DRM integration

How many DRM service provider integrated in Kaltura ?

AFAIK: WV (Goole) and PlayReady

Can I integrate Kaltura CE with Widevine?
Is it possible to use widevine of EZDRM service provider ?

Is there any documentation about how do I do ?

Since you have the entire code you should be able to do so.
But you will need to modify the integration with WV (I don’t think there is any documentation)
I guess you need to enable the WV module (for the partner) and set the props in widevine.ini
If it doesn’t work properly look in /opt/kaltura/app/plugins/drm/providers/widevine