public class

BassEnhance

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

Class Overview

bass enhance 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 BassEnhance object to instantiate and control a bass enhance engine in the audio framework.

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

To attach the BassEnhance to a particular AudioTrack or MediaPlayer, specify the audio session ID of this AudioTrack or MediaPlayer when constructing the BassEnhance. If the audio session ID 0 is specified, the BassEnhance applies to the main audio output mix.

Creating a BassEnhance on the output mix (audio session 0) requires permission MODIFY_AUDIO_SETTINGS

See getAudioSessionId() for details on audio sessions.

See AudioEffect class for more details on controlling audio effects.

Summary

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

Constants

public static final int PARAM_STRENGTH

Since: API Level 4.20

bass enhance effect strength. Parameter ID for BassEnhance.OnParameterChangeListener

Constant Value: 1 (0x00000001)

public static final int PARAM_STRENGTH_SUPPORTED

Since: API Level 4.20

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

Constant Value: 0 (0x00000000)

Public Constructors

public BassEnhance (int priority, int audioSession)

Class constructor.

Parameters
priority the priority level requested by the application for controlling the BassEnhance 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 system wide unique audio session identifier. If audioSession is not 0, the BassEnhance will be attached to the MediaPlayer or AudioTrack in the same audio session. Otherwise, the BassEnhance will apply to the output mix.
Throws
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException
RuntimeException
IllegalArgumentException
IllegalStateException
UnsupportedOperationException

Public Methods

public BassEnhance.Settings getProperties ()

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

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

public short getRoundedStrength ()

Gets the current strength of the effect.

Returns
  • 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
IllegalArgumentException
IllegalStateException

public boolean getStrengthSupported ()

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
  • true is strength parameter is supported, false otherwise

public void setParameterListener (BassEnhance.OnParameterChangeListener listener)

Registers an OnParameterChangeListener interface.

Parameters
listener OnParameterChangeListener interface registered

public void setProperties (BassEnhance.Settings settings)

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

Parameters
settings a BassEnhance.Settings object containing the properties to apply
Throws
IllegalStateException
IllegalArgumentException
UnsupportedOperationException
IllegalArgumentException
IllegalStateException

public void setStrength (short strength)

Sets the strength of the bass enhance 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 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
IllegalArgumentException
IllegalStateException