com.tagtraum.jipes.audio

Class LinearFrequencySpectrum

java.lang.Object

com.tagtraum.jipes.audio.AbstractAudioSpectrum

com.tagtraum.jipes.audio.LinearFrequencySpectrum

All Implemented Interfaces:

AudioBuffer, AudioSpectrum, Cloneable

public class LinearFrequencySpectrum
extends AbstractAudioSpectrum
implements Cloneable

Represents a spectrum with linear frequencies (as opposed to a LogFrequencySpectrum) as generated by a suitable SignalProcessor.

Even though instances are meant to be immutable, all methods return the original, internally used arrays to increase efficiency and reduce memory consumption. As a consequence you must never modify any of those arrays returned to you.

Author:

Hendrik Schreiber

Field Summary

Fields inherited from class com.tagtraum.jipes.audio.AbstractAudioSpectrum

audioFormat, frameNumber, imaginaryData, magnitudes, powers, realData

Constructor Summary

Constructors

Constructor and Description
LinearFrequencySpectrum(int frameNumber, float[] realData, float[] imaginaryData, AudioFormat audioFormat)
LinearFrequencySpectrum(LinearFrequencySpectrum linearFrequencySpectrum)

Method Summary

Modifier and Type	Method and Description
Object	clone() Creates an exact copy of this buffer.
protected float[]	computeFrequencies()
LinearFrequencySpectrum	derive(float[] real, float[] imaginary) Creates a copy of this spectrum, but replaces its values with the given real and imaginary data.
boolean	equals(Object o)
float	getBandwidth() Returns the bandwidth (or frequency resolution) of this buffer.
int	getBin(float frequency) Computes a bin/index for the given frequency.
int[]	getDeviationInSemitoneFractions(int resolution) Computes the deviation of the frequency at index i from a standard semitone in fractions of this semitone.
int[]	getDeviationsInCents() Computes the deviation of the frequency at index i from a standard semitone in cents.
float[]	getFrequencies() Array with frequency values in Hz corresponding to the bin numbers.
float	getFrequency(int bin) Returns the frequency of a given bin.
float[]	getMagnitudes() Magnitudes (square root of the powers) of the spectrum.
float[]	getPhases() Phases in radians.
float[]	getPowers() Powers (sum of the squares of the real and imaginary part) of the spectrum.
int	hashCode()
void	reuse(int frameNumber, float[] realData, float[] imaginaryData, AudioFormat audioFormat) Refills this spectrum with new data.
String	toString()

Methods inherited from class com.tagtraum.jipes.audio.AbstractAudioSpectrum

computeMagnitudes, computePowers, getAudioFormat, getData, getFrameNumber, getImaginaryData, getNumberOfSamples, getRealData, getTimestamp, getTimestamp

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

LinearFrequencySpectrum

public LinearFrequencySpectrum(int frameNumber,
                               float[] realData,
                               float[] imaginaryData,
                               AudioFormat audioFormat)

LinearFrequencySpectrum

public LinearFrequencySpectrum(LinearFrequencySpectrum linearFrequencySpectrum)

Method Detail

reuse

public void reuse(int frameNumber,
                  float[] realData,
                  float[] imaginaryData,
                  AudioFormat audioFormat)

Description copied from class: AbstractAudioSpectrum

Refills this spectrum with new data. This allows some object reuse. Use with care!

Overrides:

reuse in class AbstractAudioSpectrum

Parameters:

frameNumber - frame number

realData - real data

imaginaryData - imaginary data

audioFormat - audio format

getBandwidth

public float getBandwidth()

Returns the bandwidth (or frequency resolution) of this buffer. This the distance from one bin to the next in Hz or in other words, the width of one bin in Hz.

Returns:

frequency resolution in Hz

getDeviationsInCents

public int[] getDeviationsInCents()

Computes the deviation of the frequency at index i from a standard semitone in cents.

Returns:

array of deviations from a semitone in cents [-49,50] for each index.

getDeviationInSemitoneFractions

public int[] getDeviationInSemitoneFractions(int resolution)

Computes the deviation of the frequency at index i from a standard semitone in fractions of this semitone.

Parameters:

resolution - number of possible fractions. E.g. 100 for cents resolution

Returns:

array of deviations from a semitone in fractions of a semitone for each index.

getFrequencies

public float[] getFrequencies()

Array with frequency values in Hz corresponding to the bin numbers.

Specified by:

getFrequencies in interface AudioSpectrum

Returns:

array of length numberOfSamples/2 due to symmetry

See Also:

getFrequency(int)

computeFrequencies

protected float[] computeFrequencies()

getFrequency

public float getFrequency(int bin)

Returns the frequency of a given bin. If you need the frequencies for the whole spectrum you might rather use getFrequencies(), as it is more efficient.

Specified by:

getFrequency in interface AudioSpectrum

Overrides:

getFrequency in class AbstractAudioSpectrum

Parameters:

bin - bin number

Returns:

frequency in Hz

See Also:

getFrequencies()

getBin

public int getBin(float frequency)

Computes a bin/index for the given frequency.

Specified by:

getBin in interface AudioSpectrum

Parameters:

frequency - frequency

Returns:

bin

getPowers

public float[] getPowers()

Powers (sum of the squares of the real and imaginary part) of the spectrum.

Specified by:

getPowers in interface AudioBuffer

Overrides:

getPowers in class AbstractAudioSpectrum

Returns:

array of length numberOfSamples/2 due to symmetry

See Also:

getMagnitudes()

getMagnitudes

public float[] getMagnitudes()

Magnitudes (square root of the powers) of the spectrum.

Specified by:

getMagnitudes in interface AudioBuffer

Overrides:

getMagnitudes in class AbstractAudioSpectrum

Returns:

array of length numberOfSamples/2 due to symmetry

See Also:

getPowers()

getPhases

public float[] getPhases()

Phases in radians.

Returns:

phases

derive

public LinearFrequencySpectrum derive(float[] real,
                                      float[] imaginary)

Description copied from interface: AudioSpectrum

Creates a copy of this spectrum, but replaces its values with the given real and imaginary data. The original object remains unchanged.

Specified by:

derive in interface AudioBuffer

Specified by:

derive in interface AudioSpectrum

Parameters:

real - real data

imaginary - imaginary data

Returns:

derived copy

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

clone

public Object clone()
             throws CloneNotSupportedException

Description copied from interface: AudioBuffer

Creates an exact copy of this buffer. All AudioBuffers must be cloneable.

Specified by:

clone in interface AudioBuffer

Overrides:

clone in class AbstractAudioSpectrum

Returns:

clone

Throws:

CloneNotSupportedException