計算Mel倒譜系數的matlab程序：
MELCEPST Calculate the mel cepstrum of a signal C=(S,FS,W,NC,P,N,INC,FL,FH)
使用: c=melcepst(s,fs) ％ calculate mel cepstrum with 12 coefs, 256 sample frames
This function provides an ARMA spectral estimate which is maximum entropy satisfying correlation constraint (number of poles)and cepstrum constrains (number of ceros)
