Added in API level 9

BassBoost

---

Kotlin |Java

open class BassBoost : AudioEffect

kotlin.Any
↳	android.media.audiofx.AudioEffect
	↳	android.media.audiofx.BassBoost

Bass boost is an audio effect to boost or amplify low frequencies of the sound. It is comparable to a simple equalizer but limited to one band amplification in the low frequency range.

An application creates a BassBoost object to instantiate and control a bass boost engine in the audio framework.

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

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

NOTE: attaching a BassBoost 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	OnParameterChangeListener The OnParameterChangeListener interface defines a method called by the BassBoost when a parameter value has changed.
open	Settings The Settings class regroups all bass boost parameters.

Constants
static Int	PARAM_STRENGTH Bass boost effect strength.
static Int	PARAM_STRENGTH_SUPPORTED Is strength parameter supported by bass boost engine.

Inherited constants

From class AudioEffect 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: CONTENT_TYPE_MUSIC CONTENT_TYPE_MOVIE CONTENT_TYPE_GAME CONTENT_TYPE_VOICE 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
BassBoost(priority: Int, audioSession: Int) Class constructor.

Public methods
open BassBoost.Settings!	getProperties() Gets the bass boost properties.
open Short	getRoundedStrength() Gets the current strength of the effect.
open Boolean	getStrengthSupported() Indicates whether setting strength is supported.
open Unit	setParameterListener(listener: BassBoost.OnParameterChangeListener!) Registers an OnParameterChangeListener interface.
open Unit	setProperties(settings: BassBoost.Settings!) Sets the bass boost properties.
open Unit	setStrength(strength: Short) Sets the strength of the bass boost effect.

Inherited functions

From class AudioEffect 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

From class AudioEffect 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

Bass boost effect strength. Parameter ID for android.media.audiofx.BassBoost.OnParameterChangeListener

Value: 1

PARAM_STRENGTH_SUPPORTED

Added in API level 9

static val PARAM_STRENGTH_SUPPORTED: Int

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

Value: 0

Public constructors

BassBoost

Added in API level 9

BassBoost(
    priority: Int, 
    audioSession: Int)

Class constructor.

Parameters
priority	Int: the priority level requested by the application for controlling the BassBoost 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 BassBoost 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

getProperties

Added in API level 9

open fun getProperties(): BassBoost.Settings!

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

Return
BassBoost.Settings!	a BassBoost.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

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

getStrengthSupported

Added in API level 9

open fun getStrengthSupported(): Boolean

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

setParameterListener

Added in API level 9

open fun setParameterListener(listener: BassBoost.OnParameterChangeListener!): Unit

Registers an OnParameterChangeListener interface.

Parameters
listener	BassBoost.OnParameterChangeListener!: OnParameterChangeListener interface registered

setProperties

Added in API level 9

open fun setProperties(settings: BassBoost.Settings!): Unit

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

Parameters
settings	BassBoost.Settings!: a BassBoost.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

Sets the strength of the bass boost 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