title: ffprobe or avprobe not found. Please install one
body: <p>I want to add tags to mp3 converted by youtube-dl &amp; ffmpeg:</p>
  <blockquote>
  <p>youtube-dl -o
  '/Output/qpgTC9MDx1o.mp3' qpgTC9MDx1o -f bestaudio --extract-audio --metadata-from-title &quot;%(artist)s -
  %(title)s&quot; 2&gt;&amp;1</p>
  </blockquote>
  <p>I have this error in the output result:</p>
  <blockquote>
  <p>[youtube] qpgTC9MDx1o: Downloading webpage [youtube] qpgTC9MDx1o:
  Extracting video information [youtube] qpgTC9MDx1o: Downloading js
  player en_US-vfluGO3jj [youtube] qpgTC9MDx1o: Downloading DASH
  manifest [download]
  /var/www/vhosts/mp3-y.com/httpdocs/Mp3_Output/quick-mp3.com-JALAL-EL-HAMDAOUI-2007-ARRASSIATES-VOL2-F1P-9CDoxlQ.mp3
  has already been downloaded [download] 100% of 13.43MiB WARNING:
  qpgTC9MDx1o: writing DASH m4a. Only some players support this
  container. Install ffmpeg or avconv to fix this automatically.
  [fromtitle] parsed artist: Maroon 5 [fromtitle] parsed title: Animals
  ERROR: ffprobe or avprobe not found. Please install one.</p>
  </blockquote>