samer@0: function Y=unbuffer(X,hop)
samer@0: % UNBUFFER - Opposite of buffer using overlap and add (for sequences)
samer@0: % 
samer@0: % Usage: x=unbuffer(X,hop)
samer@0: %	X:	sequences of [[N]] frames of signal data
samer@0: %	hop:	Determines how much overlap there is between neighbouring frames
samer@0: 
samer@0: 
samer@0: 	if isa(hop,'data')
samer@0: 		Y=zipaccum(@olap2,[],{hop,X});
samer@0: 	else
samer@0: 		if isscalar(hop)
samer@0: 			N=max(size(X));
samer@0: 			ol=N-hop;
samer@0: 			if ol<=hop
samer@0: 				I=1:hop; J=1:ol; K=hop+1:N;
samer@0: 				Y=sfndata(@olap1,zeros(ol,1),X);
samer@0: 			else
samer@0: 				I=1:hop; J=hop+1:ol; K=ol+1:N;
samer@0: 				Y=sfndata(@olap3,zeros(ol,1),X);
samer@0: 			end
samer@0: 		else
samer@0: 			Y=zipaccum(@olap2,[],{windowdata(repeat(hop)),X});
samer@0: 		end
samer@0: 	end
samer@0: 
samer@0: 	function [y,s1]=olap1(x,s)
samer@0: 		y=x(I)';
samer@0: 		y(J)=y(J)+s';
samer@0: 		s1=x(K);
samer@0: 	end
samer@0: 
samer@0: 	function [y,s1]=olap3(x,s)
samer@0: 		y=(s(I)+x(I))';
samer@0: 		s1=[s(J)+x(J);x(K)];
samer@0: 	end
samer@0: 
samer@0: 	function [y,s1]=olap2(hop,x,s)
samer@0: 		ls=length(s);
samer@0: 		lx=length(x);
samer@0: 		if lx>=hop
samer@0: 			if ls>=hop
samer@0: 				% NB: this will fail if ls>lx, but this shouldn't happen since ls<=lx-hop
samer@0: 				y=(x(1:hop)+s(1:hop))';
samer@0: 				s1=[s(hop+1:ls)+x(hop+1:ls);x(ls+1:end)];
samer@0: 			else
samer@0: 				y=[x(1:ls)+s;x(ls+1:hop)]';
samer@0: 				s1=x(hop+1:end);
samer@0: 			end
samer@0: 		else
samer@0: 			if ls>=hop
samer@0: 				y=[s(1:lx)+x;s(lx+1:hop)]';
samer@0: 				s1=s(hop+1:end);
samer@0: 			else
samer@0: 				y=zeros(1,hop);
samer@0: 				y(1:ls)=y(1:ls)+s';
samer@0: 				y(1:lx)=y(1:lx)+x';
samer@0: 			end
samer@0: 		end
samer@0: 
samer@0: 		% y=x(1:hop)';
samer@0: 		% ch=min(hop,ls);
samer@0: 		% J=(1:ch)';
samer@0: 		% y(J)=y(J)+s(J)';
samer@0: 		% s1=x(hop+1:end)+[s(ch+1:end);zeros(lx-max(hop,ls),1)];
samer@0: 	end
samer@0: end
samer@0: