It depends:
OP did not mention whether it's an adult or not.
I would say:
- CAM: is more suitable for Live Streaming, something like a niche
- TUBE: Gives you broader opportunities
But in the end, it's up to the content you want to provide and the audience you choose.
From SEO pov. There is no big difference - It's just about the Brand Strategy.
I would take .tube, even though .cam is probably more saturated because of the adult niche.
Best
zotix