jAudioFeatureExtractor.AudioFeatures
Class FFTBinFrequencies

java.lang.Object
  extended by jAudioFeatureExtractor.AudioFeatures.FeatureExtractor
      extended by jAudioFeatureExtractor.AudioFeatures.FFTBinFrequencies

public class FFTBinFrequencies
extends FeatureExtractor

A "feature extractor" that calculates the bin labels, in Hz, of power spectrum or magnitude spectrum bins that would be produced by the FFT of a window of the size of that provided to the feature extractor.

Although this is not a useful feature for the purposes of classifying, it can be useful for calculating other features.

Daniel McEnnis 05-07-05 Added clone

Author:
Cory McKay

Field Summary
 
Fields inherited from class jAudioFeatureExtractor.AudioFeatures.FeatureExtractor
definition, dependencies, offsets, parent
 
Constructor Summary
FFTBinFrequencies()
          Basic constructor that sets the definition and dependencies (and their offsets) of this feature.
 
Method Summary
 java.lang.Object clone()
          Create an identical copy of this feature.
 double[] extractFeature(double[] samples, double sampling_rate, double[][] other_feature_values)
          Extracts this feature from the given samples at the given sampling rate and given the other feature values.
 
Methods inherited from class jAudioFeatureExtractor.AudioFeatures.FeatureExtractor
getDepenedencies, getDepenedencyOffsets, getElement, getFeatureDefinition, setElement, setParent, setWindow
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

FFTBinFrequencies

public FFTBinFrequencies()
Basic constructor that sets the definition and dependencies (and their offsets) of this feature.

Method Detail

extractFeature

public double[] extractFeature(double[] samples,
                               double sampling_rate,
                               double[][] other_feature_values)
                        throws java.lang.Exception
Extracts this feature from the given samples at the given sampling rate and given the other feature values.

In the case of this feature, the sampling_rate and other_feature_values parameters are ignored.

Specified by:
extractFeature in class FeatureExtractor
Parameters:
samples - The samples to extract the feature from.
sampling_rate - The sampling rate that the samples are encoded with.
other_feature_values - The values of other features that are needed to calculate this value. The order and offsets of these features must be the same as those returned by this class's getDependencies and getDependencyOffsets methods respectively. The first indice indicates the feature/window and the second indicates the value.
Returns:
The extracted feature value(s).
Throws:
java.lang.Exception - Throws an informative exception if the feature cannot be calculated.

clone

public java.lang.Object clone()
Create an identical copy of this feature. This permits FeatureExtractor to use the prototype pattern to create new composite features using metafeatures.

Specified by:
clone in class FeatureExtractor