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a-EQ: Fixed transfer functions, now boost/cut cancel out correctly

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This commit is contained in:
Damien Zammit 2016-07-14 03:05:54 +10:00
parent b77b3cbe22
commit 08f9fc40dc
1 changed files with 8 additions and 9 deletions
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17
libs/plugins/a-eq.lv2/a-eq.c
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@ -67,14 +67,14 @@ typedef enum {
AEQ_OUTPUT, AEQ_OUTPUT,
} PortIndex; } PortIndex;
static inline float static inline double
to_dB(float g) { to_dB(double g) {
return (20.f*log10(g)); return (20.0*log10(g));
} }
static inline float static inline double
from_dB(float gdb) { from_dB(double gdb) {
return (exp(gdb/20.f*log(10.f))); return (exp(gdb/20.0*log(10.0)));
} }
struct linear_svf { struct linear_svf {
@ -458,7 +458,7 @@ calc_peq(Aeq* self, int i, double omega) {
double A = pow(10.0, self->v_g[i]/40.0); double A = pow(10.0, self->v_g[i]/40.0);
double g = self->v_filter[i].g; double g = self->v_filter[i].g;
double k = self->v_filter[i].k; double k = self->v_filter[i].k * A;
double m1 = k * (A * A - 1.0) / A; double m1 = k * (A * A - 1.0) / A;
H = (g*k*zzm + A*(g*zp*(m1*zm) + (zm*zm + g*g*zp*zp))) / (g*k*zzm + A*(zm*zm + g*g*zp*zp)); H = (g*k*zzm + A*(g*zp*(m1*zm) + (zm*zm + g*g*zp*zp))) / (g*k*zzm + A*(zm*zm + g*g*zp*zp));
@ -635,9 +635,8 @@ render_inline (LV2_Handle instance, uint32_t w, uint32_t max_h)
// plot 20..20kHz +-20dB // plot 20..20kHz +-20dB
const float x_hz = 20.f * powf (1000.f, (float)x / (float)w); const float x_hz = 20.f * powf (1000.f, (float)x / (float)w);
const float y_db = to_dB(eq_curve(self, x_hz)) + self->v_master; const float y_db = to_dB(eq_curve(self, x_hz)) + self->v_master;
const float y = h * -y_db / 40.0 + h / 2; const float y = (float)h * (-y_db / 40.0 + 0.5);
cairo_line_to (cr, x, y); cairo_line_to (cr, x, y);
//printf("(hz,H,db)=(%f, %f, %f)\n", x_hz, from_dB(y_db), y_db);
} }
cairo_stroke_preserve (cr); cairo_stroke_preserve (cr);