Can you have two different video inputs into the encoder? One into HDMI and one into USB? I understand USB video input is a beta feature, but what can I do with this beta feature at the moment?
Would the encoder allow me to upload multi-camera-angle video to YouTube? Or maybe something else?
You can indeed use a USB webcam on the Webcaster X2 along with the HDMI input. Then you can have these as a picture in picture or picture beside picture as well as switching between them. This would still just be a single stream to YouTube though, not a multi-camera-angle video.
This is detailed in the online user guide here: https://www.epiphan.com/userguides/webcaster-x2/Content/3_Shared/usb-camera-intro.htm