Well that worked 
must look at throttling back the cpu useage though as it runs all my cores at full 100% and gets very warm. I’m happy for it to take longer and run a bit cooler.
So now I can get the videos into cubase and process the audio. I take it since a Cubase strips the audio from the video I can’t save it back into the video and will have to use another program to re-combine them? Think it’s time to read the manual again now I can get the videos working in cubase.
Cheers for the link. Nice and simple just as I asked 