import type { VideoSource } from './types.js';
export declare function extensionToMimeType(filename: string): string | undefined;
export declare function prepareVideoSources(source: string | string[] | undefined): VideoSource[];
export declare function uid(): string;
export declare function preloadImage(url: string): Promise<HTMLImageElement | void>;
export declare function formatTime(seconds?: number, showHours?: boolean): string;