title: Is there a more suitable way to merge video and audio files in Python than ffmpeg?
body: <p>Somehow only 1080p60fps files can be rendered with the following command:</p>
  <pre><code>ffmpeg.output(input_au, input_vi,&quot;movie.mp4&quot;).run() 
  </code></pre>
  <p>For example, if I use a YouTube video that has only 1080p but no 60fps, the error message:</p>
  <pre><code>&quot;ffmpeg error (see stderr output for detail)&quot; 
  </code></pre>
  <p>appears. So how can I render video and audio files in case you want to download YouTube videos with bigger resolutions than 720p? (I'm using pytube dash download, i.e. getting video without audio and the audio as an extra file). Maybe there is also solution to come without ffmpeg, e.g. download the highest available resolution. But as far as I know the pytube library doesn't support progressive downloads for higher resolutions.</p>