winamp/Src/Winamp/benskiQ/Biquad.h

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2024-09-24 12:54:57 +00:00
#pragma once
class Biquad
{
public:
Biquad();
void copy_filter(const Biquad &other);
void SetSampleRate(double fs);
void set_freq(double f0);
void set_s_eq(const double b[3], const double a[3]);
void transform_s_to_z();
void process_block(float *dest_ptr, const float *src_ptr, long nbr_spl);
void clear_buffers();
private:
double _s_eq_b[3]; // Coefs for numerator (zeros)
double _s_eq_a[3]; // Coefs for denominator (poles)
double _z_eq_b[3]; // Direct coefficients, order z^(-n)
double _z_eq_a[3]; // Recursive coefficients, order z^(-n)
double sampleRate; // Hz, > 0
double _f0; // Hz, > 0, _f0 % (_sample_freq/2) != 0
double xn[2]; // Input memory, order z^(-n)
double yn[2]; // Output memory, order z^(-n)
int _mem_pos; // 0 or 1
inline double process_sample(double x);
};