Any video format which the iPad accepts can be used by Foliobook. 

There is an easy way to check if your video is correct for the iPad.

Firstly

You must sync your video with the 'Photo's' part of iTunes. If iTunes won't load it you probably have the wrong format or a corrupt file. 

Secondly

Open the 'Photos' app on the iPad.  Find the video you loaded.  If it plays in the Photo's app then Foliobook will be able to play it too.