sdrangel/sdrbase/dsp/filterrc.h

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2.0 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2015 F4EXB //
// written by Edouard Griffiths //
// //
// 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 //
// //
// 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 INCLUDE_DSP_FILTERRC_H_
#define INCLUDE_DSP_FILTERRC_H_
#include "dsp/dsptypes.h"
#include "export.h"
/** First order low-pass IIR filter for real-valued signals. */
class SDRBASE_API LowPassFilterRC
{
public:
/**
* Construct 1st order low-pass IIR filter.
*
* timeconst :: RC time constant in seconds (1 / (2 * PI * cutoff_freq)
*/
LowPassFilterRC(Real timeconst);
/**
* Reconfigure filter with new time constant
*/
void configure(Real timeout);
/** Process samples. */
void process(const Real& sample_in, Real& sample_out);
private:
Real m_timeconst;
Real m_y1;
Real m_a1;
Real m_b0;
};
#endif /* INCLUDE_DSP_FILTERRC_H_ */