edu.cmu.sphinx.frontend.feature

Class AbstractFeatureExtractor

java.lang.Object

edu.cmu.sphinx.util.props.ConfigurableAdapter

edu.cmu.sphinx.frontend.BaseDataProcessor

edu.cmu.sphinx.frontend.feature.AbstractFeatureExtractor

All Implemented Interfaces:

DataProcessor, Configurable

Direct Known Subclasses:

ConcatFeatureExtractor, DeltasFeatureExtractor, KaldiDeltasFeatureExtractor, S3FeatureExtractor

public abstract class AbstractFeatureExtractor
extends BaseDataProcessor

Abstract base class for windowed feature extractors like DeltasFeatureExtractor, ConcatFeatureExtractor or S3FeatureExtractor. The main purpose of this it to collect window size cepstra frames in a buffer and let the extractor compute the feature frame with them.

Field Summary

Fields

Modifier and Type	Field and Description
protected DoubleData[]	cepstraBuffer
protected int	cepstraBufferEdge
protected int	cepstraBufferSize
protected int	currentPosition
static java.lang.String	PROP_FEATURE_WINDOW The property for the window of the DeltasFeatureExtractor.
protected int	window

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

logger

Constructor Summary

Constructors

Constructor and Description
AbstractFeatureExtractor()
AbstractFeatureExtractor(int window)

Method Summary

Modifier and Type	Method and Description
protected abstract Data	computeNextFeature() Computes the next feature.
Data	getData() Returns the next Data object produced by this DeltasFeatureExtractor.
void	initialize() Initializes this DataProcessor.
void	newProperties(PropertySheet ps) This method is called when this configurable component needs to be reconfigured.

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

getPredecessor, 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

Field Detail

PROP_FEATURE_WINDOW

@S4Integer(defaultValue=3)
public static final java.lang.String PROP_FEATURE_WINDOW

The property for the window of the DeltasFeatureExtractor.

See Also:

Constant Field Values

cepstraBufferEdge

protected int cepstraBufferEdge

window

protected int window

currentPosition

protected int currentPosition

cepstraBufferSize

protected int cepstraBufferSize

cepstraBuffer

protected DoubleData[] cepstraBuffer

Constructor Detail

AbstractFeatureExtractor

public AbstractFeatureExtractor(int window)

AbstractFeatureExtractor

public AbstractFeatureExtractor()

Method Detail

newProperties

public void newProperties(PropertySheet ps)
                   throws PropertyException

Description copied from interface: Configurable

This method is called when this configurable component needs to be reconfigured.

Specified by:

newProperties in interface Configurable

Overrides:

newProperties in class ConfigurableAdapter

Parameters:

ps - a property sheet holding the new data

Throws:

PropertyException - if there is a problem with the properties.

initialize

public void initialize()

Description copied from class: BaseDataProcessor

Initializes this DataProcessor. This is typically called after the DataProcessor has been configured.

Specified by:

initialize in interface DataProcessor

Overrides:

initialize in class BaseDataProcessor

getData

public Data getData()
             throws DataProcessingException

Returns the next Data object produced by this DeltasFeatureExtractor.

Specified by:

getData in interface DataProcessor

Specified by:

getData in class BaseDataProcessor

Returns:

the next available Data object, returns null if no Data is available

Throws:

DataProcessingException - if there is a data processing error

computeNextFeature

protected abstract Data computeNextFeature()

Computes the next feature. Advances the pointers as well.

Returns:

the feature Data computed