33 lines
663 B
C
33 lines
663 B
C
/**
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* @file rem_goertzel.h Goertzel algorithm
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*
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* Copyright (C) 2010 Creytiv.com
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*/
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/** Defines the goertzel algorithm state */
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struct goertzel {
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double q1; /**< current state */
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double q2; /**< previous state */
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double coef; /**< coefficient */
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};
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void goertzel_init(struct goertzel *g, double freq, unsigned srate);
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void goertzel_reset(struct goertzel *g);
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double goertzel_result(struct goertzel *g);
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/**
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* Process sample
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*
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* @param g Goertzel state
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* @param samp Sample value
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*/
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static inline void goertzel_update(struct goertzel *g, int16_t samp)
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{
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double q0 = g->coef*g->q1 - g->q2 + (double)samp;
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g->q2 = g->q1;
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g->q1 = q0;
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}
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