Fill Image Motion Duration
fill-image-motion-dur
Sets how long the fill-image-motion effect takes to complete, in seconds. Accepts any positive float.
By default, the motion spans the entire clip. When set to a value shorter than the clip length, the motion completes at that time and holds the final framing for the remainder of the clip — for example, a 2-second push-in at the start of a 30-second audiogram, then a steady zoomed-in background for the rest.
Interaction with video-speed
fill-image-motion-dur is measured in the clip’s own timeline before any speed adjustment. If video-speed is applied, the motion duration scales with it: a fill-image-motion-dur=3 under video-speed=2 plays in 1.5 seconds of wall-clock time, staying in sync with the sped-up audio.