Built a small utility to use my iPhone as a webcam for my Mac, so I can use in my Mandarin classes. Was a pretty fun project: the iPhone gets the raw pixel buffer, live-encodes it to H.264 (using Apple's C-based VideoToolbox), passes it through USB 1/
to an app running on the Mac which decodes the H.264 stream (using the same VideoToolbox API) and sends it, via UNIX socket, to my fake webcam driver that I wrote so it appears as a webcam on Zoom calls! 2/
Was pretty fun learning how to use those APIs. VideoToolbox is old, but great to use (and I learned a lot about encoding). usbmuxd was used to make the USB transfer of the feed and I already knew about the good old UNIX sockets. 3/