virtual void CbSignal()
{
int n = Blocksize()/2;
t_sample const *in = InSig(0);
float df = Samplerate()/2/n;
float a = 0,b = 0;
for(int i = 1; i <= n; ++i) {
float f = log(i*df);
a += f*in[i];
b += in[i];
}
centroid = exp(a/b);
if(autobang)
tmr.Now();
}
// override signal function
virtual void CbSignal()
{
_engine.audio_callback(Blocksize(), InSig(), OutSig());
}