An HFR (48 fps) interpolation of the The Hobbit:Desolation of Smaug trailer has been created by HFR enthusiast, Michael Sanders.
In a post to hfrmovies about the trailer, Michael said that,
“Faster actions scenes proved somewhat problematic, but overall it turned out pretty interesting… The true frame rate is 48fps, but the actual video file is rendered in 60fps, since many players (including VLC) can have trouble with 48.”
He went on to explain just how he made the trailer,
I used Adobe After Effects CS6. For each cut, I would try both AE’s built-in pixel motion and Re:Vision’s Twixtor plugin, and use whichever one had better results. For some pieces of the cuts where the warping and ghosting artifacts really got out of hand, I just used plain old frame blending which just layers the previous frame over the next frame. At 48fps, it goes by so quick you can generally get away with it in very short spurts. however, I plan on revisiting these cuts in particular with Twixtor using tracking points and/or foreground masks. And of course, the most important thing is you always have to separate out the first and last frame of a cut and leave it un-interpolated so you don’t get a real nasty “morph” between cuts. That’s probably one of the more time-consuming parts with really fast trailers with lots of cuts.