I’d really love it if picture-in-picture could auto-play the next video in the folder. I’ve had a play with AVQueuePlayer in Xcode and it definitely works with PiP for MP4 files. That said, I don’t know what kind of witchcraft you’re using to get MKVs to play in PiP , but hopefully it would still be compatible with using AVQueuePlayer to control auto-playing the next video. Cheers!