How to get the video duration with the API Metacafe

I wonder how I can retrieve the length of a video with the API Metacafe.

I get the information from the API with the simplexml_load_file function PHP.
Here is an example of url of the API:
but I can not get the video length with SimpleXML PHP DOM

Here the piece of code that comes from the API’s XML file which gives the length of the video:
<media:content url=“” type=“application/x-shockwave-flash” medium=“video” height=“360” width=“640” duration=“62” />

Have you any idea how I could do?

Thank you

Anyone know the solution