audiocapture.java

java开发的netbeans插件中的application原型

/*
 *	AudioCapture.java
 */

/*
 *  Copyright (c) 2001 by Florian Bomers <[e-mail]>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library General Public License as published
 *   by the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program 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 Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

package cn.edu.tsinghua.thss.talkie.audio;

//import	org.jsresources.apps.am.Debug;
import	java.io.*;
import	javax.sound.sampled.*;

// class that provides an AudioInputStream that reads its data from the soundcard input
public class AudioCapture implements LineListener {
    
    private AudioInputStream m_stream;
    private AudioFormat m_format;
    private int m_formatCode;
    private long m_startTime;
    
    private int bufferSizeDefault;
    private int bufferSize;
    private TargetDataLine m_line;
    
    public AudioCapture(int formatCode) {
        super();
        m_format = AMAudioFormat.getLineAudioFormat(formatCode);
        m_formatCode=formatCode;
        bufferSizeDefault = (int) m_format.getSampleRate(); // 500ms
    }
    
    public void update(LineEvent event) {
        if (event.getType().equals(LineEvent.Type.START)) {
            m_startTime=System.currentTimeMillis();
        } else
            if (event.getType().equals(LineEvent.Type.STOP)
            || event.getType().equals(LineEvent.Type.CLOSE)) {
            m_startTime=0;
            }
    }
    
    // opens the sound hardware
    public void open() throws Exception {
        DataLine.Info info = new DataLine.Info(TargetDataLine.class, m_format);
        
        // get and open the target data line for capture.
        m_line = null;
        try {
            m_line = (TargetDataLine) AudioSystem.getLine(info);
            m_line.addLineListener(this);
            m_line.open(m_format, bufferSizeDefault);
        } catch (LineUnavailableException ex) {
            throw new Exception("Unable to open the line: "+ex.getMessage());
        }
        bufferSize = m_line.getBufferSize();
        
        //see below
        //m_stream = new AudioInputStream(m_line);
        m_stream = new AudioInputStream(new TargetDataLineIS(m_line), m_line.getFormat(), AudioSystem.NOT_SPECIFIED);
    }
    
    public AudioInputStream getAudioInputStream() {
        return m_stream;
    }
    
    public int getBufferSizeInBytes() {
        return bufferSize;
    }
    
    public int getFormatCode() {
        return m_formatCode;
    }
    
    public void start() throws Exception {
        m_line.flush();
        m_line.start();
    }
    
    public void close() {
        if (m_stream!=null) {
            try {
                m_stream.close();
                // hmmm... the next lines cause a deadlock...
                // but the above doesn't close the line !
                //if (m_line!=null) {
                //	m_line.close();
                //}
            } catch(IOException ioe) {}

        }
    }
    
    public long getTime() {
        if (m_startTime!=0) {
            return System.currentTimeMillis()-m_startTime;
        } else {
            return -1;
        }
    }
    
    //////////////////////////////////////////////////////////////////////
    
    // Bug: the implementation of "new AudioInputStream(TargetDataLine)" does
    // not forward close() to the line !
    // so this is a blunt copy of Sun's implementation !
    private class TargetDataLineIS extends InputStream {
        TargetDataLine line;
        
        TargetDataLineIS(TargetDataLine line) {
            super();
            this.line = line;
        }
        
        public int available() throws IOException {
            return line.available();
        }
        
        public int read() throws IOException {
            byte[] b = new byte[1];
            
            int value = read(b, 0, 1);
            
            if (value == -1) {
                return -1;
            }
            return (int)b[0];
        }
        
        
        public int read(byte[] b, int off, int len) throws IOException {
            try {
                return line.read(b, off, len);
            } catch (IllegalArgumentException e) {
                throw new IOException(e.getMessage());
            }
        }
        
        public void close() throws IOException {
            // SunBug: strangely enough, the line needs to be flushed and
            // stopped to avoid a dead lock...
            if (line.isActive()) {
                line.flush();
                line.stop();
            }
            line.close();
        }
    } // TargetDataLineIS
    
}


/*** AudioCapture.java ***/