<video> doesn't get muted

components.video-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: 'video',
  attributeBindings: ['_muted:muted', 'playsinline', 'autoplay', 'src', 'controls'],
  _muted: Ember.computed(function(){
    return true;
  }),
  muted: true,
  playsinline: true,
  autoplay: true,
  controls: true,
  src: 'http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4'
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{video-component}}
<br>
<br>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}