648 //==================================================================================================
649 // command: EFFECT_CMD_SET_INPUT_DEVICE
650 //--------------------------------------------------------------------------------------------------
651 // description:
652 //  Set the capture device the audio input path is connected to. See audio.h, audio_devices_t
653 //  for device values.
654 //  The effect implementation must set EFFECT_FLAG_DEVICE_IND flag in its descriptor to receive this
655 //  command when the device changes
656 //--------------------------------------------------------------------------------------------------
657 // command format:
658 //  size: sizeof(uint32_t)
659 //  data: uint32_t
660 //--------------------------------------------------------------------------------------------------
661 // reply format:
662 //  size: 0
663 //  data: N/A
664 //==================================================================================================
665 // command: EFFECT_CMD_GET_CONFIG
666 //--------------------------------------------------------------------------------------------------
667 // description:
668 //  Read audio parameters configurations for input and output buffers
669 //--------------------------------------------------------------------------------------------------
670 // command format:
671 //  size: 0
672 //  data: N/A
673 //--------------------------------------------------------------------------------------------------
674 // reply format:
675 //  size: sizeof(effect_config_t)
676 //  data: effect_config_t
677 //==================================================================================================
678 // command: EFFECT_CMD_GET_CONFIG_REVERSE
679 //--------------------------------------------------------------------------------------------------
680 // description:
681 //  Read audio parameters configurations for input and output buffers of reverse stream
682 //--------------------------------------------------------------------------------------------------
683 // command format:
684 //  size: 0
685 //  data: N/A
686 //--------------------------------------------------------------------------------------------------
687 // reply format:
688 //  size: sizeof(effect_config_t)
689 //  data: effect_config_t
690 //==================================================================================================
691 // command: EFFECT_CMD_GET_FEATURE_SUPPORTED_CONFIGS
692 //--------------------------------------------------------------------------------------------------
693 // description:
694 //  Queries for supported configurations for a particular feature (e.g. get the supported
695 // combinations of main and auxiliary channels for a noise suppressor).
696 // The command parameter is the feature identifier (See effect_feature_e for a list of defined
697 // features) followed by the maximum number of configuration descriptor to return.
698 // The reply is composed of:
699 //  - status (uint32_t):
700 //          - 0 if feature is supported
701 //          - -ENOSYS if the feature is not supported,
702 //          - -ENOMEM if the feature is supported but the total number of supported configurations
703 //          exceeds the maximum number indicated by the caller.
704 //  - total number of supported configurations (uint32_t)
705 //  - an array of configuration descriptors.
706 // The actual number of descriptors returned must not exceed the maximum number indicated by
707 // the caller.
708 //--------------------------------------------------------------------------------------------------
709 // command format:
710 //  size: 2 x sizeof(uint32_t)
711 //  data: effect_feature_e + maximum number of configurations to return
712 //--------------------------------------------------------------------------------------------------
713 // reply format:
714 //  size: 2 x sizeof(uint32_t) + n x sizeof (<config descriptor>)
715 //  data: status + total number of configurations supported + array of n config descriptors
716 //==================================================================================================
717 // command: EFFECT_CMD_GET_FEATURE_CONFIG
718 //--------------------------------------------------------------------------------------------------
719 // description:
720 //  Retrieves current configuration for a given feature.
721 // The reply status is:
722 //      - 0 if feature is supported
723 //      - -ENOSYS if the feature is not supported,
724 //--------------------------------------------------------------------------------------------------
725 // command format:
726 //  size: sizeof(uint32_t)
727 //  data: effect_feature_e
728 //--------------------------------------------------------------------------------------------------
729 // reply format:
730 //  size: sizeof(uint32_t) + sizeof (<config descriptor>)
731 //  data: status + config descriptor
732 //==================================================================================================
733 // command: EFFECT_CMD_SET_FEATURE_CONFIG
734 //--------------------------------------------------------------------------------------------------
735 // description:
736 //  Sets current configuration for a given feature.
737 // The reply status is:
738 //      - 0 if feature is supported
739 //      - -ENOSYS if the feature is not supported,
740 //      - -EINVAL if the configuration is invalid
741 //--------------------------------------------------------------------------------------------------
742 // command format:
743 //  size: sizeof(uint32_t) + sizeof (<config descriptor>)
744 //  data: effect_feature_e + config descriptor
745 //--------------------------------------------------------------------------------------------------
746 // reply format:
747 //  size: sizeof(uint32_t)
748 //  data: status
749 //==================================================================================================
750 // command: EFFECT_CMD_SET_AUDIO_SOURCE
751 //--------------------------------------------------------------------------------------------------
752 // description:
753 //  Set the audio source the capture path is configured for (Camcorder, voice recognition...).
754 //  See audio.h, audio_source_t for values.
755 //--------------------------------------------------------------------------------------------------
756 // command format:
757 //  size: sizeof(uint32_t)
758 //  data: uint32_t
759 //--------------------------------------------------------------------------------------------------
760 // reply format:
761 //  size: 0
762 //  data: N/A
763 //==================================================================================================
764 // command: EFFECT_CMD_OFFLOAD
765 //--------------------------------------------------------------------------------------------------
766 // description:
767 //  1.indicate if the playback thread the effect is attached to is offloaded or not
768 //  2.update the io handle of the playback thread the effect is attached to
769 //--------------------------------------------------------------------------------------------------
770 // command format:
771 //  size: sizeof(effect_offload_param_t)
772 //  data: effect_offload_param_t
773 //--------------------------------------------------------------------------------------------------
774 // reply format:
775 //  size: sizeof(uint32_t)
776 //  data: uint32_t
777 //--------------------------------------------------------------------------------------------------
778 // command: EFFECT_CMD_FIRST_PROPRIETARY
779 //--------------------------------------------------------------------------------------------------
780 // description:
781 //  All proprietary effect commands must use command codes above this value. The size and format of
782 //  command and response fields is free in this case
783 //==================================================================================================
784 
785 
786 // Audio buffer descriptor used by process(), bufferProvider() functions and buffer_config_t
787 // structure. Multi-channel audio is always interleaved. The channel order is from LSB to MSB with
788 // regard to the channel mask definition in audio.h, audio_channel_mask_t e.g :
789 // Stereo: left, right
790 // 5 point 1: front left, front right, front center, low frequency, back left, back right
791 // The buffer size is expressed in frame count, a frame being composed of samples for all
792 // channels at a given time. Frame size for unspecified format (AUDIO_FORMAT_OTHER) is 8 bit by
793 // definition
794 struct audio_buffer_s {
795     size_t   frameCount;        // number of frames in buffer
796     union {
797         void*       raw;        // raw pointer to start of buffer
798         int32_t*    s32;        // pointer to signed 32 bit data at start of buffer
799         int16_t*    s16;        // pointer to signed 16 bit data at start of buffer
800         uint8_t*    u8;         // pointer to unsigned 8 bit data at start of buffer
801     };
802 };
803 
804 // The buffer_provider_s structure contains functions that can be used
805 // by the effect engine process() function to query and release input
806 // or output audio buffer.
807 // The getBuffer() function is called to retrieve a buffer where data
808 // should read from or written to by process() function.
809 // The releaseBuffer() function MUST be called when the buffer retrieved
810 // with getBuffer() is not needed anymore.
811 // The process function should use the buffer provider mechanism to retrieve
812 // input or output buffer if the inBuffer or outBuffer passed as argument is NULL
813 // and the buffer configuration (buffer_config_t) given by the EFFECT_CMD_SET_CONFIG
814 // command did not specify an audio buffer.
815 
816 typedef int32_t (* buffer_function_t)(void *cookie, audio_buffer_t *buffer);
817 
818 typedef struct buffer_provider_s {
819     buffer_function_t getBuffer;       // retrieve next buffer
820     buffer_function_t releaseBuffer;   // release used buffer
821     void       *cookie;                // for use by client of buffer provider functions
822 } buffer_provider_t;
823 
824 
825 // The buffer_config_s structure specifies the input or output audio format
826 // to be used by the effect engine. It is part of the effect_config_t
827 // structure that defines both input and output buffer configurations and is
828 // passed by the EFFECT_CMD_SET_CONFIG or EFFECT_CMD_SET_CONFIG_REVERSE command.
829 typedef struct buffer_config_s {
830     audio_buffer_t  buffer;     // buffer for use by process() function if not passed explicitly
831     uint32_t   samplingRate;    // sampling rate
832     uint32_t   channels;        // channel mask (see audio_channel_mask_t in audio.h)
833     buffer_provider_t bufferProvider;   // buffer provider
834     uint8_t    format;          // Audio format (see audio_format_t in audio.h)
835     uint8_t    accessMode;      // read/write or accumulate in buffer (effect_buffer_access_e)
836     uint16_t   mask;            // indicates which of the above fields is valid
837 } buffer_config_t;
838 
839 // Values for "accessMode" field of buffer_config_t:
840 //   overwrite, read only, accumulate (read/modify/write)
841 enum effect_buffer_access_e {
842     EFFECT_BUFFER_ACCESS_WRITE,
843     EFFECT_BUFFER_ACCESS_READ,
844     EFFECT_BUFFER_ACCESS_ACCUMULATE
845 
846 };
847 
848 // feature identifiers for EFFECT_CMD_GET_FEATURE_SUPPORTED_CONFIGS command
849 enum effect_feature_e {
850     EFFECT_FEATURE_AUX_CHANNELS, // supports auxiliary channels (e.g. dual mic noise suppressor)
851     EFFECT_FEATURE_CNT
852 };
853 
854 // EFFECT_FEATURE_AUX_CHANNELS feature configuration descriptor. Describe a combination
855 // of main and auxiliary channels supported
856 typedef struct channel_config_s {
857     audio_channel_mask_t main_channels; // channel mask for main channels
858     audio_channel_mask_t aux_channels;  // channel mask for auxiliary channels
859 } channel_config_t;
860 
861 
862 // Values for bit field "mask" in buffer_config_t. If a bit is set, the corresponding field
863 // in buffer_config_t must be taken into account when executing the EFFECT_CMD_SET_CONFIG command
864 #define EFFECT_CONFIG_BUFFER    0x0001  // buffer field must be taken into account
865 #define EFFECT_CONFIG_SMP_RATE  0x0002  // samplingRate field must be taken into account
866 #define EFFECT_CONFIG_CHANNELS  0x0004  // channels field must be taken into account
867 #define EFFECT_CONFIG_FORMAT    0x0008  // format field must be taken into account
868 #define EFFECT_CONFIG_ACC_MODE  0x0010  // accessMode field must be taken into account
869 #define EFFECT_CONFIG_PROVIDER  0x0020  // bufferProvider field must be taken into account
870 #define EFFECT_CONFIG_ALL (EFFECT_CONFIG_BUFFER | EFFECT_CONFIG_SMP_RATE | \
871                            EFFECT_CONFIG_CHANNELS | EFFECT_CONFIG_FORMAT | \
872                            EFFECT_CONFIG_ACC_MODE | EFFECT_CONFIG_PROVIDER)
873 
874 
875 // effect_config_s structure describes the format of the pCmdData argument of EFFECT_CMD_SET_CONFIG
876 // command to configure audio parameters and buffers for effect engine input and output.
877 typedef struct effect_config_s {
878     buffer_config_t   inputCfg;
879     buffer_config_t   outputCfg;
880 } effect_config_t;
881 
882 
883 // effect_param_s structure describes the format of the pCmdData argument of EFFECT_CMD_SET_PARAM
884 // command and pCmdData and pReplyData of EFFECT_CMD_GET_PARAM command.
885 // psize and vsize represent the actual size of parameter and value.
886 //
887 // NOTE: the start of value field inside the data field is always on a 32 bit boundary:
888 //
889 //  +-----------+
890 //  | status    | sizeof(int)
891 //  +-----------+
892 //  | psize     | sizeof(int)
893 //  +-----------+
894 //  | vsize     | sizeof(int)
895 //  +-----------+
896 //  |           |   |           |
897 //  ~ parameter ~   > psize     |
898 //  |           |   |           >  ((psize - 1)/sizeof(int) + 1) * sizeof(int)
899 //  +-----------+               |
900 //  | padding   |               |
901 //  +-----------+
902 //  |           |   |
903 //  ~ value     ~   > vsize
904 //  |           |   |
905 //  +-----------+
906 
907 typedef struct effect_param_s {
908     int32_t     status;     // Transaction status (unused for command, used for reply)
909     uint32_t    psize;      // Parameter size
910     uint32_t    vsize;      // Value size
911     char        data[];     // Start of Parameter + Value data
912 } effect_param_t;
913 
914 // Maximum effect_param_t size
915 #define EFFECT_PARAM_SIZE_MAX       65536
916 
917 // structure used by EFFECT_CMD_OFFLOAD command
918 typedef struct effect_offload_param_s {
919     bool isOffload;         // true if the playback thread the effect is attached to is offloaded
920     int ioHandle;           // io handle of the playback thread the effect is attached to
921 } effect_offload_param_t;
922 
923 
924 /////////////////////////////////////////////////
925 //      Effect library interface
926 /////////////////////////////////////////////////
927 
928 // Effect library interface version 3.0
929 // Note that EffectsFactory.c only checks the major version component, so changes to the minor
930 // number can only be used for fully backwards compatible changes
931 #define EFFECT_LIBRARY_API_VERSION EFFECT_MAKE_API_VERSION(3,0)
932 
933 #define AUDIO_EFFECT_LIBRARY_TAG ((('A') << 24) | (('E') << 16) | (('L') << 8) | ('T'))
934 
935 // Every effect library must have a data structure named AUDIO_EFFECT_LIBRARY_INFO_SYM
936 // and the fields of this data structure must begin with audio_effect_library_t
937 
938 typedef struct audio_effect_library_s {
939     // tag must be initialized to AUDIO_EFFECT_LIBRARY_TAG
940     uint32_t tag;
941     // Version of the effect library API : 0xMMMMmmmm MMMM: Major, mmmm: minor
942     uint32_t version;
943     // Name of this library
944     const char *name;
945     // Author/owner/implementor of the library
946     const char *implementor;
947 
948     ////////////////////////////////////////////////////////////////////////////////
949     //
950     //    Function:        create_effect
951     //
952     //    Description:    Creates an effect engine of the specified implementation uuid and
953     //          returns an effect control interface on this engine. The function will allocate the
954     //          resources for an instance of the requested effect engine and return
955     //          a handle on the effect control interface.
956     //
957     //    Input:
958     //          uuid:    pointer to the effect uuid.
959     //          sessionId:  audio session to which this effect instance will be attached.
960     //              All effects created with the same session ID are connected in series and process
961     //              the same signal stream. Knowing that two effects are part of the same effect
962     //              chain can help the library implement some kind of optimizations.
963     //          ioId:   identifies the output or input stream this effect is directed to in
964     //              audio HAL.
965     //              For future use especially with tunneled HW accelerated effects
966     //
967     //    Input/Output:
968     //          pHandle:        address where to return the effect interface handle.
969     //
970     //    Output:
971     //        returned value:    0          successful operation.
972     //                          -ENODEV     library failed to initialize
973     //                          -EINVAL     invalid pEffectUuid or pHandle
974     //                          -ENOENT     no effect with this uuid found
975     //        *pHandle:         updated with the effect interface handle.
976     //
977     ////////////////////////////////////////////////////////////////////////////////
978     int32_t (*create_effect)(const effect_uuid_t *uuid,
979                              int32_t sessionId,
980                              int32_t ioId,
981                              effect_handle_t *pHandle);
982 
983     ////////////////////////////////////////////////////////////////////////////////
984     //
985     //    Function:        release_effect
986     //
987     //    Description:    Releases the effect engine whose handle is given as argument.
988     //          All resources allocated to this particular instance of the effect are
989     //          released.
990     //
991     //    Input:
992     //          handle:         handle on the effect interface to be released.
993     //
994     //    Output:
995     //        returned value:    0          successful operation.
996     //                          -ENODEV     library failed to initialize
997     //                          -EINVAL     invalid interface handle
998     //
999     ////////////////////////////////////////////////////////////////////////////////
1000     int32_t (*release_effect)(effect_handle_t handle);
1001 
1002     ////////////////////////////////////////////////////////////////////////////////
1003     //
1004     //    Function:        get_descriptor
1005     //
1006     //    Description:    Returns the descriptor of the effect engine which implementation UUID is
1007     //          given as argument.
1008     //
1009     //    Input/Output:
1010     //          uuid:           pointer to the effect uuid.
1011     //          pDescriptor:    address where to return the effect descriptor.
1012     //
1013     //    Output:
1014     //        returned value:    0          successful operation.
1015     //                          -ENODEV     library failed to initialize
1016     //                          -EINVAL     invalid pDescriptor or uuid
1017     //        *pDescriptor:     updated with the effect descriptor.
1018     //
1019     ////////////////////////////////////////////////////////////////////////////////
1020     int32_t (*get_descriptor)(const effect_uuid_t *uuid,
1021                               effect_descriptor_t *pDescriptor);
1022 } audio_effect_library_t;
1023 
1024 // Name of the hal_module_info
1025 #define AUDIO_EFFECT_LIBRARY_INFO_SYM         AELI
1026 
1027 // Name of the hal_module_info as a string
1028 #define AUDIO_EFFECT_LIBRARY_INFO_SYM_AS_STR  "AELI"
1029 
1030 __END_DECLS
1031 
1032 #endif  // ANDROID_AUDIO_EFFECT_H
1033