MFCC real time?

can i use mfcc real time?

Depends on the processing power available surely? I presume you mean Practical Cryptography

esp32 can do it?

I suspect few have tried this. Are there any Arduino libraries for this - if not it suggests no-one's tried it, although some of the faster Arduino's should be viable I would guess.

Do you have any code samples for me to study?

No, no experience with MFCC or I've have said. I presume you've not found any existing Arduino libraries?

What are you actually trying to do?