Call quality issues

Can't join a call#

Symptom: clicking Join does nothing or returns an error.

Causes:

Browser permissions: microphone / camera not granted. Click the camera icon in the address bar to allow. After granting, refresh the call.
LiveKit unreachable from your network: corporate firewall blocking UDP/WebRTC. The call panel shows SW_CALL_LIVEKIT_UNREACHABLE. Admin: check SCAIWAVE_LIVEKIT_URL and that the LiveKit instance accepts connections from your network.
Already in another call elsewhere: the client can only be in one call at a time. Leave the other first.

You can hear them; they can't hear you. Or vice versa.

Mic muted: check the mute button — sometimes auto-muted on join if the room has > 4 participants.
Wrong input device: ScaiWave defaults to the OS default mic. Switch via the call panel's ⚙️ menu → Audio.
OS-level mute: Windows / macOS sometimes have separate app-level mute. Check OS sound settings.

Almost always one participant not using headphones with their mic. The SFU does AEC but not perfectly when there's a hardware loop.

Quick test: mute everyone except the suspected loud one; echo should disappear when you find them.

Tab is in the background and the browser is throttling. Refocus the tab.
Bandwidth low. LiveKit's adaptive bitrate should handle it; if not, the ⚙️ menu → Video → cap at 360p to force a lower bitrate.
Hardware acceleration glitch (Linux + nouveau is the common culprit). Force CPU encode via chrome://flags.

The sharer started, you see "X is sharing" but no video.

Browser permission for screen share isn't system-level the way camera is — usually permission was denied at the OS picker. Sharer: re-click Share screen, pick a source, allow.
ScaiWave's PiP popout doesn't render screen share on Firefox (the Document PiP API isn't available there). View in the main window.

Started a recording but it doesn't appear in the room afterwards.

LiveKit egress can take up to a minute after the call ends before the file is finalised and the webhook fires.
Check GET /v1/calls/{id}/recordings — if empty after 5 minutes, admin checks LiveKit egress logs and MinIO bucket permissions.

Audio quality too low (very quiet, lots of background noise).
Wrong language hint — ScaiGrid's speech model picks better when given a hint via the Language picker before starting.