audio.processing.modulation

Class VariableDelayEffect

java.lang.Object

triana.types.audio.AudioEffect16Bit

audio.processing.modulation.VariableDelayEffect

public class VariableDelayEffect
extends AudioEffect16Bit

A Variable-delay Effect which allows user to create a chorus or flanger unit by adjusting variables. A single delay is created using a feedforward comb filter. These effects work on the principle of varying the length of the delay. The user can set the attenuation the level of the delayed signal and also adjust the delay time, period length and amplitude by adjusting the settings using the GUI. VariableDelayEffect extends AudioEffect 16bit to allow for chunked data.

See Also:

VariableDelay

Field Summary

Fields inherited from class triana.types.audio.AudioEffect16Bit

ADD, DO_NOTHING, MULTIPLY

Constructor Summary

Constructors

Constructor and Description
VariableDelayEffect(int forwardMemSize, int feedback, java.lang.String LFOType, java.lang.String filterType, int oscillationPeriod, java.lang.String summingType, int amplitude, float delayInMs, boolean chunked, float sampleRate) Creates an variable delay effect with a particular forward memory size and oscillation type.

Method Summary

Methods

Modifier and Type	Method and Description
short[]	process(short[] input) Process method calls appropriate Variable delay Process method depending on the users decision to use or not chunked data.
void	setAmplitude(int amp) Sets the size of the amplitude of the LFO waveform.
void	setChunked(boolean chunk) Determines whether chunked data is being used or not
void	setDelayOffset(float offset) Sets the delay size in samples that the delayed signal will be delayed by.
void	setFeedback(int feed) Sets the feedback factor.
void	setFilterType(java.lang.String filt) Sets the type of filter to be used to create the delay.
void	setLFOType(java.lang.String lowfreqosc) Determines which type of low frequency oscillator will be instantiated
void	setOscillationPeriod(int osc) Sets the size of the oscillationPeriod of one complete cycle of the LFO waveform, in samples.
void	setSummingType(java.lang.String summer) Sets the type of summing of the original signal with the varied signal.
short[]	variProcess(short[] input) Method for non chunked data.
short[]	variProcessChunked(short[] input) Method for chunked data.

Methods inherited from class triana.types.audio.AudioEffect16Bit

getData, getStart, initialiseForward, initialiseForward, preProcess, setForwardMathOperation

Methods inherited from class java.lang.Object

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

Constructor Detail

VariableDelayEffect

public VariableDelayEffect(int forwardMemSize,
                   int feedback,
                   java.lang.String LFOType,
                   java.lang.String filterType,
                   int oscillationPeriod,
                   java.lang.String summingType,
                   int amplitude,
                   float delayInMs,
                   boolean chunked,
                   float sampleRate)

Creates an variable delay effect with a particular forward memory size and oscillation type. A new instance of lfo is created depending on the type of oscillation required.

Parameters:

forwardMemSize - the size of the forward memory to be used by AudioEffect16bit class.

feedback - the level of attenutation of the delayed signal in the the feedback comb filter. Should be divided by 100 to give value in percent.

LFOType - chooses the type of oscillation to use.

oscillationPeriod - sets time it takes for one complete oscillilation

summingType - sets the way to add the returned oscillator value to the original delay

filterType - sets which type of filter to use. Can be comb, allpass, or delay only

amplitude - sets level amplitude (ie sets the maximum 'peak' value and minimum 'trough' value) of the waveform.

delayOffset - the size of the delay in samples. Used to calculate appropriate buffer size

chunked - boolean value to indicate if the user is using chunked data. Used by process method to choose suitable method.

Method Detail

setFeedback

public void setFeedback(int feed)

Sets the feedback factor. To be specific this sets how loud the delayed signal will be.

Parameters:

feed - the level of feedback. This value must be divided by 100 in order to be used, as the feedback factor must be less than 1.

setDelayOffset

public void setDelayOffset(float offset)

Sets the delay size in samples that the delayed signal will be delayed by.

Parameters:

offset - this is the size of the delay in samples. This is used to set the forward buffer when using chunks, and also to calculate the size of the final output array.

setChunked

public void setChunked(boolean chunk)

Determines whether chunked data is being used or not

Parameters:

chunk - returns true if the user has indicated that chunked data is being used.

setLFOType

public void setLFOType(java.lang.String lowfreqosc)

Determines which type of low frequency oscillator will be instantiated

Parameters:

lowfreqosc - the type of LFO waveform that is being used. At present can be triangular or sinusoidal, but more LFO waveforms can be implemented in the future.

setSummingType

public void setSummingType(java.lang.String summer)

Sets the type of summing of the original signal with the varied signal. The variable delay line can be added to the original delay in three different ways.

Parameters:

summer - the type of summing algorithm to be applied

setFilterType

public void setFilterType(java.lang.String filt)

Sets the type of filter to be used to create the delay. This can be a comb filter, an allpass filter, or the delay only can be used, in order to only give the oscillating delayed signal

Parameters:

filt - the type of filter to create the delay

setOscillationPeriod

public void setOscillationPeriod(int osc)

Sets the size of the oscillationPeriod of one complete cycle of the LFO waveform, in samples.

Parameters:

osc - the size of the oscillation period in samples.

setAmplitude

public void setAmplitude(int amp)

Sets the size of the amplitude of the LFO waveform. This is essentially the maximum and minimum values that the delay can vary by.

Parameters:

amp - the size if the amplitude of the LFO

process

public short[] process(short[] input)

Process method calls appropriate Variable delay Process method depending on the users decision to use or not chunked data. Returns manipulated data.

Parameters:

input - short array containing the input data to be passed on to respective method

variProcess

public short[] variProcess(short[] input)

Method for non chunked data. Creates a delayed signal after the original data which varies in length. Works in 32bit (ints) to avoid any (unintentional) clipping from using shorts.

Parameters:

input - short array containing the input data to be passed on to respective method

variProcessChunked

public short[] variProcessChunked(short[] input)

Method for chunked data. Creates a delayed signal after the original data which varies in length. Works in 32bit (ints) to avoid any (unintentional) clipping from using shorts.