ee.ioc.phon.netspeechapi.Recognizer.java Source code

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Here is the source code for ee.ioc.phon.netspeechapi.Recognizer.java

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/*
 * This file is part of Net Speech API.
 * Copyright 2011, Institute of Cybernetics at Tallinn University of Technology
 *
 * Net Speech API is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software Foundation,
 * either version 3 of the License, or (at your option) any later version.
 *
 * Net Speech API is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with ACE View.
 * If not, see http://www.gnu.org/licenses/.
 */

package ee.ioc.phon.netspeechapi;

import java.io.File;
import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ByteArrayEntity;
import org.apache.http.entity.FileEntity;

/**
 * <p>POSTs a file to the recognizer service, similarly to:</p>
 * 
 * <pre>
 * curl -X POST --data-binary @test.flac -H "Content-Type: audio/x-flac; rate=16000" $mWsUrl
 * </pre>
 * 
 * @author Kaarel Kaljurand
 */
public class Recognizer extends AbstractUserAgent {

    public static final String DEFAULT_WS_URL = "http://bark.phon.ioc.ee/speech-api/v1/recognize";

    private final String mWsUrl;

    /**
     * <p>Constructs the Recognizer using the given webservice URL.</p>
     * 
     * @param wsUrl Speech recognizer webservice URL.
     */
    public Recognizer(String wsUrl) {
        mWsUrl = wsUrl;
    }

    /**
     * <p>Constructs the Recognizer using the default webservice URL.</p>
     */
    public Recognizer() {
        this(DEFAULT_WS_URL);
    }

    /**
     * <p>Posts the given audio file with the given MIME type and the given
     * sample rate to the recognizer webservice.
     * Returns the webservice response (JSON) as string.</p>
     * 
     * @param file audio file
     * @param mimeType MIME type e.g. "audio/wav"
     * @param rate sample rate, e.g. 16000 for 16kHz
     * @return JSON string
     * @throws ClientProtocolException
     * @throws IOException
     */
    public String recognize(File file, String mimeType, int rate) throws ClientProtocolException, IOException {
        return postFile(file, mimeType, rate);
    }

    /**
     * <p>Posts the given byte array with the given MIME type and the given
     * sample rate to the recognizer webservice.
     * Returns the webservice response (JSON) as string.</p>
     * 
     * @param bytes audio content as byte array
     * @param mimeType MIME type e.g. "audio/wav"
     * @param rate sample rate, e.g. 16000 for 16kHz
     * @return JSON string
     * @throws ClientProtocolException
     * @throws IOException
     */
    public String recognize(byte[] bytes, String mimeType, int rate) throws ClientProtocolException, IOException {
        return postByteArray(bytes, mimeType, rate);
    }

    private String postFile(File file, String mime, int rate) throws ClientProtocolException, IOException {
        HttpPost post = new HttpPost(mWsUrl);
        setUserAgent(post);

        HttpEntity entity = new FileEntity(file, mime + "; rate=" + rate);
        post.setEntity(entity);

        return Utils.getResponseEntityAsString(post);
    }

    private String postByteArray(byte[] bytes, String mime, int rate) throws ClientProtocolException, IOException {
        HttpPost post = new HttpPost(mWsUrl);
        setUserAgent(post);

        ByteArrayEntity entity = new ByteArrayEntity(bytes);
        entity.setContentType(mime + "; rate=" + rate);
        post.setEntity(entity);

        return Utils.getResponseEntityAsString(post);
    }
}