I'm working on a multi anime project, and since I'm using both 4:3 xvid footage and 16:9 dvd-rips I thought I'd go ahead and run the project in widescreen and blow up all of the 4:3 to fit the frame. I'm running the xvid footage through avisynth as premiere really isn't liking most of them straight. The problem is, the footage seems to be really quite grainy after being imported, more so than from simply being blown up.
This is the footage in VLC compared with Premiere.


Is there some line I need to put in the avs file to make it more widescreen friendly? Or am I an idiot to even try to put it in a widescreen format?