title: ffprobe get bit depth from audio file
body: <p>For one of my script I need to read out the bit depth of a wav file.</p>
  
  <pre><code>ffprobe -v error -show_entries format=bits_per_sample -of default=noprint_wrappers=1 test.wav
  </code></pre>
  
  <p>there is no output at all -  I use this in the same way for the duration (format=duration) and it works fine.</p>