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MIDI music and soundfonts work

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John Alanbrook
2022-07-10 18:04:24 +00:00
parent e57bf668c2
commit d8640bed5a
6 changed files with 63 additions and 45 deletions
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60
source/engine/iir.c
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@@ -43,6 +43,7 @@
#include "limits.h"
#include "iir.h"
#include "dsp.h"
#include "log.h"
/**********************************************************************
binomial_mult - multiplies a series of binomials together and returns
@@ -649,17 +650,25 @@ float *fir_bpf(int n, double fcf1, double fcf2)
/* Biquad filters */
struct dsp_iir biquad_iir()
struct dsp_iir make_iir(int cofs, int order)
{
struct dsp_iir new;
new.dcof = malloc(sizeof(float) * 3);
new.ccof = malloc(sizeof(float) * 3);
new.dx = malloc(sizeof(float) * 3);
new.dy = malloc(sizeof(float) * 3);
new.n = 3;
new.n = cofs;
new.order = order;
new.dcof = calloc(sizeof(float), cofs *order);
new.ccof = calloc(sizeof(float), cofs *order);
new.dx = calloc(sizeof(float), cofs *order);
new.dy = calloc(sizeof(float), cofs *order);
return new;
}
struct dsp_iir biquad_iir()
{
return make_iir(3, 1);
}
void biquad_iir_fill(struct dsp_iir bq, double *a, double *b)
{
bq.ccof[0] = (b[0] / a[0]);
@@ -842,7 +851,7 @@ void p2_ccalc(double fcf, double p, double g, double *a, double *b)
double w0 = tan(M_PI * fcf);
double k[2];
k[0] = p * w0;
k[1] = g * pow2(w0);
k[1] = g * pow(w0, 2);
a[0] = k[1] / (1 + k[0] + k[1]);
a[1] = 2 * a[0];
@@ -962,8 +971,8 @@ struct dsp_iir che_lp(int order, double fcf, double e)
double a = tan(M_PI * fcf);
double a2 = pow2(a);
double u = log((1.f + sqrt(1.f + pow2(e)))/e);
double a2 = pow(a, 2);
double u = log((1.f + sqrt(1.f + pow(e, 2)))/e);
double su = sinh(u/new.order);
double cu = cosh(u/new.order);
double b, c, s;
@@ -973,7 +982,7 @@ struct dsp_iir che_lp(int order, double fcf, double e)
{
b = sin(M_PI * (2.f*i + 1.f)/(2.f*new.order)) * su;
c = cos(M_PI * (2.f*i + 1.f)/(2.f*new.order)) * cu;
c = pow2(b) + pow2(c);
c = pow(b, 2) + pow(c, 2);
s = a2*c + 2.f*a*b + 1.f;
double A = a2/(4.f);
@@ -994,8 +1003,8 @@ struct dsp_iir che_hp(int order, double fcf, double e)
struct dsp_iir new = che_lp(order, fcf, e);
double a = tan(M_PI * fcf);
double a2 = pow2(a);
double u = log((1.f + sqrt(1.f + pow2(e)))/e);
double a2 = pow(a, 2);
double u = log((1.f + sqrt(1.f + pow(e, 2)))/e);
double su = sinh(u/new.order);
double cu = cosh(u/new.order);
double b, c, s;
@@ -1005,7 +1014,7 @@ struct dsp_iir che_hp(int order, double fcf, double e)
{
b = sin(M_PI * (2.f*i + 1.f)/(2.f*new.order)) * su;
c = cos(M_PI * (2.f*i + 1.f)/(2.f*new.order)) * cu;
c = pow2(b) + pow2(c);
c = pow(b, 2) + pow(c, 2);
s = a2*c + 2.f*a*b + 1.f;
double A = 1.f/(4.f);
@@ -1031,10 +1040,10 @@ struct dsp_iir che_bp(int order, double s, double fcf1, double fcf2, double e)
struct dsp_iir new = p2_iir_order(order);
double a = cos(M_PI*(fcf1+fcf2)/2) / cos(M_PI*(fcf2-fcf1)/s);
double a2 = pow2(a);
double a2 = pow(a, 2);
double b = tan(M_PI*(fcf2-fcf1)/s);
double b2 = pow2(b);
double u = log((1.f+sqrt(1.f+pow2(e)))/e);
double b2 = pow(b, 2);
double u = log((1.f+sqrt(1.f+pow(e, 2)))/e);
double su = sinh(2.f*u/new.order);
double cu = cosh(2.f*u/new.order);
double A = b2/(4.f);
@@ -1043,7 +1052,7 @@ struct dsp_iir che_bp(int order, double s, double fcf1, double fcf2, double e)
for (int i = 0; i < new.order; ++i) {
r = sin(M_PI*(2.f*i+1.f)/new.order)*su;
c = cos(M_PI*(2.f*i+1.f)/new.order)*su;
c = pow2(r) + pow2(c);
c = pow(r, 2) + pow(c, 2);
s = b2*c + 2.f*b*r + 1.f;
new.ccof[0*i] = ep * 1.f/A;
@@ -1060,7 +1069,7 @@ struct dsp_iir che_bp(int order, double s, double fcf1, double fcf2, double e)
return new;
}
struct dsp_iir che_notch(int order, double fcf1, double fcf2, double e)
struct dsp_iir che_notch(int order, double s, double fcf1, double fcf2, double e)
{
if (order %4 != 0) {
YughWarn("Tried to make a filter with wrong order. Given order was %d, but order should be 4, 8, 12, ...", order);
@@ -1068,29 +1077,30 @@ struct dsp_iir che_notch(int order, double fcf1, double fcf2, double e)
int n = order / 4;
double ep = 2.f/e;
struct dsp_iir new = p2_iir_order(order);
double a = cos(M_PI*(fcf1+fcf2)/2) / cos(M_PI*(fcf2-fcf1)/s);
double a2 = pow2(a);
double a2 = pow(a, 2);
double b = tan(M_PI*(fcf2-fcf1)/s);
double b2 = pow2(b);
double u = log((1.f+sqrt(1.f+pow2(e)))/e);
double b2 = pow(b, 2);
double u = log((1.f+sqrt(1.f+pow(e, 2)))/e);
double su = sinh(2.f*u/n);
double cu = cosh(2.f*u/n);
double A = b2/(4.f*s);
double r, c, s;
double r, c;
for (int i = 0; i < new.order; ++i) {
r = sin(M_PI*(2.f*i+1.f)/new.order)*su;
c = cos(M_PI*(2.f*i+1.f)/ew.order)*su;
c = pow2(r) + pow2(c);
c = cos(M_PI*(2.f*i+1.f)/new.order)*su;
c = pow(r, 2) + pow(c, 2);
s = b2*c + 2.f*b*r + 1.f;
new.ccof[0*i] = ep * 1.f/A;
new.ccof[1*i] = ep * -2.f/A;
new.ccof[2*i] = ep * 1.f/A;
new.ddof[0*i] = 0.f;
new.dcof[0*i] = 0.f;
new.dcof[1*i] = ep * 4.f*a*(c+b*r)/s;
new.dcof[2*i] = ep * 2.f*(b2-2.f*a2*c-c)/s;
new.dcof[3*i] = ep * 4.f*a*(c-b*r)/s;