Latest-wins seek for a gesture in flight; returns without settling.
Optionalintent: PresentedFrameSeekIntentSeek that settles: resolves once the producer has landed on timeMs.
Walks one real source frame in presentation order.
Forward playback speed, in media seconds per wall second. Throws on a rate the producer cannot play, reverse included.
Freezes a playing producer for the length of a drag.
Resumes play only if beginInteractiveSeek was what paused it.
The frame plane plus the transport that moves it. Everything below the frames is the playhead, and the producer owns it: a renderer holding this channel asks rather than decides.