How to get video duration from Graph API?

Are there any methods to query the duration of Facebook Video by Graph API?

There's no related field from document.

http://developers.facebook.com/docs/reference/api开发者_如何学Python/video/

If Graph API does not support now, will it support in the future and when? Great thanks for any inputs.

Now in 2015, Facebook provides the video duration with the "length" field:

• https://developers.facebook.com/docs/graph-api/reference/video

to get the video duration, get the video and then get the duration directly by "Decoding" or parsing the video file.