SequenceAudioInputStream.java

/*
 *	SequenceAudioInputStream.java
 *
 *	This file is part of jsresources.org
 */

/*
 * Portions Copyright 2006 DFKI GmbH.
 * Portions Copyright (c) 1999 - 2001 by Matthias Pfisterer
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.jsresources;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;

public class SequenceAudioInputStream extends AudioInputStream {

	protected List m_audioInputStreamList;
	protected int m_nCurrentStream;

	public SequenceAudioInputStream(AudioFormat audioFormat, Collection audioInputStreams) {
		super(new ByteArrayInputStream(new byte[0]), audioFormat, AudioSystem.NOT_SPECIFIED);
		m_audioInputStreamList = new ArrayList(audioInputStreams);
		m_nCurrentStream = 0;
		// correct frameLength if possible:
		Iterator streamIterator = m_audioInputStreamList.iterator();
		frameLength = 0;
		while (streamIterator.hasNext()) {
			AudioInputStream stream = (AudioInputStream) streamIterator.next();
			long lLength = stream.getFrameLength();
			if (lLength == AudioSystem.NOT_SPECIFIED) {
				frameLength = AudioSystem.NOT_SPECIFIED;
				break;
			} else {
				frameLength += lLength;
			}
		}
	}

	private AudioInputStream getCurrentStream() {
		return (AudioInputStream) m_audioInputStreamList.get(m_nCurrentStream);
	}

	private boolean advanceStream() {
		m_nCurrentStream++;
		boolean bAnotherStreamAvailable = (m_nCurrentStream < m_audioInputStreamList.size());
		return bAnotherStreamAvailable;
	}

	public int read() throws IOException {
		AudioInputStream stream = getCurrentStream();
		int nByte = stream.read();
		if (nByte == -1) {
			/*
			 * The end of the current stream has been signaled. We try to advance to the next stream.
			 */
			boolean bAnotherStreamAvailable = advanceStream();
			if (bAnotherStreamAvailable) {
				/*
				 * There is another stream. We recurse into this method to read from it.
				 */
				return read();
			} else {
				/*
				 * No more data. We signal EOF.
				 */
				return -1;
			}
		} else {
			/*
			 * The most common case: We return the byte.
			 */
			return nByte;
		}
	}

	public int read(byte[] abData, int nOffset, int nLength) throws IOException {
		AudioInputStream stream = getCurrentStream();
		int nBytesRead = stream.read(abData, nOffset, nLength);
		if (nBytesRead == -1) {
			/*
			 * The end of the current stream has been signaled. We try to advance to the next stream.
			 */
			boolean bAnotherStreamAvailable = advanceStream();
			if (bAnotherStreamAvailable) {
				/*
				 * There is another stream. We recurse into this method to read from it.
				 */
				return read(abData, nOffset, nLength);
			} else {
				/*
				 * No more data. We signal EOF.
				 */
				return -1;
			}
		} else {
			/*
			 * The most common case: We return the length.
			 */
			return nBytesRead;
		}
	}

	public long skip(long lLength) throws IOException {
		throw new IOException("skip() is not implemented in class SequenceInputStream. Mail if you need this feature.");
	}

	public int available() throws IOException {
		return getCurrentStream().available();
	}

	public void close() throws IOException {
		// TODO: should we close all streams in the list?
	}

	public void mark(int nReadLimit) {
		throw new RuntimeException("mark() is not implemented in class SequenceInputStream. Mail if you need this feature.");
	}

	public void reset() throws IOException {
		throw new IOException("reset() is not implemented in class SequenceInputStream. Mail if you need this feature.");
	}

	public boolean markSupported() {
		return false;
	}

}