edu.cmu.sphinx.frontend

Class AutoCepstrum

java.lang.Object

edu.cmu.sphinx.util.props.ConfigurableAdapter

edu.cmu.sphinx.frontend.BaseDataProcessor

edu.cmu.sphinx.frontend.AutoCepstrum

All Implemented Interfaces:

DataProcessor, Configurable

public class AutoCepstrum
extends BaseDataProcessor

Cepstrum is an auto-configurable DataProcessor which is used to compute a specific cepstrum (for a target acoustic model) given the spectrum. The Cepstrum is computed using a pipeline of front end components which are selected, customized or ignored depending on the feat.params file which characterizes the target acoustic model for which this cepstrum is computed. A typical legacy MFCC Cepstrum will use a MelFrequencyFilterBank, followed by a DiscreteCosineTransform. A typical denoised MFCC Cepstrum will use a MelFrequencyFilterBank, followed by a Denoise component, followed by a DiscreteCosineTransform2, followed by a Lifter component. The MelFrequencyFilterBank parameters (numberFilters, minimumFrequency and maximumFrequency) are auto-configured based on the values found in feat.params.

Field Summary

Fields

Modifier and Type	Field and Description
protected DiscreteCosineTransform	dct The property specifying the DCT which will be used for creating the cepstrum.
protected Denoise	denoise The denoise component which could be used for creating the cepstrum.
protected BaseDataProcessor	filterBank The filter bank which will be used for creating the cepstrum.
protected Lifter	lifter The lifter component which could be used for creating the cepstrum.
protected Loader	loader
static java.lang.String	PROP_LOADER The property specifying the acoustic model for which this cepstrum will be configured.
protected java.util.List<DataProcessor>	selectedDataProcessors The list of DataProcessors which were auto-configured for this Cepstrum component.

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

logger

Constructor Summary

Constructors

Constructor and Description
AutoCepstrum()
AutoCepstrum(Loader loader)

Method Summary

Modifier and Type	Method and Description
Data	getData() Returns the processed Data output, basically calls getData() on the last processor.
void	initialize() Initializes this DataProcessor.
void	newProperties(PropertySheet ps) This method is called when this configurable component needs to be reconfigured.
void	setPredecessor(DataProcessor predecessor) Sets the predecessor for this DataProcessor.
java.lang.String	toString() Returns a description of this Cepstrum component in the format: <cepstrum name> {<DataProcessor1>, <DataProcessor2> ...

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

getPredecessor

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

getName, initLogger

Methods inherited from class java.lang.Object

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

Field Detail

PROP_LOADER

@S4Component(type=Loader.class)
public static final java.lang.String PROP_LOADER

The property specifying the acoustic model for which this cepstrum will be configured. For this acoustic model (AM) it is mandatory to specify a location in the configuration file. The Cepstrum will be configured based on the feat.params file that will be found in the specified AM location.

See Also:

Constant Field Values

loader

protected Loader loader

filterBank

protected BaseDataProcessor filterBank

The filter bank which will be used for creating the cepstrum. The filter bank is always inserted in the pipeline and its minimum frequency, maximum frequency and number of filters are configured based on the "lowerf", "upperf" and "nfilt" values in the feat.params file of the target acoustic model.

denoise

protected Denoise denoise

The denoise component which could be used for creating the cepstrum. The denoise component is inserted in the pipeline only if "-remove_noise yes" is specified in the feat.params file of the target acoustic model.

dct

protected DiscreteCosineTransform dct

The property specifying the DCT which will be used for creating the cepstrum. If "-transform legacy" is specified in the feat.params file of the target acoustic model or if the "-transform" parameter does not appear in this file at all, the legacy DCT component is inserted in the pipeline. If "-transform dct" is specified in the feat.params file of the target acoustic model, then the current DCT component is inserted in the pipeline.

lifter

protected Lifter lifter

The lifter component which could be used for creating the cepstrum. The lifter component is inserted in the pipeline only if "-lifter <lifterValue>" is specified in the feat.params file of the target acoustic model.

selectedDataProcessors

protected java.util.List<DataProcessor> selectedDataProcessors

The list of DataProcessors which were auto-configured for this Cepstrum component.

Constructor Detail

AutoCepstrum

public AutoCepstrum(Loader loader)
             throws java.io.IOException

Throws:

java.io.IOException

AutoCepstrum

public AutoCepstrum()

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 processed Data output, basically calls getData() on the last processor.

Specified by:

getData in interface DataProcessor

Specified by:

getData in class BaseDataProcessor

Returns:

a Data object that has been processed by the cepstrum

Throws:

DataProcessingException - if a data processor error occurs

setPredecessor

public void setPredecessor(DataProcessor predecessor)

Sets the predecessor for this DataProcessor. The predecessor is actually the spectrum builder.

Specified by:

setPredecessor in interface DataProcessor

Overrides:

setPredecessor in class BaseDataProcessor

Parameters:

predecessor - the predecessor of this DataProcessor

toString

public java.lang.String toString()

Returns a description of this Cepstrum component in the format: <cepstrum name> {<DataProcessor1>, <DataProcessor2> ... <DataProcessorN>}

Overrides:

toString in class ConfigurableAdapter

Returns:

a description of this Cepstrum