/*
* _______ _____ _____ _____
* |__ __| | __ \ / ____| __ \
* | | __ _ _ __ ___ ___ ___| | | | (___ | |__) |
* | |/ _` | '__/ __|/ _ \/ __| | | |\___ \| ___/
* | | (_| | | \__ \ (_) \__ \ |__| |____) | |
* |_|\__,_|_| |___/\___/|___/_____/|_____/|_|
*
* -------------------------------------------------------------
*
* TarsosDSP is developed by Joren Six at IPEM, University Ghent
*
* -------------------------------------------------------------
*
* Info: http://0110.be/tag/TarsosDSP
* Github: https://github.com/JorenSix/TarsosDSP
* Releases: http://0110.be/releases/TarsosDSP/
*
* TarsosDSP includes modified source code by various authors,
* for credits and info, see README.
*
*/
/*
* _______ _____ _____ _____
* |__ __| | __ \ / ____| __ \
* | | __ _ _ __ ___ ___ ___| | | | (___ | |__) |
* | |/ _` | '__/ __|/ _ \/ __| | | |\___ \| ___/
* | | (_| | | \__ \ (_) \__ \ |__| |____) | |
* |_|\__,_|_| |___/\___/|___/_____/|_____/|_|
*
* -----------------------------------------------------------
*
* TarsosDSP is developed by Joren Six at
* The School of Arts,
* University College Ghent,
* Hoogpoort 64, 9000 Ghent - Belgium
*
* -----------------------------------------------------------
*
* Info: http://tarsos.0110.be/tag/TarsosDSP
* Github: https://github.com/JorenSix/TarsosDSP
* Releases: http://tarsos.0110.be/releases/TarsosDSP/
*
* TarsosDSP includes modified source code by various authors,
* for credits and info, see README.
*
*/
package be.tarsos.dsp.effects;
import be.tarsos.dsp.AudioEvent;
import be.tarsos.dsp.AudioProcessor;
/**
* <p>
* Adds a flanger effect to a signal. The implementation is done with a delay
* buffer and an LFO in the form of a sine wave. It is probably the most
* straightforward flanger implementation possible.
* </p>
*
* @author Joren Six
*/
public class FlangerEffect implements AudioProcessor {
/**
* A simple delay buffer, it holds a number of samples determined by the
* maxFlangerLength and the sample rate.
*/
private float[] flangerBuffer;
/**
* The position in the delay buffer to store the current sample.
*/
private int writePosition;
/**
* Determines the factor of original signal that remains in the final mix.
* Dry should always equal 1-wet).
*/
private float dry;
/**
* Determines the factor of flanged signal that is mixed in the final mix.
* Wet should always equal 1-dry.
*/
private float wet;
/**
* The frequency for the LFO (sine).
*/
private double lfoFrequency;
/**
* The sample rate is neede to calculate the length of the delay buffer.
*/
private double sampleRate;
/**
* @param maxFlangerLength
* in seconds
* @param wet
* The 'wetness' of the flanging effect. A value between 0 and 1.
* Zero meaning no flanging effect in the resulting signal, one
* means total flanging effect and no original signal left. The
* dryness of the signal is determined by dry = "1-wet".
* @param sampleRate
* the sample rate in Hz.
* @param lfoFrequency
* in Hertz
*/
public FlangerEffect(double maxFlangerLength, double wet,
double sampleRate, double lfoFrequency) {
flangerBuffer = new float[(int) (sampleRate * maxFlangerLength)];
this.sampleRate = sampleRate;
this.lfoFrequency = lfoFrequency;
this.wet = (float) wet;
this.dry = (float) (1 - wet);
}
@Override
public boolean process(AudioEvent audioEvent) {
float[] audioFloatBuffer = audioEvent.getFloatBuffer();
int overlap = audioEvent.getOverlap();
// Divide f by two, to counter rectifier below, which effectively
// doubles the frequency
double twoPIf = 2 * Math.PI * lfoFrequency / 2.0;
double time = audioEvent.getTimeStamp();
double timeStep = 1.0 / sampleRate;
for (int i = overlap; i < audioFloatBuffer.length; i++) {
// Calculate the LFO delay value with a sine wave:
//fix by hans bickel
double lfoValue = (flangerBuffer.length - 1) * Math.sin(twoPIf * time);
// add a time step, each iteration
time += timeStep;
// Make the delay a positive integer
int delay = (int) (Math.round(Math.abs(lfoValue)));
// store the current sample in the delay buffer;
if (writePosition >= flangerBuffer.length) {
writePosition = 0;
}
flangerBuffer[writePosition] = audioFloatBuffer[i];
// find out the position to read the delayed sample:
int readPosition = writePosition - delay;
if (readPosition < 0) {
readPosition += flangerBuffer.length;
}
//increment the write position
writePosition++;
// Output is the input summed with the value at the delayed flanger
// buffer
audioFloatBuffer[i] = dry * audioFloatBuffer[i] + wet * flangerBuffer[readPosition];
}
return true;
}
@Override
public void processingFinished() {
}
/**
* Set the new length of the delay LineWavelet.
*
* @param flangerLength
* The new length of the delay LineWavelet, in seconds.
*/
public void setFlangerLength(double flangerLength) {
flangerBuffer = new float[(int) (sampleRate * flangerLength)];
}
/**
* Sets the frequency of the LFO (sine wave), in Hertz.
*
* @param lfoFrequency
* The new LFO frequency in Hertz.
*/
public void setLFOFrequency(double lfoFrequency) {
this.lfoFrequency = lfoFrequency;
}
/**
* Sets the wetness and dryness of the effect. Should be a value between
* zero and one (inclusive), the dryness is determined by 1-wet.
*
* @param wet
* A value between zero and one (inclusive) that determines the
* wet and dryness of the resulting mix.
*/
public void setWet(double wet) {
this.wet = (float) wet;
this.dry = (float) (1 - wet);
}
/**
* Sets the wetness and wetness of the effect. Should be a value between
* zero and one (inclusive), the wetness is determined by 1-dry.
*
* @param dry
* A value between zero and one (inclusive) that determines the
* wet and dryness of the resulting mix.
*/
public void setDry(double dry) {
this.dry = (float) dry;
this.wet = (float) (1 - dry);
}
}