org.jitsi.service.neomedia

Class BasicVolumeControl

java.lang.Object

org.jitsi.service.neomedia.BasicVolumeControl

All Implemented Interfaces:

javax.media.Control, javax.media.GainControl, VolumeControl

Direct Known Subclasses:

HardwareVolumeControl

public class BasicVolumeControl
extends Object
implements VolumeControl, javax.media.GainControl

Provides a basic implementation of VolumeControl which stores the volume level/value set on it in the ConfigurationService.

Author:

Damian Minkov, Lyubomir Marinov

Field Summary

Fields

Modifier and Type	Field and Description
protected static float	MAX_VOLUME_LEVEL The maximum volume level accepted by AbstractVolumeControl.
static int	MAX_VOLUME_PERCENT The maximum volume level expressed in percent accepted by AbstractVolumeControl.
protected static float	MIN_VOLUME_LEVEL The minimum volume level accepted by AbstractVolumeControl.
static int	MIN_VOLUME_PERCENT The minimum volume level expressed in percent accepted by AbstractVolumeControl.
protected float	volumeLevel The current volume level.

Fields inherited from interface org.jitsi.service.neomedia.VolumeControl

CAPTURE_VOLUME_LEVEL_PROPERTY_NAME, PLAYBACK_VOLUME_LEVEL_PROPERTY_NAME

Constructor Summary

Constructors

Constructor and Description
BasicVolumeControl(String volumeLevelConfigurationPropertyName) Creates volume control instance and initializes initial level value if stored in the configuration service.

Method Summary

Modifier and Type	Method and Description
void	addGainChangeListener(javax.media.GainChangeListener listener) Register for gain change update events.
void	addVolumeChangeListener(VolumeChangeListener listener) Adds a VolumeChangeListener to be informed for any change in the volume levels.
static void	applyGain(javax.media.GainControl gainControl, byte[] buffer, int offset, int length) Applies the gain specified by gainControl to the signal defined by the length number of samples given in buffer starting at offset.
Component	getControlComponent() Not used.
float	getDB() Get the current gain set for this object in dB.
protected static float	getDefaultVolumeLevel() Returns the default volume level.
protected static float	getGainReferenceLevel() Returns the reference volume level for computing the gain.
float	getLevel() Get the current gain set for this object as a value between 0.0 and 1.0
float	getMaxValue() Returns the maximum allowed volume value.
float	getMinValue() Returns the minimum allowed volume value.
boolean	getMute() Get mute state of sound.
float	getVolume() Current volume value.
protected void	loadVolume() Reads the initial volume level from the system.
void	removeGainChangeListener(javax.media.GainChangeListener listener) Remove interest in gain change update events.
void	removeVolumeChangeListener(VolumeChangeListener listener) Removes a VolumeChangeListener.
float	setDB(float gain) Set the gain in decibels.
float	setLevel(float level) Set the gain using a floating point scale with values between 0.0 and 1.0.
void	setMute(boolean mute) Mutes current sound.
float	setVolume(float value) Changes volume level.
protected void	updateHardwareVolume() Modifies the hardware microphone sensibility (hardware amplification).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_VOLUME_LEVEL

protected static final float MAX_VOLUME_LEVEL

The maximum volume level accepted by AbstractVolumeControl.

See Also:

Constant Field Values

MAX_VOLUME_PERCENT

public static final int MAX_VOLUME_PERCENT

The maximum volume level expressed in percent accepted by AbstractVolumeControl.

See Also:

Constant Field Values

MIN_VOLUME_LEVEL

protected static final float MIN_VOLUME_LEVEL

The minimum volume level accepted by AbstractVolumeControl.

See Also:

Constant Field Values

MIN_VOLUME_PERCENT

public static final int MIN_VOLUME_PERCENT

The minimum volume level expressed in percent accepted by AbstractVolumeControl.

See Also:

Constant Field Values

volumeLevel

protected float volumeLevel

The current volume level.

Constructor Detail

BasicVolumeControl

public BasicVolumeControl(String volumeLevelConfigurationPropertyName)

Creates volume control instance and initializes initial level value if stored in the configuration service.

Parameters:

volumeLevelConfigurationPropertyName - the name of the configuration property which specifies the value of the volume level of the new instance

Method Detail

applyGain

public static void applyGain(javax.media.GainControl gainControl,
                             byte[] buffer,
                             int offset,
                             int length)

Applies the gain specified by gainControl to the signal defined by the length number of samples given in buffer starting at offset.

Parameters:

gainControl - the GainControl which specifies the gain to apply

buffer - the samples of the signal to apply the gain to

offset - the start of the samples of the signal in buffer

length - the number of samples of the signal given in buffer

getDefaultVolumeLevel

protected static float getDefaultVolumeLevel()

Returns the default volume level.

Returns:

The default volume level.

getGainReferenceLevel

protected static float getGainReferenceLevel()

Returns the reference volume level for computing the gain.

Returns:

The reference volume level for computing the gain.

addGainChangeListener

public void addGainChangeListener(javax.media.GainChangeListener listener)

Register for gain change update events. A GainChangeEvent is posted when the state of the GainControl changes.

Specified by:

addGainChangeListener in interface javax.media.GainControl

Parameters:

listener - The object to deliver events to.

addVolumeChangeListener

public void addVolumeChangeListener(VolumeChangeListener listener)

Adds a VolumeChangeListener to be informed for any change in the volume levels.

Specified by:

addVolumeChangeListener in interface VolumeControl

Parameters:

listener - volume change listener.

getControlComponent

public Component getControlComponent()

Not used.

Specified by:

getControlComponent in interface javax.media.Control

Returns:

null

getDB

public float getDB()

Get the current gain set for this object in dB.

Specified by:

getDB in interface javax.media.GainControl

Returns:

The gain in dB.

getLevel

public float getLevel()

Get the current gain set for this object as a value between 0.0 and 1.0

Specified by:

getLevel in interface javax.media.GainControl

Returns:

The gain in the level scale (0.0-1.0).

See Also:

GainControl

getMaxValue

public float getMaxValue()

Returns the maximum allowed volume value.

Specified by:

getMaxValue in interface VolumeControl

Returns:

the maximum allowed volume value.

See Also:

VolumeControl

getMinValue

public float getMinValue()

Returns the minimum allowed volume value.

Specified by:

getMinValue in interface VolumeControl

Returns:

the minimum allowed volume value.

See Also:

VolumeControl

getMute

public boolean getMute()

Get mute state of sound.

Specified by:

getMute in interface javax.media.GainControl

Specified by:

getMute in interface VolumeControl

Returns:

mute state of sound.

getVolume

public float getVolume()

Current volume value.

Specified by:

getVolume in interface VolumeControl

Returns:

the current volume level.

See Also:

VolumeControl

loadVolume

protected void loadVolume()

Reads the initial volume level from the system.

removeGainChangeListener

public void removeGainChangeListener(javax.media.GainChangeListener listener)

Remove interest in gain change update events.

Specified by:

removeGainChangeListener in interface javax.media.GainControl

Parameters:

listener - The object that has been receiving events.

removeVolumeChangeListener

public void removeVolumeChangeListener(VolumeChangeListener listener)

Removes a VolumeChangeListener.

Specified by:

removeVolumeChangeListener in interface VolumeControl

Parameters:

listener - the volume change listener to be removed.

setDB

public float setDB(float gain)

Set the gain in decibels. Setting the gain to 0.0 (the default) implies that the audio signal is neither amplified nor attenuated. Positive values amplify the audio signal and negative values attenuate the signal.

Specified by:

setDB in interface javax.media.GainControl

Parameters:

gain - The new gain in dB.

Returns:

The gain that was actually set.

See Also:

GainControl

setLevel

public float setLevel(float level)

Set the gain using a floating point scale with values between 0.0 and 1.0. 0.0 is silence; 1.0 is the loudest useful level that this GainControl supports.

Specified by:

setLevel in interface javax.media.GainControl

Parameters:

level - The new gain value specified in the level scale.

Returns:

The level that was actually set.

See Also:

GainControl

setMute

public void setMute(boolean mute)

Mutes current sound.

Specified by:

setMute in interface javax.media.GainControl

Specified by:

setMute in interface VolumeControl

Parameters:

mute - mutes/unmutes.

setVolume

public float setVolume(float value)

Changes volume level.

Specified by:

setVolume in interface VolumeControl

Parameters:

value - the new level to set.

Returns:

the actual level which was set.

See Also:

VolumeControl

updateHardwareVolume

protected void updateHardwareVolume()

Modifies the hardware microphone sensibility (hardware amplification). This is a void function for AbstractVolumeControl since it does not have any connection to hardware volume. But, this function must be redefined by any extending class.