remotion-dev/remotion · error

Unexpected sample rate ${sampleRate}

Error message

Unexpected sample rate ${sampleRate}

What it means

Thrown by getConfigForSampleRate in @remotion/media-parser when constructing AAC codec private data from a sample rate that is not one of the 13 standard MPEG-4 AAC frequencies (96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000, 7350). The encoder cannot map the rate to a valid 4-bit frequency index.

Source

Thrown at packages/media-parser/src/aac-codecprivate.ts:106

	}

	if (sampleRate === 12000) {
		return 9;
	}

	if (sampleRate === 11025) {
		return 10;
	}

	if (sampleRate === 8000) {
		return 11;
	}

	if (sampleRate === 7350) {
		return 12;
	}

	throw new Error(`Unexpected sample rate ${sampleRate}`);
};

export const createAacCodecPrivate = ({
	audioObjectType,
	sampleRate,
	channelConfiguration,
	codecPrivate,
}: {
	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;

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Resample the audio to a standard rate before encoding: ffmpeg -i in.wav -ar 48000 -c:a aac out.m4a.
2. Use a source file authored at a standard sample rate.
3. Verify the source's sample rate with ffprobe and correct the upstream pipeline.

Example fix

# before: source at a non-standard rate
remotion render --props='{"src":"odd.wav"}'

# after: resample to 48000 Hz
ffmpeg -i odd.wav -ar 48000 -c:a aac standard.m4a
remotion render --props='{"src":"standard.m4a"}'

const STANDARD_RATES = [96000,88200,64000,48000,44100,32000,24000,22050,16000,12000,11025,8000,7350];
const isStandardRate = (r: number) => STANDARD_RATES.includes(r);

const STANDARD_AAC_RATES = new Set([96000,88200,64000,48000,44100,32000,24000,22050,16000,12000,11025,8000,7350]);
const isStandardAacRate = (r: number): boolean => STANDARD_AAC_RATES.has(r);

When it happens

Trigger: Calling createAacCodecPrivate with a sampleRate outside the supported set (e.g. 44101, 22049, or any non-standard frequency). Encountered when the media pipeline hands the AAC codec-private builder a non-standard rate.

Common situations: An audio source with an unusual sample rate (e.g. 11024 Hz, or a rate altered by incorrect resampling), or a corrupt file reporting an odd rate. Most common when ingesting audio that bypassed proper resampling.

Related errors

• Unexpected sampling frequency index ${samplingFrequencyIndex
• Invalid channel configuration ${channelConfiguration}
• Unexpected audio object type ${audioObjectType}
• Expected AAC codec private data
• Could not find number of channels

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/74b2fc997ad40537. Report an issue: GitHub.