remotion-dev/remotion · error · Error

Expected CueClusterPosition

Error message

Expected CueClusterPosition

What it means

Inside a CueTrackPositions, formatCues requires a CueClusterPosition child (the absolute byte position of the cluster within the Segment); without it the cue cannot resolve to a byte offset for seeking, so parsing throws.

Source

Thrown at packages/media-parser/src/containers/webm/seek/format-cues.ts:45

			(c) => c.type === 'CueTrackPositions',
		);
		if (!cueTrackPositions) {
			throw new Error('Expected CueTrackPositions');
		}

		const cueTimeValue = cueTime.value.value;
		const cueTrack = cueTrackPositions.value.find(
			(_c) => _c.type === 'CueTrack',
		);
		if (!cueTrack) {
			throw new Error('Expected CueTrack');
		}

		const cueClusterPosition = cueTrackPositions.value.find(
			(_c) => _c.type === 'CueClusterPosition',
		);
		if (!cueClusterPosition) {
			throw new Error('Expected CueClusterPosition');
		}

		const cueRelativePosition = cueTrackPositions.value.find(
			(_c) => _c.type === 'CueRelativePosition',
		);

		const matroskaCue: MatroskaCue = {
			trackId: cueTrack.value.value,
			timeInTimescale: cueTimeValue,
			clusterPositionInSegment: cueClusterPosition.value.value,
			relativePosition: cueRelativePosition?.value.value ?? 0,
		};

		matroskaCues.push(matroskaCue);
	}

	return matroskaCues;
};

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Re-mux with ffmpeg to rebuild the seek table.
2. Re-encode from the original source.
3. Try Mediabunny.

try {
  await parseMedia({src: 'in.mkv', fields: {durationInSeconds: true}});
} catch (err) {
  if (err instanceof Error && /Expected CueClusterPosition/.test(err.message)) {
    throw new Error('Incomplete CueClusterPosition; re-mux the file.', {cause: err});
  }
  throw err;
}

When it happens

Trigger: A CueTrackPositions element that lacks CueClusterPosition - incomplete seek table entry. Note CueRelativePosition is optional (it uses ?.value ?? 0), but CueClusterPosition is mandatory.

Common situations: Corrupt Cues section, partially written seek index, or non-conformant muxer.

Related errors

• Expected CuePoint
• Expected CueTime
• Expected CueTrackPositions
• Expected CueTrack
• Could not find sample rate or number of channels

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/25ed7242a5db1c7f. Report an issue: GitHub.