edu.cmu.sphinx.linguist.aflat

Class AFlatLinguist

java.lang.Object

edu.cmu.sphinx.linguist.aflat.AFlatLinguist

All Implemented Interfaces:

Linguist, Configurable

public class AFlatLinguist
extends java.lang.Object
implements Linguist, Configurable

A simple form of the linguist. It makes the following simplifying assumptions: 1) Zero or one word per grammar node 2) No fan-in allowed ever 3) No composites (yet) 4) Only Unit, HMMState, and pronunciation states (and the initial/final grammar state are in the graph (no word, alternative or grammar states attached). 5) Only valid transitions (matching contexts) are allowed 6) No tree organization of units 7) Branching grammar states are allowed

This is a dynamic version of the flat linguist that is more efficient in terms of startup time and overall footprint

Note that all probabilities are maintained in the log math domain

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	AFlatLinguist.GrammarState Represents a grammar node in the search graph.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	ACOUSTIC_MODEL The property used to define the acoustic model to use when building the search graph
static java.lang.String	ADD_OUT_OF_GRAMMAR_BRANCH The property that specifies whether to add a branch for detecting out-of-grammar utterances.
static java.lang.String	GRAMMAR The property used to define the grammar to use when building the search graph
static java.lang.String	OUT_OF_GRAMMAR_PROBABILITY The property for the probability of entering the out-of-grammar branch.
static java.lang.String	PHONE_INSERTION_PROBABILITY The property for the probability of inserting a CI phone in the out-of-grammar ci phone loop
static java.lang.String	PHONE_LOOP_ACOUSTIC_MODEL The property for the acoustic model to use to build the phone loop that detects out of grammar utterances.
java.lang.Runtime	runtime
static java.lang.String	UNIT_MANAGER The property used to define the unit manager to use when building the search graph

Fields inherited from interface edu.cmu.sphinx.linguist.Linguist

PROP_FILLER_INSERTION_PROBABILITY, PROP_LANGUAGE_WEIGHT, PROP_SILENCE_INSERTION_PROBABILITY, PROP_UNIT_INSERTION_PROBABILITY, PROP_WORD_INSERTION_PROBABILITY

Constructor Summary

Constructors

Constructor and Description
AFlatLinguist()
AFlatLinguist(AcousticModel acousticModel, Grammar grammar, UnitManager unitManager, double wordInsertionProbability, double silenceInsertionProbability, double unitInsertionProbability, double fillerInsertionProbability, float languageWeight, boolean addOutOfGrammarBranch, double outOfGrammarBranchProbability, double phoneInsertionProbability, AcousticModel phoneLoopAcousticModel)

Method Summary

Modifier and Type	Method and Description
void	allocate() Allocates the linguist.
protected void	allocateAcousticModel() Allocates the acoustic model.
void	deallocate() Deallocates the linguist.
float	getLogSilenceInsertionProbability() Returns the log silence insertion probability.
SearchGraph	getSearchGraph() Returns the search graph
void	newProperties(PropertySheet ps) This method is called when this configurable component needs to be reconfigured.
protected void	setupAcousticModel(PropertySheet ps) Sets up the acoustic model.
void	startRecognition() Called before a recognition.
void	stopRecognition() Called after a recognition.

Methods inherited from class java.lang.Object

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

Field Detail

GRAMMAR

@S4Component(type=Grammar.class)
public static final java.lang.String GRAMMAR

The property used to define the grammar to use when building the search graph

See Also:

Constant Field Values

UNIT_MANAGER

@S4Component(type=UnitManager.class)
public static final java.lang.String UNIT_MANAGER

The property used to define the unit manager to use when building the search graph

See Also:

Constant Field Values

ACOUSTIC_MODEL

@S4Component(type=AcousticModel.class)
public static final java.lang.String ACOUSTIC_MODEL

The property used to define the acoustic model to use when building the search graph

See Also:

Constant Field Values

ADD_OUT_OF_GRAMMAR_BRANCH

@S4Boolean(defaultValue=false)
public static final java.lang.String ADD_OUT_OF_GRAMMAR_BRANCH

The property that specifies whether to add a branch for detecting out-of-grammar utterances.

See Also:

Constant Field Values

OUT_OF_GRAMMAR_PROBABILITY

@S4Double(defaultValue=1.0)
public static final java.lang.String OUT_OF_GRAMMAR_PROBABILITY

The property for the probability of entering the out-of-grammar branch.

See Also:

Constant Field Values

PHONE_INSERTION_PROBABILITY

@S4Double(defaultValue=1.0)
public static final java.lang.String PHONE_INSERTION_PROBABILITY

The property for the probability of inserting a CI phone in the out-of-grammar ci phone loop

See Also:

Constant Field Values

PHONE_LOOP_ACOUSTIC_MODEL

@S4Component(type=AcousticModel.class)
public static final java.lang.String PHONE_LOOP_ACOUSTIC_MODEL

The property for the acoustic model to use to build the phone loop that detects out of grammar utterances.

See Also:

Constant Field Values

runtime

public java.lang.Runtime runtime

Constructor Detail

AFlatLinguist

public AFlatLinguist(AcousticModel acousticModel,
                     Grammar grammar,
                     UnitManager unitManager,
                     double wordInsertionProbability,
                     double silenceInsertionProbability,
                     double unitInsertionProbability,
                     double fillerInsertionProbability,
                     float languageWeight,
                     boolean addOutOfGrammarBranch,
                     double outOfGrammarBranchProbability,
                     double phoneInsertionProbability,
                     AcousticModel phoneLoopAcousticModel)

AFlatLinguist

public AFlatLinguist()

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

Parameters:

ps - a property sheet holding the new data

Throws:

PropertyException - if there is a problem with the properties.

getSearchGraph

public SearchGraph getSearchGraph()

Returns the search graph

Specified by:

getSearchGraph in interface Linguist

Returns:

the search graph

setupAcousticModel

protected void setupAcousticModel(PropertySheet ps)
                           throws PropertyException

Sets up the acoustic model.

Parameters:

ps - the PropertySheet from which to obtain the acoustic model

Throws:

PropertyException - something went wrong

allocate

public void allocate()
              throws java.io.IOException

Description copied from interface: Linguist

Allocates the linguist. Resources allocated by the linguist are allocated here. This method may take many seconds to complete depending upon the linguist.

Implementor's Note - A well written linguist will allow allocate to be called multiple times without harm. This will allow a linguist to be shared by multiple search managers.

Specified by:

allocate in interface Linguist

Throws:

java.io.IOException - if an IO error occurs

allocateAcousticModel

protected void allocateAcousticModel()
                              throws java.io.IOException

Allocates the acoustic model.

Throws:

java.io.IOException - loading failed

deallocate

public void deallocate()

Description copied from interface: Linguist

Deallocates the linguist. Any resources allocated by this linguist are released.

Implementor's Note - if the linguist is being shared by multiple searches, the deallocate should only actually deallocate things when the last call to deallocate is made. Two approaches for dealing with this:

(1) Keep an allocation counter that is incremented during allocate and decremented during deallocate. Only when the counter reaches zero should the actually deallocation be performed.

(2) Do nothing in dellocate - just the the GC take care of things

Specified by:

deallocate in interface Linguist

getLogSilenceInsertionProbability

public float getLogSilenceInsertionProbability()

Returns the log silence insertion probability.

Returns:

the log silence insertion probability.

startRecognition

public void startRecognition()

Description copied from interface: Linguist

Called before a recognition. This method gives a linguist the opportunity to prepare itself before a recognition begins.

Implementor's Note - Some linguists (or underlying lanaguge or acoustic models) may keep caches or pools that need to be initialzed before a recognition. A linguist may implement this method to perform such initialization. Note however, that an ideal linguist will, once allocated, be state-less. This will allow the linguist to be shared by multiple simulataneous searches. Reliance on a 'startRecognition' may prevent a linguist from being used in a multi-threaded search.

Specified by:

startRecognition in interface Linguist

stopRecognition

public void stopRecognition()

Description copied from interface: Linguist

Called after a recognition. This method gives a linguist the opportunity to clean up after a recognition has been completed.

Implementor's Note - Some linguists (or underlying lanaguge or acoustic models) may keep caches or pools that need to be flushed after a recognition. A linguist may implement this method to perform such flushing. Note however, that an ideal linguist will once allocated, be state-less. This will allow the linguist to be shared by multiple simulataneous searches. Reliance on a 'stopRecognition' may prevent a linguist from being used in a multi-threaded search.

Specified by:

stopRecognition in interface Linguist