InitialObjectDescriptor.java

/*
 *  Copyright (C) 2011 in-somnia
 * 
 *  This file is part of JAAD.
 * 
 *  JAAD 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 3 of the 
 *  License, or (at your option) any later version.
 *
 *  JAAD 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, see <http://www.gnu.org/licenses/>.
 */
package net.sourceforge.jaad.mp4.od;

import java.io.IOException;
import net.sourceforge.jaad.mp4.MP4InputStream;

/**
 * The <code>InitialObjectDescriptor</code> is a variation of the
 * <code>ObjectDescriptor</code> that shall be used to gain initial access to
 * content.
 *
 * @author in-somnia
 */
public class InitialObjectDescriptor extends Descriptor {

	private int objectDescriptorID;
	private boolean urlPresent, includeInlineProfiles;
	private String url;
	private int odProfile, sceneProfile, audioProfile, visualProfile, graphicsProfile;

	@Override
	void decode(MP4InputStream in) throws IOException {
		//10 bits objectDescriptorID, 1 bit url flag, 1 bit
		//includeInlineProfiles flag, 4 bits reserved
		final int x = (int) in.readBytes(2);
		objectDescriptorID = (x>>6)&0x3FF;
		urlPresent = ((x>>5)&1)==1;
		includeInlineProfiles = ((x>>4)&1)==1;

		if(urlPresent) url = in.readString(size-2);
		else {
			odProfile = in.read();
			sceneProfile = in.read();
			audioProfile = in.read();
			visualProfile = in.read();
			graphicsProfile = in.read();
		}

		readChildren(in);
	}

	/**
	 * The ID uniquely identifies this ObjectDescriptor within its name scope.
	 * It should be within 0 and 1023 exclusively. The value 0 is forbidden and
	 * the value 1023 is reserved.
	 *
	 * @return this ObjectDescriptor's ID
	 */
	public int getObjectDescriptorID() {
		return objectDescriptorID;
	}

	/**
	 * A flag that, if set, indicates that the subsequent profile indications
	 * take into account the resources needed to process any content that may
	 * be inlined.
	 *
	 * @return true if this ObjectDescriptor includes inline profiles
	 */
	public boolean includesInlineProfiles() {
		return includeInlineProfiles;
	}

	/**
	 * A flag that indicates the presence of a URL. If set, no profiles are
	 * present.
	 *
	 * @return true if a URL is present
	 */
	public boolean isURLPresent() {
		return urlPresent;
	}

	/**
	 * A URL String that shall point to another InitialObjectDescriptor. If no
	 * URL is present (if <code>isURLPresent()</code> returns false) this method
	 * returns null.
	 *
	 * @return a URL String or null if none is present
	 */
	public String getURL() {
		return url;
	}

	/**
	 * A flag that indicates the presence of profiles. If set, no URL is
	 * present.
	 *
	 * @return true if profiles are present
	 */
	public boolean areProfilesPresent() {
		return !urlPresent;
	}

	//TODO: javadoc
	public int getODProfile() {
		return odProfile;
	}

	/**
	 * An indication of the scene description profile required to process the
	 * content associated with this InitialObjectDescriptor.<br />
	 * The value should be one of the following:
	 * 0x00: reserved for ISO use
	 * 0x01: ISO 14496-1 XXXX profile
	 * 0x02-0x7F: reserved for ISO use
	 * 0x80-0xFD: user private
	 * 0xFE: no scene description profile specified
	 * 0xFF: no scene description capability required
	 *
	 * @return the scene profile
	 */
	public int getSceneProfile() {
		return sceneProfile;
	}

	/**
	 * An indication of the audio profile required to process the content
	 * associated with this InitialObjectDescriptor.<br />
	 * The value should be one of the following:
	 * 0x00: reserved for ISO use
	 * 0x01: ISO 14496-3 XXXX profile
	 * 0x02-0x7F: reserved for ISO use
	 * 0x80-0xFD: user private
	 * 0xFE: no audio profile specified
	 * 0xFF: no audio capability required
	 *
	 * @return the audio profile
	 */
	public int getAudioProfile() {
		return audioProfile;
	}

	/**
	 * An indication of the visual profile required to process the content
	 * associated with this InitialObjectDescriptor.<br />
	 * The value should be one of the following:
	 * 0x00: reserved for ISO use
	 * 0x01: ISO 14496-2 XXXX profile
	 * 0x02-0x7F: reserved for ISO use
	 * 0x80-0xFD: user private
	 * 0xFE: no visual profile specified
	 * 0xFF: no visual capability required
	 *
	 * @return the visual profile
	 */
	public int getVisualProfile() {
		return visualProfile;
	}

	/**
	 * An indication of the graphics profile required to process the content
	 * associated with this InitialObjectDescriptor.<br />
	 * The value should be one of the following:
	 * 0x00: reserved for ISO use
	 * 0x01: ISO 14496-1 XXXX profile
	 * 0x02-0x7F: reserved for ISO use
	 * 0x80-0xFD: user private
	 * 0xFE: no graphics profile specified
	 * 0xFF: no graphics capability required
	 *
	 * @return the graphics profile
	 */
	public int getGraphicsProfile() {
		return graphicsProfile;
	}
}