Neither is significantly sharper than the 50mm f1.8 at the same stop (maybe scientifically you can tell the difference, but for video no way and for stills it's purely academic--serious), just faster and with better bokeh. I'd get the 50mm f1.4 Zeiss for video (better focusing ring) and the 50mm f1.2 for stills if those are the only two choices. Imo, neither is even remotely worth the money unless you have a lot to spend and/or already own a full complement of primes, especially with the 50mm f1.4 Canon, which isn't that great either, for $300 now. For video I'd get a 17-55mm (or 17-50mm Sigma) zoom before a faster 50mm (to be fair, I can't stand the focal length on APS-C because I think it requires too good an eye for composition as the flat but not orthographic-feeling sense of depth requires an amazing eye for composition to use well, which I lack), but I am not a professional, just an advanced amateur (?) at this point. Or get a bunch of old manual focus lenses and adapters for video.
The 50mm f1.4 Canon is $300 now and the 30mm f1.4 sigma is $350. Those plus the kit lens and an 85mm f1.8 Canon would make a great set for video for the cost of either overpriced fifty on its own. Unfortunately a super speed UWA is not available for crop; that would complete the set.