notchDuck
2-pole resonant band-pass filter (biquad)
Inlets
frac32buffer filter input
frac32buffer add
frac32 pitch
frac32 filter resonance
frac32 duck
Outlets
frac32buffer filter output
Parameters
frac32.s.map.pitch pitch
frac32.u.map.filterq reso
biquad_state bs;
biquad_coefficients bc;
int32_t prev;
int32_t step;
int32_t out[BUFSIZE];
int i;biquad_clearstate(&bs);int32_t freq;
MTOF(param_pitch + inlet_pitch, freq);
biquad_bp_coefs(&bc, freq,
INT_MAX - (__USAT(inlet_reso + param_reso, 27) << 4));
biquad_dsp(&bs, &bc, inlet_in, out);
step = (inlet_duck - prev) >> 4;
int32_t j = prev;
prev = inlet_duck;
for (i = 0; i < BUFSIZE; i++) {
j += step;
outlet_out[i] = inlet_add[i] + inlet_in[i] - ___SMMUL(out[i] << 2, j << 3);
}