import { EventEmitter } from 'events';
import { QualityLevel } from './types.js';
export declare abstract class VideoEngine extends EventEmitter {
    abstract processChunk(inputPath: string, outputPath: string, startTime: number, quality: QualityLevel): Promise<void>;
    abstract extractScreenshot(inputPath: string, outputPath: string, time: number): Promise<void>;
    abstract getDuration(inputPath: string): Promise<number>;
}