i have a dvd , which i have created a d2v of. Now, megui shows max. resized resolution of 720x400, nero recode shows 720x408, and gknot also shows 720x400, but it also shows lower resolutions like 640x352, with which it shows 0.0 aspect ratio error. so, exactly which output resolution should i use for my avs script. i am trying to make a good quality rip using x264.

please help me!

Try opening the d2v file with Aspect, crop the black, and see what's suggested. Green res give the lower AR error. The result is calculated with the bit per pixel average value, so the resolution you can choose depends on the source quality. Sorry if this doesn't help.