type Media = {
    durationMs: number;
    hasAudio: boolean;
};
/** These overrides are for local tests only; never accept them from a website request. */
export type TikwmDownloadOptions = {
    keyFile?: string;
    cacheDir?: string;
    fetch?: typeof fetch;
    now?: () => number;
    lockWaitMs?: number;
};
export declare function downloadTikwmReference(sourceUrl: string, workDir: string, maxBytes: number, inspectCallback: (file: string, workDir: string) => Promise<Media>, options?: TikwmDownloadOptions): Promise<{
    file: string;
    media: Media;
    transcript: string;
    provenance: "tikwm-cache";
} | {
    file: string;
    media: Media;
    transcript: string;
    provenance: "tikwm-api";
} | null>;
export {};