Hi Saifi! I read this in the weekly newsletter that the website www.linux-mag.com send me. There are utilities called the *split *and *csplit* which you may try using. But i'm not too sure if you can control the split on timing. It does on size though.
Alternatively, try using Audacity ( I've never used it. So I can't give you an exact method of doing it). The last time I used any audio/video editing was while I was still oblivious of the world of Linux using a software called Blaze Media Pro. Regards, -- Navneet Sreeraman
