diff options
Diffstat (limited to 'blog/custom-rtmp.md')
| -rw-r--r-- | blog/custom-rtmp.md | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/blog/custom-rtmp.md b/blog/custom-rtmp.md new file mode 100644 index 0000000..e1a89fb --- /dev/null +++ b/blog/custom-rtmp.md @@ -0,0 +1,91 @@ +--- +title: Self-hosting a Live Stream Server +author: Cara Salter +date: 2022-06-15 +--- + +This Sunday, I will be running the technical side of an online Pride event +hosted by my partner. Part of this includes live music performances that all +need to go to the same stream output. I also need to be able to scale and +transcode the streams appropriately. There are, of course, commercial options +available, but that wouldn't be very fun (or cheap!). What fun is having servers +if I can't also mess around with them? + +The specific final destination has particular codecs and resolutions, and they +recommend something like [Oven Media Engine][ome] to take in all the streams and +allow them to be rebroadcasted into their intake server. I spent most of today +trying to make it work, and while I was able to successfully *send* to it, I +couldn't get anything out of it, no matter how much I tried. This was mostly +because of a lack of understanding on my part, but also the relatively +confusing-to-newcomers way that the configuration and documentation is +presented. + +That's not to say that it's unfriendly to new users, just that it requires a lot +more prior knowledge and research than I expected or was capable of dealing with +in the moment. I'm sure it's a wonderfully useful software, it just didn't +fulfill my need for something that could be set up and tested for this weekend. + +Eventually I remembered an [old post][ddevault] by Drew DeVault that talked +about self-hosting his own live-streaming server with `nginx`. In it, he streams +a screengrab of an X11 window via `ffmpeg`[^1] into a DASH[^2] sink using the +`nginx-rtmp` module. + +This looks great! Streaming into nginx that then can be republished and pulled +into OBS for transcoding and restreaming. I ended up installing the RTMP module +on one of my servers, and wrote the following configuration: + +``` +rtmp { + server { + listen 1935; + chunk_size 4096; + + application live { + live on; + record off; + } + } +} +``` + +That's really all it takes. `1935` is used because it's the standard RTMP port, +but really any one can be used. This lets me send streams to +`rtmp://<my-server>:1935/live/<key or name>`. Where it says `<key or name>`, +that's the bit where you can separate each stream. Then, I can add a Media +Source to OBS or VLC with that same URL, and it will automatically pull the +stream down. By managing stream keys, you can have multiple people streaming in +at once, and then switch between them using software like OBS. + +I'm mostly using the stock OBS settings, but I'm making sure to use the `x264` +encoder and the `veryfast` encoder preset, which is easier on web browsers. +There's no noticable difference in quality, so in my opinion there's no need to +go any higher. + +The RTMP module also lets you use the nginx `allow` and `deny` directives, for +access control based on IP addresses or subnets. For example, if I only wanted +to be able to stream from within my VPN, I could set + +``` +allow publish <my-laptops-vpn-ip>; +deny publish all; +``` + +which would only let my laptop (or any other IP I wanted) broadcast. I'm sure +there's some way to do this better, like predetermining which stream keys are +able to play, but I haven't been able to find it yet, so I've just been +disabling the module when I don't need it. + +To recap, the general steps I took were: +1. Install and configure the nginx RTMP module +2. Configure OBS to stream to the RTMP URL +3. Add a media source to VLC with that same URL to play + +I hope this was able to help! I plan on looking into this more, especially the +access control bits, so I'll be sure to update this post with anything I find. + +[^1]: Which, if you didn't know, is a really wonderful tool that can do +basically anything related to A/V including transcoding and streaming. +[^2]: Dynamic Adaptive Streaming over HTTP + +[ome]: https://ovenmediaengine.com +[ddevault]: https://drewdevault.com/2018/08/26/Self-hosted-livestreaming.html |