title: How to encrypt WebM or MP4 file using ClearKey and then play it
body: <p>I'm currently researching the subject of encrypting  and playing encrypted videos in browser. I already have some successes with castlabs' DRMToday and Shaka Player while using Widevine.</p>
  
  <p>Now I'm trying to encrypt video without external services using ClearKey and play it in Chrome (using whatever js player which can handle).</p>
  
  <p>I did manage to encrypt single mp4 file using MP4Box (and mse-eme for creating crypt configuration) but I have no idea how to play it in browser. HTML5's Video didn't even trigger "encrypted" event on it. Encryption itself works fine - I was able to decrypt it back using the same tool with proper key.</p>
  
  <p>I tried to create a DASH out of this encrypted file and play it in Shaka Player. I created manifest using MP4Box. I had to manually add a missing xmlns to this file (xmlns:cenc="urn:mpeg:cenc:2013") so DOMParser parses it properly. I don't know how should I handle the license.</p>
  
  <p>I found few working examples of playing encoded webm files (including Shaka Player's demo page). How can I encrypt webm file? I did found <a href="https://github.com/webmproject/webm-tools" rel="noreferrer">https://github.com/webmproject/webm-tools</a> but it seems to require building entire Chromium in order to work.</p>
  
  <p>Are there any other tools that can encrypt webm files?</p>