remotion-dev/remotion · error · TypeError

outputTimestamp must be a finite, non-negative number.

Error message

outputTimestamp must be a finite, non-negative number.

What it means

The writeAudioUntil() handle returned by prepareAudio() validates its outputTimestamp argument: it must be a finite number >= 0. Negative, NaN, Infinity, or non-number values are rejected with a TypeError so the WebCodecs audio writer never receives an invalid media timestamp.

Source

Thrown at packages/video-matting/src/prepare-audio.ts:236

				}
			}
		};

		return {
			prime: async () => {
				if (primed || finished || canceled) {
					return;
				}

				primed = true;
				await writePacketsUntil({
					outputTimestamp: 0,
					writeAtLeastOne: true,
				});
			},
			writeAudioUntil: async (outputTimestamp) => {
				if (!Number.isFinite(outputTimestamp) || outputTimestamp < 0) {
					throw new TypeError(
						'outputTimestamp must be a finite, non-negative number.',
					);
				}

				if (outputTimestamp < lastWriteTimestamp) {
					throw new RangeError(
						'writeAudioUntil() timestamps must be monotonically increasing.',
					);
				}

				if (finished || canceled) {
					return;
				}

				lastWriteTimestamp = outputTimestamp;
				await writePacketsUntil({
					outputTimestamp: Math.min(
						outputTimestamp,

View on GitHub (pinned to b2f4e34732)

Solutions

1. Pass a finite non-negative number of seconds for outputTimestamp.
2. Guard computed timestamps with Number.isFinite(t) && t >= 0 before calling.
3. Fix the upstream arithmetic (undefined duration/fps) that produces NaN or negative values.
4. Clamp negative values to 0 if a sentinel is being used.

Example fix

// before
await audio.writeAudioUntil(frame / fps); // fps undefined -> NaN
// after
const t = frame / (fps ?? 30);
if (Number.isFinite(t) && t >= 0) await audio.writeAudioUntil(t);

const isValidTs = (t: unknown) => typeof t === 'number' && Number.isFinite(t) && t >= 0;
if (!isValidTs(t)) throw new TypeError('bad timestamp: ' + t);

const isValidTimestamp = (t: unknown): t is number => typeof t === 'number' && Number.isFinite(t) && t >= 0;

try { await audio.writeAudioUntil(t); } catch (e) { if (e instanceof TypeError && e.message.includes('outputTimestamp')) { console.error('invalid timestamp', t); return; } throw e; }

When it happens

Trigger: Calling writeAudioUntil(-0.5), writeAudioUntil(NaN), writeAudioUntil(Infinity), or writeAudioUntil(undefined) on the returned audio pipeline handle.

Common situations: Timestamp arithmetic producing NaN (e.g. dividing by an undefined fps or duration); timestamps initialized to -1 as a sentinel; passing a string from JSON-parsed timeline data.

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

• Argument missing for parameter "frame"
• Argument passed for "frame" is not a number: ${frame}
• You have passed a volume of type ${typeof props.volume} to y
• You have passed a volume below 0 to your <${component} /> co
• You have passed a playbackRate of type ${typeof props.playba

AI-assisted analysis of remotion-dev/remotion@b2f4e34732 (2026-09-09). Data as JSON: /api/errors/0ef5eb4474fd2d4c. Report an issue: GitHub.