SLConfigDescriptor.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;

//ISO 14496-1 - 10.2.3
//TODO: not working: reads too much! did the specification change?
public class SLConfigDescriptor extends Descriptor {

	private boolean useAccessUnitStart, useAccessUnitEnd, useRandomAccessPoint,
			usePadding, useTimeStamp, useWallClockTimeStamp, useIdle, duration;
	private long timeStampResolution, ocrResolution;
	private int timeStampLength, ocrLength, instantBitrateLength,
			degradationPriorityLength, seqNumberLength;
	private long timeScale;
	private int accessUnitDuration, compositionUnitDuration;
	private long wallClockTimeStamp, startDecodingTimeStamp, startCompositionTimeStamp;
	private boolean ocrStream;
	private int ocrES_ID;

	@Override
	void decode(MP4InputStream in) throws IOException {
		int tmp;

		final boolean predefined = in.read()==1;
		if(!predefined) {
			//flags
			tmp = in.read();
			useAccessUnitStart = ((tmp>>7)&1)==1;
			useAccessUnitEnd = ((tmp>>6)&1)==1;
			useRandomAccessPoint = ((tmp>>5)&1)==1;
			usePadding = ((tmp>>4)&1)==1;
			useTimeStamp = ((tmp>>3)&1)==1;
			useWallClockTimeStamp = ((tmp>>2)&1)==1;
			useIdle = ((tmp>>1)&1)==1;
			duration = (tmp&1)==1;

			timeStampResolution = in.readBytes(4);
			ocrResolution = in.readBytes(4);
			timeStampLength = in.read();
			ocrLength = in.read();
			instantBitrateLength = in.read();
			tmp = in.read();
			degradationPriorityLength = (tmp>>4)&15;
			seqNumberLength = tmp&15;

			if(duration) {
				timeScale = in.readBytes(4);
				accessUnitDuration = (int) in.readBytes(2);
				compositionUnitDuration = (int) in.readBytes(2);
			}

			if(!useTimeStamp) {
				if(useWallClockTimeStamp) wallClockTimeStamp = in.readBytes(4);
				tmp = (int) Math.ceil((double) (2*timeStampLength)/8);
				final long tmp2 = in.readBytes(tmp);
				final long mask = ((1<<timeStampLength)-1);
				startDecodingTimeStamp = (tmp2>>timeStampLength)&mask;
				startCompositionTimeStamp = tmp2&mask;
			}
		}

		tmp = in.read();
		ocrStream = ((tmp>>7)&1)==1;
		if(ocrStream) ocrES_ID = (int) in.readBytes(2);
	}
}