I have had video working on V7R1 and V7R2 with STMI4 cards, and it is very limited in scope. It requires each side to have an OS60 running SIP software and a USB webcam from a specified list. There are special settings in the phone's profile in the system, and there are also several settings on the phone itself. I had originally set it up for a front desk help phone at a clinic where they were too cheap to have a person out front anymore, and it worked good for the customer to press a speed dial key to reach the other phone.
Back in V5 (which I did have for a while) I don't think there were any provisions for video on the system, and I'm not sure there are many options for video on a 4K at all unless they beefed them up in V8, or possibly with very specific SIP phones or something like Jitsi or another PC-based client.
Don Bruechert, Voice Comm Analyst II
CareTech Solutions @ Holy Family Memorial
Manitowoc, WI, USA