u -Law and Inverse u-Law

The functions u-law and Inverse u law used to perform u-law compression and expansion

function [Cx,Xmax] =  mulaw(x,mu)
  //Non-linear Quantization
  //mulaw: mulaw nonlinear quantization
  //x = input vector
  //Cx = mulaw compressor output
  //Xmax = maximum of input vector x
  Xmax  = max(abs(x));
  if(log(1+mu)~=0)
    Cx = (log(1+mu*abs(x/Xmax))./log(1+mu));
  else
    Cx = x/Xmax;
  end
  
  Cx = Cx/Xmax; //normalization of output vector
endfunction

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function x =  invmulaw(y,mu)
  //Non-linear Quantization
  //invmulaw: inverse mulaw nonlinear quantization
  //x = output vector 
  //y = input vector (using mulaw nonlinear comression)
  x = (((1+mu).^(abs(y))-1)./mu)  
endfunction