I have installed Cineform, I have used it as well, I just wasn't sure if i really had to go through the process of converting all my videos to 30 fps before importing to iMovie. iMovie used to work without Cineform conversion with 120fps WVGA videos back when I had my GoPro 2, but does not seem to handle 120fps 720p with my new GoPro 3+ (unless I did something wrong, but I don't think so...).
Guess I won't take chances anymore and just convert all my videos just to be sure...
One last thing, I converted a 120fps 720p into a 30fps 720p... After importing in iMovie, it plays back at normal speed and shows a kind of round symbol in the top left corner of my clip. I thought i had lost much of the frames of the video, BUT NO, I could slow it down to 25% and was still very fluid! Which tells me that iMovie HAD imported all the 120fps, but detected that the video had been slowed down, so it accelerated the playback speed so that it played normally. Here is my question: what the **** is that round symbol and do videos converted with Cineform tell iMovie the right speed at which they should play?!
I have like 1000000 question right now, but i'd be happy if only one of them could be answered! No manual on Apple's website explain that kind of stuff and I couldn't find anything on youtube either 😟
