org.openimaj.audio.features.MFCC Maven / Gradle / Ivy
/**
* Copyright (c) 2011, The University of Southampton and the individual contributors.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the University of Southampton nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
*
*/
package org.openimaj.audio.features;
import org.openimaj.audio.AudioStream;
import org.openimaj.audio.samples.SampleBuffer;
/**
* A wrapper around the MFCC implementation of jAudio (which itself
* is a wrapper around the OrangeCow Volume implementation of FFT).
*
* @author David Dupplaw ([email protected])
* @created 5 Mar 2013
* @version $Author$, $Revision$, $Date$
*/
public class MFCC extends JAudioFeatureExtractor
{
/** Processor for magnitude spectrum */
private MagnitudeSpectrum magSpec = null;
/**
* Default constructor
*/
public MFCC()
{
this.featureExtractor = new jAudioFeatureExtractor.AudioFeatures.MFCC();
this.magSpec = new MagnitudeSpectrum();
}
/**
* Constructor for chaining to a stream
* @param as The audio stream
*/
public MFCC( final AudioStream as )
{
super( as );
this.featureExtractor = new jAudioFeatureExtractor.AudioFeatures.MFCC();
this.magSpec = new MagnitudeSpectrum();
}
/**
* Calculate the MFCCs for the given sample buffer.
* @param sb The sample buffer
* @return The MFCCs
*/
public double[][] calculateMFCC( final SampleBuffer sb )
{
this.process( sb );
return this.getLastCalculatedFeature();
}
/**
* {@inheritDoc}
* @see org.openimaj.audio.features.JAudioFeatureExtractor#getExtraInputs(double[], double)
*/
@Override
public double[][] getExtraInputs( final double[] samples, final double sampleRate )
{
return new double[][] { this.magSpec.process( samples, sampleRate ) };
}
/**
* Returns the MFCCs with the first coefficient set to zero.
* @return The MFCCs with the first set to zero.
*/
public double[][] getLastCalculatedFeatureWithoutFirst()
{
final double[][] d = this.getLastCalculatedFeature();
for( final double[] dd : d )
dd[0] = 0;
return d;
}
}