Change resolution without re-encoding?

ive been playing with encoding, but i mistakenly set tmpeg to 16:9 instead of 4:3, now my mpeg1 file is uber widescreen, is there any way of changing the resolution by editing the header? are there any programs that do this?

search for ReStream by shh. It can open MPEG1/2 elementary video streams, and edit their preferences such as aspect ratio (but also much more).

cheers mate

when i do this i get a flashing green bar at the bottom of the window, im presuming it cant change the physical resolution so its created empty space. any way of fixing this without re-encode?

i just change the aspec ratio to 4:3 then click write, everything else standard