Always much simpler, if the person that originally does the encoding of
a transfer/dvdrip, sets the aspect ration correctly to begin with. The
easiest way to determine what the correct aspect ratio from a DVD,
would be to simply look on the back of the DVD box that it came in,
where that info is given almost always. VHS tape Laserdisc transfers,
are even simpler. Without exception, they're always 4:3.
Any movie or video that I download from someone else, that I plan on
keeping for myself, is always corrected with another encode, and the
original out of kilter video thrown away.
The below site, is great in helping one determine the resolutions for
any particular video one has, as well as the resolutions that one needs
to get to, to do a re-encode to get it to the correct aspect ratio.....
http://www.digitalrebellion.com/weba...pect_calc.html
Of course one won't always have a dvd box to see what the aspect
ratio is that the video is supposed to be, but for anything with a listing
at IMDB, that aspect ratio can be found in the listings "technical" data.