embedding Facebook Video with oembed What is the proper way to embed a (public) facebook video with the oembed field module?

I tried including a video with a link like https://www.facebook.com/video.php?v=55555555555 but when I tested the link I got an error message (log didn't reveal details).


  https://www.facebook.com/video.php?v=55555555555 is not valid oEmbed URL. Please check the error log for messages.


It also doesn't show up in the content type field.

The default schemes didn't do the trick:

http://www.facebook.com/video/video.php*
https://www.facebook.com/photo.php*
https://www.facebook.com/video/video.php*


So I've added this https://www.facebook.com/video.php?v=* in the media - oembed settings for facebook.

still, it didnt work.

Any ideas on what URL I have to provide for this to work?

EDIT:

I've posted an answer that worked for me. 

Ideally, it should work without an embed.ly API key.
turned out i needed an API key for embedly service from http://embed.ly/. here is a good guide on oembed http://mustardseedmedia.com/podcast/episode54 

strange. some images showed up even without an API key.