/**
 * 将音频文件从一种格式转换为另一种格式
 *
 * @param url - 输入音频文件网址
 * @param desType - 目标音频格式 (例如: 'mp3', 'wav', 'ogg', 'flac')
 * @param srcType - 源音频格式 (可选，如果未提供将通过检测文件头来确定)
 * @returns Promise<string> - 转换后的文件路径
 *
 * @example
 * // 将 input.wav 转换为 MP3 格式
 * const outputPath = await convertAudio('https://site/to/path/sound.wav', 'mp3');
 *
 */
export declare function convertAudio(url: string, desType: string, srcType?: string): Promise<string>;
export declare function mergeVideoAndAudio(videoUrl: string, audioUrl: string, audioType?: 'wav' | 'mp3' | 'ogg' | 'm4a' | 'aac'): Promise<string>;
interface IAssEvents {
    text: string;
    effect?: string;
    layer?: number;
    start?: string;
    end?: string;
    style?: string;
    name?: string;
    marginL?: number;
    marginR?: number;
    marginV?: number;
}
/**
 * 合成字幕到视频（ASS方式 + 样式）
 */
export declare function burnASSSubtitleToVideo(videoUrl: string, contents: IAssEvents[]): Promise<string>;
/**
 * 将多个视频文件按顺序合并成一个视频
 *
 * @param urls - 视频文件URL数组，按照需要合并的顺序排列
 * @param outputFormat - 输出视频格式，默认为'mp4'
 * @returns Promise<string> - 合并后的视频文件路径
 *
 * @example
 * // 合并三个视频文件
 * const outputPath = await joinVideos([
 *   'https://example.com/video1.mp4',
 *   'https://example.com/video2.mp4',
 *   'https://example.com/video3.mp4'
 * ]);
 */
export declare function joinVideos(urls: string[], outputFormat?: string): Promise<string>;
export declare function mergeWithDelayAndStretch(videoUrl: string, audioUrl: string, videoDuration?: number, audioDuration?: number, subtitle?: string): Promise<string>;
export {};