As we all know, the GoPro HD cameras records videos in .mp4 file type. The file type is a compressed output format and not an ideal editing format. Meanwhile the .mp4 file type is not supported by Apple's Final Cut software including FCE, FCP and iMovie'11. Therefore, directly editing
GoPro videos in Final Cut Express is just a blue moon.
To ingest GoPro MP4 files to FCE, the easy workaround is to convert your files to a more editing friendly format for FCE. To get work done, you must use 3rd party software such as Brorsoft Video Converter for Mac, which is an ideal tool for you to trim clips download and export the clips you'll want to use in your edit. With it, you can effortlessly transcode GoPro MP4 to Apple InterMediate Codec(*.mov), which will do fine for keeping the GoPro quality the same and creating a Final Cut Express friendly file format.