com.jsyn.util

Class AutoCorrelator

java.lang.Object

com.jsyn.util.AutoCorrelator

All Implemented Interfaces:

SignalCorrelator

public class AutoCorrelator
extends java.lang.Object
implements SignalCorrelator

Calculate period of a repeated waveform in an array. This algorithm is based on a normalized auto-correlation function as dewscribed in: "A Smarter Way to Find Pitch" by Philip McLeod and Geoff Wyvill

Author:

(C) 2004 Mobileer, PROPRIETARY and CONFIDENTIAL

Constructor Summary

Constructors

Constructor and Description
AutoCorrelator(int numFrames)

Method Summary

Modifier and Type	Method and Description
boolean	addSample(double value) Add a sample to be analyzed.
double	getConfidence() Measure of how confident the analyzer is of the last result.
float[]	getDiffs() For internal debugging.
double	getPeriod()
float	getPitchCorrectionFactor()
protected static double	interpolatePeak(double d1, double d2, double d3)
void	setPitchCorrectionFactor(float pitchCorrectionFactor)

Methods inherited from class java.lang.Object

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

Constructor Detail

AutoCorrelator

public AutoCorrelator(int numFrames)

Method Detail

interpolatePeak

protected static double interpolatePeak(double d1,
                                        double d2,
                                        double d3)

getDiffs

public float[] getDiffs()

Description copied from interface: SignalCorrelator

For internal debugging.

Specified by:

getDiffs in interface SignalCorrelator

addSample

public boolean addSample(double value)

Description copied from interface: SignalCorrelator

Add a sample to be analyzed. The samples will generally be held in a circular buffer.

Specified by:

addSample in interface SignalCorrelator

Returns:

true if a new period value has been generated

getPeriod

public double getPeriod()

Specified by:

getPeriod in interface SignalCorrelator

Returns:

the estimated period of the waveform in samples

getConfidence

public double getConfidence()

Description copied from interface: SignalCorrelator

Measure of how confident the analyzer is of the last result.

Specified by:

getConfidence in interface SignalCorrelator

Returns:

quality of the estimate between 0.0 and 1.0

getPitchCorrectionFactor

public float getPitchCorrectionFactor()

setPitchCorrectionFactor

public void setPitchCorrectionFactor(float pitchCorrectionFactor)