Hi Philip,
I have had a play with gopro hero 4. In QC on any 1080P output 25FPS to 60 FPS works fine even when I switch video res in QC to 720P. No video feed on 720p 25/50 FPS and 30/50 FPS Pal/NTSC. Definitely getting video output and at correct FPS checked with a TV. Suspect the 1080P/720P switch in QC Video tab is not switching as 1080P works when the switch is on 720P. Herelink/QC can definitely handle different frame rates. Thanks for your prompt support.
Regards
Mark Rosser