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      1 /*
      2  * Copyright (C) 2010 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_EFFECTAPI_H_
     18 #define ANDROID_EFFECTAPI_H_
     19 
     20 #include <errno.h>
     21 #include <stdint.h>
     22 #include <sys/types.h>
     23 
     24 #if __cplusplus
     25 extern "C" {
     26 #endif
     27 
     28 /////////////////////////////////////////////////
     29 //      Effect control interface
     30 /////////////////////////////////////////////////
     31 
     32 // The effect control interface is exposed by each effect engine implementation. It consists of
     33 // a set of functions controlling the configuration, activation and process of the engine.
     34 // The functions are grouped in a structure of type effect_interface_s:
     35 //    struct effect_interface_s {
     36 //        effect_process_t process;
     37 //        effect_command_t command;
     38 //    };
     39 
     40 
     41 // effect_interface_t: Effect control interface handle.
     42 // The effect_interface_t serves two purposes regarding the implementation of the effect engine:
     43 // - 1 it is the address of a pointer to an effect_interface_s structure where the functions
     44 // of the effect control API for a particular effect are located.
     45 // - 2 it is the address of the context of a particular effect instance.
     46 // A typical implementation in the effect library would define a structure as follows:
     47 // struct effect_module_s {
     48 //        const struct effect_interface_s *itfe;
     49 //        effect_config_t config;
     50 //        effect_context_t context;
     51 // }
     52 // The implementation of EffectCreate() function would then allocate a structure of this
     53 // type and return its address as effect_interface_t
     54 typedef struct effect_interface_s **effect_interface_t;
     55 
     56 
     57 // Effect API version 1.0
     58 #define EFFECT_API_VERSION 0x0100 // Format 0xMMmm MM: Major version, mm: minor version
     59 
     60 // Maximum length of character strings in structures defines by this API.
     61 #define EFFECT_STRING_LEN_MAX 64
     62 
     63 //
     64 //--- Effect descriptor structure effect_descriptor_t
     65 //
     66 
     67 // Unique effect ID (can be generated from the following site:
     68 //  http://www.itu.int/ITU-T/asn1/uuid.html)
     69 // This format is used for both "type" and "uuid" fields of the effect descriptor structure.
     70 // - When used for effect type and the engine is implementing and effect corresponding to a standard
     71 // OpenSL ES interface, this ID must be the one defined in OpenSLES_IID.h for that interface.
     72 // - When used as uuid, it should be a unique UUID for this particular implementation.
     73 typedef struct effect_uuid_s {
     74     uint32_t timeLow;
     75     uint16_t timeMid;
     76     uint16_t timeHiAndVersion;
     77     uint16_t clockSeq;
     78     uint8_t node[6];
     79 } effect_uuid_t;
     80 
     81 // NULL UUID definition (matches SL_IID_NULL_)
     82 #define EFFECT_UUID_INITIALIZER { 0xec7178ec, 0xe5e1, 0x4432, 0xa3f4, \
     83                                   { 0x46, 0x57, 0xe6, 0x79, 0x52, 0x10 } }
     84 static const effect_uuid_t EFFECT_UUID_NULL_ = EFFECT_UUID_INITIALIZER;
     85 const effect_uuid_t * const EFFECT_UUID_NULL = &EFFECT_UUID_NULL_;
     86 const char * const EFFECT_UUID_NULL_STR = "ec7178ec-e5e1-4432-a3f4-4657e6795210";
     87 
     88 // The effect descriptor contains necessary information to facilitate the enumeration of the effect
     89 // engines present in a library.
     90 typedef struct effect_descriptor_s {
     91     effect_uuid_t type;     // UUID of to the OpenSL ES interface implemented by this effect
     92     effect_uuid_t uuid;     // UUID for this particular implementation
     93     uint16_t apiVersion;    // Version of the effect API implemented: matches EFFECT_API_VERSION
     94     uint32_t flags;         // effect engine capabilities/requirements flags (see below)
     95     uint16_t cpuLoad;       // CPU load indication (see below)
     96     uint16_t memoryUsage;   // Data Memory usage (see below)
     97     char    name[EFFECT_STRING_LEN_MAX];   // human readable effect name
     98     char    implementor[EFFECT_STRING_LEN_MAX];    // human readable effect implementor name
     99 } effect_descriptor_t;
    100 
    101 // CPU load and memory usage indication: each effect implementation must provide an indication of
    102 // its CPU and memory usage for the audio effect framework to limit the number of effects
    103 // instantiated at a given time on a given platform.
    104 // The CPU load is expressed in 0.1 MIPS units as estimated on an ARM9E core (ARMv5TE) with 0 WS.
    105 // The memory usage is expressed in KB and includes only dynamically allocated memory
    106 
    107 // Definitions for flags field of effect descriptor.
    108 //  +---------------------------+-----------+-----------------------------------
    109 //  | description               | bits      | values
    110 //  +---------------------------+-----------+-----------------------------------
    111 //  | connection mode           | 0..1      | 0 insert: after track process
    112 //  |                           |           | 1 auxiliary: connect to track auxiliary
    113 //  |                           |           |  output and use send level
    114 //  |                           |           | 2 replace: replaces track process function;
    115 //  |                           |           |   must implement SRC, volume and mono to stereo.
    116 //  |                           |           | 3 reserved
    117 //  +---------------------------+-----------+-----------------------------------
    118 //  | insertion preference      | 2..4      | 0 none
    119 //  |                           |           | 1 first of the chain
    120 //  |                           |           | 2 last of the chain
    121 //  |                           |           | 3 exclusive (only effect in the insert chain)
    122 //  |                           |           | 4..7 reserved
    123 //  +---------------------------+-----------+-----------------------------------
    124 //  | Volume management         | 5..6      | 0 none
    125 //  |                           |           | 1 implements volume control
    126 //  |                           |           | 2 requires volume indication
    127 //  |                           |           | 3 reserved
    128 //  +---------------------------+-----------+-----------------------------------
    129 //  | Device indication         | 7..8      | 0 none
    130 //  |                           |           | 1 requires device updates
    131 //  |                           |           | 2..3 reserved
    132 //  +---------------------------+-----------+-----------------------------------
    133 //  | Sample input mode         | 9..10     | 0 direct: process() function or EFFECT_CMD_CONFIGURE
    134 //  |                           |           |   command must specify a buffer descriptor
    135 //  |                           |           | 1 provider: process() function uses the
    136 //  |                           |           |   bufferProvider indicated by the
    137 //  |                           |           |   EFFECT_CMD_CONFIGURE command to request input.
    138 //  |                           |           |   buffers.
    139 //  |                           |           | 2 both: both input modes are supported
    140 //  |                           |           | 3 reserved
    141 //  +---------------------------+-----------+-----------------------------------
    142 //  | Sample output mode        | 11..12    | 0 direct: process() function or EFFECT_CMD_CONFIGURE
    143 //  |                           |           |   command must specify a buffer descriptor
    144 //  |                           |           | 1 provider: process() function uses the
    145 //  |                           |           |   bufferProvider indicated by the
    146 //  |                           |           |   EFFECT_CMD_CONFIGURE command to request output
    147 //  |                           |           |   buffers.
    148 //  |                           |           | 2 both: both output modes are supported
    149 //  |                           |           | 3 reserved
    150 //  +---------------------------+-----------+-----------------------------------
    151 //  | Hardware acceleration     | 13..15    | 0 No hardware acceleration
    152 //  |                           |           | 1 non tunneled hw acceleration: the process() function
    153 //  |                           |           |   reads the samples, send them to HW accelerated
    154 //  |                           |           |   effect processor, reads back the processed samples
    155 //  |                           |           |   and returns them to the output buffer.
    156 //  |                           |           | 2 tunneled hw acceleration: the process() function is
    157 //  |                           |           |   transparent. The effect interface is only used to
    158 //  |                           |           |   control the effect engine. This mode is relevant for
    159 //  |                           |           |   global effects actually applied by the audio
    160 //  |                           |           |   hardware on the output stream.
    161 //  +---------------------------+-----------+-----------------------------------
    162 //  | Audio Mode indication     | 16..17    | 0 none
    163 //  |                           |           | 1 requires audio mode updates
    164 //  |                           |           | 2..3 reserved
    165 //  +---------------------------+-----------+-----------------------------------
    166 
    167 // Insert mode
    168 #define EFFECT_FLAG_TYPE_MASK           0x00000003
    169 #define EFFECT_FLAG_TYPE_INSERT         0x00000000
    170 #define EFFECT_FLAG_TYPE_AUXILIARY      0x00000001
    171 #define EFFECT_FLAG_TYPE_REPLACE        0x00000002
    172 
    173 // Insert preference
    174 #define EFFECT_FLAG_INSERT_MASK         0x0000001C
    175 #define EFFECT_FLAG_INSERT_ANY          0x00000000
    176 #define EFFECT_FLAG_INSERT_FIRST        0x00000004
    177 #define EFFECT_FLAG_INSERT_LAST         0x00000008
    178 #define EFFECT_FLAG_INSERT_EXCLUSIVE    0x0000000C
    179 
    180 
    181 // Volume control
    182 #define EFFECT_FLAG_VOLUME_MASK         0x00000060
    183 #define EFFECT_FLAG_VOLUME_CTRL         0x00000020
    184 #define EFFECT_FLAG_VOLUME_IND          0x00000040
    185 #define EFFECT_FLAG_VOLUME_NONE         0x00000000
    186 
    187 // Device indication
    188 #define EFFECT_FLAG_DEVICE_MASK         0x00000180
    189 #define EFFECT_FLAG_DEVICE_IND          0x00000080
    190 #define EFFECT_FLAG_DEVICE_NONE         0x00000000
    191 
    192 // Sample input modes
    193 #define EFFECT_FLAG_INPUT_MASK          0x00000600
    194 #define EFFECT_FLAG_INPUT_DIRECT        0x00000000
    195 #define EFFECT_FLAG_INPUT_PROVIDER      0x00000200
    196 #define EFFECT_FLAG_INPUT_BOTH          0x00000400
    197 
    198 // Sample output modes
    199 #define EFFECT_FLAG_OUTPUT_MASK          0x00001800
    200 #define EFFECT_FLAG_OUTPUT_DIRECT        0x00000000
    201 #define EFFECT_FLAG_OUTPUT_PROVIDER      0x00000800
    202 #define EFFECT_FLAG_OUTPUT_BOTH          0x00001000
    203 
    204 // Hardware acceleration mode
    205 #define EFFECT_FLAG_HW_ACC_MASK          0x00006000
    206 #define EFFECT_FLAG_HW_ACC_SIMPLE        0x00002000
    207 #define EFFECT_FLAG_HW_ACC_TUNNEL        0x00004000
    208 
    209 // Audio mode indication
    210 #define EFFECT_FLAG_AUDIO_MODE_MASK      0x00018000
    211 #define EFFECT_FLAG_AUDIO_MODE_IND       0x00008000
    212 #define EFFECT_FLAG_AUDIO_MODE_NONE      0x00000000
    213 
    214 // Forward definition of type audio_buffer_t
    215 typedef struct audio_buffer_s audio_buffer_t;
    216 
    217 ////////////////////////////////////////////////////////////////////////////////
    218 //
    219 //    Function:       process
    220 //
    221 //    Description:    Effect process function. Takes input samples as specified
    222 //          (count and location) in input buffer descriptor and output processed
    223 //          samples as specified in output buffer descriptor. If the buffer descriptor
    224 //          is not specified the function must use either the buffer or the
    225 //          buffer provider function installed by the EFFECT_CMD_CONFIGURE command.
    226 //          The effect framework will call the process() function after the EFFECT_CMD_ENABLE
    227 //          command is received and until the EFFECT_CMD_DISABLE is received. When the engine
    228 //          receives the EFFECT_CMD_DISABLE command it should turn off the effect gracefully
    229 //          and when done indicate that it is OK to stop calling the process() function by
    230 //          returning the -ENODATA status.
    231 //
    232 //    NOTE: the process() function implementation should be "real-time safe" that is
    233 //      it should not perform blocking calls: malloc/free, sleep, read/write/open/close,
    234 //      pthread_cond_wait/pthread_mutex_lock...
    235 //
    236 //    Input:
    237 //          effect_interface_t: handle to the effect interface this function
    238 //              is called on.
    239 //          inBuffer:   buffer descriptor indicating where to read samples to process.
    240 //              If NULL, use the configuration passed by EFFECT_CMD_CONFIGURE command.
    241 //
    242 //          inBuffer:   buffer descriptor indicating where to write processed samples.
    243 //              If NULL, use the configuration passed by EFFECT_CMD_CONFIGURE command.
    244 //
    245 //    Output:
    246 //        returned value:    0 successful operation
    247 //                          -ENODATA the engine has finished the disable phase and the framework
    248 //                                  can stop calling process()
    249 //                          -EINVAL invalid interface handle or
    250 //                                  invalid input/output buffer description
    251 ////////////////////////////////////////////////////////////////////////////////
    252 typedef int32_t (*effect_process_t)(effect_interface_t self,
    253                                     audio_buffer_t *inBuffer,
    254                                     audio_buffer_t *outBuffer);
    255 
    256 ////////////////////////////////////////////////////////////////////////////////
    257 //
    258 //    Function:       command
    259 //
    260 //    Description:    Send a command and receive a response to/from effect engine.
    261 //
    262 //    Input:
    263 //          effect_interface_t: handle to the effect interface this function
    264 //              is called on.
    265 //          cmdCode:    command code: the command can be a standardized command defined in
    266 //              effect_command_e (see below) or a proprietary command.
    267 //          cmdSize:    size of command in bytes
    268 //          pCmdData:   pointer to command data
    269 //          pReplyData: pointer to reply data
    270 //
    271 //    Input/Output:
    272 //          replySize: maximum size of reply data as input
    273 //                      actual size of reply data as output
    274 //
    275 //    Output:
    276 //          returned value: 0       successful operation
    277 //                          -EINVAL invalid interface handle or
    278 //                                  invalid command/reply size or format according to command code
    279 //              The return code should be restricted to indicate problems related to the this
    280 //              API specification. Status related to the execution of a particular command should be
    281 //              indicated as part of the reply field.
    282 //
    283 //          *pReplyData updated with command response
    284 //
    285 ////////////////////////////////////////////////////////////////////////////////
    286 typedef int32_t (*effect_command_t)(effect_interface_t self,
    287                                     uint32_t cmdCode,
    288                                     uint32_t cmdSize,
    289                                     void *pCmdData,
    290                                     uint32_t *replySize,
    291                                     void *pReplyData);
    292 
    293 
    294 // Effect control interface definition
    295 struct effect_interface_s {
    296     effect_process_t process;
    297     effect_command_t command;
    298 };
    299 
    300 
    301 //
    302 //--- Standardized command codes for command() function
    303 //
    304 enum effect_command_e {
    305    EFFECT_CMD_INIT,                 // initialize effect engine
    306    EFFECT_CMD_CONFIGURE,            // configure effect engine (see effect_config_t)
    307    EFFECT_CMD_RESET,                // reset effect engine
    308    EFFECT_CMD_ENABLE,               // enable effect process
    309    EFFECT_CMD_DISABLE,              // disable effect process
    310    EFFECT_CMD_SET_PARAM,            // set parameter immediately (see effect_param_t)
    311    EFFECT_CMD_SET_PARAM_DEFERRED,   // set parameter deferred
    312    EFFECT_CMD_SET_PARAM_COMMIT,     // commit previous set parameter deferred
    313    EFFECT_CMD_GET_PARAM,            // get parameter
    314    EFFECT_CMD_SET_DEVICE,           // set audio device (see audio_device_e)
    315    EFFECT_CMD_SET_VOLUME,           // set volume
    316    EFFECT_CMD_SET_AUDIO_MODE,       // set the audio mode (normal, ring, ...)
    317    EFFECT_CMD_FIRST_PROPRIETARY = 0x10000 // first proprietary command code
    318 };
    319 
    320 //==================================================================================================
    321 // command: EFFECT_CMD_INIT
    322 //--------------------------------------------------------------------------------------------------
    323 // description:
    324 //  Initialize effect engine: All configurations return to default
    325 //--------------------------------------------------------------------------------------------------
    326 // command format:
    327 //  size: 0
    328 //  data: N/A
    329 //--------------------------------------------------------------------------------------------------
    330 // reply format:
    331 //  size: sizeof(int)
    332 //  data: status
    333 //==================================================================================================
    334 // command: EFFECT_CMD_CONFIGURE
    335 //--------------------------------------------------------------------------------------------------
    336 // description:
    337 //  Apply new audio parameters configurations for input and output buffers
    338 //--------------------------------------------------------------------------------------------------
    339 // command format:
    340 //  size: sizeof(effect_config_t)
    341 //  data: effect_config_t
    342 //--------------------------------------------------------------------------------------------------
    343 // reply format:
    344 //  size: sizeof(int)
    345 //  data: status
    346 //==================================================================================================
    347 // command: EFFECT_CMD_RESET
    348 //--------------------------------------------------------------------------------------------------
    349 // description:
    350 //  Reset the effect engine. Keep configuration but resets state and buffer content
    351 //--------------------------------------------------------------------------------------------------
    352 // command format:
    353 //  size: 0
    354 //  data: N/A
    355 //--------------------------------------------------------------------------------------------------
    356 // reply format:
    357 //  size: 0
    358 //  data: N/A
    359 //==================================================================================================
    360 // command: EFFECT_CMD_ENABLE
    361 //--------------------------------------------------------------------------------------------------
    362 // description:
    363 //  Enable the process. Called by the framework before the first call to process()
    364 //--------------------------------------------------------------------------------------------------
    365 // command format:
    366 //  size: 0
    367 //  data: N/A
    368 //--------------------------------------------------------------------------------------------------
    369 // reply format:
    370 //  size: sizeof(int)
    371 //  data: status
    372 //==================================================================================================
    373 // command: EFFECT_CMD_DISABLE
    374 //--------------------------------------------------------------------------------------------------
    375 // description:
    376 //  Disable the process. Called by the framework after the last call to process()
    377 //--------------------------------------------------------------------------------------------------
    378 // command format:
    379 //  size: 0
    380 //  data: N/A
    381 //--------------------------------------------------------------------------------------------------
    382 // reply format:
    383 //  size: sizeof(int)
    384 //  data: status
    385 //==================================================================================================
    386 // command: EFFECT_CMD_SET_PARAM
    387 //--------------------------------------------------------------------------------------------------
    388 // description:
    389 //  Set a parameter and apply it immediately
    390 //--------------------------------------------------------------------------------------------------
    391 // command format:
    392 //  size: sizeof(effect_param_t) + size of param and value
    393 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset
    394 //--------------------------------------------------------------------------------------------------
    395 // reply format:
    396 //  size: sizeof(int)
    397 //  data: status
    398 //==================================================================================================
    399 // command: EFFECT_CMD_SET_PARAM_DEFERRED
    400 //--------------------------------------------------------------------------------------------------
    401 // description:
    402 //  Set a parameter but apply it only when receiving EFFECT_CMD_SET_PARAM_COMMIT command
    403 //--------------------------------------------------------------------------------------------------
    404 // command format:
    405 //  size: sizeof(effect_param_t) + size of param and value
    406 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset
    407 //--------------------------------------------------------------------------------------------------
    408 // reply format:
    409 //  size: 0
    410 //  data: N/A
    411 //==================================================================================================
    412 // command: EFFECT_CMD_SET_PARAM_COMMIT
    413 //--------------------------------------------------------------------------------------------------
    414 // description:
    415 //  Apply all previously received EFFECT_CMD_SET_PARAM_DEFERRED commands
    416 //--------------------------------------------------------------------------------------------------
    417 // command format:
    418 //  size: 0
    419 //  data: N/A
    420 //--------------------------------------------------------------------------------------------------
    421 // reply format:
    422 //  size: sizeof(int)
    423 //  data: status
    424 //==================================================================================================
    425 // command: EFFECT_CMD_GET_PARAM
    426 //--------------------------------------------------------------------------------------------------
    427 // description:
    428 //  Get a parameter value
    429 //--------------------------------------------------------------------------------------------------
    430 // command format:
    431 //  size: sizeof(effect_param_t) + size of param
    432 //  data: effect_param_t + param
    433 //--------------------------------------------------------------------------------------------------
    434 // reply format:
    435 //  size: sizeof(effect_param_t) + size of param and value
    436 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset
    437 //==================================================================================================
    438 // command: EFFECT_CMD_SET_DEVICE
    439 //--------------------------------------------------------------------------------------------------
    440 // description:
    441 //  Set the rendering device the audio output path is connected to. See audio_device_e for device
    442 //  values.
    443 //  The effect implementation must set EFFECT_FLAG_DEVICE_IND flag in its descriptor to receive this
    444 //  command when the device changes
    445 //--------------------------------------------------------------------------------------------------
    446 // command format:
    447 //  size: sizeof(uint32_t)
    448 //  data: audio_device_e
    449 //--------------------------------------------------------------------------------------------------
    450 // reply format:
    451 //  size: 0
    452 //  data: N/A
    453 //==================================================================================================
    454 // command: EFFECT_CMD_SET_VOLUME
    455 //--------------------------------------------------------------------------------------------------
    456 // description:
    457 //  Set and get volume. Used by audio framework to delegate volume control to effect engine.
    458 //  The effect implementation must set EFFECT_FLAG_VOLUME_IND or EFFECT_FLAG_VOLUME_CTRL flag in
    459 //  its descriptor to receive this command before every call to process() function
    460 //  If EFFECT_FLAG_VOLUME_CTRL flag is set in the effect descriptor, the effect engine must return
    461 //  the volume that should be applied before the effect is processed. The overall volume (the volume
    462 //  actually applied by the effect engine multiplied by the returned value) should match the value
    463 //  indicated in the command.
    464 //--------------------------------------------------------------------------------------------------
    465 // command format:
    466 //  size: n * sizeof(uint32_t)
    467 //  data: volume for each channel defined in effect_config_t for output buffer expressed in
    468 //      8.24 fixed point format
    469 //--------------------------------------------------------------------------------------------------
    470 // reply format:
    471 //  size: n * sizeof(uint32_t) / 0
    472 //  data: - if EFFECT_FLAG_VOLUME_CTRL is set in effect descriptor:
    473 //              volume for each channel defined in effect_config_t for output buffer expressed in
    474 //              8.24 fixed point format
    475 //        - if EFFECT_FLAG_VOLUME_CTRL is not set in effect descriptor:
    476 //              N/A
    477 //  It is legal to receive a null pointer as pReplyData in which case the effect framework has
    478 //  delegated volume control to another effect
    479 //==================================================================================================
    480 // command: EFFECT_CMD_SET_AUDIO_MODE
    481 //--------------------------------------------------------------------------------------------------
    482 // description:
    483 //  Set the audio mode. The effect implementation must set EFFECT_FLAG_AUDIO_MODE_IND flag in its
    484 //  descriptor to receive this command when the audio mode changes.
    485 //--------------------------------------------------------------------------------------------------
    486 // command format:
    487 //  size: sizeof(uint32_t)
    488 //  data: audio_mode_e
    489 //--------------------------------------------------------------------------------------------------
    490 // reply format:
    491 //  size: 0
    492 //  data: N/A
    493 //==================================================================================================
    494 // command: EFFECT_CMD_FIRST_PROPRIETARY
    495 //--------------------------------------------------------------------------------------------------
    496 // description:
    497 //  All proprietary effect commands must use command codes above this value. The size and format of
    498 //  command and response fields is free in this case
    499 //==================================================================================================
    500 
    501 
    502 // Audio buffer descriptor used by process(), bufferProvider() functions and buffer_config_t
    503 // structure. Multi-channel audio is always interleaved. The channel order is from LSB to MSB with
    504 // regard to the channel mask definition in audio_channels_e e.g :
    505 // Stereo: left, right
    506 // 5 point 1: front left, front right, front center, low frequency, back left, back right
    507 // The buffer size is expressed in frame count, a frame being composed of samples for all
    508 // channels at a given time. Frame size for unspecified format (AUDIO_FORMAT_OTHER) is 8 bit by
    509 // definition
    510 struct audio_buffer_s {
    511     size_t   frameCount;        // number of frames in buffer
    512     union {
    513         void*       raw;        // raw pointer to start of buffer
    514         int32_t*    s32;        // pointer to signed 32 bit data at start of buffer
    515         int16_t*    s16;        // pointer to signed 16 bit data at start of buffer
    516         uint8_t*    u8;         // pointer to unsigned 8 bit data at start of buffer
    517     };
    518 };
    519 
    520 // The buffer_provider_s structure contains functions that can be used
    521 // by the effect engine process() function to query and release input
    522 // or output audio buffer.
    523 // The getBuffer() function is called to retrieve a buffer where data
    524 // should read from or written to by process() function.
    525 // The releaseBuffer() function MUST be called when the buffer retrieved
    526 // with getBuffer() is not needed anymore.
    527 // The process function should use the buffer provider mechanism to retrieve
    528 // input or output buffer if the inBuffer or outBuffer passed as argument is NULL
    529 // and the buffer configuration (buffer_config_t) given by the EFFECT_CMD_CONFIGURE
    530 // command did not specify an audio buffer.
    531 
    532 typedef int32_t (* buffer_function_t)(void *cookie, audio_buffer_t *buffer);
    533 
    534 typedef struct buffer_provider_s {
    535     buffer_function_t getBuffer;       // retrieve next buffer
    536     buffer_function_t releaseBuffer;   // release used buffer
    537     void       *cookie;                // for use by client of buffer provider functions
    538 } buffer_provider_t;
    539 
    540 
    541 // The buffer_config_s structure specifies the input or output audio format
    542 // to be used by the effect engine. It is part of the effect_config_t
    543 // structure that defines both input and output buffer configurations and is
    544 // passed by the EFFECT_CMD_CONFIGURE command.
    545 typedef struct buffer_config_s {
    546     audio_buffer_t  buffer;     // buffer for use by process() function if not passed explicitly
    547     uint32_t   samplingRate;    // sampling rate
    548     uint32_t   channels;        // channel mask (see audio_channels_e)
    549     buffer_provider_t bufferProvider;   // buffer provider
    550     uint8_t    format;          // Audio format  (see audio_format_e)
    551     uint8_t    accessMode;      // read/write or accumulate in buffer (effect_buffer_access_e)
    552     uint16_t   mask;            // indicates which of the above fields is valid
    553 } buffer_config_t;
    554 
    555 // Sample format
    556 enum audio_format_e {
    557     SAMPLE_FORMAT_PCM_S15,   // PCM signed 16 bits
    558     SAMPLE_FORMAT_PCM_U8,    // PCM unsigned 8 bits
    559     SAMPLE_FORMAT_PCM_S7_24, // PCM signed 7.24 fixed point representation
    560     SAMPLE_FORMAT_OTHER      // other format (e.g. compressed)
    561 };
    562 
    563 // Channel mask
    564 enum audio_channels_e {
    565     CHANNEL_FRONT_LEFT = 0x1,                   // front left channel
    566     CHANNEL_FRONT_RIGHT = 0x2,                  // front right channel
    567     CHANNEL_FRONT_CENTER = 0x4,                // front center channel
    568     CHANNEL_LOW_FREQUENCY = 0x8,               // low frequency channel
    569     CHANNEL_BACK_LEFT = 0x10,                   // back left channel
    570     CHANNEL_BACK_RIGHT = 0x20,                  // back right channel
    571     CHANNEL_FRONT_LEFT_OF_CENTER = 0x40,       // front left of center channel
    572     CHANNEL_FRONT_RIGHT_OF_CENTER = 0x80,      // front right of center channel
    573     CHANNEL_BACK_CENTER = 0x100,                // back center channel
    574     CHANNEL_MONO = CHANNEL_FRONT_LEFT,
    575     CHANNEL_STEREO = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT),
    576     CHANNEL_QUAD = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT |
    577             CHANNEL_BACK_LEFT | CHANNEL_BACK_RIGHT),
    578     CHANNEL_SURROUND = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT |
    579             CHANNEL_FRONT_CENTER | CHANNEL_BACK_CENTER),
    580     CHANNEL_5POINT1 = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT |
    581             CHANNEL_FRONT_CENTER | CHANNEL_LOW_FREQUENCY | CHANNEL_BACK_LEFT | CHANNEL_BACK_RIGHT),
    582     CHANNEL_7POINT1 = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT |
    583             CHANNEL_FRONT_CENTER | CHANNEL_LOW_FREQUENCY | CHANNEL_BACK_LEFT | CHANNEL_BACK_RIGHT |
    584             CHANNEL_FRONT_LEFT_OF_CENTER | CHANNEL_FRONT_RIGHT_OF_CENTER),
    585 };
    586 
    587 // Render device
    588 enum audio_device_e {
    589     DEVICE_EARPIECE = 0x1,                      // earpiece
    590     DEVICE_SPEAKER = 0x2,                       // speaker
    591     DEVICE_WIRED_HEADSET = 0x4,                 // wired headset, with microphone
    592     DEVICE_WIRED_HEADPHONE = 0x8,               // wired headphone, without microphone
    593     DEVICE_BLUETOOTH_SCO = 0x10,                // generic bluetooth SCO
    594     DEVICE_BLUETOOTH_SCO_HEADSET = 0x20,        // bluetooth SCO headset
    595     DEVICE_BLUETOOTH_SCO_CARKIT = 0x40,         // bluetooth SCO car kit
    596     DEVICE_BLUETOOTH_A2DP = 0x80,               // generic bluetooth A2DP
    597     DEVICE_BLUETOOTH_A2DP_HEADPHONES = 0x100,   // bluetooth A2DP headphones
    598     DEVICE_BLUETOOTH_A2DP_SPEAKER = 0x200,      // bluetooth A2DP speakers
    599     DEVICE_AUX_DIGITAL = 0x400,                 // digital output
    600     DEVICE_EXTERNAL_SPEAKER = 0x800             // external speaker (stereo and High quality)
    601 };
    602 
    603 // Audio mode
    604 enum audio_mode_e {
    605     AUDIO_MODE_NORMAL,      // phone idle
    606     AUDIO_MODE_RINGTONE,    // phone ringing
    607     AUDIO_MODE_IN_CALL      // phone call connected
    608 };
    609 
    610 // Values for "accessMode" field of buffer_config_t:
    611 //   overwrite, read only, accumulate (read/modify/write)
    612 enum effect_buffer_access_e {
    613     EFFECT_BUFFER_ACCESS_WRITE,
    614     EFFECT_BUFFER_ACCESS_READ,
    615     EFFECT_BUFFER_ACCESS_ACCUMULATE
    616 
    617 };
    618 
    619 // Values for bit field "mask" in buffer_config_t. If a bit is set, the corresponding field
    620 // in buffer_config_t must be taken into account when executing the EFFECT_CMD_CONFIGURE command
    621 #define EFFECT_CONFIG_BUFFER    0x0001  // buffer field must be taken into account
    622 #define EFFECT_CONFIG_SMP_RATE  0x0002  // samplingRate field must be taken into account
    623 #define EFFECT_CONFIG_CHANNELS  0x0004  // channels field must be taken into account
    624 #define EFFECT_CONFIG_FORMAT    0x0008  // format field must be taken into account
    625 #define EFFECT_CONFIG_ACC_MODE  0x0010  // accessMode field must be taken into account
    626 #define EFFECT_CONFIG_PROVIDER  0x0020  // bufferProvider field must be taken into account
    627 #define EFFECT_CONFIG_ALL (EFFECT_CONFIG_BUFFER | EFFECT_CONFIG_SMP_RATE | \
    628                            EFFECT_CONFIG_CHANNELS | EFFECT_CONFIG_FORMAT | \
    629                            EFFECT_CONFIG_ACC_MODE | EFFECT_CONFIG_PROVIDER)
    630 
    631 
    632 // effect_config_s structure describes the format of the pCmdData argument of EFFECT_CMD_CONFIGURE
    633 // command to configure audio parameters and buffers for effect engine input and output.
    634 typedef struct effect_config_s {
    635     buffer_config_t   inputCfg;
    636     buffer_config_t   outputCfg;;
    637 } effect_config_t;
    638 
    639 
    640 // effect_param_s structure describes the format of the pCmdData argument of EFFECT_CMD_SET_PARAM
    641 // command and pCmdData and pReplyData of EFFECT_CMD_GET_PARAM command.
    642 // psize and vsize represent the actual size of parameter and value.
    643 //
    644 // NOTE: the start of value field inside the data field is always on a 32 bit boundary:
    645 //
    646 //  +-----------+
    647 //  | status    | sizeof(int)
    648 //  +-----------+
    649 //  | psize     | sizeof(int)
    650 //  +-----------+
    651 //  | vsize     | sizeof(int)
    652 //  +-----------+
    653 //  |           |   |           |
    654 //  ~ parameter ~   > psize     |
    655 //  |           |   |           >  ((psize - 1)/sizeof(int) + 1) * sizeof(int)
    656 //  +-----------+               |
    657 //  | padding   |               |
    658 //  +-----------+
    659 //  |           |   |
    660 //  ~ value     ~   > vsize
    661 //  |           |   |
    662 //  +-----------+
    663 
    664 typedef struct effect_param_s {
    665     int32_t     status;     // Transaction status (unused for command, used for reply)
    666     uint32_t    psize;      // Parameter size
    667     uint32_t    vsize;      // Value size
    668     char        data[];     // Start of Parameter + Value data
    669 } effect_param_t;
    670 
    671 
    672 /////////////////////////////////////////////////
    673 //      Effect library interface
    674 /////////////////////////////////////////////////
    675 
    676 // An effect library is required to implement and expose the following functions
    677 // to enable effect enumeration and instantiation. The name of these functions must be as
    678 // specified here as the effect framework will get the function address with dlsym():
    679 //
    680 // - effect_QueryNumberEffects_t EffectQueryNumberEffects;
    681 // - effect_QueryEffect_t EffectQueryEffect;
    682 // - effect_CreateEffect_t EffectCreate;
    683 // - effect_ReleaseEffect_t EffectRelease;
    684 
    685 
    686 ////////////////////////////////////////////////////////////////////////////////
    687 //
    688 //    Function:       EffectQueryNumberEffects
    689 //
    690 //    Description:    Returns the number of different effects exposed by the
    691 //          library. Each effect must have a unique effect uuid (see
    692 //          effect_descriptor_t). This function together with EffectQueryEffect()
    693 //          is used to enumerate all effects present in the library.
    694 //
    695 //    Input/Output:
    696 //          pNumEffects:    address where the number of effects should be returned.
    697 //
    698 //    Output:
    699 //        returned value:    0          successful operation.
    700 //                          -ENODEV     library failed to initialize
    701 //                          -EINVAL     invalid pNumEffects
    702 //        *pNumEffects:     updated with number of effects in library
    703 //
    704 ////////////////////////////////////////////////////////////////////////////////
    705 typedef int32_t (*effect_QueryNumberEffects_t)(uint32_t *pNumEffects);
    706 
    707 ////////////////////////////////////////////////////////////////////////////////
    708 //
    709 //    Function:       EffectQueryEffect
    710 //
    711 //    Description:    Returns the descriptor of the effect engine which index is
    712 //          given as first argument.
    713 //          See effect_descriptor_t for details on effect descriptors.
    714 //          This function together with EffectQueryNumberEffects() is used to enumerate all
    715 //          effects present in the library. The enumeration sequence is:
    716 //              EffectQueryNumberEffects(&num_effects);
    717 //              for (i = 0; i < num_effects; i++)
    718 //                  EffectQueryEffect(i,...);
    719 //
    720 //    Input/Output:
    721 //          index:          index of the effect
    722 //          pDescriptor:    address where to return the effect descriptor.
    723 //
    724 //    Output:
    725 //        returned value:    0          successful operation.
    726 //                          -ENODEV     library failed to initialize
    727 //                          -EINVAL     invalid pDescriptor or index
    728 //                          -ENOSYS     effect list has changed since last execution of
    729 //                                      EffectQueryNumberEffects()
    730 //                          -ENOENT     no more effect available
    731 //        *pDescriptor:     updated with the effect descriptor.
    732 //
    733 ////////////////////////////////////////////////////////////////////////////////
    734 typedef int32_t (*effect_QueryEffect_t)(uint32_t index,
    735                                         effect_descriptor_t *pDescriptor);
    736 
    737 ////////////////////////////////////////////////////////////////////////////////
    738 //
    739 //    Function:       EffectCreate
    740 //
    741 //    Description:    Creates an effect engine of the specified type and returns an
    742 //          effect control interface on this engine. The function will allocate the
    743 //          resources for an instance of the requested effect engine and return
    744 //          a handle on the effect control interface.
    745 //
    746 //    Input:
    747 //          uuid:    pointer to the effect uuid.
    748 //          sessionId:  audio session to which this effect instance will be attached. All effects
    749 //              created with the same session ID are connected in series and process the same signal
    750 //              stream. Knowing that two effects are part of the same effect chain can help the
    751 //              library implement some kind of optimizations.
    752 //          ioId:   identifies the output or input stream this effect is directed to at audio HAL.
    753 //              For future use especially with tunneled HW accelerated effects
    754 //
    755 //    Input/Output:
    756 //          pInterface:    address where to return the effect interface.
    757 //
    758 //    Output:
    759 //        returned value:    0          successful operation.
    760 //                          -ENODEV     library failed to initialize
    761 //                          -EINVAL     invalid pEffectUuid or pInterface
    762 //                          -ENOENT     no effect with this uuid found
    763 //        *pInterface:     updated with the effect interface handle.
    764 //
    765 ////////////////////////////////////////////////////////////////////////////////
    766 typedef int32_t (*effect_CreateEffect_t)(effect_uuid_t *uuid,
    767                                          int32_t sessionId,
    768                                          int32_t ioId,
    769                                          effect_interface_t *pInterface);
    770 
    771 ////////////////////////////////////////////////////////////////////////////////
    772 //
    773 //    Function:       EffectRelease
    774 //
    775 //    Description:    Releases the effect engine whose handle is given as argument.
    776 //          All resources allocated to this particular instance of the effect are
    777 //          released.
    778 //
    779 //    Input:
    780 //          interface:    handle on the effect interface to be released.
    781 //
    782 //    Output:
    783 //        returned value:    0          successful operation.
    784 //                          -ENODEV     library failed to initialize
    785 //                          -EINVAL     invalid interface handle
    786 //
    787 ////////////////////////////////////////////////////////////////////////////////
    788 typedef int32_t (*effect_ReleaseEffect_t)(effect_interface_t interface);
    789 
    790 
    791 #if __cplusplus
    792 }  // extern "C"
    793 #endif
    794 
    795 
    796 #endif /*ANDROID_EFFECTAPI_H_*/
    797