Are you sure? On xda this bug is known but only in 1 modded rev of miui camera in videomode had autofocus
My camera with desire and 11.19 don t have autofocus in videomode and camera app is no so good as camera in sense rom
I've request it on the begin of miui development about this but without positive responses
So many others surplus features where implemented .Camera is an important feature in last generation smartphone....