samer@0: function u=construct(s,sizes_in)
samer@0: 	src=construct(s.source);
samer@0: 	ch=channels(s.source);
samer@0: 
samer@0: 	span=s.block;
samer@0: 	jump=s.hop;
samer@0: 	olap=span-jump;
samer@0: 	rdr=src.reader(jump);
samer@0: 
samer@0: 	if olap>0
samer@0: 		buf=[zeros(ch,jump),sigreadn(src,olap)]; % preload with overlap
samer@0: 		OL1=1:olap;
samer@0: 		OL=(jump+1):span;
samer@0: 		HOP=(olap+1):span;
samer@0: 		process=@proc;
samer@0: 		fprintf('  Using signal reader with overlap=%d.\n',olap);
samer@0: 	else
samer@0: 		process=@proc0;
samer@0: 		fprintf('  Using zero-overlap signal reader.\n');
samer@0: 	end
samer@0: 
samer@0: 	u=mkunit(s);
samer@0: 	u.starting  = src.start;
samer@0: 	u.stopping  = src.stop;
samer@0: 	u.dispose   = src.dispose;
samer@0: 	u.process   = process;
samer@0: 	u.sizes_out = {[ch,span]};
samer@0: 
samer@0: 	function out=proc0, 
samer@0: 		[out,rem]=rdr();
samer@0: 		if rem>0, error('ARROW:EOF','End of stream'); end
samer@0: 	end
samer@0: 
samer@0: 	function out=proc, 
samer@0: 		buf(:,OL1)=buf(:,OL); % copy overlap from end of buf to head
samer@0: 		[buf(:,HOP),rem]=rdr();
samer@0: 		if rem>0, error('ARROW:EOF','End of stream'); end
samer@0: 		%out=[buf,chunk];
samer@0: 		out=buf;
samer@0: 	end
samer@0: 
samer@0: 	% old version
samer@0: 	function out=proc1, 
samer@0: 		[chunk,rem]=rdr();
samer@0: 		if rem>0, error('ARROW:EOF','End of stream'); end
samer@0: 		out=[buf,chunk];
samer@0: 		buf=out(:,OL);
samer@0: 	end
samer@0: end