hufflen.m

matlab huffman encoder

function HL = hufflen(S)
% Based on probability (or number of occurences) of each symbol 
% the length for the Huffman codewords are calculated.
% 
% HL = hufflen(S);
% ------------------------------------------------------------------
% Arguments:
%  S  a vector with number of occurences or probability of each symbol
%     Only positive elements of S are used, zero (or negative)
%     elements get length 0.
%  HL length (bits) for the codeword for each symbol 
% ------------------------------------------------------------------
% Example:
% hufflen([1,0,4,2,0,1])  =>  ans = [3,0,1,2,0,3]
% hufflen([10,40,20,10])  =>  ans = [3,1,2,3]

%----------------------------------------------------------------------
% Copyright (c) 1999.  Karl Skretting.  All rights reserved.
% Hogskolen in Stavanger (Stavanger University), Signal Processing Group
% Mail:  [e-mail]   Homepage:  http://www.ux.his.no/~karlsk/
% 
% HISTORY:
% Ver. 1.0  28.08.98  KS: Function made as part of Signal Compression Project 98
% Ver. 1.1  25.12.98  English version of program
%----------------------------------------------------------------------

if nargin<1
   error('hufflen: see help.')
end

%  Algorithm "explained" in Norwegian:
%   En bygger opp "treet" ved