56 lines
1.1 KiB
C
56 lines
1.1 KiB
C
#include "math.h"
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#define LIMIT(v,l,u) ((v)<(l)?(l):((v)>(u)?(u):(v)))
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#define DB2LIN(x) ((x) > -90 ? pow(10, (x) * 0.05) : 0)
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/* frequency to rads/sec (angular frequency) */
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#define ANGULAR(fc, fs) (2 * M_PI / (fs) * (fc))
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#define ANGULAR_LIM(fc, fs) (2 * M_PI / (fs) * LIMIT((fc), 1, (fs)/2))
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/* this is pretty gross;
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* it's too easy to define BIQUAD_DOUBLE in one file and not another */
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#ifdef BIQUAD_DOUBLE
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typedef double bq_t;
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#else
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typedef float bq_t;
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#endif
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typedef struct {
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bq_t a1, a2, b0, b1, b2, x1, x2, y1, y2;
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} biquad;
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typedef struct {
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double b0, b1, b2, a0, a1, a2;
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} biquad_interim;
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static float
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whitenoise();
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static void
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biquad_init(biquad *bq);
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/* types: TODO: enum
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0: peaking
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1: lowshelf
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2: highshelf
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3: lowpass
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4: highpass
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5: allpass
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6: bandpass 1
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7: bandpass 2
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8: notch
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9: gain
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*/
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static biquad
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biquad_gen(int type, double fc, double gain, double bw, double fs);
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/* s-plane to z-plane */
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static biquad_interim
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design(double cw, double sw,
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double num0, double num1, double num2,
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double den0, double den1, double den2);
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static bq_t
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biquad_run(biquad *bq, bq_t x);
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#include "crap_util_def.h"
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