function getVideoDuration(url) {
  return new Promise((resolve, reject) => {
    const video = document.createElement('video');
    video.src = url;
    video.addEventListener('loadedmetadata', () => {
      resolve(video.duration);
      video.remove();
    });
    video.addEventListener('error', () => {
      resolve(null);
      video.remove();
    });
    document.body.appendChild(video);
  });
}
// Example usage
const videoUrl = 'https://www.example.com/video.mp4';
getVideoDuration(videoUrl)
  .then((duration) => {
    if (duration) {
      console.log('Video duration:', duration);
    } else {
      console.log('Failed to get video duration');
    }
  });

 beforeVideoUpload = (file: File) => {
    return new Observable((observer: Observer<boolean>) => {
      // 判斷文件類型
      const isVideoFile = /video\/(wmv|asf|asx|rm|rmvb|mpg|mpeg|mpe|3gp|mov|mp4|m4v|avi|dat|mkv|flv|vob)$/.test(file.type);
      console.log('是否為視頻類型:', isVideoFile);
      // 獲取視頻時長
      const url = URL.createObjectURL(file);
      const audioElement = new Audio(url);
      let videoSeconds;
      audioElement.addEventListener('loadedmetadata', (_event) => {
        videoSeconds = Math.floor(audioElement.duration);
        console.log('視頻時長為', videoSeconds);
        observer.next(true);
        observer.complete();
      });
    });
  };