remotion-dev/remotion · error

Invalid channel configuration ${channelConfiguration}

Error message

Invalid channel configuration ${channelConfiguration}

What it means

Thrown by createAacCodecPrivate in @remotion/media-parser when channelConfiguration is 0 or greater than 7. MPEG-4 AAC channel configurations 1-7 are defined (mono, stereo, 2.1, etc.); 0 is invalid and values above 7 are not standard preset configurations. The codec-private byte sequence cannot be built for such values.

Source

Thrown at packages/media-parser/src/aac-codecprivate.ts:133

	audioObjectType: number;
	sampleRate: number;
	channelConfiguration: number;
	codecPrivate: Uint8Array | null;
}) => {
	if (codecPrivate !== null && codecPrivate.length > 2) {
		// Video submitted
		// submitted by Yossi Elkrief
		// TOOD: Check if we are now parsing correctly
		return codecPrivate;
	}

	const bits = `${audioObjectType.toString(2).padStart(5, '0')}${getConfigForSampleRate(sampleRate).toString(2).padStart(4, '0')}${channelConfiguration.toString(2).padStart(4, '0')}000`;
	if (bits.length !== 16) {
		throw new Error('Invalid AAC codec private ' + bits.length);
	}

	if (channelConfiguration === 0 || channelConfiguration > 7) {
		throw new Error('Invalid channel configuration ' + channelConfiguration);
	}

	const firstByte = parseInt(bits.slice(0, 8), 2);
	const secondByte = parseInt(bits.slice(8, 16), 2);

	return new Uint8Array([firstByte, secondByte]);
};

export const parseAacCodecPrivate = (bytes: Uint8Array) => {
	if (bytes.length < 2) {
		throw new Error('Invalid AAC codec private length');
	}

	const bits = [...bytes].map((b) => b.toString(2).padStart(8, '0')).join('');

	let offset = 0;
	const audioObjectType = parseInt(bits.slice(offset, offset + 5), 2);
	offset += 5;

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Re-encode the audio with a standard channel layout: ffmpeg -i in.mp4 -ac 2 -c:a aac out.mp4 (stereo) or -ac 1 (mono).
2. Use a well-formed source file.
3. If authoring programmatically, restrict channelConfiguration to 1-7.

Example fix

# before: file with malformed channel config
remotion render --props='{"src":"bad.mp4"}'

# after: re-encode to standard stereo
ffmpeg -i bad.mp4 -ac 2 -c:a aac -b:a 128k good.mp4
remotion render --props='{"src":"good.mp4"}'

const isValidChannelConfig = (c: number) => c >= 1 && c <= 7;

const isValidAacChannelConfig = (c: number): boolean => c >= 1 && c <= 7;

When it happens

Trigger: Calling createAacCodecPrivate with channelConfiguration set to 0, 8, or higher. Typically arises from parsing a corrupt or non-standard AAC stream where the channel_configuration field is out of range.

Common situations: A corrupt MP4/M4A file with a malformed audio sample descriptor, a non-standard encoder, or damaged codec-private atoms. Well-authored files use channel configs 1 (mono) or 2 (stereo).

Related errors

• Unexpected sampling frequency index ${samplingFrequencyIndex
• Unexpected sample rate ${sampleRate}
• Invalid syncword: ${syncWord}
• Only supporting layer 0 for .aac
• Expected AAC codec private data

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/09c2175d51d24a9c. Report an issue: GitHub.