Added in API level 9
Deprecated in API level 35

Virtualizer


open class Virtualizer : AudioEffect

An audio virtualizer is a general name for an effect to spatialize audio channels. The exact behavior of this effect is dependent on the number of audio input channels and the types and number of audio output channels of the device. For example, in the case of a stereo input and stereo headphone output, a stereo widening effect is used when this effect is turned on.

An application creates a Virtualizer object to instantiate and control a virtualizer engine in the audio framework.

The methods, parameter types and units exposed by the Virtualizer implementation are directly mapping those defined by the OpenSL ES 1.0.1 Specification (http://www.khronos.org/opensles/) for the SLVirtualizerItf interface. Please refer to this specification for more details.

To attach the Virtualizer to a particular AudioTrack or MediaPlayer, specify the audio session ID of this AudioTrack or MediaPlayer when constructing the Virtualizer.

NOTE: attaching a Virtualizer to the global audio output mix by use of session 0 is deprecated.

See android.media.MediaPlayer#getAudioSessionId() for details on audio sessions.

See android.media.audiofx.AudioEffect class for more details on controlling audio effects.

Summary

Nested classes
abstract

The OnParameterChangeListener interface defines a method called by the Virtualizer when a parameter value has changed.

open

The Settings class regroups all virtualizer parameters.

Constants
static Int

Virtualizer effect strength.

static Int

Is strength parameter supported by virtualizer engine.

static Int

A virtualization mode used to indicate the virtualizer effect must stop forcing the processing to a particular mode in forceVirtualizationMode(int).

static Int

A virtualization mode typically used over headphones.

static Int

A virtualization mode indicating virtualization processing is not active.

static Int

A virtualization mode typically used over speakers.

Inherited constants
String ACTION_CLOSE_AUDIO_EFFECT_CONTROL_SESSION

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.

String ACTION_DISPLAY_AUDIO_EFFECT_CONTROL_PANEL

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.

String ACTION_OPEN_AUDIO_EFFECT_CONTROL_SESSION

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.

Int ALREADY_EXISTS

Internal operation status. Not returned by any method.

Int CONTENT_TYPE_GAME

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

Int CONTENT_TYPE_MOVIE

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

Int CONTENT_TYPE_MUSIC

Value for EXTRA_CONTENT_TYPE when the type of content played is music

Int CONTENT_TYPE_VOICE

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

String EFFECT_AUXILIARY

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.

String EFFECT_INSERT

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.

String EFFECT_POST_PROCESSING

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

String EFFECT_PRE_PROCESSING

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

Int ERROR

Unspecified error.

Int ERROR_BAD_VALUE

Operation failed due to bad parameter value.

Int ERROR_DEAD_OBJECT

Operation failed due to dead remote object.

Int ERROR_INVALID_OPERATION

Operation failed because it was requested in wrong state.

Int ERROR_NO_INIT

Operation failed due to bad object initialization.

Int ERROR_NO_MEMORY

Operation failed due to lack of memory.

String EXTRA_AUDIO_SESSION

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.

String EXTRA_CONTENT_TYPE

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.

String EXTRA_PACKAGE_NAME

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.

Int SUCCESS

Successful operation.

Public constructors
Virtualizer(priority: Int, audioSession: Int)

Class constructor.

Public methods
open Boolean
canVirtualize(inputChannelMask: Int, virtualizationMode: Int)

Checks if the combination of a channel mask and virtualization mode is supported by this virtualizer.

open Boolean
forceVirtualizationMode(virtualizationMode: Int)

Forces the virtualizer effect to use the given processing mode.

open Virtualizer.Settings!

Gets the virtualizer properties.

open Short

Gets the current strength of the effect.

open Boolean
getSpeakerAngles(inputChannelMask: Int, virtualizationMode: Int, angles: IntArray!)

Queries the virtual speaker angles (azimuth and elevation) for a combination of a channel mask and virtualization mode.

open Boolean

Indicates whether setting strength is supported.

open Int

Return the virtualization mode being used, if any.

open Unit

Registers an OnParameterChangeListener interface.

open Unit

Sets the virtualizer properties.

open Unit
setStrength(strength: Short)

Sets the strength of the virtualizer effect.

Inherited functions
Unit finalize()

AudioEffect.Descriptor! getDescriptor()

Get the effect descriptor.

Boolean getEnabled()

Returns effect enabled state

Int getId()

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)

Boolean hasControl()

Checks if this AudioEffect object is controlling the effect engine.

Array<AudioEffect.Descriptor!>! queryEffects()

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

Unit release()

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.

Unit setControlStatusListener(listener: AudioEffect.OnControlStatusChangeListener!)

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

Unit setEnableStatusListener(listener: AudioEffect.OnEnableStatusChangeListener!)

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

Int setEnabled(enabled: Boolean)

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.

Inherited properties
UUID! EFFECT_TYPE_AEC

UUID for Acoustic Echo Canceler (AEC)

UUID! EFFECT_TYPE_AGC

UUID for Automatic Gain Control (AGC)

UUID! EFFECT_TYPE_BASS_BOOST

UUID for bass boost effect

UUID! EFFECT_TYPE_DYNAMICS_PROCESSING

UUID for Dynamics Processing

UUID! EFFECT_TYPE_ENV_REVERB

UUID for environmental reverberation effect

UUID! EFFECT_TYPE_EQUALIZER

UUID for equalizer effect

UUID EFFECT_TYPE_HAPTIC_GENERATOR

UUID for Haptic Generator.

UUID! EFFECT_TYPE_LOUDNESS_ENHANCER

UUID for Loudness Enhancer

UUID! EFFECT_TYPE_NS

UUID for Noise Suppressor (NS)

UUID! EFFECT_TYPE_PRESET_REVERB

UUID for preset reverberation effect

UUID! EFFECT_TYPE_VIRTUALIZER

UUID for virtualizer effect

Constants

PARAM_STRENGTH

Added in API level 9
static val PARAM_STRENGTH: Int

Deprecated: Deprecated in Java.

Virtualizer effect strength. Parameter ID for android.media.audiofx.Virtualizer.OnParameterChangeListener

Value: 1

PARAM_STRENGTH_SUPPORTED

Added in API level 9
static val PARAM_STRENGTH_SUPPORTED: Int

Deprecated: Deprecated in Java.

Is strength parameter supported by virtualizer engine. Parameter ID for getParameter().

Value: 0

VIRTUALIZATION_MODE_AUTO

Added in API level 21
Deprecated in API level 35
static val VIRTUALIZATION_MODE_AUTO: Int

Deprecated: Deprecated in Java.

A virtualization mode used to indicate the virtualizer effect must stop forcing the processing to a particular mode in forceVirtualizationMode(int).

Value: 1

VIRTUALIZATION_MODE_BINAURAL

Added in API level 21
Deprecated in API level 35
static val VIRTUALIZATION_MODE_BINAURAL: Int

Deprecated: Deprecated in Java.

A virtualization mode typically used over headphones. Binaural virtualization describes an audio processing configuration for virtualization where the left and right channels are respectively reaching the left and right ear of the user, without also feeding the opposite ear (as is the case when listening over speakers).

Such a mode is therefore meant to be used when audio is playing over stereo wired headphones or headsets, but also stereo headphones through a wireless A2DP Bluetooth link.

See canVirtualize(int,int) to verify this mode is supported by this Virtualizer.

Value: 2

VIRTUALIZATION_MODE_OFF

Added in API level 21
Deprecated in API level 35
static val VIRTUALIZATION_MODE_OFF: Int

Deprecated: Deprecated in Java.

A virtualization mode indicating virtualization processing is not active. See getVirtualizationMode() as one of the possible return value.

Value: 0

VIRTUALIZATION_MODE_TRANSAURAL

Added in API level 21
Deprecated in API level 35
static val VIRTUALIZATION_MODE_TRANSAURAL: Int

Deprecated: Deprecated in Java.

A virtualization mode typically used over speakers. Transaural virtualization describes an audio processing configuration that differs from binaural (as described in VIRTUALIZATION_MODE_BINAURAL in that cross-talk is present, i.e. audio played from the left channel also reaches the right ear of the user, and vice-versa.

When supported, such a mode is therefore meant to be used when audio is playing over the built-in stereo speakers of a device, if they are featured.

See canVirtualize(int,int) to verify this mode is supported by this Virtualizer.

Value: 3

Public constructors

Virtualizer

Added in API level 9
Virtualizer(
    priority: Int,
    audioSession: Int)

Class constructor.

Parameters
priority Int: the priority level requested by the application for controlling the Virtualizer engine. As the same engine can be shared by several applications, this parameter indicates how much the requesting application needs control of effect parameters. The normal priority is 0, above normal is a positive number, below normal a negative number.
audioSession Int: system wide unique audio session identifier. The Virtualizer will be attached to the MediaPlayer or AudioTrack in the same audio session.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException
java.lang.RuntimeException

Public methods

canVirtualize

Added in API level 21
Deprecated in API level 35
open fun canVirtualize(
    inputChannelMask: Int,
    virtualizationMode: Int
): Boolean

Deprecated: Deprecated in Java.

Checks if the combination of a channel mask and virtualization mode is supported by this virtualizer. Some virtualizer implementations may only support binaural processing (i.e. only support headphone output, see VIRTUALIZATION_MODE_BINAURAL), some may support transaural processing (i.e. for speaker output, see VIRTUALIZATION_MODE_TRANSAURAL) for the built-in speakers. Use this method to query the virtualizer implementation capabilities.

Parameters
inputChannelMask Int: the channel mask of the content to virtualize.
virtualizationMode Int: the mode for which virtualization processing is to be performed, one of VIRTUALIZATION_MODE_BINAURAL, VIRTUALIZATION_MODE_TRANSAURAL. Value is android.media.audiofx.Virtualizer#VIRTUALIZATION_MODE_BINAURAL, or android.media.audiofx.Virtualizer#VIRTUALIZATION_MODE_TRANSAURAL
Return
Boolean true if the combination of channel mask and virtualization mode is supported, false otherwise.
An indication that a certain channel mask is not supported doesn't necessarily mean you cannot play content with that channel mask, it more likely implies the content will be downmixed before being virtualized. For instance a virtualizer that only supports a mask such as AudioFormat.CHANNEL_OUT_STEREO will still be able to process content with a mask of AudioFormat.CHANNEL_OUT_5POINT1, but will downmix the content to stereo first, and then will virtualize, as opposed to virtualizing each channel individually.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

forceVirtualizationMode

Added in API level 21
Deprecated in API level 35
open fun forceVirtualizationMode(virtualizationMode: Int): Boolean

Deprecated: Deprecated in Java.

Forces the virtualizer effect to use the given processing mode. The effect must be enabled for the forced mode to be applied.

Return
Boolean true if the processing mode is supported, and it is successfully set, or forcing was successfully disabled, false otherwise.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getProperties

Added in API level 9
open fun getProperties(): Virtualizer.Settings!

Deprecated: Deprecated in Java.

Gets the virtualizer properties. This method is useful when a snapshot of current virtualizer settings must be saved by the application.

Return
Virtualizer.Settings! a Virtualizer.Settings object containing all current parameters values
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getRoundedStrength

Added in API level 9
open fun getRoundedStrength(): Short

Deprecated: Deprecated in Java.

Gets the current strength of the effect.

Return
Short the strength of the effect. The valid range for strength is [0, 1000], where 0 per mille designates the mildest effect and 1000 per mille the strongest
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getSpeakerAngles

Added in API level 21
Deprecated in API level 35
open fun getSpeakerAngles(
    inputChannelMask: Int,
    virtualizationMode: Int,
    angles: IntArray!
): Boolean

Deprecated: Deprecated in Java.

Queries the virtual speaker angles (azimuth and elevation) for a combination of a channel mask and virtualization mode. If the virtualization configuration (mask and mode) is supported (see canVirtualize(int,int), the array angles will contain upon return the definition of each virtual speaker and its azimuth and elevation angles relative to the listener.
Note that in some virtualizer implementations, the angles may be strength-dependent.

Parameters
inputChannelMask Int: the channel mask of the content to virtualize.
virtualizationMode Int: the mode for which virtualization processing is to be performed, one of VIRTUALIZATION_MODE_BINAURAL, VIRTUALIZATION_MODE_TRANSAURAL. Value is android.media.audiofx.Virtualizer#VIRTUALIZATION_MODE_BINAURAL, or android.media.audiofx.Virtualizer#VIRTUALIZATION_MODE_TRANSAURAL
angles IntArray!: a non-null array whose length is 3 times the number of channels in the channel mask. If the method indicates the configuration is supported, the array will contain upon return triplets of values: for each channel i among the channels of the mask:
  • the element at index 3*i in the array contains the speaker identification (e.g. AudioFormat.CHANNEL_OUT_FRONT_LEFT),
  • the element at index 3*i+1 contains its corresponding azimuth angle expressed in degrees, where 0 is the direction the listener faces, 180 is behind the listener, and -90 is to her/his left,
  • the element at index 3*i+2 contains its corresponding elevation angle where +90 is directly above the listener, 0 is the horizontal plane, and -90 is directly below the listener.
Return
Boolean true if the combination of channel mask and virtualization mode is supported, false otherwise.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getStrengthSupported

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

Deprecated: Deprecated in Java.

Indicates whether setting strength is supported. If this method returns false, only one strength is supported and the setStrength() method always rounds to that value.

Return
Boolean true is strength parameter is supported, false otherwise

getVirtualizationMode

Added in API level 21
Deprecated in API level 35
open fun getVirtualizationMode(): Int

Deprecated: Deprecated in Java.

Return the virtualization mode being used, if any.

Return
Int the virtualization mode being used. If virtualization is not active, the virtualization mode will be VIRTUALIZATION_MODE_OFF. Otherwise the value will be VIRTUALIZATION_MODE_BINAURAL or VIRTUALIZATION_MODE_TRANSAURAL. Virtualization may not be active either because the effect is not enabled or because the current output device is not compatible with this virtualization implementation.
Exceptions
java.lang.IllegalStateException
java.lang.UnsupportedOperationException

setParameterListener

Added in API level 9
open fun setParameterListener(listener: Virtualizer.OnParameterChangeListener!): Unit

Deprecated: Deprecated in Java.

Registers an OnParameterChangeListener interface.

Parameters
listener Virtualizer.OnParameterChangeListener!: OnParameterChangeListener interface registered

setProperties

Added in API level 9
open fun setProperties(settings: Virtualizer.Settings!): Unit

Deprecated: Deprecated in Java.

Sets the virtualizer properties. This method is useful when virtualizer settings have to be applied from a previous backup.

Parameters
settings Virtualizer.Settings!: a Virtualizer.Settings object containing the properties to apply
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setStrength

Added in API level 9
open fun setStrength(strength: Short): Unit

Deprecated: Deprecated in Java.

Sets the strength of the virtualizer effect. If the implementation does not support per mille accuracy for setting the strength, it is allowed to round the given strength to the nearest supported value. You can use the getRoundedStrength() method to query the (possibly rounded) value that was actually set.

Parameters
strength Short: strength of the effect. The valid range for strength strength is [0, 1000], where 0 per mille designates the mildest effect and 1000 per mille designates the strongest.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException