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sdrangel/sdrbase/dsp/afsquelch.h
2024-04-20 19:10:18 +02:00

92 lines
3.3 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
// //
// 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 INCLUDE_GPL_DSP_AFSQUELCH_H_
#define INCLUDE_GPL_DSP_AFSQUELCH_H_
#include "dsp/movingaverage.h"
#include "export.h"
/** AFSquelch: AF squelch class based on the Modified Goertzel
* algorithm.
*/
class SDRBASE_API AFSquelch {
public:
// constructor with default values
AFSquelch();
virtual ~AFSquelch();
// setup the basic parameters and coefficients
void setCoefficients(
unsigned int N, //!< the algorithm "block" size
unsigned int nbAvg, //!< averaging size
unsigned int sampleRate, //!< input signal sample rate
unsigned int samplesAttack, //!< number of results before squelch opens
unsigned int samplesDecay, //!< number of results keeping squelch open
const double *tones); //!< center frequency of tones tested
// set the detection threshold
void setThreshold(double _threshold);
// analyze a sample set and optionally filter
// the tone frequencies.
bool analyze(double sample); // input signal sample
bool evaluate(); // evaluate result
// get the tone set
const double *getToneSet() const
{
return m_toneSet;
}
bool open() const {
return m_isOpen;
}
void reset(); // reset the analysis algorithm
protected:
void feedback(double sample);
void feedForward();
private:
unsigned int m_nbAvg; //!< number of power samples taken for moving average
unsigned int m_N;
unsigned int m_sampleRate;
unsigned int m_samplesProcessed;
unsigned int m_samplesAvgProcessed;
unsigned int m_maxPowerIndex;
unsigned int m_nTones;
unsigned int m_samplesAttack;
unsigned int m_attackCount;
unsigned int m_samplesDecay;
unsigned int m_decayCount;
unsigned int m_squelchCount;
bool m_isOpen;
double m_threshold;
double *m_k;
double *m_coef;
double *m_toneSet;
double *m_u0;
double *m_u1;
double *m_power;
std::vector<MovingAverage<double> > m_movingAverages;
};
#endif /* INCLUDE_GPL_DSP_CTCSSDETECTOR_H_ */