fix(web): disable adaptiveStream so screen-share video isn't paused#29
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Web SFU viewers got the host's audio but a black screen for the screen share. The room was created with adaptiveStream:true, which pauses video tracks that livekit doesn't see attached to a visible element via track.attach(). The viewer renders through a manually built MediaStream on a <video> srcObject, so livekit never registers the element and paused the video at the SFU — audio (unaffected by adaptiveStream) kept flowing, video stayed black. Disable adaptiveStream: the viewer always shows the single presenter stream, so there's nothing to adaptively pause. (Pairs with the prior fresh-MediaStream -reference fix so Firefox actually re-binds srcObject when the video arrives.) Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
vu1nz Security Review0 finding(s) in PR #? No security issues found. |
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Bug
Web SFU viewers got the host's audio but a black screen for the screen share (even after the fresh-MediaStream-reference fix #28 deployed).
Root cause
useWebRTCSFUcreates the Room withadaptiveStream: true. adaptiveStream pauses video tracks that livekit doesn't see attached to a visible element viatrack.attach(). This code renders through a manually built MediaStream on a<video>srcObject (it never callstrack.attach), so livekit saw no visible element and paused the screen-share video at the SFU. Audio is unaffected by adaptiveStream → audio played, video stayed black. (The Chrome egress uses its own subscription, which is why the composite/restream was always fine.)Fix
adaptiveStream: false. The viewer always shows the single presenter stream, so there's nothing to adaptively pause. Pairs with #28 (fresh MediaStream reference) so Firefox re-bindssrcObjectwhen the video arrives.Test
Assert the Room is constructed with
adaptiveStream: false; existing track-merge test still passes. Lint clean.🤖 Generated with Claude Code