161   double w0, A, alpha, mult;  in start()  local
182   alpha = 0, mult = dB_to_linear(max(p->gain, 0));  in start()
195       alpha = sin(w0)/2 * sqrt((A + 1/A)*(1/p->width - 1) + 2);  in start()
199       alpha = sin(w0)/(2*p->width);  in start()
203       alpha = sin(w0)*sinh(log(2.)/2 * p->width * w0/sin(w0));  in start()
207       alpha = sin(w0)/(2*p->fc/p->width);  in start()
213       alpha = tan(M_PI * p->width / effp->in_signal.rate);  in start()
221       p->a0 =   1 + alpha;  in start()
223       p->a2 =   1 - alpha;  in start()
230       p->a0 =   1 + alpha;  in start()
232       p->a2 =   1 - alpha;  in start()
239       p->a0 =   1 + alpha;  in start()
241       p->a2 =   1 - alpha;  in start()
245       p->b0 =   alpha;  in start()
247       p->b2 =  -alpha;  in start()
248       p->a0 =   1 + alpha;  in start()
250       p->a2 =   1 - alpha;  in start()
257       p->a0 =   1 + alpha;  in start()
259       p->a2 =   1 - alpha;  in start()
263       p->b0 =   1 - alpha;  in start()
265       p->b2 =   1 + alpha;  in start()
266       p->a0 =   1 + alpha;  in start()
268       p->a2 =   1 - alpha;  in start()
274       p->b0 =   1 + alpha*A;  in start()
276       p->b2 =   1 - alpha*A;  in start()
277       p->a0 =   1 + alpha/A;  in start()
279       p->a2 =   1 - alpha/A;  in start()
285       p->b0 =    A*( (A+1) - (A-1)*cos(w0) + 2*sqrt(A)*alpha );  in start()
287       p->b2 =    A*( (A+1) - (A-1)*cos(w0) - 2*sqrt(A)*alpha );  in start()
288       p->a0 =        (A+1) + (A-1)*cos(w0) + 2*sqrt(A)*alpha;  in start()
290       p->a2 =        (A+1) + (A-1)*cos(w0) - 2*sqrt(A)*alpha;  in start()
298       p->b0 =    A*( (A+1) + (A-1)*cos(w0) + 2*sqrt(A)*alpha );  in start()
300       p->b2 =    A*( (A+1) + (A-1)*cos(w0) - 2*sqrt(A)*alpha );  in start()
301       p->a0 =        (A+1) - (A-1)*cos(w0) + 2*sqrt(A)*alpha;  in start()
303       p->a2 =        (A+1) - (A-1)*cos(w0) - 2*sqrt(A)*alpha;  in start()