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sdrangel/sdrbase/dsp/recursivefilters.h

50 lines
2.1 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2017 Edouard Griffiths, F4EXB //
// //
// 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 as version 3 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 V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#ifndef SDRBASE_DSP_RECURSIVEFILTERS_H_
#define SDRBASE_DSP_RECURSIVEFILTERS_H_
#include "export.h"
/**
* \Brief: This is a second order bandpass filter using recursive method. r is in range ]0..1[ the higher the steeper the filter.
* inspired by:http://www.ece.umd.edu/~tretter/commlab/c6713slides/FSKSlides.pdf
*/
class SDRBASE_API SecondOrderRecursiveFilter
{
public:
SecondOrderRecursiveFilter(float samplingFrequency, float centerFrequency, float r);
~SecondOrderRecursiveFilter();
void setFrequencies(float samplingFrequency, float centerFrequency);
void setR(float r);
short run(short sample);
float run(float sample);
private:
void init();
float m_r;
float m_frequencyRatio;
float m_f;
float m_v[3];
};
#endif /* SDRBASE_DSP_RECURSIVEFILTERS_H_ */