Media over QUIC #

Streamplace nodes hand live streams to each other over moq-lite (draft 06). The implementation is pkg/moq; the node's listener and the segment-bus publisher are pkg/api/moq.go; the pull side is the websocketrep replicator, which prefers an origin's MoQ URL over its websocket when one is advertised.

Wire convention #

The payload is MUXL and nothing else.

A subscriber validates every source frame with MediaManager.ValidateMP4, exactly as the websocket path does, and verifies every rendition addendum with muxl verify. A frame that is not MUXL fails validation and ends the session; the publisher side refuses to send a segment that does not lead with a uuid box at all.

Subscriptions start at the live edge: the publisher primes a new subscriber with the last few segments, like place.stream.live.subscribeSegments. Every group is served whole, in order, on its own QUIC stream; FETCH and PROBE are refused, and nothing is sent as a datagram.

Bindings #

One UDP port serves both bindings, selected by ALPN:

• raw QUIC with ALPN moq-lite-06 (moqt://host:port), which the SETUP Path parameter carries the URL's path and query over;
• WebTransport over HTTP/3 (https://host:port/<any path>), with moq-lite-06 negotiated as the WebTransport subprotocol. This is the binding a browser uses.

Configuration #

The listener terminates TLS itself, even on a node behind an HTTPS proxy:

• with --secure, it serves the node's certificate (ACME or --tls-cert/--tls-key);
• otherwise it mints a self-signed ECDSA certificate, valid for two weeks and rotated weekly (the limits a browser puts on a pinned certificate), and advertises its SHA-256 as the certhash query parameter of the MoQ URL. A subscriber pins exactly that certificate.

Discovery #

The advertised URL travels two ways, like the websocket URL:

• the moqURL field of the streamer's place.stream.broadcast.origin record on the firehose;
• the moq_url column of the station's shared broadcast_origins table, written by the ingest node on every local segment, so nodes sharing a statedb find each other without a relay.