title: child process spawn output file and directory in NodeJs
body: <p>I am using ffmpeg with child process to merge audio and video, but when i am trying to download the file, it is downloading in the same folder, but i want it to download it in the public folder.</p>
  <p>following is my code for the child process spawn.</p>
  <pre><code>// Start the ffmpeg child process
  const ffmpegProcess = cp.spawn(ffmpeg, [
      // Remove ffmpeg's console spamming
      '-loglevel', '8', '-hide_banner',
      // Redirect/Enable progress messages
      '-progress', 'pipe:3',
      // Set inputs
      '-i', 'pipe:4',
      '-i', 'pipe:5',
      // Map audio &amp; video from streams
      '-map', '0:a',
      '-map', '1:v',
      // Keep encoding
      '-c:v', 'copy',
      // Define output file
      'title.mp4',
  ], {
      windowsHide: true,
      stdio: [
          /* Standard: stdin, stdout, stderr */
          'inherit', 'inherit', 'inherit',
          /* Custom: pipe:3, pipe:4, pipe:5 */
          'pipe', 'pipe', 'pipe',
      ],
  });
  </code></pre>