/*
* Copyright (c) 2007 - 2008 by Damien Di Fede <ddf@compartmental.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package ddf.minim.effects;
/**
* HighPassSP is a single pole high pass filter. It is not super high quality, but it gets
* the job done.
*
* @author Damien Di Fede
*
*/
public class HighPassSP extends IIRFilter
{
/**
* Constructs a high pass filter with a cutoff frequency of <code>freq</code> that will be
* used to filter audio recorded at <code>sampleRate</code>.
*
* @param freq the cutoff frequency
* @param sampleRate the sample rate of audio that will be filtered
*/
public HighPassSP(float freq, float sampleRate)
{
super(freq, sampleRate);
}
protected void calcCoeff()
{
float fracFreq = frequency()/sampleRate();
float x = (float)Math.exp(-2 * Math.PI * fracFreq);
a = new float[] { (1+x)/2, -(1+x)/2 };
b = new float[] { x };
}
}