I have a Canon 1200D DSLR camera and last night I was recording a 20 minute live show but my 32GB card filled up in just under 10 minutes. I was shooting at 1920x1080 50FPS.
I had checked the manual before hand and it said I should have had 44 minutes on a 16GB card which equates to roughly 88 minutes on my 32GB card.
So why did this happen? Cheers!