desc:Mid/Side Encoder
//tags: utility mid-side processing
//author: Cockos

in_pin:left input
in_pin:right input
out_pin:mid output
out_pin:side output

@sample
spl0orig=spl0;
spl1orig=spl1;
spl0 = (spl0orig+spl1orig) * 0.5;
spl1 = (spl0orig-spl1orig) * 0.5;
