jAudioFeatureExtractor.AudioFeatures
Class RMS

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

public class RMS
extends FeatureExtractor

A feature extractor that extracts the Root Mean Square (RMS) from a set of samples. This is a good measure of the power of a signal.

RMS is calculated by summing the squares of each sample, dividing this by the number of samples in the window, and finding the square root of the result.

No extracted feature values are stored in objects of this class.

Author:
Cory McKay

Field Summary
 
Fields inherited from class jAudioFeatureExtractor.AudioFeatures.FeatureExtractor
definition, dependencies, offsets, parent
 
Constructor Summary
RMS()
          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

RMS

public RMS()
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