Package com.tagtraum.audiokern.math

Class FFTSupport

java.lang.Object

com.tagtraum.audiokern.math.FFTSupport

public class FFTSupport
extends Object

Provides support for FFT implementations.

Author:

Hendrik Schreiber

Constructor Summary

Constructors

Constructor	Description
FFTSupport()

Method Summary

Modifier and Type	Method	Description
static double	bandwidth(int numSamples, float sampleRate)	Computes the frequency resolution, i.e.
static int	frequencyToIndex(int numSamples, float sampleRate, double frequency)	Returns the index in the fourier result that corresponds to a frequency.
static double	indexToFrequency(int numSamples, float sampleRate, int index)	Returns the frequency for a particular value in the fourier result.
static boolean	isNativeFFTSupport()

Methods inherited from class java.lang.Object

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

Constructor Detail

FFTSupport

public FFTSupport()

Method Detail

isNativeFFTSupport

public static boolean isNativeFFTSupport()

indexToFrequency

public static double indexToFrequency(int numSamples,
                                      float sampleRate,
                                      int index)

Returns the frequency for a particular value in the fourier result.

Parameters:

numSamples - number of samples originally used for the FFT

sampleRate - sample rate, e.g. 44,100Hz

index - index

Returns:

frequency of the power at the given index of the fourier result

frequencyToIndex

public static int frequencyToIndex(int numSamples,
                                   float sampleRate,
                                   double frequency)

Returns the index in the fourier result that corresponds to a frequency.

Parameters:

numSamples - number of samples

sampleRate - sample rate

frequency - frequency

Returns:

index

bandwidth

public static double bandwidth(int numSamples,
                               float sampleRate)

Computes the frequency resolution, i.e. the distance in Hz between adjacent indices.

Parameters:

numSamples - number of samples

sampleRate - sample rate

Returns:

frequency resolution in Hz