import type { TranscriptLine } from "./transcript.js";
/**
 * Creates a WebVTT string from a transcript which can be used for <track> elements of a <video> or <audio> tag.
 *
 * References:
 * - https://en.wikipedia.org/wiki/WebVTT
 * - https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API
 *
 * @throws If a timestamp has an invalid length
 * @throws If start > end
 */
export declare function createWebVttString(transcript: TranscriptLine[]): string;