samer@0: function o=aolapadd(N,hop)
samer@0: % aolapadd - overlap-and-add signal reconstruction arrow
samer@0: % 
samer@0: % aolapadd ::
samer@0: %    N:natural ~'frame size',
samer@0: %    M:natural ~'hop size'
samer@0: % -> arrow( {[[N]]}, {[[M]]}, [[N-M]]).
samer@0: 
samer@0: 
samer@0: 	I=1:hop;
samer@0: 	ol=N-hop;
samer@0: 
samer@0: 	o=loop1(1,1,@olapadd);
samer@0: 
samer@0: 	function [fn,s0]=olapadd(sz)
samer@0: 		s0=zeros(ol,1);
samer@0: 		if ol<=hop, J=1:ol; K=hop+1:N; fn=ifx(sz(2)==1,@st1,@st2);
samer@0: 		else    J=hop+1:ol; K=ol+1:N; fn=ifx(sz(2)==1,@st3,@st4);
samer@0: 		end
samer@0: 
samer@0: 		function [y,s]=st1(x,s)
samer@0: 			y=x(I);
samer@0: 			y(J)=y(J)+s;
samer@0: 			s=x(K);
samer@0: 		end
samer@0: 
samer@0: 		function [y,s]=st2(x,s)
samer@0: 			width=size(x,2);
samer@0: 			y=zeros(hop,width);
samer@0: 			for i=1:width
samer@0: 				y(:,i)=x(I,i);
samer@0: 				y(J,i)=y(J,i)+s;
samer@0: 				s=x(K,i);
samer@0: 			end
samer@0: 		end
samer@0: 
samer@0: 		function [y,s]=st3(x,s)
samer@0: 			y=(s(I)+x(I));
samer@0: 			s=[s(J)+x(J);x(K)];
samer@0: 		end
samer@0: 
samer@0: 		function [y,s]=st4(x,s)
samer@0: 			width=size(x,2);
samer@0: 			y=zeros(hop,width);
samer@0: 			for i=1:width
samer@0: 				y(:,i)=(s(I)+x(I,i));
samer@0: 				s=[s(J)+x(J,i);x(K,i)];
samer@0: 			end
samer@0: 		end
samer@0: 	end
samer@0: end
samer@0: