How do I import a TED Talk?

Edit Subject

I am attempting to insert a TED talk into my prezi, as I would import a youtube video.

TED talks show as html files in my browser, but allow you to download them to your computer; this I did - it saved as an mp4 file on my desktop.

Can I import from the browser directly?
Is prezi not recognizing it because it is html?
Is there a file type I can convert it to in order to have prezi recognize/import? (I have the capability to convert to a number of different formats).

Please advise.
Thanks in advance.
http://video.ted.com/talk/podcast/201...