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function y=udecode(u,n,v,saturatemode)
//Decodes the input uniformly quantized values
//Calling Sequence
//y=uencode(u,n,v,'saturatemode')
//Parameters
//u
//A vector, matrix or n-dimensional array of integers
//n
//An integer between 2 and 32
//v
//A positive real scalar
//'saturatemode'
//A string which can take only 2 values 'saturate' or 'wrap'
//Description
//Uniformly decodes the input vector or n-dimensional array of integers u with peak values +/- v
//If u has only positive values, the range of integers is assumed to be [0,2^n-1]
//If u has positive and negative values the range of integers is assumed to be [-2^(n-1),2^(n-1)-1]
//If v is not specified, its default value is 1
//If saturatemode='wrap' the output is wrapped using modulo arithmetic if overflow occurs
//If saturatemode='saturate' the output is saturated if overflow accors
//Example
//u = int8([-1 1 2 -5]);
//ysat = udecode(u,3)
//ysat =
//
// - 0.25 0.25 0.5 - 1.
//Author
//Ankur Mallick
//[1] International Telecommunication Union. General Aspects of Digital Transmission Systems: Vocabulary of Digital Transmission and Multiplexing, and Pulse Code Modulation (PCM) Terms. ITU-T Recommendation G.701. March, 1993.
//See also
//uencode
//floor
funcprot(0);
if(argn(2)<4)
saturatemode='saturate';
if(argn(2)<3)
v=1;
end
end
if(argn(2)>4|argn(2)<2)
error('Incorrect number of input arguments.');
elseif(saturatemode~='saturate'&saturatemode~='wrap')
error('Saturate mode must be saturate or wrap');
elseif(~isscalar(v)|abs(v)~=v)
error('Peak value must be a positive real scalar');
elseif(~isscalar(n)|round(n)~=n|n<2|n>32)
error('n must be an integer between 2 and 32')
elseif(type(u)~=8)
error('Input value must be an integer');
else
if(inttype(u)==1|inttype(u)==2|inttype(u)==4)
u=u+2^(n-1); //Converting signed to unsigned
end
if(saturatemode=='wrap')
u=pmodulo(double(u),2^n);
end
u(u<0)=0;
u(u>(2^n-1))=2^n-1;
L=2*v/(2^n);
y=L*double(u)-v;
// y(y<-v)=-v;
// y(y>v)=v;
end
endfunction
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