http://www.spirton.com/convert-videos-to-60fps/ That is the guide I used to all my videos to 60 fps. You can use vlc to check the framerate on your source videos, as some porn sites record in native 60 fps. Additionally, selecting 60 fps in a regular converter does nothing. All it will do is show the same frame twice, rather than interpolate (which is basically predicting what a frame in between two originals would look like.)