Android APIs
public class

BassBoost

extends AudioEffect
java.lang.Object
   ↳ android.media.audiofx.AudioEffect
     ↳ android.media.audiofx.BassBoost

Class Overview

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 getAudioSessionId() for details on audio sessions.

See AudioEffect class for more details on controlling audio effects.

Summary

Nested Classes
interface BassBoost.OnParameterChangeListener The OnParameterChangeListener interface defines a method called by the BassBoost when a parameter value has changed. 
class BassBoost.Settings The Settings class regroups all bass boost parameters. 
Constants
int PARAM_STRENGTH Bass boost effect strength.
int PARAM_STRENGTH_SUPPORTED Is strength parameter supported by bass boost engine.
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Inherited Constants
From class android.media.audiofx.AudioEffect
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Inherited Fields
From class android.media.audiofx.AudioEffect
Public Constructors
BassBoost(int priority, int audioSession)
Class constructor.
Public Methods
BassBoost.Settings getProperties()
Gets the bass boost properties.
short getRoundedStrength()
Gets the current strength of the effect.
boolean getStrengthSupported()
Indicates whether setting strength is supported.
void setParameterListener(BassBoost.OnParameterChangeListener listener)
Registers an OnParameterChangeListener interface.
void setProperties(BassBoost.Settings settings)
Sets the bass boost properties.
void setStrength(short strength)
Sets the strength of the bass boost effect.
[Expand]
Inherited Methods
From class android.media.audiofx.AudioEffect
From class java.lang.Object

Constants

public static final int PARAM_STRENGTH

Added in API level 9

Bass boost effect strength. Parameter ID for BassBoost.OnParameterChangeListener

Constant Value: 1 (0x00000001)

public static final int PARAM_STRENGTH_SUPPORTED

Added in API level 9

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

Constant Value: 0 (0x00000000)

Public Constructors

public BassBoost (int priority, int audioSession)

Added in API level 9

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.
Throws
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException
RuntimeException
IllegalStateException
IllegalArgumentException
UnsupportedOperationException

Public Methods

public BassBoost.Settings getProperties ()

Added in API level 9

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

Returns
BassBoost.Settings a BassBoost.Settings object containing all current parameters values
Throws
IllegalStateException
IllegalArgumentException
UnsupportedOperationException
IllegalStateException
IllegalArgumentException

public short getRoundedStrength ()

Added in API level 9

Gets the current strength of the effect.

Returns
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
Throws
IllegalStateException
IllegalArgumentException
UnsupportedOperationException
IllegalStateException
IllegalArgumentException

public boolean getStrengthSupported ()

Added in API level 9

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.

Returns
boolean true is strength parameter is supported, false otherwise

public void setParameterListener (BassBoost.OnParameterChangeListener listener)

Added in API level 9

Registers an OnParameterChangeListener interface.

Parameters
listener BassBoost.OnParameterChangeListener: OnParameterChangeListener interface registered

public void setProperties (BassBoost.Settings settings)

Added in API level 9

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
Throws
IllegalStateException
IllegalArgumentException
UnsupportedOperationException
IllegalStateException
IllegalArgumentException

public void setStrength (short strength)

Added in API level 9

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.
Throws
IllegalStateException
IllegalArgumentException
UnsupportedOperationException
IllegalStateException
IllegalArgumentException