/**
* Expands the given hmm state tree
* package edu.cmu.sphinx.linguist.KWSFlatLinguist;
*
* public class PhoneLoopCI {
*
* }
*
* @param parent the parent of the tree
* @param tree the tree to expand
* @return the final state in the tree
*/
protected HMMStateState expandHMMTree(UnitState parent,
HMMStateState tree)
{
HMMStateState retState = tree;
foreach (HMMStateArc arc in tree.getHMMState().getSuccessors())
{
HMMStateState newState;
if (arc.getHMMState().isEmitting())
{
newState = new HMMStateState
(parent, arc.getHMMState());
}
else
{
newState = new NonEmittingHMMState
(parent, arc.getHMMState());
}
SentenceHMMState existingState = getExistingState(newState);
float logProb = arc.getLogProbability();
if (existingState != null)
{
attachState(tree, existingState, logOne, logProb);
}
else
{
attachState(tree, newState, logOne, logProb);
addStateToCache(newState);
retState = expandHMMTree(parent, newState);
}
}
return(retState);
}
/**
* Creates the CIPhoneLoop with the given acoustic model and phone insertion probability
*
* @param model the acoustic model
* @param logPhoneInsertionProbability the insertion probability
*/
public PhoneLoopCI(AcousticModel model,
float logPhoneInsertionProbability,
SentenceHMMState initialState)
{
this.model = model;
this.logPhoneInsertionProbability =
logPhoneInsertionProbability;
this.inititalState = initialState;
}
protected void attachState(SentenceHMMState prevState,
SentenceHMMState nextState,
float logLanguageProbability,
float logInsertionProbability)
{
SentenceHMMStateArc arc = new SentenceHMMStateArc
(nextState,
logLanguageProbability,
logInsertionProbability);
prevState.connect(arc);
}
/** Constructs a phone loop search graph. */
public PhoneLoopSearchGraph(SentenceHMMState initState, AcousticModel model, float logPhoneInsertionProbability)
{
this.inititalState = initState;
this.model = model;
this.logPhoneInsertionProbability = logPhoneInsertionProbability;
existingStates = new Dictionary <string, SearchState>();
firstState = new UnknownWordState();
SentenceHMMState branchState = new BranchOutState(firstState);
attachState(firstState, branchState, logOne, logOne);
SentenceHMMState lastState = new LoopBackState(firstState);
//lastState.setFinalState(true);
//attachState(lastState, branchState, LogMath.getLogZero(),
// LogMath.getLogZero());
attachState(lastState, inititalState, logOne, logOne);
for (java.util.Iterator i = model.getContextIndependentUnitIterator(); i.hasNext();)
{
Unit unit = (Unit)i.next();
UnitState unitState = new UnitState(unit, HMMPosition.UNDEFINED);
// attach unit state to the branch out state
attachState(branchState, unitState, logOne, logPhoneInsertionProbability);
HMM hmm = model.lookupNearestHMM
(unitState.getUnit(), unitState.getPosition(), false);
HMMState initialState = hmm.getInitialState();
HMMStateState hmmTree = new HMMStateState(unitState, initialState);
addStateToCache(hmmTree);
// attach first HMM state to the unit state
attachState(unitState, hmmTree, logOne, logOne);
// expand the HMM tree
HMMStateState finalState = expandHMMTree(unitState, hmmTree);
// attach final state of HMM tree to the loopback state
attachState(finalState, lastState, logOne, logOne);
}
}
public BranchOutState(SentenceHMMState parent) : base("BranchOutState", parent, 0)
{
}
public LoopBackState(SentenceHMMState parent) : base("CIPhonesLoopBackState", parent, 0)
{
}
/**
* Adds the given state to the cache of states
*
* @param state the state to add
*/
protected void addStateToCache(SentenceHMMState state)
{
existingStates.Add(state.getSignature(), state);
}
/**
* Checks to see if a state that matches the given state already exists
*
* @param state the state to check
* @return true if a state with an identical signature already exists.
*/
private SentenceHMMState getExistingState(SentenceHMMState state)
{
return((SentenceHMMState)existingStates[state.getSignature()]);
}
internal BranchOutState(SentenceHMMState parent) : base("BranchOutState", parent, 0)
{
}