Conductor downlink through LiveKit

The room publishes a stereo click reference and a “conductor cam” that flashes on the beat, stamping every beat over the data channel. A player subscribes, detects each click and flash as it arrives, and reports the delay — the mouth-to-ear number this platform lives on. Open the two roles in two tabs (or the player on another device).

Room side · Player side · Both in this tab — audio and beat stamps measure fine from a background tab; the video flash detector needs a visible one, so for a same-machine test use “both”.