Added in API level 9

AudioEffect

open class AudioEffect
kotlin.Any
   ↳ android.media.audiofx.AudioEffect

AudioEffect is the base class for controlling audio effects provided by the android audio framework.

Applications should not use the AudioEffect class directly but one of its derived classes to control specific effects:

To apply the audio effect to a specific AudioTrack or MediaPlayer instance, the application must specify the audio session ID of that instance when creating the AudioEffect. (see android.media.MediaPlayer#getAudioSessionId() for details on audio sessions).

NOTE: attaching insert effects (equalizer, bass boost, virtualizer) to the global audio output mix by use of session 0 is deprecated.

Creating an AudioEffect object will create the corresponding effect engine in the audio framework if no instance of the same effect type exists in the specified audio session. If one exists, this instance will be used.

The application creating the AudioEffect object (or a derived class) will either receive control of the effect engine or not depending on the priority parameter. If priority is higher than the priority used by the current effect engine owner, the control will be transfered to the new object. Otherwise control will remain with the previous object. In this case, the new application will be notified of changes in effect engine state or control ownership by the appropriate listener.

Summary

Nested classes
open

The effect descriptor contains information on a particular effect implemented in the audio framework:

The method queryEffects() returns an array of Descriptors to facilitate effects enumeration.

abstract

The OnControlStatusChangeListener interface defines a method called by the AudioEffect when control of the effect engine is gained or lost by the application

abstract

The OnEnableStatusChangeListener interface defines a method called by the AudioEffect when the enabled state of the effect engine was changed by the controlling application.

Constants
static String

Intent to signal to the effect control application or service that an audio session is closed and that effects should not be applied anymore.

static String

Intent to launch an audio effect control panel UI.

static String

Intent to signal to the effect control application or service that a new audio session is opened and requires audio effects to be applied.

static Int

Internal operation status.

static Int

Value for EXTRA_CONTENT_TYPE when the type of content played is game audio

static Int

Value for EXTRA_CONTENT_TYPE when the type of content played is video or movie

static Int

Value for EXTRA_CONTENT_TYPE when the type of content played is music

static Int

Value for EXTRA_CONTENT_TYPE when the type of content played is voice audio

static String

Effect connection mode is auxiliary.

static String

Effect connection mode is insert.

static String

Effect connection mode is post processing.

static String

Effect connection mode is pre processing.

static Int

Unspecified error.

static Int

Operation failed due to bad parameter value.

static Int

Operation failed due to dead remote object.

static Int

Operation failed because it was requested in wrong state.

static Int

Operation failed due to bad object initialization.

static Int

Operation failed due to lack of memory.

static String

Contains the ID of the audio session the effects should be applied to.

static String

Indicates which type of content is played by the application.

static String

Contains the package name of the calling application.

static Int

Successful operation.

Public methods
open AudioEffect.Descriptor!

Get the effect descriptor.

open Boolean

Returns effect enabled state

open Int

Returns effect unique identifier.

open Boolean

Checks if this AudioEffect object is controlling the effect engine.

open static Array<AudioEffect.Descriptor!>!

Query all effects available on the platform.

open Unit

Releases the native AudioEffect resources.

open Unit

Sets the listener AudioEffect notifies when the effect engine control is taken or returned.

open Unit

Sets the listener AudioEffect notifies when the effect engine is enabled or disabled.

open Int
setEnabled(enabled: Boolean)

Enable or disable the effect.

Protected methods
open Unit

Properties
static UUID!

UUID for Acoustic Echo Canceler (AEC)

static UUID!

UUID for Automatic Gain Control (AGC)

static UUID!

UUID for bass boost effect

static UUID!

UUID for Dynamics Processing

static UUID!

UUID for environmental reverberation effect

static UUID!

UUID for equalizer effect

static UUID

UUID for Haptic Generator.

static UUID!

UUID for Loudness Enhancer

static UUID!

UUID for Noise Suppressor (NS)

static UUID!

UUID for preset reverberation effect

static UUID!

UUID for virtualizer effect

Constants

ACTION_CLOSE_AUDIO_EFFECT_CONTROL_SESSION

Added in API level 9
static val ACTION_CLOSE_AUDIO_EFFECT_CONTROL_SESSION: String

Intent to signal to the effect control application or service that an audio session is closed and that effects should not be applied anymore.

The effect control application receiving this intent will delete all effects on this session and store current settings in package specific storage.

The calling package name is indicated by the EXTRA_PACKAGE_NAME extra and the audio session ID by the EXTRA_AUDIO_SESSION extra. Both extras are mandatory.

It is good practice for applications to broadcast this intent when music playback stops and/or when exiting to free system resources consumed by audio effect engines.

Value: "android.media.action.CLOSE_AUDIO_EFFECT_CONTROL_SESSION"

ACTION_DISPLAY_AUDIO_EFFECT_CONTROL_PANEL

Added in API level 9
static val ACTION_DISPLAY_AUDIO_EFFECT_CONTROL_PANEL: String

Intent to launch an audio effect control panel UI.

The goal of this intent is to enable separate implementations of music/media player applications and audio effect control application or services. This will allow platform vendors to offer more advanced control options for standard effects or control for platform specific effects.

The intent carries a number of extras used by the player application to communicate necessary pieces of information to the control panel application.

The calling application must use the android.app.Activity#startActivityForResult(Intent, int) method to launch the control panel so that its package name is indicated and used by the control panel application to keep track of changes for this particular application.

The EXTRA_AUDIO_SESSION extra will indicate an audio session to which the audio effects should be applied. If no audio session is specified, either one of the follownig will happen:

- If an audio session was previously opened by the calling application with ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION intent, the effect changes will be applied to that session.

- If no audio session is opened, the changes will be stored in the package specific storage area and applied whenever a new audio session is opened by this application.

The EXTRA_CONTENT_TYPE extra will help the control panel application customize both the UI layout and the default audio effect settings if none are already stored for the calling application.

Value: "android.media.action.DISPLAY_AUDIO_EFFECT_CONTROL_PANEL"

ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION

Added in API level 9
static val ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION: String

Intent to signal to the effect control application or service that a new audio session is opened and requires audio effects to be applied.

This is different from ACTION_DISPLAY_AUDIO_EFFECT_CONTROL_PANEL in that no UI should be displayed in this case. Music player applications can broadcast this intent before starting playback to make sure that any audio effect settings previously selected by the user are applied.

The effect control application receiving this intent will look for previously stored settings for the calling application, create all required audio effects and apply the effect settings to the specified audio session.

The calling package name is indicated by the EXTRA_PACKAGE_NAME extra and the audio session ID by the EXTRA_AUDIO_SESSION extra. Both extras are mandatory.

If no stored settings are found for the calling application, default settings for the content type indicated by EXTRA_CONTENT_TYPE will be applied. The default settings for a given content type are platform specific.

Value: "android.media.action.OPEN_AUDIO_EFFECT_CONTROL_SESSION"

ALREADY_EXISTS

Added in API level 9
static val ALREADY_EXISTS: Int

Internal operation status. Not returned by any method.

Value: -2

CONTENT_TYPE_GAME

Added in API level 9
static val CONTENT_TYPE_GAME: Int

Value for EXTRA_CONTENT_TYPE when the type of content played is game audio

Value: 2

CONTENT_TYPE_MOVIE

Added in API level 9
static val CONTENT_TYPE_MOVIE: Int

Value for EXTRA_CONTENT_TYPE when the type of content played is video or movie

Value: 1

CONTENT_TYPE_MUSIC

Added in API level 9
static val CONTENT_TYPE_MUSIC: Int

Value for EXTRA_CONTENT_TYPE when the type of content played is music

Value: 0

CONTENT_TYPE_VOICE

Added in API level 9
static val CONTENT_TYPE_VOICE: Int

Value for EXTRA_CONTENT_TYPE when the type of content played is voice audio

Value: 3

EFFECT_AUXILIARY

Added in API level 9
static val EFFECT_AUXILIARY: String

Effect connection mode is auxiliary.

Auxiliary effects must be created on session 0 (global output mix). In order for a MediaPlayer or AudioTrack to be fed into this effect, they must be explicitely attached to this effect and a send level must be specified.

Use the effect ID returned by getId() to designate this particular effect when attaching it to the MediaPlayer or AudioTrack.

Value: "Auxiliary"

EFFECT_INSERT

Added in API level 9
static val EFFECT_INSERT: String

Effect connection mode is insert. Specifying an audio session ID when creating the effect will insert this effect after all players in the same audio session.

Value: "Insert"

EFFECT_POST_PROCESSING

Added in API level 30
static val EFFECT_POST_PROCESSING: String

Effect connection mode is post processing. The audio post processing effects are attached to an audio output stream or device

Value: "Post Processing"

EFFECT_PRE_PROCESSING

Added in API level 30
static val EFFECT_PRE_PROCESSING: String

Effect connection mode is pre processing. The audio pre processing effects are attached to an audio input stream or device

Value: "Pre Processing"

ERROR

Added in API level 9
static val ERROR: Int

Unspecified error.

Value: -1

ERROR_BAD_VALUE

Added in API level 9
static val ERROR_BAD_VALUE: Int

Operation failed due to bad parameter value.

Value: -4

ERROR_DEAD_OBJECT

Added in API level 9
static val ERROR_DEAD_OBJECT: Int

Operation failed due to dead remote object.

Value: -7

ERROR_INVALID_OPERATION

Added in API level 9
static val ERROR_INVALID_OPERATION: Int

Operation failed because it was requested in wrong state.

Value: -5

ERROR_NO_INIT

Added in API level 9
static val ERROR_NO_INIT: Int

Operation failed due to bad object initialization.

Value: -3

ERROR_NO_MEMORY

Added in API level 9
static val ERROR_NO_MEMORY: Int

Operation failed due to lack of memory.

Value: -6

EXTRA_AUDIO_SESSION

Added in API level 9
static val EXTRA_AUDIO_SESSION: String

Contains the ID of the audio session the effects should be applied to.

This extra is for use with ACTION_DISPLAY_AUDIO_EFFECT_CONTROL_PANEL, ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION and ACTION_CLOSE_AUDIO_EFFECT_CONTROL_SESSION intents.

The extra value is of type int and is the audio session ID.

Value: "android.media.extra.AUDIO_SESSION"

EXTRA_CONTENT_TYPE

Added in API level 9
static val EXTRA_CONTENT_TYPE: String

Indicates which type of content is played by the application.

This extra is for use with ACTION_DISPLAY_AUDIO_EFFECT_CONTROL_PANEL and ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION intents.

This information is used by the effect control application to customize UI and select appropriate default effect settings. The content type is one of the following:

If omitted, the content type defaults to CONTENT_TYPE_MUSIC.
Value: "android.media.extra.CONTENT_TYPE"

EXTRA_PACKAGE_NAME

Added in API level 9
static val EXTRA_PACKAGE_NAME: String

Contains the package name of the calling application.

This extra is for use with ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION and ACTION_CLOSE_AUDIO_EFFECT_CONTROL_SESSION intents.

The extra value is a string containing the full package name.

Value: "android.media.extra.PACKAGE_NAME"

SUCCESS

Added in API level 9
static val SUCCESS: Int

Successful operation.

Value: 0

Public methods

getDescriptor

Added in API level 9
open fun getDescriptor(): AudioEffect.Descriptor!

Get the effect descriptor.

Exceptions
java.lang.IllegalStateException

getEnabled

Added in API level 9
open fun getEnabled(): Boolean

Returns effect enabled state

Return
Boolean true if the effect is enabled, false otherwise.
Exceptions
java.lang.IllegalStateException

getId

Added in API level 9
open fun getId(): Int

Returns effect unique identifier. This system wide unique identifier can be used to attach this effect to a MediaPlayer or an AudioTrack when the effect is an auxiliary effect (Reverb)

Return
Int the effect identifier.
Exceptions
java.lang.IllegalStateException

hasControl

Added in API level 9
open fun hasControl(): Boolean

Checks if this AudioEffect object is controlling the effect engine.

Return
Boolean true if this instance has control of effect engine, false otherwise.
Exceptions
java.lang.IllegalStateException

queryEffects

Added in API level 9
open static fun queryEffects(): Array<AudioEffect.Descriptor!>!

Query all effects available on the platform. Returns an array of android.media.audiofx.AudioEffect.Descriptor objects

Exceptions
java.lang.IllegalStateException

release

Added in API level 9
open fun release(): Unit

Releases the native AudioEffect resources. It is a good practice to release the effect engine when not in use as control can be returned to other applications or the native resources released.

setControlStatusListener

Added in API level 9
open fun setControlStatusListener(listener: AudioEffect.OnControlStatusChangeListener!): Unit

Sets the listener AudioEffect notifies when the effect engine control is taken or returned.

Parameters
listener AudioEffect.OnControlStatusChangeListener!:

setEnableStatusListener

Added in API level 9
open fun setEnableStatusListener(listener: AudioEffect.OnEnableStatusChangeListener!): Unit

Sets the listener AudioEffect notifies when the effect engine is enabled or disabled.

Parameters
listener AudioEffect.OnEnableStatusChangeListener!:

setEnabled

Added in API level 9
open fun setEnabled(enabled: Boolean): Int

Enable or disable the effect. Creating an audio effect does not automatically apply this effect on the audio source. It creates the resources necessary to process this effect but the audio signal is still bypassed through the effect engine. Calling this method will make that the effect is actually applied or not to the audio content being played in the corresponding audio session.

Parameters
enabled Boolean: the requested enable state
Return
Int SUCCESS in case of success, ERROR_INVALID_OPERATION or ERROR_DEAD_OBJECT in case of failure.
Exceptions
java.lang.IllegalStateException

Protected methods

finalize

Added in API level 9
protected open fun finalize(): Unit
Exceptions
java.lang.Throwable the Exception raised by this method

Properties

EFFECT_TYPE_AEC

Added in API level 18
static val EFFECT_TYPE_AEC: UUID!

UUID for Acoustic Echo Canceler (AEC)

EFFECT_TYPE_AGC

Added in API level 18
static val EFFECT_TYPE_AGC: UUID!

UUID for Automatic Gain Control (AGC)

EFFECT_TYPE_BASS_BOOST

Added in API level 18
static val EFFECT_TYPE_BASS_BOOST: UUID!

UUID for bass boost effect

EFFECT_TYPE_DYNAMICS_PROCESSING

Added in API level 28
static val EFFECT_TYPE_DYNAMICS_PROCESSING: UUID!

UUID for Dynamics Processing

EFFECT_TYPE_ENV_REVERB

Added in API level 18
static val EFFECT_TYPE_ENV_REVERB: UUID!

UUID for environmental reverberation effect

EFFECT_TYPE_EQUALIZER

Added in API level 18
static val EFFECT_TYPE_EQUALIZER: UUID!

UUID for equalizer effect

EFFECT_TYPE_HAPTIC_GENERATOR

Added in API level 31
static val EFFECT_TYPE_HAPTIC_GENERATOR: UUID

UUID for Haptic Generator.

EFFECT_TYPE_LOUDNESS_ENHANCER

Added in API level 19
static val EFFECT_TYPE_LOUDNESS_ENHANCER: UUID!

UUID for Loudness Enhancer

EFFECT_TYPE_NS

Added in API level 18
static val EFFECT_TYPE_NS: UUID!

UUID for Noise Suppressor (NS)

EFFECT_TYPE_PRESET_REVERB

Added in API level 18
static val EFFECT_TYPE_PRESET_REVERB: UUID!

UUID for preset reverberation effect

EFFECT_TYPE_VIRTUALIZER

Added in API level 18
static val EFFECT_TYPE_VIRTUALIZER: UUID!

UUID for virtualizer effect