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Very good progress, I have been keeping an eye on quic for some time, I have yet to use it in the wild. The article mentions the prioritization of the frames and keeping it in the RAM, I am a bit confused, so.. it’s sent delayed later or is it only added in non-priority stream? Also slightly far from that, how does that work with FEC? I built before a streaming platform for drones but it utilized gstreamer primarily over udp, different codecs based in the hardware, one of the issues was what you mentioned in the article of having one subscriber only at a time, so we had some duct tape solutions if we needed more but it wasn’t really great.
QUIC libraries work by looping over pending streams (in priority order) to determine which UDP packet to send next. If there's more stream data than available congestion control, the data will send there in the stream send buffer.

Either side can abort a stream if it's taking too long, clearing the send buffer and officially dropping the data. It's a lot more flexible than opaque UDP send buffers and random packet loss.

FEC would make the most sense at the QUIC level because random packet loss is primarily hop-by-hop. But I'm not aware of any serious efforts to do that. There's a lot of ideas out there, but TBH MoQ is too young to have the production usage required to evaluate a FEC scheme.

Pull-based streaming can work with webrtc. I implemented it for my custom ip camera nvr solution. I just open N streams on the client and when one is deactivated (typically by scrolling it out of the viewport), the client sends an unsubscribe message over a separate control channel and the server just stops sending video until they resubscribe.

I'm currently switching to a quic-based solution for other reasons, mainly that webrtc is a giant blackbox which provides very limited control[1], yet requires deep understanding of its implementation[2] and I'm tired[3].

I looked at moq-lite but decided against it for some reason. I think because I have <5 clients and don't need the fanout. The auth strategy is very different than what I currently use too.

[1] Why is firefox now picking that (wrong) ice candidate?

[2] rtp, ice, sdp, etc

[3] webrtc isn't bad for the video conferencing use-case but anything else is a pain

Never had to work with moq, got me to read the whole thing. There's still a place for good writing.
I like the ability to choose what you want to pull.

I’ve been thinking about an application where people consume all their media, and having the ability to pick which tracks to pull for any content you want to stream would be great.

Apart from actual support on real networks, isn't this the problem IP multicast was supposed to solve ages ago?
Ship-to-shore SAT link, 800 ms RTT, 2 % burst loss. We muxed 4 K pps telemetry + 1 Mbps H264 over QUIC last year. Head-of-line blocking vanished - TCP would have stalled 12 s on each 200 ms fade. FEC at the stream frame, not packet, let us ride fades with 3 % overhead. QUIC’s real win is acking individual frames; we saw 40 % better goodput vs TCP + application FEC at the same latency.
Do we have UDP in browser yet? Last I checked (mid 2024) it was soon-ish?

Edit: https://caniuse.com/?search=webtransport

Looks like the situation is the same as in 2024: "Yes, except for Apple devices?" If I'm reading this right, it looks like Safari will support it next week though...