b@0: function y = MS2LR(x)
b@0: % LR2MS Converts stereo audio signal to MS (mid side).
b@0: % 
b@0: % by Brecht De Man at Centre for Digital Music, 4 June 2013
b@0: 
b@0: if size(x,2) ~= 2
b@0:     error('Function MS2LR needs a stereo audio input file.');
b@0: end
b@0: 
b@0: y = zeros(size(x));
b@0: 
b@0: % L = (M + S)/2, R = (M-S)/2
b@0: y(:,1) = (x(:,1)+x(:,2))/2; % left channel
b@0: y(:,2) = (x(:,1)-x(:,2))/2; % right channel
b@0: 
b@0: end