Live video streaming in UE4. How to use this great plugin ?

Hi guys,

I’m new in UE, I come from the VFX field. I’m tring to do real time chroma key in UE4 like this:Unreal Engine 4 Misc - #01 Chroma Material 1/2 UE4 Video Player - YouTube

But with live video feed from a blackmagic capture card with this plugin:
https://github.com/themill/DeckLinkMedia

The plugin come with no explaination or tutorial. could someone explain to me how to use it with the media player ? How do I use the stream from the decklink as a source ?
Thanks a lot.