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			47 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			47 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|  | ///////////////////////////////////////////////////////////////////////////////////
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|  | // Copyright (C) 2020 Jon Beniston, M7RCE                                        //
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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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|  | 
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|  | #ifndef INCLUDE_GOERTZEL_H
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|  | #define INCLUDE_GOERTZEL_H
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|  | 
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|  | #include <complex>
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|  | 
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|  | #include "export.h"
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|  | 
 | ||
|  | // Goertzel filter for calculting discrete Fourier transform for a single frequency
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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 | ||
|  | { | ||
|  | public: | ||
|  |     Goertzel(double frequency, int sampleRate); | ||
|  |     void reset(); | ||
|  |     void filter(double sample); | ||
|  |     std::complex<double> goertzel(double lastSample); | ||
|  |     double mag(); | ||
|  |     double phase(); | ||
|  |     int size() { return m_sampleCount; } | ||
|  | 
 | ||
|  | private: | ||
|  |     double m_s0, m_s1, m_s2; | ||
|  |     double m_a, m_b; | ||
|  |     std::complex<double> m_c, m_z; | ||
|  |     int m_sampleCount; | ||
|  | }; | ||
|  | 
 | ||
|  | #endif // INCLUDE_GOERTZEL_H
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