mirror of https://github.com/f4exb/sdrangel.git
55 lines
1.0 KiB
C++
55 lines
1.0 KiB
C++
/*
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* fftfilt.h -- Fast convolution FIR filter
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*/
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#ifndef _FFTFILT_H
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#define _FFTFILT_H
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#include "complex.h"
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#include "gfft.h"
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//----------------------------------------------------------------------
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class fftfilt {
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enum {NONE, BLACKMAN, HAMMING, HANNING};
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protected:
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int flen;
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int flen2;
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g_fft<float> *fft;
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g_fft<float> *ift;
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cmplx *ht;
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cmplx *filter;
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cmplx *timedata;
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cmplx *freqdata;
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cmplx *ovlbuf;
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cmplx *output;
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int inptr;
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int pass;
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int window;
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inline float fsinc(float fc, int i, int len) {
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return (i == len/2) ? 2.0 * fc:
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sin(2 * M_PI * fc * (i - len/2)) / (M_PI * (i - len/2));
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}
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inline float _blackman(int i, int len) {
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return (0.42 -
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0.50 * cos(2.0 * M_PI * i / len) +
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0.08 * cos(4.0 * M_PI * i / len));
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}
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void init_filter();
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public:
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fftfilt(float f1, float f2, int len);
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fftfilt(float f, int len);
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~fftfilt();
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// f1 < f2 ==> bandpass
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// f1 > f2 ==> band reject
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void create_filter(float f1, float f2);
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void rtty_filter(float);
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int run(const cmplx& in, cmplx **out);
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};
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#endif
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