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A standalone RTMP client library ported from the Red5 project
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package org.red5.io.mp4;

/*
 * RED5 Open Source Flash Server - http://code.google.com/p/red5/
 * 
 * Copyright (c) 2006-2007 by respective authors (see below). All rights reserved.
 * 
 * This library 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 2.1 of the License, or (at your option) any later 
 * version. 
 * 
 * This library 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 this library; if not, write to the Free Software Foundation, Inc., 
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
 */

/**
 This software module was originally developed by Apple Computer, Inc.
 in the course of development of MPEG-4. 
 This software module is an implementation of a part of one or 
 more MPEG-4 tools as specified by MPEG-4. 
 ISO/IEC gives users of MPEG-4 free license to this
 software module or modifications thereof for use in hardware 
 or software products claiming conformance to MPEG-4.
 Those intending to use this software module in hardware or software
 products are advised that its use may infringe existing patents.
 The original developer of this software module and his/her company,
 the subsequent editors and their companies, and ISO/IEC have no
 liability for use of this software module or modifications thereof
 in an implementation.
 Copyright is not released for non MPEG-4 conforming
 products. Apple Computer, Inc. retains full right to use the code for its own
 purpose, assign or donate the code to a third party and to
 inhibit third parties from using the code for non 
 MPEG-4 conforming products.
 This copyright notice must be included in all copies or
 derivative works. Copyright (c) 1999, 2000.
 */

import java.io.IOException;
import java.util.Vector;

/**
 * MP4Descriptor
 * 
 */
public class MP4Descriptor {

	public final static int MP4ES_DescriptorTag = 3;

	public final static int MP4DecoderConfigDescriptorTag = 4;

	public final static int MP4DecSpecificInfoDescriptorTag = 5;

	protected int type;

	protected int size;

	protected int readed;

	protected Vector children = new Vector();

	public MP4Descriptor(int type, int size) {
		super();
		this.readed = 0;
		this.type = type;
		this.size = size;
	}

	public static MP4Descriptor createDescriptor(MP4DataStream bitstream) throws IOException {
		int tag = (int) bitstream.readBytes(1);
		int readed = 1;
		int size = 0;
		int b = 0;
		do {
			b = (int) bitstream.readBytes(1);
			size <<= 7;
			size |= b & 0x7f;
			readed++;
		} while ((b & 0x80) == 0x80);
		MP4Descriptor descriptor = new MP4Descriptor(tag, size);
		switch (tag) {
			case MP4ES_DescriptorTag:
				descriptor.createES_Descriptor(bitstream);
				break;
			case MP4DecoderConfigDescriptorTag:
				descriptor.createDecoderConfigDescriptor(bitstream);
				break;
			case MP4DecSpecificInfoDescriptorTag:
				descriptor.createDecSpecificInfoDescriptor(bitstream);
				break;
			default:
				break;
		}
		bitstream.skipBytes(descriptor.size - descriptor.readed);
		descriptor.readed = readed + descriptor.size;
		return descriptor;
	}

	/**
	 * Loads the MP4ES_Descriptor from the input bitstream.
	 * 
	 * @param bitstream
	 *            the input bitstream
	 */
	@SuppressWarnings("unused")
	public void createES_Descriptor(MP4DataStream bitstream) throws IOException {
		int ES_ID = (int) bitstream.readBytes(2);
		int flags = (int) bitstream.readBytes(1);
		boolean streamDependenceFlag = (flags & (1 << 7)) != 0;
		boolean urlFlag = (flags & (1 << 6)) != 0;
		boolean ocrFlag = (flags & (1 << 5)) != 0;
		readed += 3;
		if (streamDependenceFlag) {
			bitstream.skipBytes(2);
			readed += 2;
		}
		if (urlFlag) {
			int str_size = (int) bitstream.readBytes(1);
			bitstream.readString(str_size);
			readed += str_size + 1;
		}
		if (ocrFlag) {
			bitstream.skipBytes(2);
			readed += 2;
		}
		while (readed < size) {
			MP4Descriptor descriptor = createDescriptor(bitstream);
			children.addElement(descriptor);
			readed += descriptor.getReaded();
		}
	}

	/**
	 * Loads the MP4DecoderConfigDescriptor from the input bitstream.
	 * 
	 * @param bitstream
	 *            the input bitstream
	 */
	@SuppressWarnings("unused")
	public void createDecoderConfigDescriptor(MP4DataStream bitstream) throws IOException {
		int objectTypeIndication = (int) bitstream.readBytes(1);
		int value = (int) bitstream.readBytes(1);
		boolean upstream = (value & (1 << 1)) > 0;
		byte streamType = (byte) (value >> 2);
		value = (int) bitstream.readBytes(2);
		int bufferSizeDB = value << 8;
		value = (int) bitstream.readBytes(1);
		bufferSizeDB |= value & 0xff;
		int maxBitRate = (int) bitstream.readBytes(4);
		int minBitRate = (int) bitstream.readBytes(4);
		readed += 13;
		if (readed < size) {
			MP4Descriptor descriptor = createDescriptor(bitstream);
			children.addElement(descriptor);
			readed += descriptor.getReaded();
		}
	}

	protected int decSpecificDataSize;

	protected long decSpecificDataOffset;

	private byte[] dsid;

	public byte[] getDSID() {
		return dsid;
	}

	/**
	 * Loads the MP4DecSpecificInfoDescriptor from the input bitstream.
	 * 
	 * @param bitstream
	 *            the input bitstream
	 */
	public void createDecSpecificInfoDescriptor(MP4DataStream bitstream) throws IOException {
		decSpecificDataOffset = bitstream.getOffset();
		dsid = new byte[size];
		for (int b = 0; b < size; b++) {
			dsid[b] = (byte) bitstream.readBytes(1);
			readed++;
		}
		decSpecificDataSize = size - readed;
	}

	public long getDecSpecificDataOffset() {
		return decSpecificDataOffset;
	}

	public int getDecSpecificDataSize() {
		return decSpecificDataSize;
	}

	/**
	 * Lookups for a child descriptor with the specified type,
	 * skips the number children with the same type before
	 * finding a result.
	 * 
	 * @param type
	 *            the type of the descriptor.
	 * @param number
	 *            the number of child descriptors to skip
	 * @return the descriptor which was being searched.
	 */
	public MP4Descriptor lookup(int type, int number) {
		int position = 0;
		for (int i = 0; i < children.size(); i++) {
			MP4Descriptor descriptor = children.elementAt(i);
			if (descriptor.getType() == type) {
				if (position >= number) {
					return descriptor;
				}
				position++;
			}
		}
		return null;
	}

	/**
	 * Returns the type of this descriptor.
	 */
	public int getType() {
		return type;
	}

	/**
	 * Gets the number of data bytes which were readed from the stream;
	 * 
	 * @return the number of readed data bytes.
	 */
	public int getReaded() {
		return readed;
	}

	public Vector getChildren() {
		return children;
	}

}