For those of you who own the PS4 Pro, you might want to check an update on your console as Playstation has delivered an update that would now enable 4K video playback. As published in the PlayStation blog, the updated media app on the PS4 Pro will allow you to play 4K MP4 videos saved on a USB drive or home server, if you have formatted your external drive to save games and apps, it can't be used to save and play videos.
The most exciting update about this update is the ability to play 4K VR content as well, which will offer better clarity when viewing 360 degree videos on the PlayStation VR, by default the PS VR only supports 1920x1080 resolution, so this is a pretty huge update if you want to enjoy your 360 degree shots on PS VR. The PS4 Pro has been designed with a more powerful hardware than the non-Pro version to support 4K resolution in games and apps, there are already apps that takes advantage of the PS4's 4K resolution output which includes NetFlix, YouTube and Hulu.
Let us know about it in the comments after you update the Media Player app to the latest version.