edu.cmu.sphinx.frontend.feature
Class S3FeatureExtractor

java.lang.Object
  edu.cmu.sphinx.util.props.ConfigurableAdapter
      edu.cmu.sphinx.frontend.BaseDataProcessor
          edu.cmu.sphinx.frontend.feature.AbstractFeatureExtractor
              edu.cmu.sphinx.frontend.feature.S3FeatureExtractor

All Implemented Interfaces:

DataProcessor, Configurable

public class S3FeatureExtractor
extends AbstractFeatureExtractor

Computes the delta and double delta of input cepstrum (or plp or ...). The delta is the first order derivative and the double delta (a.k.a. delta delta) is the second order derivative of the original cepstrum. They help model the speech signal dynamics. The output data is a FloatData object with a float array of size three times the original cepstrum.

The format of the outputted feature is:

12 cepstra (c[1] through c[12])
followed by delta cepstra (delta c[1] through delta c[12])
followed by c[0], delta c[0]
followed by delta delta c[0] through delta delta c[12]

Field Summary

Fields inherited from class edu.cmu.sphinx.frontend.feature.AbstractFeatureExtractor

cepstraBuffer, cepstraBufferEdge, cepstraBufferSize, currentPosition, PROP_FEATURE_WINDOW, window

Fields inherited from class edu.cmu.sphinx.util.props.ConfigurableAdapter

logger

Constructor Summary

S3FeatureExtractor()

Method Summary

protected Data

computeNextFeature() Computes the next feature.

Methods inherited from class edu.cmu.sphinx.frontend.feature.AbstractFeatureExtractor

getData, initialize, newProperties

Methods inherited from class edu.cmu.sphinx.frontend.BaseDataProcessor

getPredecessor, getTimer, setPredecessor

Methods inherited from class edu.cmu.sphinx.util.props.ConfigurableAdapter

getName, initLogger, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

S3FeatureExtractor

public S3FeatureExtractor()

Method Detail

computeNextFeature

protected Data computeNextFeature()

Computes the next feature. Advances the pointers as well.

Specified by:

computeNextFeature in class AbstractFeatureExtractor

Returns:

the feature Data computed