Added in API level 9

EnvironmentalReverb


open class EnvironmentalReverb : AudioEffect

A sound generated within a room travels in many directions. The listener first hears the direct sound from the source itself. Later, he or she hears discrete echoes caused by sound bouncing off nearby walls, the ceiling and the floor. As sound waves arrive after undergoing more and more reflections, individual reflections become indistinguishable and the listener hears continuous reverberation that decays over time. Reverb is vital for modeling a listener's environment. It can be used in music applications to simulate music being played back in various environments, or in games to immerse the listener within the game's environment. The EnvironmentalReverb class allows an application to control each reverb engine property in a global reverb environment and is more suitable for games. For basic control, more suitable for music applications, it is recommended to use the android.media.audiofx.PresetReverb class.

An application creates a EnvironmentalReverb object to instantiate and control a reverb engine in the audio framework.

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

The EnvironmentalReverb is an output mix auxiliary effect and should be created on Audio session 0. In order for a MediaPlayer or AudioTrack to be fed into this effect, they must be explicitely attached to it and a send level must be specified. Use the effect ID returned by getId() method to designate this particular effect when attaching it to the MediaPlayer or AudioTrack.

Creating a reverb on the output mix (audio session 0) requires permission android.Manifest.permission#MODIFY_AUDIO_SETTINGS

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 EnvironmentalReverb when a parameter value has changed.

open

The Settings class regroups all environmental reverb parameters.

Constants
static Int

Decay HF ratio.

static Int

Decay time.

static Int

Density.

static Int

Diffusion.

static Int

Early reflections delay.

static Int

Early reflections level.

static Int

Reverb delay.

static Int

Reverb level.

static Int

Room HF level.

static Int

Room level.

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
EnvironmentalReverb(priority: Int, audioSession: Int)

Class constructor.

Public methods
open Short

Gets the ratio of high frequency decay time (at 5 kHz) relative to low frequencies.

open Int

Gets the decay time.

open Short

Gets the density level.

open Short

Gets diffusion level.

open EnvironmentalReverb.Settings!

Gets the environmental reverb properties.

open Int

Gets the reflections delay.

open Short

Gets the volume level of the early reflections.

open Int

Gets the reverb delay.

open Short

Gets the reverb level.

open Short

Gets the room HF level.

open Short

Gets the master volume level of the environmental reverb effect.

open Unit
setDecayHFRatio(decayHFRatio: Short)

Sets the ratio of high frequency decay time (at 5 kHz) relative to the decay time at low frequencies.

open Unit
setDecayTime(decayTime: Int)

Sets the time taken for the level of reverberation to decay by 60 dB.

open Unit
setDensity(density: Short)

Controls the modal density of the late reverberation decay.

open Unit
setDiffusion(diffusion: Short)

Sets the echo density in the late reverberation decay.

open Unit

Registers an OnParameterChangeListener interface.

open Unit

Sets the environmental reverb properties.

open Unit
setReflectionsDelay(reflectionsDelay: Int)

Sets the delay time for the early reflections.

open Unit
setReflectionsLevel(reflectionsLevel: Short)

Sets the volume level of the early reflections.

open Unit
setReverbDelay(reverbDelay: Int)

Sets the time between the first reflection and the reverberation.

open Unit
setReverbLevel(reverbLevel: Short)

Sets the volume level of the late reverberation.

open Unit

Sets the volume level at 5 kHz relative to the volume level at low frequencies of the overall reverb effect.

open Unit

Sets the master volume level of the environmental reverb 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_DECAY_HF_RATIO

Added in API level 9
static val PARAM_DECAY_HF_RATIO: Int

Decay HF ratio. Parameter ID for android.media.audiofx.EnvironmentalReverb.OnParameterChangeListener

Value: 3

PARAM_DECAY_TIME

Added in API level 9
static val PARAM_DECAY_TIME: Int

Decay time. Parameter ID for OnParameterChangeListener

Value: 2

PARAM_DENSITY

Added in API level 9
static val PARAM_DENSITY: Int

Density. Parameter ID for OnParameterChangeListener

Value: 9

PARAM_DIFFUSION

Added in API level 9
static val PARAM_DIFFUSION: Int

Diffusion. Parameter ID for OnParameterChangeListener

Value: 8

PARAM_REFLECTIONS_DELAY

Added in API level 9
static val PARAM_REFLECTIONS_DELAY: Int

Early reflections delay. Parameter ID for OnParameterChangeListener

Value: 5

PARAM_REFLECTIONS_LEVEL

Added in API level 9
static val PARAM_REFLECTIONS_LEVEL: Int

Early reflections level. Parameter ID for OnParameterChangeListener

Value: 4

PARAM_REVERB_DELAY

Added in API level 9
static val PARAM_REVERB_DELAY: Int

Reverb delay. Parameter ID for OnParameterChangeListener

Value: 7

PARAM_REVERB_LEVEL

Added in API level 9
static val PARAM_REVERB_LEVEL: Int

Reverb level. Parameter ID for OnParameterChangeListener

Value: 6

PARAM_ROOM_HF_LEVEL

Added in API level 9
static val PARAM_ROOM_HF_LEVEL: Int

Room HF level. Parameter ID for OnParameterChangeListener

Value: 1

PARAM_ROOM_LEVEL

Added in API level 9
static val PARAM_ROOM_LEVEL: Int

Room level. Parameter ID for OnParameterChangeListener

Value: 0

Public constructors

EnvironmentalReverb

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

Class constructor.

Parameters
priority Int: the priority level requested by the application for controlling the EnvironmentalReverb 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. If audioSession is not 0, the EnvironmentalReverb will be attached to the MediaPlayer or AudioTrack in the same audio session. Otherwise, the EnvironmentalReverb will apply to the output mix. As the EnvironmentalReverb is an auxiliary effect it is recommended to instantiate it on audio session 0 and to attach it to the MediaPLayer auxiliary output.
Exceptions
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException
java.lang.RuntimeException

Public methods

getDecayHFRatio

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

Gets the ratio of high frequency decay time (at 5 kHz) relative to low frequencies.

Return
Short the decay HF ration. See setDecayHFRatio(short) for units.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getDecayTime

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

Gets the decay time.

Return
Int the decay time in milliseconds.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getDensity

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

Gets the density level.

Return
Short the density level. See setDiffusion(short) for units.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getDiffusion

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

Gets diffusion level.

Return
Short the diffusion level. See setDiffusion(short) for units.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getProperties

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

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

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

getReflectionsDelay

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

Gets the reflections delay.

Return
Int the early reflections delay in milliseconds.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getReflectionsLevel

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

Gets the volume level of the early reflections.

Return
Short the early reflections level in millibels.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getReverbDelay

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

Gets the reverb delay.

Return
Int the reverb delay in milliseconds.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getReverbLevel

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

Gets the reverb level.

Return
Short the reverb level in millibels.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getRoomHFLevel

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

Gets the room HF level.

Return
Short the room HF level in millibels.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

getRoomLevel

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

Gets the master volume level of the environmental reverb effect.

Return
Short the room level in millibels.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setDecayHFRatio

Added in API level 9
open fun setDecayHFRatio(decayHFRatio: Short): Unit

Sets the ratio of high frequency decay time (at 5 kHz) relative to the decay time at low frequencies.

Parameters
decayHFRatio Short: high frequency decay ratio using a permille scale. The valid range is [100, 2000]. A ratio of 1000 indicates that all frequencies decay at the same rate.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setDecayTime

Added in API level 9
open fun setDecayTime(decayTime: Int): Unit

Sets the time taken for the level of reverberation to decay by 60 dB.

Parameters
decayTime Int: decay time in milliseconds. The valid range is [100, 20000].
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setDensity

Added in API level 9
open fun setDensity(density: Short): Unit

Controls the modal density of the late reverberation decay.

The scale should approximately map linearly to the perceived change in reverberation. A lower density creates a hollow sound that is useful for simulating small reverberation spaces such as bathrooms.

Parameters
density Short: density specified using a permille scale. The valid range is [0, 1000]. A value of 1000 o/oo indicates a natural sounding reverberation. Values below this level produce a more colored effect.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setDiffusion

Added in API level 9
open fun setDiffusion(diffusion: Short): Unit

Sets the echo density in the late reverberation decay.

The scale should approximately map linearly to the perceived change in reverberation.

Parameters
diffusion Short: diffusion specified using a permille scale. The diffusion valid range is [0, 1000]. A value of 1000 o/oo indicates a smooth reverberation decay. Values below this level give a more grainy character.
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setParameterListener

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

Registers an OnParameterChangeListener interface.

Parameters
listener EnvironmentalReverb.OnParameterChangeListener!: OnParameterChangeListener interface registered

setProperties

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

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

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

setReflectionsDelay

Added in API level 9
open fun setReflectionsDelay(reflectionsDelay: Int): Unit

Sets the delay time for the early reflections.

This method sets the time between when the direct path is heard and when the first reflection is heard.

Parameters
reflectionsDelay Int: reflections delay in milliseconds. The valid range is [0, 300].
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setReflectionsLevel

Added in API level 9
open fun setReflectionsLevel(reflectionsLevel: Short): Unit

Sets the volume level of the early reflections.

This level is combined with the overall room level (set using setRoomLevel(short)).

Parameters
reflectionsLevel Short: reflection level in millibels. The valid range is [-9000, 1000].
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setReverbDelay

Added in API level 9
open fun setReverbDelay(reverbDelay: Int): Unit

Sets the time between the first reflection and the reverberation.

Parameters
reverbDelay Int: reverb delay in milliseconds. The valid range is [0, 100].
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setReverbLevel

Added in API level 9
open fun setReverbLevel(reverbLevel: Short): Unit

Sets the volume level of the late reverberation.

This level is combined with the overall room level (set using setRoomLevel(short)).

Parameters
reverbLevel Short: reverb level in millibels. The valid range is [-9000, 2000].
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setRoomHFLevel

Added in API level 9
open fun setRoomHFLevel(roomHF: Short): Unit

Sets the volume level at 5 kHz relative to the volume level at low frequencies of the overall reverb effect.

This controls a low-pass filter that will reduce the level of the high-frequency.

Parameters
roomHF Short: high frequency attenuation level in millibels. The valid range is [-9000, 0].
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException

setRoomLevel

Added in API level 9
open fun setRoomLevel(room: Short): Unit

Sets the master volume level of the environmental reverb effect.

Parameters
room Short: room level in millibels. The valid range is [-9000, 0].
Exceptions
java.lang.IllegalStateException
java.lang.IllegalArgumentException
java.lang.UnsupportedOperationException