Put a clip inside itself. Each level places a smaller, turned copy of the frame in the middle of the previous one, and the copies repeat until they are too small to see.
Depth, scale, and rotation
Recursion Depth sets how many copies are nested, from 2 to 12. Scale per Level is each copy’s size relative to the one around it: around 60% gives a gradual tunnel, 30% a sharp drop. Rotation per Level adds a turn at every level, which accumulates into a spiral.
Motion through the tunnel
All levels play the same moment, so anything moving in the frame moves in every copy at once. Handheld footage makes the whole tunnel sway together. A locked-off shot of a person or a screen gives the clearest infinite-picture illusion.