I have a bunch of old clips with a resolution of 640x480 and frame rate of 7.96 that I want to uprez 300% to 1980 x 1080 HD for a short video project. So far I have tried to import the clips into Premiere Pro then "replace" them with files up-rezed in After Effects with the "detail preserving upscale" effect. This works better than upscaling in Premiere Pro. But perhaps you have good experiences with other software or plug-ins for doing this?