DecimationHelp.java

/*
 *  DecimationHelp.java
 *  Eisenkraut
 *
 *  Copyright (c) 2004-2016 Hanns Holger Rutz. All rights reserved.
 *
 *  This software is published under the GNU General Public License v3+
 *
 *
 *	For further information, please contact Hanns Holger Rutz at
 *	contact@sciss.de
 */

package de.sciss.eisenkraut.io;

public class DecimationHelp
{
	public final double	rate;
	public final int	shift;
	public final int	factor;
	public final int	roundAdd;
	public final long	mask;
	
	public DecimationHelp( double fullRate, int shift )
	{
		this.shift		= shift;
		factor			= 1 << shift;
		this.rate		= fullRate / factor;
		roundAdd		= factor >> 1;
		mask			= -factor;
	}
	
	/**
	 *  Converts a frame length from full rate to
	 *  decimated rate and rounds to nearest integer.
	 *
	 *  @param  full	number of frame at full rate
	 *  @return number of frames at this editor's decimated rate
	 */
	public long fullrateToSubsample( long full )
	{
		return( (full + roundAdd) >> shift );
	}
}