1. Root your X Performance (use my AndroPlus Kernel) 2. Delete following file: (yes it says Enable 4K, but actually disables 4K) /system/vendor/overlay/SuperVideoCamera-Enable-4K-Overlay-275-release.apk 3. Reboot and now 4K video should be in camera app list. If it doesn't, find Video -> 4K Video from activity launcher (use apps like Nova Launcher) and launch it.