Media Foundation API is not so friendly for extensibility, and not so popular overall, so virtual device there is an interesting thing.
FaceRig is a program enabling anyone with a webcam to digitally embody any character they want, software coming from Bucharest, Romania. Here is their announcement regarding virtual Media Foundation extension:
Support for all-new, all-special FaceRig Virtual Webcam driver. This driver was developed for us by a company employing virtual device drivers specialists, called Adoriasoft. It should have significantly better compatibility than the old virtual webcam. It works with Skype Metro, and a plethora of less known chat apps and browsers (for instace using Chrome for Chatroulette or Omegle is no longer a requirement :) ).
Indeed, their virtual camera has a device path:
The device backed by “hardware representation” is picked up by Media Foundation because starting in Windows 7, Media Foundation automatically supports audio and video capture devices. For video, the device must provide a kernel streaming (KS) minidriver in the video capture category. Media Foundation uses the PnP path to enumerate the device.
So this Adoriasoft company… appears to be a company from Kharkov, Ukraine, 20 minute drive from me. Well, good job guys!