What causes "noRepeatNgramSize must be a non-negative integer." in remotion-dev/remotion?

Pass an integer >= 0 (0 disables n-gram repetition blocking)

remotion-dev/remotion · error · TypeError

noRepeatNgramSize must be a non-negative integer.

Error message

noRepeatNgramSize must be a non-negative integer.

What it means

transcribe() validates the decoding option noRepeatNgramSize: it must be an integer >= 0 (0 disables the constraint). Fractional, negative, or non-number values are rejected with a TypeError during option validation.

Source

Thrown at packages/whisper-webgpu/src/transcribe.ts:105

		throw new TypeError('doSample must be a boolean.');
	}

	if (!Number.isFinite(temperature) || temperature <= 0) {
		throw new TypeError('temperature must be a finite number greater than 0.');
	}

	if (!Number.isInteger(topK) || topK < 0) {
		throw new TypeError('topK must be a non-negative integer.');
	}

	if (!Number.isFinite(repetitionPenalty) || repetitionPenalty <= 0) {
		throw new TypeError(
			'repetitionPenalty must be a finite number greater than 0.',
		);
	}

	if (!Number.isInteger(noRepeatNgramSize) || noRepeatNgramSize < 0) {
		throw new TypeError('noRepeatNgramSize must be a non-negative integer.');
	}

	if (task !== 'transcribe' && task !== 'translate') {
		throw new TypeError('task must be either "transcribe" or "translate".');
	}

	const {multilingual, supportsTranslation} = getModelInfo(model);
	if (task === 'translate' && !supportsTranslation) {
		throw new Error(`The model "${model}" does not support translation.`);
	}

	if (multilingual && (language === undefined || language === 'auto')) {
		throw new Error(
			`The language option is required for the multilingual model "${model}" because automatic language detection is not supported.`,
		);
	}

	if (

View on GitHub (pinned to b2f4e34732)

Solutions

Pass an integer >= 0 (0 disables n-gram repetition blocking)
Sanitize with Math.max(0, Math.round(Number(raw)))
Validate option types when loading from JSON config files

Example fix

// before
await transcribe({noRepeatNgramSize: -1});
// after
await transcribe({noRepeatNgramSize: 0}); // disabled, or e.g. 3

Defensive patterns

Strategy: validation

Validate before calling

if (!Number.isInteger(noRepeatNgramSize) || noRepeatNgramSize < 0) throw new Error('noRepeatNgramSize must be a non-negative integer');

Type guard

const isNonNegInt = (v: unknown): v is number => typeof v === 'number' && Number.isInteger(v) && v >= 0;

Try / catch

try {
  await transcribe(options);
} catch (e) {
  if (e instanceof TypeError && e.message.includes('noRepeatNgramSize')) {
    options.noRepeatNgramSize = 0;
  } else throw e;
}

Prevention

Use 0 to disable n-gram blocking, not null or negative values
Normalize all integer options with Math.round/Math.max at load time
Type sampling options as integers so TS flags float assignments

When it happens

Trigger: Passing noRepeatNgramSize as a float, negative number, NaN, or string from unconverted config input.

Common situations: Numeric strings from JSON/env config; computing the value dynamically with possible NaN; unclear about 0 being allowed to disable n-gram blocking.

Related errors

AI-assisted analysis of remotion-dev/remotion@b2f4e34732 (2026-09-09). Data as JSON: /api/errors/b312be41f57171e6. Report an issue: GitHub.