2020-11-24 12:31:16 +00:00
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///////////////////////////////////////////////////////////////////////////////////
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2023-11-19 06:43:20 +01:00
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// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
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// written by Christian Daniel //
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// Copyright (C) 2015-2016, 2018-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
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// Copyright (C) 2020 Jon Beniston, M7RCE <jon@beniston.com> //
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2020-11-24 12:31:16 +00:00
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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_GOERTZEL_H
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#define INCLUDE_GOERTZEL_H
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#include <complex>
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#include "export.h"
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2024-07-10 22:37:52 +02:00
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// Goertzel filter for calculating discrete Fourier transform for a single frequency
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2020-11-24 12:31:16 +00:00
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// Implementation supports non-integer multiples of fundamental frequency, see:
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// https://asp-eurasipjournals.springeropen.com/track/pdf/10.1186/1687-6180-2012-56.pdf
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class SDRBASE_API Goertzel
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{
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public:
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Goertzel(double frequency, int sampleRate);
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void reset();
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void filter(double sample);
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std::complex<double> goertzel(double lastSample);
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double mag();
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double phase();
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int size() { return m_sampleCount; }
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private:
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double m_s0, m_s1, m_s2;
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double m_a, m_b;
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std::complex<double> m_c, m_z;
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int m_sampleCount;
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};
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#endif // INCLUDE_GOERTZEL_H
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