Below, you can find the examples of how the embedding URL look like for each of the supported services:

Youtube - http://www.youtube.com/embed/(video code)*
Vimeo - http://player.vimeo.com/video/(video code)*
Yahoo! Screen - https://screen.yahoo.com/(video code)*.html?format=embed
DailyMotion - http://www.dailymotion.com/embed/video/(video code)*
VK - https://vk.com/video_ext.php?(video code)*

* Where (video code) should be provided in the format corresponding to the source service