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 /*

  * Copyright (C) 2010 The Android Open Source Project

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *      http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 #ifndef ANDROID_EFFECTAPI_H_

 #define ANDROID_EFFECTAPI_H_

 #include <errno.h>

 #include <stdint.h>

 #include <sys/types.h>

 #if __cplusplus

 extern "C" {

 #endif

 /////////////////////////////////////////////////

 //      Effect control interface

 /////////////////////////////////////////////////

 // The effect control interface is exposed by each effect engine implementation. It consists of

 // a set of functions controlling the configuration, activation and process of the engine.

 // The functions are grouped in a structure of type effect_interface_s:

 //    struct effect_interface_s {

 //        effect_process_t process;

 //        effect_command_t command;

 //    };

 // effect_interface_t: Effect control interface handle.

 // The effect_interface_t serves two purposes regarding the implementation of the effect engine:

 // - 1 it is the address of a pointer to an effect_interface_s structure where the functions

 // of the effect control API for a particular effect are located.

 // - 2 it is the address of the context of a particular effect instance.

 // A typical implementation in the effect library would define a structure as follows:

 // struct effect_module_s {

 //        const struct effect_interface_s *itfe;

 //        effect_config_t config;

 //        effect_context_t context;

 // }

 // The implementation of EffectCreate() function would then allocate a structure of this

 // type and return its address as effect_interface_t

 typedef struct effect_interface_s **effect_interface_t;

 // Effect API version 1.0

 #define EFFECT_API_VERSION 0x0100 // Format 0xMMmm MM: Major version, mm: minor version

 // Maximum length of character strings in structures defines by this API.

 #define EFFECT_STRING_LEN_MAX 64

 //

 //--- Effect descriptor structure effect_descriptor_t

 //

 // Unique effect ID (can be generated from the following site:

 //  http://www.itu.int/ITU-T/asn1/uuid.html)

 // This format is used for both "type" and "uuid" fields of the effect descriptor structure.

 // - When used for effect type and the engine is implementing and effect corresponding to a standard

 // OpenSL ES interface, this ID must be the one defined in OpenSLES_IID.h for that interface.

 // - When used as uuid, it should be a unique UUID for this particular implementation.

 typedef struct effect_uuid_s {

     uint32_t timeLow;

     uint16_t timeMid;

     uint16_t timeHiAndVersion;

     uint16_t clockSeq;

     uint8_t node[6];

 } effect_uuid_t;

 // NULL UUID definition (matches SL_IID_NULL_)

 #define EFFECT_UUID_INITIALIZER { 0xec7178ec, 0xe5e1, 0x4432, 0xa3f4, \

                                   { 0x46, 0x57, 0xe6, 0x79, 0x52, 0x10 } }

 static const effect_uuid_t EFFECT_UUID_NULL_ = EFFECT_UUID_INITIALIZER;

 const effect_uuid_t * const EFFECT_UUID_NULL = &EFFECT_UUID_NULL_;

 const char * const EFFECT_UUID_NULL_STR = "ec7178ec-e5e1-4432-a3f4-4657e6795210";

 // The effect descriptor contains necessary information to facilitate the enumeration of the effect

 // engines present in a library.

 typedef struct effect_descriptor_s {

     effect_uuid_t type;     // UUID of to the OpenSL ES interface implemented by this effect

     effect_uuid_t uuid;     // UUID for this particular implementation

     uint16_t apiVersion;    // Version of the effect API implemented: matches EFFECT_API_VERSION

     uint32_t flags;         // effect engine capabilities/requirements flags (see below)

     uint16_t cpuLoad;       // CPU load indication (see below)

     uint16_t memoryUsage;   // Data Memory usage (see below)

     char    name[EFFECT_STRING_LEN_MAX];   // human readable effect name

     char    implementor[EFFECT_STRING_LEN_MAX];    // human readable effect implementor name

 } effect_descriptor_t;

 // CPU load and memory usage indication: each effect implementation must provide an indication of

 // its CPU and memory usage for the audio effect framework to limit the number of effects

 // instantiated at a given time on a given platform.

 // The CPU load is expressed in 0.1 MIPS units as estimated on an ARM9E core (ARMv5TE) with 0 WS.

 // The memory usage is expressed in KB and includes only dynamically allocated memory

 // Definitions for flags field of effect descriptor.

 //  +---------------------------+-----------+-----------------------------------

 //  | description               | bits      | values

 //  +---------------------------+-----------+-----------------------------------

 //  | connection mode           | 0..1      | 0 insert: after track process

 //  |                           |           | 1 auxiliary: connect to track auxiliary

 //  |                           |           |  output and use send level

 //  |                           |           | 2 replace: replaces track process function;

 //  |                           |           |   must implement SRC, volume and mono to stereo.

 //  |                           |           | 3 reserved

 //  +---------------------------+-----------+-----------------------------------

 //  | insertion preference      | 2..4      | 0 none

 //  |                           |           | 1 first of the chain

 //  |                           |           | 2 last of the chain

 //  |                           |           | 3 exclusive (only effect in the insert chain)

 //  |                           |           | 4..7 reserved

 //  +---------------------------+-----------+-----------------------------------

 //  | Volume management         | 5..6      | 0 none

 //  |                           |           | 1 implements volume control

 //  |                           |           | 2 requires volume indication

 //  |                           |           | 3 reserved

 //  +---------------------------+-----------+-----------------------------------

 //  | Device indication         | 7..8      | 0 none

 //  |                           |           | 1 requires device updates

 //  |                           |           | 2..3 reserved

 //  +---------------------------+-----------+-----------------------------------

 //  | Sample input mode         | 9..10     | 0 direct: process() function or EFFECT_CMD_CONFIGURE

 //  |                           |           |   command must specify a buffer descriptor

 //  |                           |           | 1 provider: process() function uses the

 //  |                           |           |   bufferProvider indicated by the

 //  |                           |           |   EFFECT_CMD_CONFIGURE command to request input.

 //  |                           |           |   buffers.

 //  |                           |           | 2 both: both input modes are supported

 //  |                           |           | 3 reserved

 //  +---------------------------+-----------+-----------------------------------

 //  | Sample output mode        | 11..12    | 0 direct: process() function or EFFECT_CMD_CONFIGURE

 //  |                           |           |   command must specify a buffer descriptor

 //  |                           |           | 1 provider: process() function uses the

 //  |                           |           |   bufferProvider indicated by the

 //  |                           |           |   EFFECT_CMD_CONFIGURE command to request output

 //  |                           |           |   buffers.

 //  |                           |           | 2 both: both output modes are supported

 //  |                           |           | 3 reserved

 //  +---------------------------+-----------+-----------------------------------

 //  | Hardware acceleration     | 13..15    | 0 No hardware acceleration

 //  |                           |           | 1 non tunneled hw acceleration: the process() function

 //  |                           |           |   reads the samples, send them to HW accelerated

 //  |                           |           |   effect processor, reads back the processed samples

 //  |                           |           |   and returns them to the output buffer.

 //  |                           |           | 2 tunneled hw acceleration: the process() function is

 //  |                           |           |   transparent. The effect interface is only used to

 //  |                           |           |   control the effect engine. This mode is relevant for

 //  |                           |           |   global effects actually applied by the audio

 //  |                           |           |   hardware on the output stream.

 //  +---------------------------+-----------+-----------------------------------

 //  | Audio Mode indication     | 16..17    | 0 none

 //  |                           |           | 1 requires audio mode updates

 //  |                           |           | 2..3 reserved

 //  +---------------------------+-----------+-----------------------------------

 // Insert mode

 #define EFFECT_FLAG_TYPE_MASK           0x00000003

 #define EFFECT_FLAG_TYPE_INSERT         0x00000000

 #define EFFECT_FLAG_TYPE_AUXILIARY      0x00000001

 #define EFFECT_FLAG_TYPE_REPLACE        0x00000002

 // Insert preference

 #define EFFECT_FLAG_INSERT_MASK         0x0000001C

 #define EFFECT_FLAG_INSERT_ANY          0x00000000

 #define EFFECT_FLAG_INSERT_FIRST        0x00000004

 #define EFFECT_FLAG_INSERT_LAST         0x00000008

 #define EFFECT_FLAG_INSERT_EXCLUSIVE    0x0000000C

 // Volume control

 #define EFFECT_FLAG_VOLUME_MASK         0x00000060

 #define EFFECT_FLAG_VOLUME_CTRL         0x00000020

 #define EFFECT_FLAG_VOLUME_IND          0x00000040

 #define EFFECT_FLAG_VOLUME_NONE         0x00000000

 // Device indication

 #define EFFECT_FLAG_DEVICE_MASK         0x00000180

 #define EFFECT_FLAG_DEVICE_IND          0x00000080

 #define EFFECT_FLAG_DEVICE_NONE         0x00000000

 // Sample input modes

 #define EFFECT_FLAG_INPUT_MASK          0x00000600

 #define EFFECT_FLAG_INPUT_DIRECT        0x00000000

 #define EFFECT_FLAG_INPUT_PROVIDER      0x00000200

 #define EFFECT_FLAG_INPUT_BOTH          0x00000400

 // Sample output modes

 #define EFFECT_FLAG_OUTPUT_MASK          0x00001800

 #define EFFECT_FLAG_OUTPUT_DIRECT        0x00000000

 #define EFFECT_FLAG_OUTPUT_PROVIDER      0x00000800

 #define EFFECT_FLAG_OUTPUT_BOTH          0x00001000

 // Hardware acceleration mode

 #define EFFECT_FLAG_HW_ACC_MASK          0x00006000

 #define EFFECT_FLAG_HW_ACC_SIMPLE        0x00002000

 #define EFFECT_FLAG_HW_ACC_TUNNEL        0x00004000

 // Audio mode indication

 #define EFFECT_FLAG_AUDIO_MODE_MASK      0x00018000

 #define EFFECT_FLAG_AUDIO_MODE_IND       0x00008000

 #define EFFECT_FLAG_AUDIO_MODE_NONE      0x00000000

 // Forward definition of type audio_buffer_t

 typedef struct audio_buffer_s audio_buffer_t;

 ////////////////////////////////////////////////////////////////////////////////

 //

 //    Function:       process

 //

 //    Description:    Effect process function. Takes input samples as specified

 //          (count and location) in input buffer descriptor and output processed

 //          samples as specified in output buffer descriptor. If the buffer descriptor

 //          is not specified the function must use either the buffer or the

 //          buffer provider function installed by the EFFECT_CMD_CONFIGURE command.

 //          The effect framework will call the process() function after the EFFECT_CMD_ENABLE

 //          command is received and until the EFFECT_CMD_DISABLE is received. When the engine

 //          receives the EFFECT_CMD_DISABLE command it should turn off the effect gracefully

 //          and when done indicate that it is OK to stop calling the process() function by

 //          returning the -ENODATA status.

 //

 //    NOTE: the process() function implementation should be "real-time safe" that is

 //      it should not perform blocking calls: malloc/free, sleep, read/write/open/close,

 //      pthread_cond_wait/pthread_mutex_lock...

 //

 //    Input:

 //          effect_interface_t: handle to the effect interface this function

 //              is called on.

 //          inBuffer:   buffer descriptor indicating where to read samples to process.

 //              If NULL, use the configuration passed by EFFECT_CMD_CONFIGURE command.

 //

 //          inBuffer:   buffer descriptor indicating where to write processed samples.

 //              If NULL, use the configuration passed by EFFECT_CMD_CONFIGURE command.

 //

 //    Output:

 //        returned value:    0 successful operation

 //                          -ENODATA the engine has finished the disable phase and the framework

 //                                  can stop calling process()

 //                          -EINVAL invalid interface handle or

 //                                  invalid input/output buffer description

 ////////////////////////////////////////////////////////////////////////////////

 typedef int32_t (*effect_process_t)(effect_interface_t self,

                                     audio_buffer_t *inBuffer,

                                     audio_buffer_t *outBuffer);

 ////////////////////////////////////////////////////////////////////////////////

 //

 //    Function:       command

 //

 //    Description:    Send a command and receive a response to/from effect engine.

 //

 //    Input:

 //          effect_interface_t: handle to the effect interface this function

 //              is called on.

 //          cmdCode:    command code: the command can be a standardized command defined in

 //              effect_command_e (see below) or a proprietary command.

 //          cmdSize:    size of command in bytes

 //          pCmdData:   pointer to command data

 //          pReplyData: pointer to reply data

 //

 //    Input/Output:

 //          replySize: maximum size of reply data as input

 //                      actual size of reply data as output

 //

 //    Output:

 //          returned value: 0       successful operation

 //                          -EINVAL invalid interface handle or

 //                                  invalid command/reply size or format according to command code

 //              The return code should be restricted to indicate problems related to the this

 //              API specification. Status related to the execution of a particular command should be

 //              indicated as part of the reply field.

 //

 //          *pReplyData updated with command response

 //

 ////////////////////////////////////////////////////////////////////////////////

 typedef int32_t (*effect_command_t)(effect_interface_t self,

                                     uint32_t cmdCode,

                                     uint32_t cmdSize,

                                     void *pCmdData,

                                     uint32_t *replySize,

                                     void *pReplyData);

 // Effect control interface definition

 struct effect_interface_s {

     effect_process_t process;

     effect_command_t command;

 };

 //

 //--- Standardized command codes for command() function

 //

 enum effect_command_e {

    EFFECT_CMD_INIT,                 // initialize effect engine

    EFFECT_CMD_CONFIGURE,            // configure effect engine (see effect_config_t)

    EFFECT_CMD_RESET,                // reset effect engine

    EFFECT_CMD_ENABLE,               // enable effect process

    EFFECT_CMD_DISABLE,              // disable effect process

    EFFECT_CMD_SET_PARAM,            // set parameter immediately (see effect_param_t)

    EFFECT_CMD_SET_PARAM_DEFERRED,   // set parameter deferred

    EFFECT_CMD_SET_PARAM_COMMIT,     // commit previous set parameter deferred

    EFFECT_CMD_GET_PARAM,            // get parameter

    EFFECT_CMD_SET_DEVICE,           // set audio device (see audio_device_e)

    EFFECT_CMD_SET_VOLUME,           // set volume

    EFFECT_CMD_SET_AUDIO_MODE,       // set the audio mode (normal, ring, ...)

    EFFECT_CMD_FIRST_PROPRIETARY = 0x10000 // first proprietary command code

 };

 //==================================================================================================

 // command: EFFECT_CMD_INIT

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Initialize effect engine: All configurations return to default

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: 0

 //  data: N/A

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: sizeof(int)

 //  data: status

 //==================================================================================================

 // command: EFFECT_CMD_CONFIGURE

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Apply new audio parameters configurations for input and output buffers

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: sizeof(effect_config_t)

 //  data: effect_config_t

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: sizeof(int)

 //  data: status

 //==================================================================================================

 // command: EFFECT_CMD_RESET

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Reset the effect engine. Keep configuration but resets state and buffer content

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: 0

 //  data: N/A

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: 0

 //  data: N/A

 //==================================================================================================

 // command: EFFECT_CMD_ENABLE

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Enable the process. Called by the framework before the first call to process()

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: 0

 //  data: N/A

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: sizeof(int)

 //  data: status

 //==================================================================================================

 // command: EFFECT_CMD_DISABLE

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Disable the process. Called by the framework after the last call to process()

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: 0

 //  data: N/A

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: sizeof(int)

 //  data: status

 //==================================================================================================

 // command: EFFECT_CMD_SET_PARAM

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Set a parameter and apply it immediately

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: sizeof(effect_param_t) + size of param and value

 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: sizeof(int)

 //  data: status

 //==================================================================================================

 // command: EFFECT_CMD_SET_PARAM_DEFERRED

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Set a parameter but apply it only when receiving EFFECT_CMD_SET_PARAM_COMMIT command

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: sizeof(effect_param_t) + size of param and value

 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: 0

 //  data: N/A

 //==================================================================================================

 // command: EFFECT_CMD_SET_PARAM_COMMIT

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Apply all previously received EFFECT_CMD_SET_PARAM_DEFERRED commands

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: 0

 //  data: N/A

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: sizeof(int)

 //  data: status

 //==================================================================================================

 // command: EFFECT_CMD_GET_PARAM

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Get a parameter value

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: sizeof(effect_param_t) + size of param

 //  data: effect_param_t + param

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: sizeof(effect_param_t) + size of param and value

 //  data: effect_param_t + param + value. See effect_param_t definition below for value offset

 //==================================================================================================

 // command: EFFECT_CMD_SET_DEVICE

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Set the rendering device the audio output path is connected to. See audio_device_e for device

 //  values.

 //  The effect implementation must set EFFECT_FLAG_DEVICE_IND flag in its descriptor to receive this

 //  command when the device changes

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: sizeof(uint32_t)

 //  data: audio_device_e

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: 0

 //  data: N/A

 //==================================================================================================

 // command: EFFECT_CMD_SET_VOLUME

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Set and get volume. Used by audio framework to delegate volume control to effect engine.

 //  The effect implementation must set EFFECT_FLAG_VOLUME_IND or EFFECT_FLAG_VOLUME_CTRL flag in

 //  its descriptor to receive this command before every call to process() function

 //  If EFFECT_FLAG_VOLUME_CTRL flag is set in the effect descriptor, the effect engine must return

 //  the volume that should be applied before the effect is processed. The overall volume (the volume

 //  actually applied by the effect engine multiplied by the returned value) should match the value

 //  indicated in the command.

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: n * sizeof(uint32_t)

 //  data: volume for each channel defined in effect_config_t for output buffer expressed in

 //      8.24 fixed point format

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: n * sizeof(uint32_t) / 0

 //  data: - if EFFECT_FLAG_VOLUME_CTRL is set in effect descriptor:

 //              volume for each channel defined in effect_config_t for output buffer expressed in

 //              8.24 fixed point format

 //        - if EFFECT_FLAG_VOLUME_CTRL is not set in effect descriptor:

 //              N/A

 //  It is legal to receive a null pointer as pReplyData in which case the effect framework has

 //  delegated volume control to another effect

 //==================================================================================================

 // command: EFFECT_CMD_SET_AUDIO_MODE

 //--------------------------------------------------------------------------------------------------

 // description:

 //  Set the audio mode. The effect implementation must set EFFECT_FLAG_AUDIO_MODE_IND flag in its

 //  descriptor to receive this command when the audio mode changes.

 //--------------------------------------------------------------------------------------------------

 // command format:

 //  size: sizeof(uint32_t)

 //  data: audio_mode_e

 //--------------------------------------------------------------------------------------------------

 // reply format:

 //  size: 0

 //  data: N/A

 //==================================================================================================

 // command: EFFECT_CMD_FIRST_PROPRIETARY

 //--------------------------------------------------------------------------------------------------

 // description:

 //  All proprietary effect commands must use command codes above this value. The size and format of

 //  command and response fields is free in this case

 //==================================================================================================

 // Audio buffer descriptor used by process(), bufferProvider() functions and buffer_config_t

 // structure. Multi-channel audio is always interleaved. The channel order is from LSB to MSB with

 // regard to the channel mask definition in audio_channels_e e.g :

 // Stereo: left, right

 // 5 point 1: front left, front right, front center, low frequency, back left, back right

 // The buffer size is expressed in frame count, a frame being composed of samples for all

 // channels at a given time. Frame size for unspecified format (AUDIO_FORMAT_OTHER) is 8 bit by

 // definition

 struct audio_buffer_s {

     size_t   frameCount;        // number of frames in buffer

     union {

         void*       raw;        // raw pointer to start of buffer

         int32_t*    s32;        // pointer to signed 32 bit data at start of buffer

         int16_t*    s16;        // pointer to signed 16 bit data at start of buffer

         uint8_t*    u8;         // pointer to unsigned 8 bit data at start of buffer

     };

 };

 // The buffer_provider_s structure contains functions that can be used

 // by the effect engine process() function to query and release input

 // or output audio buffer.

 // The getBuffer() function is called to retrieve a buffer where data

 // should read from or written to by process() function.

 // The releaseBuffer() function MUST be called when the buffer retrieved

 // with getBuffer() is not needed anymore.

 // The process function should use the buffer provider mechanism to retrieve

 // input or output buffer if the inBuffer or outBuffer passed as argument is NULL

 // and the buffer configuration (buffer_config_t) given by the EFFECT_CMD_CONFIGURE

 // command did not specify an audio buffer.

 typedef int32_t (* buffer_function_t)(void *cookie, audio_buffer_t *buffer);

 typedef struct buffer_provider_s {

     buffer_function_t getBuffer;       // retrieve next buffer

     buffer_function_t releaseBuffer;   // release used buffer

     void       *cookie;                // for use by client of buffer provider functions

 } buffer_provider_t;

 // The buffer_config_s structure specifies the input or output audio format

 // to be used by the effect engine. It is part of the effect_config_t

 // structure that defines both input and output buffer configurations and is

 // passed by the EFFECT_CMD_CONFIGURE command.

 typedef struct buffer_config_s {

     audio_buffer_t  buffer;     // buffer for use by process() function if not passed explicitly

     uint32_t   samplingRate;    // sampling rate

     uint32_t   channels;        // channel mask (see audio_channels_e)

     buffer_provider_t bufferProvider;   // buffer provider

     uint8_t    format;          // Audio format  (see audio_format_e)

     uint8_t    accessMode;      // read/write or accumulate in buffer (effect_buffer_access_e)

     uint16_t   mask;            // indicates which of the above fields is valid

 } buffer_config_t;

 // Sample format

 enum audio_format_e {

     SAMPLE_FORMAT_PCM_S15,   // PCM signed 16 bits

     SAMPLE_FORMAT_PCM_U8,    // PCM unsigned 8 bits

     SAMPLE_FORMAT_PCM_S7_24, // PCM signed 7.24 fixed point representation

     SAMPLE_FORMAT_OTHER      // other format (e.g. compressed)

 };

 // Channel mask

 enum audio_channels_e {

     CHANNEL_FRONT_LEFT = 0x1,                   // front left channel

     CHANNEL_FRONT_RIGHT = 0x2,                  // front right channel

     CHANNEL_FRONT_CENTER = 0x4,                // front center channel

     CHANNEL_LOW_FREQUENCY = 0x8,               // low frequency channel

     CHANNEL_BACK_LEFT = 0x10,                   // back left channel

     CHANNEL_BACK_RIGHT = 0x20,                  // back right channel

     CHANNEL_FRONT_LEFT_OF_CENTER = 0x40,       // front left of center channel

     CHANNEL_FRONT_RIGHT_OF_CENTER = 0x80,      // front right of center channel

     CHANNEL_BACK_CENTER = 0x100,                // back center channel

     CHANNEL_MONO = CHANNEL_FRONT_LEFT,

     CHANNEL_STEREO = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT),

     CHANNEL_QUAD = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT |

             CHANNEL_BACK_LEFT | CHANNEL_BACK_RIGHT),

     CHANNEL_SURROUND = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT |

             CHANNEL_FRONT_CENTER | CHANNEL_BACK_CENTER),

     CHANNEL_5POINT1 = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT |

             CHANNEL_FRONT_CENTER | CHANNEL_LOW_FREQUENCY | CHANNEL_BACK_LEFT | CHANNEL_BACK_RIGHT),

     CHANNEL_7POINT1 = (CHANNEL_FRONT_LEFT | CHANNEL_FRONT_RIGHT |

             CHANNEL_FRONT_CENTER | CHANNEL_LOW_FREQUENCY | CHANNEL_BACK_LEFT | CHANNEL_BACK_RIGHT |

             CHANNEL_FRONT_LEFT_OF_CENTER | CHANNEL_FRONT_RIGHT_OF_CENTER),

 };

 // Render device

 enum audio_device_e {

     DEVICE_EARPIECE = 0x1,                      // earpiece

     DEVICE_SPEAKER = 0x2,                       // speaker

     DEVICE_WIRED_HEADSET = 0x4,                 // wired headset, with microphone

     DEVICE_WIRED_HEADPHONE = 0x8,               // wired headphone, without microphone

     DEVICE_BLUETOOTH_SCO = 0x10,                // generic bluetooth SCO

     DEVICE_BLUETOOTH_SCO_HEADSET = 0x20,        // bluetooth SCO headset

     DEVICE_BLUETOOTH_SCO_CARKIT = 0x40,         // bluetooth SCO car kit

     DEVICE_BLUETOOTH_A2DP = 0x80,               // generic bluetooth A2DP

     DEVICE_BLUETOOTH_A2DP_HEADPHONES = 0x100,   // bluetooth A2DP headphones

     DEVICE_BLUETOOTH_A2DP_SPEAKER = 0x200,      // bluetooth A2DP speakers

     DEVICE_AUX_DIGITAL = 0x400,                 // digital output

     DEVICE_EXTERNAL_SPEAKER = 0x800             // external speaker (stereo and High quality)

 };

 #if ANDROID_VERSION < 17

 // Audio mode

 enum audio_mode_e {

     AUDIO_MODE_NORMAL,      // device idle

     AUDIO_MODE_RINGTONE,    // device ringing

     AUDIO_MODE_IN_CALL      // audio call connected (VoIP or telephony)

 };

 #endif

 // Values for "accessMode" field of buffer_config_t:

 //   overwrite, read only, accumulate (read/modify/write)

 enum effect_buffer_access_e {

     EFFECT_BUFFER_ACCESS_WRITE,

     EFFECT_BUFFER_ACCESS_READ,

     EFFECT_BUFFER_ACCESS_ACCUMULATE

 };

 // Values for bit field "mask" in buffer_config_t. If a bit is set, the corresponding field

 // in buffer_config_t must be taken into account when executing the EFFECT_CMD_CONFIGURE command

 #define EFFECT_CONFIG_BUFFER    0x0001  // buffer field must be taken into account

 #define EFFECT_CONFIG_SMP_RATE  0x0002  // samplingRate field must be taken into account

 #define EFFECT_CONFIG_CHANNELS  0x0004  // channels field must be taken into account

 #define EFFECT_CONFIG_FORMAT    0x0008  // format field must be taken into account

 #define EFFECT_CONFIG_ACC_MODE  0x0010  // accessMode field must be taken into account

 #define EFFECT_CONFIG_PROVIDER  0x0020  // bufferProvider field must be taken into account

 #define EFFECT_CONFIG_ALL (EFFECT_CONFIG_BUFFER | EFFECT_CONFIG_SMP_RATE | \

                            EFFECT_CONFIG_CHANNELS | EFFECT_CONFIG_FORMAT | \

                            EFFECT_CONFIG_ACC_MODE | EFFECT_CONFIG_PROVIDER)

 // effect_config_s structure describes the format of the pCmdData argument of EFFECT_CMD_CONFIGURE

 // command to configure audio parameters and buffers for effect engine input and output.

 typedef struct effect_config_s {

     buffer_config_t   inputCfg;

     buffer_config_t   outputCfg;;

 } effect_config_t;

 // effect_param_s structure describes the format of the pCmdData argument of EFFECT_CMD_SET_PARAM

 // command and pCmdData and pReplyData of EFFECT_CMD_GET_PARAM command.

 // psize and vsize represent the actual size of parameter and value.

 //

 // NOTE: the start of value field inside the data field is always on a 32 bit boundary:

 //

 //  +-----------+

 //  | status    | sizeof(int)

 //  +-----------+

 //  | psize     | sizeof(int)

 //  +-----------+

 //  | vsize     | sizeof(int)

 //  +-----------+

 //  |           |   |           |

 //  ~ parameter ~   > psize     |

 //  |           |   |           >  ((psize - 1)/sizeof(int) + 1) * sizeof(int)

 //  +-----------+               |

 //  | padding   |               |

 //  +-----------+

 //  |           |   |

 //  ~ value     ~   > vsize

 //  |           |   |

 //  +-----------+

 typedef struct effect_param_s {

     int32_t     status;     // Transaction status (unused for command, used for reply)

     uint32_t    psize;      // Parameter size

     uint32_t    vsize;      // Value size

     char        data[];     // Start of Parameter + Value data

 } effect_param_t;

 /////////////////////////////////////////////////

 //      Effect library interface

 /////////////////////////////////////////////////

 // An effect library is required to implement and expose the following functions

 // to enable effect enumeration and instantiation. The name of these functions must be as

 // specified here as the effect framework will get the function address with dlsym():

 //

 // - effect_QueryNumberEffects_t EffectQueryNumberEffects;

 // - effect_QueryEffect_t EffectQueryEffect;

 // - effect_CreateEffect_t EffectCreate;

 // - effect_ReleaseEffect_t EffectRelease;

 ////////////////////////////////////////////////////////////////////////////////

 //

 //    Function:       EffectQueryNumberEffects

 //

 //    Description:    Returns the number of different effects exposed by the

 //          library. Each effect must have a unique effect uuid (see

 //          effect_descriptor_t). This function together with EffectQueryEffect()

 //          is used to enumerate all effects present in the library.

 //

 //    Input/Output:

 //          pNumEffects:    address where the number of effects should be returned.

 //

 //    Output:

 //        returned value:    0          successful operation.

 //                          -ENODEV     library failed to initialize

 //                          -EINVAL     invalid pNumEffects

 //        *pNumEffects:     updated with number of effects in library

 //

 ////////////////////////////////////////////////////////////////////////////////

 typedef int32_t (*effect_QueryNumberEffects_t)(uint32_t *pNumEffects);

 ////////////////////////////////////////////////////////////////////////////////

 //

 //    Function:       EffectQueryEffect

 //

 //    Description:    Returns the descriptor of the effect engine which index is

 //          given as first argument.

 //          See effect_descriptor_t for details on effect descriptors.

 //          This function together with EffectQueryNumberEffects() is used to enumerate all

 //          effects present in the library. The enumeration sequence is:

 //              EffectQueryNumberEffects(&num_effects);

 //              for (i = 0; i < num_effects; i++)

 //                  EffectQueryEffect(i,...);

 //

 //    Input/Output:

 //          index:          index of the effect

 //          pDescriptor:    address where to return the effect descriptor.

 //

 //    Output:

 //        returned value:    0          successful operation.

 //                          -ENODEV     library failed to initialize

 //                          -EINVAL     invalid pDescriptor or index

 //                          -ENOSYS     effect list has changed since last execution of

 //                                      EffectQueryNumberEffects()

 //                          -ENOENT     no more effect available

 //        *pDescriptor:     updated with the effect descriptor.

 //

 ////////////////////////////////////////////////////////////////////////////////

 typedef int32_t (*effect_QueryEffect_t)(uint32_t index,

                                         effect_descriptor_t *pDescriptor);

 ////////////////////////////////////////////////////////////////////////////////

 //

 //    Function:       EffectCreate

 //

 //    Description:    Creates an effect engine of the specified type and returns an

 //          effect control interface on this engine. The function will allocate the

 //          resources for an instance of the requested effect engine and return

 //          a handle on the effect control interface.

 //

 //    Input:

 //          uuid:    pointer to the effect uuid.

 //          sessionId:  audio session to which this effect instance will be attached. All effects

 //              created with the same session ID are connected in series and process the same signal

 //              stream. Knowing that two effects are part of the same effect chain can help the

 //              library implement some kind of optimizations.

 //          ioId:   identifies the output or input stream this effect is directed to at audio HAL.

 //              For future use especially with tunneled HW accelerated effects

 //

 //    Input/Output:

 //          pInterface:    address where to return the effect interface.

 //

 //    Output:

 //        returned value:    0          successful operation.

 //                          -ENODEV     library failed to initialize

 //                          -EINVAL     invalid pEffectUuid or pInterface

 //                          -ENOENT     no effect with this uuid found

 //        *pInterface:     updated with the effect interface handle.

 //

 ////////////////////////////////////////////////////////////////////////////////

 typedef int32_t (*effect_CreateEffect_t)(effect_uuid_t *uuid,

                                          int32_t sessionId,

                                          int32_t ioId,

                                          effect_interface_t *pInterface);

 ////////////////////////////////////////////////////////////////////////////////

 //

 //    Function:       EffectRelease

 //

 //    Description:    Releases the effect engine whose handle is given as argument.

 //          All resources allocated to this particular instance of the effect are

 //          released.

 //

 //    Input:

 //          interface:    handle on the effect interface to be released.

 //

 //    Output:

 //        returned value:    0          successful operation.

 //                          -ENODEV     library failed to initialize

 //                          -EINVAL     invalid interface handle

 //

 ////////////////////////////////////////////////////////////////////////////////

 typedef int32_t (*effect_ReleaseEffect_t)(effect_interface_t interface);

 #if __cplusplus

 }  // extern "C"

 #endif

 #endif /*ANDROID_EFFECTAPI_H_*/