javasoundaudiodevice.java

java for mp3 audio and speech coding

/*
 * 29/01/00		Initial version. [e-mail]
/*-----------------------------------------------------------------------
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *----------------------------------------------------------------------
 */

package javazoom.jl.player;

import javazoom.jl.decoder.*;

import javax.sound.sampled.*;

/**
 * The <code>JavaSoundAudioDevice</code> implements an audio
 * device by using the JavaSound API. 
 * 
 * @since 0.0.8
 * @author Mat McGowan
 */
public class JavaSoundAudioDevice extends AudioDeviceBase
{
	private SourceDataLine	source = null;
	
	private AudioFormat		fmt = null;
	
	private byte[]			byteBuf = new byte[1024];
	
	protected void setAudioFormat(AudioFormat fmt0)
	{
		fmt = fmt0;
	}
	
	protected AudioFormat getAudioFormat()
	{
		if (fmt==null)
		{
			Decoder decoder = getDecoder();
			fmt = new AudioFormat(decoder.getOutputFrequency(),
								  16,
								  decoder.getOutputChannels(),
								  true,
								  false);			
		}
		return fmt;
	}
	
	protected DataLine.Info getSourceLineInfo()
	{
		AudioFormat fmt = getAudioFormat();
		DataLine.Info info = new DataLine.Info(SourceDataLine.class, fmt, 4000);
		return info;
	}
	
	public void open(AudioFormat fmt) throws JavaLayerException
	{
		if (!isOpen())
		{
			setAudioFormat(fmt);
			openImpl();
			setOpen(true);
		}
	}
	
	protected void openImpl()
		throws JavaLayerException
	{
	}
	
	protected void createSource()
		throws JavaLayerException
	{
		Throwable t = null;
		try
		{
			Mixer m = AudioSystem.getMixer(null);
			AudioFormat fmt = getAudioFormat();
		
			Line.Info info = getSourceLineInfo();
			Line.Info[] lineInfos = m.getSourceLineInfo(info);
				
			Line line = null;
			if (lineInfos.length>0)
			{
				line = m.getLine(lineInfos[0]);
			}
		
			if (line instanceof SourceDataLine)
			{
				source = (SourceDataLine)line;
				source.open(fmt, millisecondsToBytes(fmt, 2000));
				source.start();
			}
		}
		catch (RuntimeException ex)
		{
			t = ex;
		}
		catch (LinkageError ex)
		{
			t = ex;	
		}
		catch (LineUnavailableException ex)
		{
			t = ex;	
		}
		
		if (source==null)
			throw new JavaLayerException("cannot obtain source audio line", t);		
	}
	
	public int millisecondsToBytes(AudioFormat fmt, int time)
	{
		return (int)(time*(fmt.getSampleRate()*fmt.getChannels()*fmt.getSampleSizeInBits())/8000.0);
	}
	
	protected void closeImpl()		
	{
		if (source!=null)
		{
			source.close();
		}
	}
	
	protected void writeImpl(short[] samples, int offs, int len)
		throws JavaLayerException
	{
		if (source==null)
			createSource();
		
		byte[] b = toByteArray(samples, offs, len);
		source.write(b, 0, len*2);
	}
	
	protected byte[] getByteArray(int length)
	{
		if (byteBuf.length < length)
		{
			byteBuf = new byte[length+1024];	
		}
		return byteBuf;
	}
	
	protected byte[] toByteArray(short[] samples, int offs, int len)
	{
		byte[] b = getByteArray(len*2);
		int idx = 0;
		short s;
		while (len-- > 0)
		{
			s = samples[offs++];
			b[idx++] = (byte)s;
			b[idx++] = (byte)(s>>>8);
		}
		return b;
	}
	
	protected void flushImpl()
	{
		if (source!=null)
		{
			source.drain();	
		}
	}
	
	public int getPosition()
	{		
		int pos = 0;
		if (source!=null)
		{
			pos = (int)(source.getMicrosecondPosition()/1000);
		}
		return pos;
	}
		
	/**
	 * Runs a short test by playing a short silent sound. 
	 */
	public void test() 
		throws JavaLayerException
	{
		try
		{
			open(new AudioFormat(22050, 16, 1, true, false));
			short[] data = new short[22050/10];
			write(data, 0, data.length);
			flush();
			close();
		}
		catch (RuntimeException ex)
		{
			throw new JavaLayerException("Device test failed: "+ex);
		}
		
	}
}