Can we add a rule that says that the files have to be in the native framerate? I see a lot of these webm files like this one (http://sakuga.yshi.org/post/show/5309/animated-beams-debris-effects-genga-hiroshi_okubo-) that have unusual framerates, like 19.8 fps in this case, which creates a pulsing effect that's undesirable.

most things should be done in 24fps, with the exception of some things with only VHS source where we have to use 30fps.