Taking a look at my video surveillance system consisting of some PoE cameras, HDMI over IP system, and Blue Iris running on a Dell PowerEdge R720 server. Parts can be purchased using affiliate links below:
OREI HDMI Splitter -
https://amzn.to/3V341XK
Cable Matters HDMI over IP System -
https://amzn.to/3V9w7Rf
Cable Matters HDMI over IP Additional Receivers -
https://amzn.to/48OargI
Reolink RLC-520A PoE IP Camera -
https://amzn.to/4bTlTds
Dell PowerEdge R720 Server -
https://amzn.to/3wGugsQ
Blue Iris NVR Software -
https://blueirissoftware.com/
Multi View RTSP URL: rtsp://username:password@BlueIrisIP:80/GroupName?h=1080
Open VLC and go to open network stream in the file menu and put the RTSP URL in there and click full screen. You can create a group in Blue Iris with the cameras you want and put the group name where it says GroupName in the example URL above. The 1080 is the height you want (1920x1080 in my case). You may not need that, but it looks better in my case with it there.