org.openimaj.audio.filters

Class FIRFilter

java.lang.Object

org.openimaj.audio.Audio

org.openimaj.audio.AudioStream

org.openimaj.audio.processor.AudioProcessor

org.openimaj.audio.processor.FixedSizeSampleAudioProcessor

org.openimaj.audio.filters.FIRFilter

All Implemented Interfaces:

Iterable<SampleChunk>

public abstract class FIRFilter
extends FixedSizeSampleAudioProcessor

FIR filter is a multiplication of the frequency domain of a signal with the frequency domain of a filter. That corresponds to a convolution in the time domain; that is, a weighted sum of the previous input.

Author:

David Dupplaw (dpd@ecs.soton.ac.uk)

Created:

22 May 2013

Field Summary

Fields inherited from class org.openimaj.audio.Audio

format

Constructor Summary

Constructors

Constructor and Description
FIRFilter(AudioStream stream)

Method Summary

Modifier and Type	Method and Description
abstract double[]	getCoefficients() Returns the coefficients for the particular filter
SampleChunk	process(SampleChunk sample) Function that takes a sample chunk and processes the chunk.

Methods inherited from class org.openimaj.audio.processor.FixedSizeSampleAudioProcessor

getWindowSize, getWindowStep, isOverlapping, nextSampleChunk, setWindowSize, setWindowStep

Methods inherited from class org.openimaj.audio.processor.AudioProcessor

getLength, getUnderlyingStream, process, processingComplete, reset, setUnderlyingStream

Methods inherited from class org.openimaj.audio.AudioStream

iterator, seek

Methods inherited from class org.openimaj.audio.Audio

getFormat, setFormat

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

FIRFilter

public FIRFilter(AudioStream stream)

Parameters:

stream -

Method Detail

getCoefficients

public abstract double[] getCoefficients()

Returns the coefficients for the particular filter

Returns:

coefficients

process

public SampleChunk process(SampleChunk sample)
                    throws Exception

Function that takes a sample chunk and processes the chunk. It should also return a sample chunk containing the processed data. If wished, the chunk may be side-affected and the input chunk returned. It should not be assumed that the input chunk will be side-affected, but it must be noted that it is possible that it could be. This process function may also return null. If null is returned it means that the rest of the audio stream is not required to be processed by this processing function. Whether the rest of the sample chunks are copied or ignored is up to the caller. The default operation of the FixedSizeSampleAudioProcessor is simply to change the shape of the sample chunk. You may override this method to process the samples directly.

Overrides:

process in class FixedSizeSampleAudioProcessor

Parameters:

sample - The sample chunk to process.

Returns:

A sample chunk containing processed data.

Throws:

Exception - If the processing could not take place

See Also:

FixedSizeSampleAudioProcessor.process(org.openimaj.audio.SampleChunk)