ChunkOffsetBox.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2011, Red Hat, Inc. and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This 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 software 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.restcomm.media.resource.player.video.mpeg;

import java.io.DataInputStream;
import java.io.IOException;

/**
 * <b>8.7.5.1 Definition</b>
 * <ul>
 * </li>
 * Box Type: �?stco’, �?co64’</li>
 * <li>Container: Sample Table Box (�?stbl’)</li>
 * <li>Mandatory: Yes</li>
 * <li>Quantity: Exactly one variant must be present</li>
 * </ul>
 * <p>
 * The chunk offset table gives the index of each chunk into the containing file. There are two variants, permitting the
 * use of 32-bit or 64-bit offsets. The latter is useful when managing very large presentations. At most one of these
 * variants will occur in any single instance of a sample table.
 * </p>
 * <p>
 * Offsets are file offsets, not the offset into any box within the file (e.g. Media Data Box). This permits referring
 * to media data in files without any box structure. It does also mean that care must be taken when constructing a
 * self-contained ISO file with its metadata (Movie Box) at the front, as the size of the Movie Box will affect the
 * chunk offsets to the media data.
 * </p>
 * 
 * @author amit bhayani
 * 
 */
public class ChunkOffsetBox extends FullBox {

	// File Type = stsd
	static byte[] TYPE = new byte[] { AsciiTable.ALPHA_s, AsciiTable.ALPHA_t, AsciiTable.ALPHA_c, AsciiTable.ALPHA_o };
	static String TYPE_S = "stco";
	static {
		bytetoTypeMap.put(TYPE, TYPE_S);
	}

	private long[] chunkOffset;

	public ChunkOffsetBox(long size) {
		super(size, TYPE_S);
	}

	@Override
	protected int load(DataInputStream fin) throws IOException {
		super.load(fin);

		long entryCount = readU32(fin);
		chunkOffset = new long[(int)entryCount];
		for (int i = 0; i < entryCount; i++) {
			chunkOffset[i] = this.readU32(fin);
		}

		return (int) this.getSize();

	}

	public long[] getChunkOffset() {
		return chunkOffset;
	}

}