How to Prepare GoPro Hero 4K for iMovie Editing on macOS Sierra?

As the 4K video recorded by GoPro Hero camera was compressed with H.264 codec, which is not designed for editing, therefore, you should convert your files into the GoPro/CineForm file format, which is specifically designed for editing and is compatible with most popular non-linear editing applications not only iMovie but also Final Cut Pro, Premiere, AVID, Vegas, etc. http://www.pavtube.com/prepare-gopro-hero-4k-for-imovie-editing.html