5ndft_vhdl/winograd5.m

function output = winograd55(input, w)
in = [input(1,:); input(4,:); input(5,:); input(3,:); input(2,:)];
s1 = [in(1,:); in(2,:)+in(4,:); in(3,:)+in(5,:); in(2,:)-in(4,:); in(5,:)-in(3,:)];
s2 = [s1(1,:); s1(2,:)+s1(3,:); s1(3,:)-s1(2,:); s1(4,:); s1(5,:); s1(4,:)+s1(5,:)];
mult = [1 (cos(2*pi/5)+cos(4*pi/5))/2-1 (cos(2*pi/5)-cos(4*pi/5))/2 sin(2*pi/5)-sin(4*pi/5) sin(2*pi/5)+sin(4*pi/5) sin(4*pi/5)];
mult = fi(mult, 1, w, w-2);
mult = mult.data;
s4 = [s2(1,:)+s2(2,:); s2(2,:)*mult(2); s2(3,:)*mult(3); s2(4,:)*1i*mult(4); s2(5,:)*1i*mult(5); s2(6,:)*1i*mult(6)];
s5 = [s4(1,:); s4(1,:)+s4(2,:); s4(3,:); s4(4,:); s4(5,:); s4(6,:)];
s6 = [s5(1,:); s5(2,:)-s5(3,:); s5(2,:)+s5(3,:); s5(4,:)+s5(6,:); s5(6,:)-s5(5,:)];
output = [s6(1,:); s6(3,:)+s6(5,:); s6(2,:)-s6(4,:); s6(2,:)+s6(4,:); s6(3,:)-s6(5,:)];
end

function output = radix2(input, w)

s1 = [input(1) input(2)*w];
output = [s1(1)+s1(2) s1(1)-s1(2)];
end