Minimal AVFoundation video recorder
An adaptation of Apple's AVRecorder
Tested with GoPro Hero4 + BlackMagic Ultrastudio Express + MacBook 2011 Make sure to add AVFoundation.framework https://www.blackmagicdesign.com/support DesktopVideo_10.6.4.dmg
Make sure GoPro dimensions and framerate are the same as in Black Magic Desktop video, only successful with 1080p @ 29.97 (although GoPro says 30)
Created by Andreas Borg on 4/25/16
Copyright (c) 2015-2016 Andreas Borg localprojects.com