title: video not loading in html5
body: <p>I'm having a problem with the HTML5 video player, doesn't show the video, in a html file I have:</p>
  
  <pre><code>&lt;video&gt;
            &lt;source src="video.mp4" type='video/mp4; codecs="avc1.42E01E, mp4a.40.2"' /&gt;
            Video tag not supported.
  &lt;video&gt;
  </code></pre>
  
  <p>I even tried without the <em>codec</em> atributte in chrome I gets nothing, only the black square of the reproductor</p>
  
  <p>the file <em>video.mp4</em> is inside the same folder of the html, it doesn't even show a preview, nothing!</p>