parallelacousticscorer.java

来自「It is the Speech recognition software. 」· Java 代码 · 共 174 行

/*
 * Copyright 1999-2002 Carnegie Mellon University.  
 * Portions Copyright 2002 Sun Microsystems, Inc.  
 * Portions Copyright 2002 Mitsubishi Electric Research Laboratories.
 * All Rights Reserved.  Use is subject to license terms.
 * 
 * See the file "license.terms" for information on usage and
 * redistribution of this file, and for a DISCLAIMER OF ALL 
 * WARRANTIES.
 *
 */

package edu.cmu.sphinx.research.parallel;

import edu.cmu.sphinx.frontend.Data;
import edu.cmu.sphinx.frontend.DataEndSignal;
import edu.cmu.sphinx.frontend.DataStartSignal;
import edu.cmu.sphinx.frontend.DataProcessingException;
import edu.cmu.sphinx.frontend.FrontEnd;
import edu.cmu.sphinx.frontend.Signal;

import edu.cmu.sphinx.decoder.scorer.AcousticScorer;
import edu.cmu.sphinx.decoder.scorer.Scoreable;

import edu.cmu.sphinx.decoder.search.Token;

import edu.cmu.sphinx.util.props.Configurable;
import edu.cmu.sphinx.util.props.PropertyException;
import edu.cmu.sphinx.util.props.PropertySheet;
import edu.cmu.sphinx.util.props.PropertyType;
import edu.cmu.sphinx.util.props.Registry;

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import java.io.IOException;


/**
 * A parallel acoustic scorer that is capable of scoring multiple
 * feature streams.
 */
public class ParallelAcousticScorer implements AcousticScorer {

    private String name;


    /* (non-Javadoc)
     * @see edu.cmu.sphinx.util.props.Configurable#register(java.lang.String, edu.cmu.sphinx.util.props.Registry)
     */
    public void register(String name, Registry registry)
        throws PropertyException {
        this.name = name;
    }


    /* (non-Javadoc)
     * @see edu.cmu.sphinx.util.props.Configurable#newProperties(edu.cmu.sphinx.util.props.PropertySheet)
     */
    public void newProperties(PropertySheet ps) throws PropertyException {
    }


    /**
     * Scores the given set of Tokens. All Tokens in the given
     * list are assumed to belong to the same acoustic model.
     *
     * @param scoreableList a list containing StateToken objects to
     * be scored
     *
     * @return the best scoring scorable, or null if there are
     *          no more frames to score
     */
    public Scoreable calculateScores(List scoreableList) {

        assert scoreableList.size() > 0;
        	
	try {
	    FrontEnd frontEnd = getFrontEnd(scoreableList);
	    Data data = frontEnd.getData();
	 
	    if (data == null) {
                return null;
            }

	    if (data instanceof DataStartSignal) {
                data = frontEnd.getData();
                if (data == null) {
                    return null;
                }
	    }

	    if (data instanceof DataEndSignal) {
		return null;
	    }

            if (data instanceof Signal) {
                throw new Error("trying to score non-content feature");
            }

            float logMaxScore = -Float.MAX_VALUE;
	    Scoreable bestScoreable = null;
	    for (Iterator i = scoreableList.iterator(); i.hasNext(); ) {
                Scoreable scoreable = (Scoreable) i.next();
                float logScore =  scoreable.calculateScore(data, false, 1.0f);
                if (logScore > logMaxScore) {
                    logMaxScore = logScore;
		    bestScoreable = scoreable;
                }
	    }
	    return bestScoreable;
	} catch (DataProcessingException dpe) {
            dpe.printStackTrace();
            return null;
        }
    }


    /**
     * Returns the acoustic model name of the Tokens in the given
     * list .
     *
     * @return the acoustic model name of the Tokens
     */
    private FrontEnd getFrontEnd(List activeList) {
	if (activeList.size() > 0) {
	    Iterator i = activeList.iterator();
	    if (i.hasNext()) {
		ParallelToken token = (ParallelToken) i.next();
                return token.getFeatureStream().getFrontEnd();
	    }
	}
	return null;
    }


    /*
     * (non-Javadoc)
     *
     * @see edu.cmu.sphinx.util.props.Configurable#getName()
     */
    public String getName() {
        return name;
    }


    /**
     * Allocates resources for this scorer
     *
     */
    public void allocate() throws IOException {}


    /**
     * Deallocates resouces for this scorer
     *
     */
    public void deallocate() {}


    /**
     * starts the scorer
     */
    public void startRecognition() {}


    /**
     * stops the scorer
     */
    public void stopRecognition() {}
}