function S=tfl(samples,N,M,NFFT,ven);
x=samples;
L=length(x);
nt=round(L/M);
x=[zeros(N-1,1);x];
for i=1:nt-round(N/M)
 j=(i-1)*M+N+1;
 if(ven>0)
  X=20*log10(abs(fft(x(j-N+1:j).*hamming(N),NFFT)));
 else
  X=20*log10(abs(fft(x(j-N+1:j),NFFT)));
 end
 S(:,i)=X(1:NFFT/2);
end