www.pudn.com > huffman.rar > huffcode.m

function HK = huffcode(HL,Display) 
% Based on the codeword lengths this function find the Huffman codewords 
% 
% HK = huffcode(HL,Display); 
% HK = huffcode(HL); 
% ------------------------------------------------------------------
% Arguments: 
%  HL     length (bits) for the codeword for each symbol  
%         This is usually found by the hufflen function 
%  HK     The Huffman codewords, a matrix of ones or zeros 
%         the code for each symbol is a row in the matrix 
%         Code for symbol S(i) is: HK(i,1:HL(i)) 
%         ex: HK(i,1:L)=[0,1,1,0,1,0,0,0] and HL(i)=6 ==>  
%             Codeword for symbol S(i) = '011010' 
%  Display==1  ==> Codewords are displayed on screen, Default=0 
% ------------------------------------------------------------------ 
 
%---------------------------------------------------------------------- 
% Copyright (c) 1999.  Karl Skretting.  All rights reserved. 
% Hogskolen in Stavanger (Stavanger University), Signal Processing Group 
% Mail:  karl.skretting@tn.his.no   Homepage:  http://www.ux.his.no/~karlsk/ 
%  
% HISTORY: 
% Ver. 1.0  25.08.98  KS: Function made as part of Signal Compression Project 98 
% Ver. 1.1  25.12.98  English version of program 
%---------------------------------------------------------------------- 
 
if nargin<1 
   error('huffcode: see help.') 
end 
if nargin<2 
  Display = 0; 
end 
if (Display ~= 1) 
   Display = 0; 
end 
 
N=length(HL); 
L=max(HL); 
HK=zeros(N,L); 
[HLs,HLi] = sort(HL); 
Code=zeros(1,L);  
for n=1:N 
   if (HLs(n)>0) 
      HK(HLi(n),:) = Code; 
      k = HLs(n); 
      while (k>0)                 % actually always!  break ends loop 
         Code(k) = Code(k) + 1; 
         if (Code(k)==2) 
            Code(k) = 0; 
            k=k-1; 
         else 
            break 
         end 
      end 
   end 
end 
 
if Display 
   for n=1:N 
      Linje = ['  Symbol ',int2str(n)]; 
      for i=length(Linje):15 
         Linje = [Linje,' ']; 
      end 
      Linje = [Linje,'  gets code: ']; 
      for i=1:HL(n) 
         if (HK(n,i)==0) 
            Linje = [Linje,'0']; 
         else 
            Linje = [Linje,'1']; 
         end 
      end 
      disp(Linje); 
   end 
end          
    
return;