title: VLC: How to convert from mp4 to webm
body: <p>How can I convert from mp4 to webm using VLC, if possible? What codec should I choose? Do I need to recode the sound?</p>
  
  <p>I'm trying to put html5 video on a website with flash as fallback. As I understand it, it's the only format (webm) that Firefox allows (unless you are on windows 7 64bit?). Theora seems to work but from what I understand it's a bit old, also it takes a while before it renders the picture correctly and provides no thumbnail :(</p>
  
  <pre><code>&lt;video controls width="500"&gt;  
      &lt;!-- if Firefox --&gt;  
      &lt;source src="video/45-theora.ogg" type="video/ogg" /&gt;
      &lt;!-- if Safari/Chrome--&gt;  
      &lt;source src="video/45.mp4" type="video/mp4" /&gt;
  &lt;/video&gt;
  </code></pre>
  
  <p>Oh and I'm on Mac OS Lion but I have access to Windows 7, Vista and XP if it makes it easier for someone.</p>
  
  <p>Thanks for any help!</p>