Ok, I've run the test on a Pi4B 4GB and my Laptop. The Pi4B is hard wired to a gigabit network, the laptop on WiFi AC. The Pi is using a Microsoft LiveCam USB webcam, the laptop is using the built in (1080p?) camera.

The Pi is running the Raspberry Pi OS desktop which I've just downloaded/installed and fully updated and is using the Chromium Browser.

Laptop running Ubuntu 20.04 and Firefox.

The Pi decodes HD reasonably well with some occasional glitching but only encodes SD, Jitsi complains about the network being non-optimal but that appears to be a red-herring, all 4 cores are at 100%. If I lower the "call quality" slider to SD the network issue goes away.

The video received on the laptop from the Microsoft HD webcam on the Pi is 420x270. it's smooth and the frame rate and latency is "good" but it's pretty "soft" at full screen due to the low resolution.

In conclusion, I don't believe you're reasonably going to be able to get 720p or 1080p encoding out of it with Jitsi Meet in Chromium.

Anything else you'd like to know?

Awesome, thank you! Even though it's not what I was hoping for. If you're still set up, you could try with Chrome on both ends, since a single Firefox participant is known to degrade the quality for the whole conference. (I'll try to find a reference once I'm at my desk.) I suppose if the rpi is at 100% cpu that's unrelated, though.

Edit: The issue I mentioned appears to be fixed for a while: https://github.com/jitsi/jitsi-meet/issues/5439 More discussion here: https://github.com/jitsi/jitsi-meet/issues/4758

Ok, so I gave it a test with Chrome on the Laptop and Chromium on the Pi. It starts at 720p ~10fps and then drops to 270p ~30fps after a few seconds (I'm not actively cooling the Pi). This is a slight improvement since it didn't hit "HD" at all in the first test. Note the camera connected to the Pi is only 720p so it's at its top resolution.

I can add active cooling to the Pi and test further once I find the fan I have lying around here somewhere.

EDIT: Added active cooling and increased video memory from 76MB to 512MB (although I think it's capped at ~400MB if I remember correctly), I'm now getting encode of 640x360 @ 15FPS on the Pi, so a slight improvement.

Thanks for your effort, very cool.

Hey, I'm not morsch, just wanted to thank you for testing and posting the results :)

Too bad, but probably to be expected. The RasPi wasn't really meant for tasks like this. Still, actually interesting that it would suffice in a pinch if you just needed to just stream some video, even if the quality isn't really good.

No problem, hopefully it helps answer some peoples questions about the kind of performance to expect.

I imagine Jitsi isn't taking advantage of hardware encoding capability (It's using VP8/Opus in my testing) but it gives an idea of what's currently possible.

That said, as I mostly work on native code for the communications work I do, I imagine the Pi would do a much better job with a native client and the right codecs.

You can use native code to stream to Jitsi using UV4L[1]. At least I think you could, at some point. It's a bit odd, certainly not as plug and play as using the browser.

[1] http://www.linux-projects.org/uv4l/

Understood. I was planning to spin up the server on a "proper" server machine and just use the Pi as a client (which is the metric I believe you're interested in). If public servers are available, I can just spin up two clients on Pis and give it a test calling between the two. I don't have many options for USB cameras but I can figure something out. I do have a CSI camera I can test on one Pi though.

I've made a note to test this. I'll need some time as they're mounted in a server rack case I built and will need to be removed and re-installed with a DE to test at my desk.