import type { TitleCue } from './titles.js';
/**
 * Rasterize each cue to a transparent PNG. Returns null when Chrome can't be
 * reached, so the caller renders without titles rather than failing the trailer.
 */
export declare function rasterizeTitles(cues: readonly TitleCue[], width: number, height: number, outDir: string, fontFile: string): Promise<string[] | null>;