remotion-dev/remotion · error · TypeError

videoStartTimestamp must be a finite number.

Error message

videoStartTimestamp must be a finite number.

What it means

prepareAudio validates its videoStartTimestamp argument with Number.isFinite and throws a TypeError when it is not a finite number (NaN, Infinity, -Infinity or a non-number from JS callers). Timestamps drive audio trimming, so non-finite values cannot be planned.

Source

Thrown at packages/video-matting/src/prepare-audio.ts:60

	baseOutput,
	foregroundOutput,
	destination,
	videoStartTimestamp,
	videoEndTimestamp,
	audioQuality,
	forceTranscode,
}: {
	input: Input;
	baseOutput: Output<WebMOutputFormat, BaseTarget>;
	foregroundOutput: Output<WebMOutputFormat, ForegroundTarget>;
	destination: VideoMattingAudioDestination;
	videoStartTimestamp: number;
	videoEndTimestamp: number;
	audioQuality: Quality | null;
	forceTranscode: boolean;
}): Promise<PreparedVideoMattingAudio> => {
	if (!Number.isFinite(videoStartTimestamp)) {
		throw new TypeError('videoStartTimestamp must be a finite number.');
	}

	if (!Number.isFinite(videoEndTimestamp)) {
		throw new TypeError('videoEndTimestamp must be a finite number.');
	}

	if (videoEndTimestamp < videoStartTimestamp) {
		throw new RangeError(
			'videoEndTimestamp must be greater than or equal to videoStartTimestamp.',
		);
	}

	if (typeof forceTranscode !== 'boolean') {
		throw new TypeError('forceTranscode must be a boolean.');
	}

	if (destination === 'none') {
		return {

View on GitHub (pinned to b2f4e34732)

Solutions

1. Ensure videoStartTimestamp is computed from valid, finite numbers before calling prepareAudio
2. Check upstream metadata for null/undefined before deriving the timestamp
3. Default to 0 when the value cannot be determined

Example fix

// before
const start = totalDuration / fpsCount; // NaN when fpsCount is 0
// after
const start = fpsCount > 0 && Number.isFinite(totalDuration) ? totalDuration / fpsCount : 0;

if (!Number.isFinite(videoStartTimestamp)) {
  throw new TypeError('videoStartTimestamp must be finite before calling prepareAudio');
}

const isFiniteNumber = (v: unknown): v is number =>
  typeof v === 'number' && Number.isFinite(v);

try {
  await prepareAudio({videoStartTimestamp, ...});
} catch (e) {
  if (e instanceof TypeError && e.message.includes('videoStartTimestamp')) {
    videoStartTimestamp = 0;
  }
  throw e;
}

When it happens

Trigger: Passing NaN/Infinity as videoStartTimestamp to prepareAudio, or a value computed from division by zero, missing metadata, or unparsed JSON.

Common situations: Metadata lookup returned null and the code did arithmetic with it; dividing durations that were undefined; JS (non-TS) callers passing strings that silently become NaN in arithmetic.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• videoEndTimestamp must be a finite number.
• Argument passed to "${api}" for param "${param}" is ${JSON.s
• Invalid timestamp:${time}
• Threshold is NaN
• Frame ${frame} is not finite

AI-assisted analysis of remotion-dev/remotion@b2f4e34732 (2026-09-09). Data as JSON: /api/errors/a5fd4699f4c12f90. Report an issue: GitHub.