Getting the MEdia file URL

Hi all,

the embed is working good.
But, I would like to know if it’s possible de extract the url of the image or media which is in the MEDIA column of my source file ?
MEDIA is like : http://mydomain.com/picts/image1.jpg

need to extract it when the wordpress page loads to put it in a og:image property to have it in facebook publish article.

Any Idea?
thanks for help
B

http://wordpress.org/extend/plugins/timeline-verite-shortcode/