remotion-dev/remotion · error · Error

Invalid marker bits: ${markerBits}

Error message

Invalid marker bits: ${markerBits}

What it means

Thrown at parse-pes.ts:28 when the two 'marker_bits' of a PES header (the first two bits after the PES_packet_length) are not equal to binary '10'. Per ISO/IEC 13818-1 these bits are fixed at '10' in MPEG-2; any deviation means the bytes are not a valid MPEG-2 PES header (possibly an MPEG-1 stream or corrupted data).

Source

Thrown at packages/media-parser/src/containers/transport-stream/parse-pes.ts:28

export const parsePes = ({
	iterator,
	offset,
}: {
	iterator: BufferIterator;
	offset: number;
}) => {
	const ident = iterator.getUint24();
	if (ident !== 0x000001) {
		throw new Error(`Unexpected PES packet start code: ${ident.toString(16)}`);
	}

	const streamId = iterator.getUint8();
	iterator.getUint16(); // PES packet length, is most of the time 0, so useless
	iterator.startReadingBits();
	const markerBits = iterator.getBits(2);
	if (markerBits !== 0b10) {
		throw new Error(`Invalid marker bits: ${markerBits}`);
	}

	const scrambled = iterator.getBits(2);
	if (scrambled !== 0b00) {
		throw new Error(`Only supporting non-scrambled streams`);
	}

	const priority = iterator.getBits(1);
	iterator.getBits(1); // data alignment indicator
	iterator.getBits(1); // copy right
	iterator.getBits(1); // original or copy
	const ptsPresent = iterator.getBits(1);
	const dtsPresent = iterator.getBits(1);
	if (!ptsPresent && dtsPresent) {
		throw new Error(
			`DTS is present but not PTS, this is not allowed in the spec`,
		);
	}

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Re-mux as MPEG-2 transport stream: ffmpeg -i in.mp4 -c copy -f mpegts out.ts.
2. If the source is genuinely MPEG-1, transcode to a supported container/codec.
3. Verify the PES header bytes with a hex dump or dvbsnoop.
4. If the file parses in ffprobe but not here, file a bug with the sample attached.

try { await parseMedia({src: tsUrl}); }
catch (e) {
  if (e instanceof Error && e.message.startsWith('Invalid marker bits')) {
    // not a valid MPEG-2 PES - re-encode
    await runFfmpeg(['-i', tsUrl, '-c:v', 'libx264', '-c:a', 'aac', '-f', 'mpegts', outUrl]);
    await parseMedia({src: outUrl});
  } else throw e;
}

When it happens

Trigger: parsePes reads getBits(2) and compares to 0b10; mismatch throws. Triggered by MPEG-1 system streams (which use different marker conventions), by feeding a non-PES payload to parsePes, or by bit corruption in the PES header.

Common situations: Source files muxed as MPEG-1 instead of MPEG-2; corrupt captures from faulty encoders; misrouted elementary-stream bytes; partial files where the header bytes are missing.

Related errors

• Unexpected PES packet start code: ${ident.toString(16)}
• DTS is present but not PTS, this is not allowed in the spec
• Invalid PTS marker bits: ${fourBits}
• Invalid DTS marker bits: ${_fourBits}
• Invalid table ID: ${tableId}

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/5b5b8cbba834b5da. Report an issue: GitHub.