- refactored

common/fft/pfftfilt.m

@@ -0,0 +1,51 @@
+% pfftfilt(x,b)
+function y = pfftfilt(x,h,P,S,L)
+
+N = length(h);
+Lx = length(x);
+C = 2^ceil(log(L+S*L-1)/log(2));
+Np = S*L;
+K = Lx/L;
+
+y = zeros(Lx,1);
+Hp = zeros(C,P);
+Xkps = zeros(C,S*P);
+yk = zeros(C,1);
+Y  = zeros(C,1);
+xzp = zeros(Lx+C-L,1);
+pidTbl = [2:P*S];
+pidTbl(P*S) = 1;
+pStbl = [0:P*S-1];
+pStbl(1) = 10;
+
+pid = 1;
+
+% h(k) => Hp(k)
+for p=1:P,
+  Hp(1:C,p) = fft([h((p-1)*Np+1:p*Np);zeros(C-Np,1)],C);
+end;
+
+xzp(C-L+1:Lx+C-L) = x;
+
+for k=1:K,
+  
+  kL = (k-1)*L;
+  
+  Xkps(1:C,pid) = fft(xzp(kL+1:kL+C),C);
+    
+  pS = pid;
+  Y = Hp(1:C,1).*Xkps(1:C,pid);
+  for p=2:P,
+    for i = 1:S
+      pS = pStbl(pS);
+    end;
+    Y   = Y + Hp(1:C,p).*Xkps(1:C,pS);
+  end;
+
+  yk = ifft(Y,C);
+ 
+  y(kL+1:kL+L) = yk(C-L+1:C);
+ 
+  pid = pidTbl(pid);
+
+end;