I know this is a long shot but is there an apple tv app in development? Would be amazing to deploy apple tv's to display video walls on dedicated camera tv's instead of having to configure a computer to display the website.
You'll find it easier to use RTSP to HDMI converters like the Axis T8705.
I didn't know about this device, it seems like a really good solution for a video-wall. The only drawback (at least I didn't find anything in the install-guide and data-sheet) is that it can not be powerded by PoE.