This tutorial from LoadedNewsletter's Jonathan Jelkin gives a simple process on how to prepare H.264 video footage for quick editing. H.264 video footage is shot by popular cameras such as the Canon 5d/7d, Flip cam, GoProHD. This is a great format for straight upload to YouTube, but if you want to edit you need to transcode it to something else. The first step is to download and install a free program called MPEGSTREAMCLIP. Once it is installed you can process all of your files by loading the files into the program. Next choose Apple Intermediate Codec (AIC) as your exported file type. Now, once the files are finished exporting to the AIC codec you are able to edit them in any video editor.
Have an iPhone? Check out all 200+ new features coming in iOS 13.