If you want to do it natively with FFmpeg then would look at miniDLNA for the announcement.
Alternatively look for an IPTV app on LG (hopefully there is at least one) which should be able to take in something natively from FFmpeg.
Please note I have not personally tried either solution (well I’ve used IPTV for non-CCTV RTSP streams).
if you have an AppleTV, FireTV or Chromecast then you may have better luck with HLS. The AppleTV app isn’t sufficient has to be a physical one. This is a solution I’ve done before (well to AppleTV, but have heard it’s similar for FireTV/Chromecast) and lets you go full resolution h265, but needs an external device.
feel your pain on this, took me a while to find Serviio and it’s been my go to ever since (I deal with HikVision, Synology, Ubiquiti and Avigilion), but if it’s causing you pain am hoping you’ll find a solution more suitable. Best of luck!