I'm newbie macOS. I'd like to make a virtual camera like CIFilterCam. But, there are no tutorial or reference documents. apple developer page just provide short class descriptions. It is not enough to start develop virtual camera. Camera extension template code can be generated by XCode. but, it shows the way streaming camera source, not consuming sink stream. CIFilterCam implements output device and application which filters images and pass it to output device. I also want to implement it. Is there any tutorial, document or sample code which makes CoreMedia IO extension supporting output sink?