61 lines
1.6 KiB
C++
61 lines
1.6 KiB
C++
|
/*
|
||
|
|
* Copyright (C) 2015-2020 by Jonathan Naylor G4KLX
|
||
|
|
* Copyright (C) 2020 by Geoffrey Merck - F4FXL KC3FRA
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU 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 General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with this program; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "IIRDirectForm1Filter.h"
|
||
|
|
#include "math.h"
|
||
|
|
|
||
|
|
CIIRDirectForm1Filter::CIIRDirectForm1Filter(float b0, float b1, float b2, float , float a1, float a2, float addtionalGaindB) :
|
||
|
|
m_x2(0.0F),
|
||
|
|
m_y2(0.0F),
|
||
|
|
m_x1(0.0F),
|
||
|
|
m_y1(0.0F),
|
||
|
|
m_b0(b0),
|
||
|
|
m_b1(b1),
|
||
|
|
m_b2(b2),
|
||
|
|
m_a1(a1),
|
||
|
|
m_a2(a2),
|
||
|
|
m_additionalGainLin(0.0F)
|
||
|
|
{
|
||
|
|
m_additionalGainLin = ::powf(10.0F, addtionalGaindB / 20.0F);
|
||
|
|
}
|
||
|
|
|
||
|
|
float CIIRDirectForm1Filter::filter(float sample)
|
||
|
|
{
|
||
|
|
float output = m_b0 * sample
|
||
|
|
+ m_b1 * m_x1
|
||
|
|
+ m_b2 * m_x2
|
||
|
|
- m_a1 * m_y1
|
||
|
|
- m_a2 * m_y2;
|
||
|
|
|
||
|
|
m_x2 = m_x1;
|
||
|
|
m_y2 = m_y1;
|
||
|
|
m_x1 = sample;
|
||
|
|
m_y1 = output;
|
||
|
|
|
||
|
|
return output * m_additionalGainLin;
|
||
|
|
}
|
||
|
|
|
||
|
|
void CIIRDirectForm1Filter::reset()
|
||
|
|
{
|
||
|
|
m_x1 = 0.0f;
|
||
|
|
m_x2 = 0.0f;
|
||
|
|
m_y1 = 0.0f;
|
||
|
|
m_y2 = 0.0f;
|
||
|
|
}
|