title: How to draw a waveform of an audio stream in html5?
body: <p>I have a media stream from webcam. I need to draw a waveform of the audio (extracted from the media stream) on the fly. How to do this in HTML5 using JS?</p>
  
  <p>I checked: </p>
  
  <p><a href="https://github.com/soundcloud/waveformjs" rel="nofollow">https://github.com/soundcloud/waveformjs</a></p>
  
  <p><a href="https://github.com/katspaugh/wavesurfer.js" rel="nofollow">https://github.com/katspaugh/wavesurfer.js</a></p>
  
  <p>They all seem to work with an audio file. How to do it for a stream?</p>