com.tagtraum.pcmsampledsp

Class Resampler

java.lang.Object

com.tagtraum.pcmsampledsp.Resampler

public class Resampler
extends Object

Resamples the input by upsampling, low pass filtering and then downsampling by the given factors. The implementation aims for efficiency by not computing samples that are later dropped anyway (polyphase decomposition).

Author:

Hendrik Schreiber

Constructor Summary

Constructors

Constructor and Description
Resampler(double[] coefficients, Rational factor) Creates a resampler using a FIR filter based on the given coefficients and the given up- and down-sample factors.
Resampler(FIRFilter filter, Rational factor) Creates a resampler using a FIR low pass filter and the given up- and down-sample factors.
Resampler(Rational factor) Creates a resampler using a simple fir1 29th order (=30taps) low pass filter and the given up- and down-sample factors.

Method Summary

Modifier and Type	Method and Description
Rational	getFactor() Resampling factor.
int	resample(double[] in, double[] out, int channel, int channelCount)
int	resample(float[] in, float[] out, int channel, int channelCount)
int	resample(int[] in, int[] out, int channel, int channelCount)
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Resampler

public Resampler(Rational factor)

Creates a resampler using a simple fir1 29th order (=30taps) low pass filter and the given up- and down-sample factors. The filter used is based on the maximum of the two factors. Internally the up- and down-factors are divided by their greatest common divisor to increase efficiency.

Parameters:

factor - resample factor

Throws:

IllegalArgumentException - if a filter for the factor max(upFactor,downFactor) is not supported

See Also:

FIRFilter

Resampler

public Resampler(double[] coefficients,
                 Rational factor)

Creates a resampler using a FIR filter based on the given coefficients and the given up- and down-sample factors. The coefficients must be appropriate for the given factors. Internally the up- and down-factors are divided by their greatest common divisor to increase efficiency.

Parameters:

coefficients - FIR filter coefficients

factor - resample factor

Resampler

public Resampler(FIRFilter filter,
                 Rational factor)

Creates a resampler using a FIR low pass filter and the given up- and down-sample factors. The filter must be appropriate for the given factors. Internally the up- and down-factors are divided by their greatest common divisor to increase efficiency.

Parameters:

filter - FIR filter

factor - resample factor

Method Detail

getFactor

public Rational getFactor()

Resampling factor.

Returns:

factor

resample

public int resample(int[] in,
                    int[] out,
                    int channel,
                    int channelCount)

resample

public int resample(float[] in,
                    float[] out,
                    int channel,
                    int channelCount)

resample

public int resample(double[] in,
                    double[] out,
                    int channel,
                    int channelCount)

toString

public String toString()

Overrides:

toString in class Object