mirror of https://github.com/f4exb/sdrangel.git
95 lines
3.7 KiB
C++
95 lines
3.7 KiB
C++
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// Copyright (C) 2015-2016, 2018, 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
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// //
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// See: http://www.embedded.com/design/connectivity/4025660/Detecting-CTCSS-tones-with-Goertzel-s-algorithm //
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// //
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// This program is free software; you can redistribute it and/or modify //
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// it under the terms of the GNU General Public License as published by //
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// the Free Software Foundation as version 3 of the License, or //
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// (at your option) any later version. //
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// //
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// This program is distributed in the hope that it will be useful, //
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// but WITHOUT ANY WARRANTY; without even the implied warranty of //
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
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// GNU General Public License V3 for more details. //
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// //
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// You should have received a copy of the GNU General Public License //
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// along with this program. If not, see <http://www.gnu.org/licenses/>. //
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//////////////////////////////////////////////////////////////////////////////////////////////////////////////
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#ifndef INCLUDE_GPL_DSP_CTCSSDETECTOR_H_
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#define INCLUDE_GPL_DSP_CTCSSDETECTOR_H_
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#include "dsp/dsptypes.h"
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#include "export.h"
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#include "ctcssfrequencies.h"
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/** CTCSSDetector: Continuous Tone Coded Squelch System
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* tone detector class based on the Modified Goertzel
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* algorithm.
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*/
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class SDRBASE_API CTCSSDetector {
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public:
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CTCSSDetector();
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virtual ~CTCSSDetector();
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// setup the basic parameters and coefficients
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void setCoefficients(
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int N, // the algorithm "block" size
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int sampleRate // input signal sample rate
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);
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// set the detection threshold
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void setThreshold(double thold);
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// analyze a sample set and optionally filter the tone frequencies.
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bool analyze(Real *sample); // input signal sample
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// get the number of defined tones.
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static int getNTones() {
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return CTCSSFrequencies::m_nbFreqs;
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}
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// get the tone set
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static const Real *getToneSet() {
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return CTCSSFrequencies::m_Freqs;
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}
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// get the currently detected tone, if any
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bool getDetectedTone(int &maxTone) const
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{
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maxTone = m_maxPowerIndex;
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return m_toneDetected;
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}
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// Get the max m_power at the detected tone.
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Real getMaxPower() const {
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return m_maxPower;
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}
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void reset(); // reset the analysis algorithm
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protected:
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// Override these to change behavior of the detector
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virtual void initializePower();
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virtual void evaluatePower();
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void feedback(Real sample);
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void feedForward();
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private:
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int m_N;
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int m_sampleRate;
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int m_samplesProcessed;
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int m_maxPowerIndex;
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bool m_toneDetected;
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Real m_maxPower;
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Real *m_k;
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Real *m_coef;
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Real *m_u0;
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Real *m_u1;
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Real *m_power;
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};
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#endif /* INCLUDE_GPL_DSP_CTCSSDETECTOR_H_ */
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