com.tagtraum.jipes.math

Class MultirateFilters.Resampler

java.lang.Object

com.tagtraum.jipes.math.MultirateFilters.Resampler

All Implemented Interfaces:

MapFunction<float[]>, StatefulMapFunction<float[]>

Enclosing class:

MultirateFilters

public static class MultirateFilters.Resampler
extends Object
implements StatefulMapFunction<float[]>

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.

Constructor Summary

Constructors

Constructor and Description
Resampler(double[] coefficients, int upFactor, int downFactor) Creates a resampler using a FIR filter based on the given coefficients and the given up- and down-sample factors.
Resampler(Filters.FIRFilter filter, int upFactor, int downFactor) Creates a resampler using a FIR low pass filter and the given up- and down-sample factors.
Resampler(int upFactor, int downFactor) Creates a resampler using a simple fir1 16th order low pass filter and the given up- and down-sample factors.

Method Summary

Modifier and Type	Method and Description
int	getDownFactor() Down-sampling factor.
float	getFactor() Resampling factor.
int	getUpFactor() Up-sampling factor.
float[]	map(float[] data) Maps an object (usually an array, an RealAudioBuffer or a List) to another one of the same size.
void	reset() Resets the function's state.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Resampler

public Resampler(int upFactor,
                 int downFactor)

Creates a resampler using a simple fir1 16th order 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:

upFactor - upsample factor

downFactor - downsample factor

Throws:

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

See Also:

Filters.createFir1_16thOrderLowpass(int)

Resampler

public Resampler(double[] coefficients,
                 int upFactor,
                 int downFactor)

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

upFactor - upsample factor

downFactor - downsample factor

Resampler

public Resampler(Filters.FIRFilter filter,
                 int upFactor,
                 int downFactor)

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

upFactor - upsample factor

downFactor - downsample factor

Method Detail

reset

public void reset()

Description copied from interface: StatefulMapFunction

Resets the function's state.

Specified by:

reset in interface StatefulMapFunction<float[]>

getUpFactor

public int getUpFactor()

Up-sampling factor.

Returns:

factor

getDownFactor

public int getDownFactor()

Down-sampling factor.

Returns:

factor

getFactor

public float getFactor()

Resampling factor.

Returns:

factor

map

public float[] map(float[] data)

Description copied from interface: MapFunction

Maps an object (usually an array, an RealAudioBuffer or a List) to another one of the same size.

Specified by:

map in interface MapFunction<float[]>

Parameters:

data - data

Returns:

mapped data

toString

public String toString()

Overrides:

toString in class Object