When converting .avi to VCD the edges of a clip where not shown on tv. To fix this I made the following change: CENTER (CUSTOM SIZE) 316 x 216 pixels This way, I could see the complete image on my regular TV. Now that I'm converting .avi to DVD I have the same problem. I know I should use the CENTER (CUSTOM SIZE) again, but should I use the same size pixels or is it diferent?
Overscanning is completely normal. Your TV cuts off some of every TV show, tape or DVD you watch. With these downloaded files though you never know quite what you're getting, so I will give you the benefit of the doubt that these files were really screwed up. If they are good though "fixing" them like this is just degrading whatever picture quality you have.
Instead of coding to dvd in tmpgenc you could master it as an mpg then use a separate authoring software such as tmpgencs dvd author or dvd lab pro where you will be able to adjust output settings without affecting the quality too much. I tried to convert Lost to dvd in tmpgenc express and I suffered the loss of quality and audio sync issues but when I used tmpgenc express to convert it to mpeg instead and then dvd lab pro to author I found that in dvd lab pro I could make adjustments to the output size and suffered very little if any loss.