cceps (complex cepstrum) function in Matlab

My doubt is in regards to the usage of the function cceps in Matlab.

The function is giving me the cepstrum for the entire speech signal of 3 or 4sec. This works well when I play back the signal after taking the inverse (using theicceps function). However, in order to analyze the given speech signal, we are supposed to only consider 20ms frame.

Is taking the complex cepstrum throughout the signal valid? Why is it working out here?

• Matlab cceps provided two ways to calculate the ceptrum, the default way is to use fft and phase unwrap， But I found it, at least in my condition, it often gave the wrong answer and the second method is also unreliable. I doulbt if using 20-30ms can solve this problem? I mean neither long signal nor short signal is reliable for cceps in matlab. – QZHua Jan 8 '18 at 3:49

• If my purpose of using complex cepstrum is not to analyze signal change every frame, but to use it only for compression of the entire speech signal, then is it correct to cceps function over the entire .wav file? – Shabaz Dec 27 '13 at 2:47