
The VMS I use, Bluecherry, pulls in its live feeds over ffmpeg. Really just spit balling to get ideas rolling, even if they're not great. Is it possible to embed an RTSP stream right within a video element of HTML code these days? If so, it stands to reason that you could whip up your own local.html file with a basic web page layout that pulls in the streams. I've been out of the HTML game for a number of years. I'm not sure what Windows' capability is with commanding an application to launch at an exact point on the screen, but if so that could be a quick and dirty idea (re: while this worked great on my Linux rig and can't comment on Windows, I'm not necessarily saying this is a great idea, but possibly 'an' idea). A quick script later, bound to a shortcut key, and I was literally able to hit that keystroke and all of them would pop up in the exact order and positioning that was set for each window. That way I could launch, basically, 8 instances of MPV, VLC, etc and they would all line up at the exact points they were designated to. Something I did once upon a time on a Linux system was set up shortcuts to a video player that would launch that video player to exact parameters of the screen.

Who knows though, maybe things have changed since then - been a long while since I last tried. I received some help from VLC devs in their IRC but the general vibe I got from them wasn't too high regarding getting that to work, which ultimately resulted in me exhausting what documentation I could find to no success. I looked into that a while back and was unable to get it working. I'd be curious if the VLC Mosaic feature works.
