HTML5 Audio + Video multiple sources

Hi all,

    

    Is it possible in html5 output of audio and video to have multiple
    sources and fallback?

    

    I'm thinking specifically of for example:

    

    <video>

      <source src="" type="video/ogg" />  

      <source src="" type="video/mp4" /> 

      <source src="" type="
    
    video/webm">

    </video>

    

    If tried different ways but haven't been able to do it yet, is it
    possible?

    

    Many thanks,

    

    Peter