Advances the smoother with one raw sample.
The client's current audio activity (null = no metering capability).
A monotonic clock reading (e.g. performance.now()).
The render-ready frame, or null when un-metered.
Resets all smoothing state (call between sessions).
Per-overlay smoothing state machine. Feed it one raw RealtimeAudioActivity sample per animation frame via Next; render the returned frame.
nullin →nullout (the driver attached no meters — the host keeps turn-state visuals).