How to remove (obscure) a logo

[mrlewp]

Isnt the timestamp on a home video equivalent to a TV logo? Anyway, I tinkered with the logo tool, and get nothing. I have no
idea how it's supposed to work. I was not expecting the timestamp to be gone, but blurred maybe? I read info at the Wiki site,
but only found stuff about command lines ? , or that's what it looked like.
How does it work?