function dekoder(inname, outname);
% inname je jmeno souboru se vstupem - napr. out.kod
% outname je jmeno souboru s vystupem - napr. synt.wav

lseg = 200; 
rseg = 120; % shift je tedy 80 => 100 vektoru za sekundu
shift = lseg-rseg; 
P = 10;

%%% read the matrix 
ff = fopen (inname,'r');
inp = fread (ff,[P+2 inf],'float');
fclose (ff);
% get its size 
Nfr = size (inp,2); 
% and separate it into LPC, energy, LAGS
A = [ones(1,Nfr); inp(1:P,:)];
E = inp(P+1,:); 
LAGS = inp(P+2,:); 

%%% generate excitation 
% first part of the first frame will be simply set to zeros. 
exc = zeros(1,lseg);
% define last - position of peak last related to the beginning of NEXT
% VOICED FRAME.
last = 1;
for ii=1:Nfr;
  l=floor(LAGS(ii)); % floor to be sure ...
  % in case of unvoiced frame, generate noise.
  if (l==0)
    e = randn(1,shift);
  % voiced - generate pulses.
  else
    e = zeros(1,shift);
    pulses = last:l:shift;
    % pulses can be only in 1:80. Limit them !
    pulses = pulses(find(pulses >= 1));
    % where is the last pulse ? In case it exists, remember for the next frame
    % and generate the pulses.
    if ~isempty(pulses)
      lastpulse = max(pulses);
      last = -shift -1 + lastpulse; 
      e(pulses) = 1;
    % if there's no pulse, just re-compute the position of the last
    % generate nothing, let zeros. 
    else
      last = last - shift;
    end
  end
  % add just generated excitation to the global one:
  exc = [exc e];
end

%%%%%%%%%%% divide excitation again into frames ... 
er = frame (exc, lseg, rseg);
synt = zeros(1,lseg);
for ii=1:Nfr,
  e = er(:,ii); 
  a = A (:,ii);
  ss = filter(1,a,e); % has 200 samples but I want just 80 !
  ss = ss(rseg+1:lseg);
  % now must correct the energy 
  Ewanted = E(ii);
  Eactual = 1/shift * sum(ss.^2);
  ratio = Ewanted / Eactual;
  ss = ss * sqrt(ratio);
  synt = [synt ss'];
end

plot(synt); title('synt');
soundsc(synt);
wavwrite(synt,8000,16,outname);