Change a shot duration

Stretch or shorten a shot timeline with an explicit rounding and audio policy. Review its editorial uses before reducing the source duration.

Give the movement more time. What changes when a shot lasts twice as long?

Compare both versions at frame 12, then compare the slower version at frame 24. Retiming moves keys to a new time scale; it does not redraw the movement.

Retime an independent shotCopy Anchor Link

retimeShotAnimation(animation, options) returns a detached { animation, report } for inspection before editing. Apply the same options through timing.retime in an ordinary shot edit or version-pinned animation.edit plan:

const options = {
  durationFrames: 48,
  rounding: 'exact' as const,
  audio: 'scale-starts' as const,
};
const preview = retimeShotAnimation(animation, options);
project.editShotAnimation(animation.id, [{ op: 'timing.retime', ...options }]);

Every local frame position scales by new duration / old duration. A 12-to-24-frame change maps frame 11 to 22 and the exclusive end 12 to 24; it does not pin the last key to frame 23. This includes camera/layer keys, exposures, drawing substitutions, stroke reveal intervals, controller keys/ranges, mesh/curve/envelope keys and compositing curves. Signed preroll and postroll positions scale too, without trimming. Pen sample timestamps and bind geometry stay unchanged. Optional frameRate sets the target rational rate; otherwise the old rate remains.

The default exact policy rejects fractional frames. Explicit nearest, floor or ceil permits quantization, but distinct keys mapping to one frame and collapsed intervals still reject. The source snapshot remains untouched on failure. The report counts mapped positions, moved positions and quantized positions, plus audio clips and changed cue starts.

Audio policy is required: preserve-seconds retains cue times; scale-starts multiplies starts by the new physical duration / old physical duration, accounting for both frame rates with exact rational arithmetic. Neither policy stretches source samples or fades. Cues can extend beyond the new duration; playback conform clips them to the shot window.

Editorial cuts are not conformed automatically. Shortening a referenced shot can invalidate a cut's source range; revise its use before applying the shorter shot. Within a batch, the shot must already be valid when timing.retime runs. Board retiming remains independent.