I have a 120 fps footage captured with a GoPro that I'd like to slow down with easing, like the slow motion playback functionality on iPhone 5s.
Is that possible without any extra plugins in Final Cut Pro X? I know how to slow down a footage, but I'd really like the effect from normal speed to slow motion.
You can do it by adding transitions between the speed changed clips as described in the documentation section titled Add Transitions Between Speed Segments. They say:
When two adjacent speed segments are set to play at different speeds, you can control how smoothly the video switches between the playback speeds. When there’s no transition between the segments, playback shifts suddenly from one speed to another. By adding a transition between the segments, you can create a more gradual, or ramped, effect. You can also control how quickly that transition takes place.
