Awesome! I was looking for something like this when trying to play a local multiplayer game via the Internet in an early lockdown.
There are, or were, no good turnkey solutions for this. Twitch and Youtube have 5-10s latency, which is often not good enough. Mixer promised (and presumably delivered) ~1s latency using the FTL protocol you use, but they had a wait list of a couple of days or weeks, and of course now, they don't exist anymore. Even Steam Play Together, ostensibly built for this purpose, wasn't low latency enough in my limited experience (this really surprised me, so maybe I'm doing it wrong).
The easiest solution, use the share desktop function of whatever video conference tool, almost works, but they universally seemed reduce the frame rate, which is ok for presentations but unsuitable for games (also, no audio). My solution was to output OBS to a virtual webcam device and use Jitsi Meet. A bit roundabout, but it worked wonderfully.
Ideally, I'd forgo the DO droplet, and just run everything locally. 20% of a small droplet is even less of a modern desktop computer's CPU. Which leaves upload bandwidth for broadcast, which depends on your connection and how many people you need to be able to stream to.
On the client side you have two options:
1. For low-latency game streaming, I would suggest watching through the RTMP stream. The RTMP module for nginx will re-broadcast your RTMP stream to all the clients that connect. I was able to get a latency of around 1 second by watching through:
ffplay -fflags nobuffer -loglevel verbose rtmp://my-servers-ip-address/live/test
I would expect better latency from a webrtc solution like Lightspeed but 1 second latency is pretty good for only having to install nginx.2. HLS/Dash. The nginx RTMP module will also expose the video stream as HLS/Dash which is just cutting the stream up into files and serving them over http. Personally I set my segment size to 1 second and my playlist size to 4 seconds. Through this I get approximately a 4-second latency. Not great for competitive multiplayer games like Jackbox but if you're playing something like a world building game with friends then its acceptable. The real benefit to HLS/Dash is you can easily watch it through an html5 web video player or even a chromecast[2].
Bits you can add on top:
- I put my HLS/Dash directories in a tmpfs mount for speed and reduced wear on the drives
- I put the nginx stream module in front of my rtmp module so that it can handle TLS (making it RTMPS)
[1] https://github.com/arut/nginx-rtmp-module
On FreeBSD it was just a checkbox in the nginx port, so the work involved may vary by distro.
[2] I haven't attempted to play the RTMP stream through chromecast so for all I know, that might be supported too. All I've tested so far on chromecast is an HLS stream using the "castnow" CLI program. The Shaka player, which is a web player, will support chromecasting an HLS stream from your browser but I've only tested their demo videos, not my personal streams, and I had to use official google chrome, not chromium, but it worked on both android and linux.