smallest 4k player?

[luv2liv]

what is the smallest 4k player that can play mp4 or mkv files from usb flash drive? or through a nas?
i have been using raspberry pi to play 1080p videos for my aunt's restaurant. now that she upgraded the tv to 4k tv, it would be nice to show off some 4k clips. but the rpi3 cant handle 4k resolution.
it is not clear roky 4 ultra can do this. seems playing mkv or mp4 files locally is a taboo....

 

[luv2liv]

looks like roku 4 with usb port can do it. https://support.roku.com/article/20...yer-playing-your-personal-videos-music-photos
not sure why its not advertised on amazon nor best buy

 

[Kartajan]

xiaomi mi box (Walmart)

 

[luv2liv]

awesome! i didnt know xiaomi mi can do mkv 4k vids from usb port. the price is much better too!