SignalSplitter.java

/*
 *  Copyright (c) 2007 - 2008 by Damien Di Fede <ddf@compartmental.net>
 *
 *   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 ddf.minim;

import java.util.Vector;

import ddf.minim.javax.sound.sampled.AudioFormat;

/**
 * A <code>SignalSplitter</code> acts exactly like a headphone splitter. When
 * you pass it audio with the <code>samples</code> method, it echoes that audio
 * out to all of its listeners, giving each their own copy of the audio. In
 * other words, changes that the listeners make to the float arrays they receive
 * from a <code>SignalSplitter</code> will not be reflected in the arrays you
 * pass to <code>samples</code>. <code>SignalSplitter</code> is fully
 * <code>synchronized</code> so that listeners cannot be added and removed while
 * it is in the midst transmitting.
 * 
 * @author Damien Di Fede
 * @invisible
 *
 */

public class SignalSplitter implements Recordable, AudioListener {
	private Vector<AudioListener> listeners;
	private AudioFormat f;
	private int bs;

	/**
	 * Construct a <code>SignalSplitter</code> that will receive audio in the
	 * given format and in buffers the size of <code>bufferSize</code>. Strictly
	 * speaking, a <code>SignalSplitter</code> doesn't care about either of
	 * these things because it does nothing with the samples it receives other
	 * than pass them on. But both things are required to fulfill the
	 * <code>Recordable</code> contract.
	 * 
	 * @param format
	 *            the <code>AudioFormat</code> of samples that this will receive
	 * @param bufferSize
	 *            the size of the float arrays this will receive
	 */
	public SignalSplitter(AudioFormat format, int bufferSize) {
		f = format;
		bs = bufferSize;
		listeners = new Vector<AudioListener>(5);
	}

	public int bufferSize() {
		return bs;
	}

	public AudioFormat getFormat() {
		return f;
	}

	public int type() {
		return f.getChannels();
	}

	public synchronized void addListener(AudioListener listener) {
		if (!listeners.contains(listener)) {
			listeners.add(listener);
		}
	}

	public synchronized void removeListener(AudioListener listener) {
		listeners.remove(listener);
	}

	public synchronized void samples(float[] samp) {
		for (int i = 0; i < listeners.size(); i++) {
			AudioListener al = listeners.get(i);
			float[] copy = new float[samp.length];
			System.arraycopy(samp, 0, copy, 0, copy.length);
			al.samples(copy);
		}
	}

	public synchronized void samples(float[] sampL, float[] sampR) {
		for (int i = 0; i < listeners.size(); i++) {
			AudioListener al = listeners.get(i);
			float[] copyL = new float[sampL.length];
			float[] copyR = new float[sampR.length];
			System.arraycopy(sampL, 0, copyL, 0, copyL.length);
			System.arraycopy(sampR, 0, copyR, 0, copyR.length);
			al.samples(copyL, copyR);
		}
	}

	public float sampleRate() {
		return f.getSampleRate();
	}
}