Function normalizeTiming

packages/sdk/examples/headless-agent.ts:193–217

(html: string, totalDuration: number)

// ── Timing normalization agent ────────────────────────────────────────────────

export async function normalizeTiming(html: string, totalDuration: number): Promise<string> {
  const comp = await openComposition(html);

  const timedEls = comp.getElements().filter((el) => el.start !== null && el.duration !== null);

  const lastEnd = timedEls.reduce(
    (max, el) => Math.max(max, (el.start ?? 0) + (el.duration ?? 0)),
    0,
  );
  if (lastEnd === 0) return comp.serialize();

  const scale = totalDuration / lastEnd;

  comp.batch(() => {
    for (const el of timedEls) {
      comp.setTiming(el.id, {
        start: Math.round((el.start ?? 0) * scale * 100) / 100,
        duration: Math.round((el.duration ?? 0) * scale * 100) / 100,
      });
    }
    comp.dispatch({ type: "setCompositionMetadata", duration: totalDuration });
  });

  return comp.serialize();
}