title: Video.js not playing only audio with black screen
body: <p>I have initialized video js player on my webpage 
  and i have a function that is triggered on a button click to load source to the video . and show the player and start playing it (auto start is set to true) </p>
  
  <pre><code>function playVid(x) {
              videojs("vidPlay").src({type: "video/mp4", src: "http://www.domain.com/getVid?id=" + x});
              showPlayer();
          }
  </code></pre>
  
  <p>this works very well in firefox but in other browsers it only plays the audio with black video...
  what is wrong here ?
  how can i fix this ?</p>