Stuttering playback on 4K UHD movies

Hi all,

I’ve seen this posted a few times on this forum but thought I’d add my experience as well. I have a few $K UHD movies on my Synology DS-216. I also have a load of 1080p bluray rips. The HD rips play fine. They start within a few secs and play smoothly.

On the other hand, the 4k UHD files do not play smoothly. They start after a few secs, then freeze, while the audio plays in the background. I’ve tried a few files:
John Wick 2
Alien Covenant

My set up is:
Apple 32gb Apple TV 4K (set to output 4K SDR)
Synology DS-216ii+
Ethernet the whole ay (though it is a mix of gigabit and 10/100)
Hi-speed HDMI from ATV to my Samsung KS-8000

I don’t have the file details unfortunately. Could anyone give me an idea what could be the issue? Maybe a fix?

Cheers in advance.


We’ve made a number of improvements for 4K videos, and it’s likely this issue will be resolved in the upcoming 5.6 update.

5.6 will add HDR support as well. :slight_smile:

I don’t understand this. How do you get these UHD movies into your NAS? As far as I know UHD blu-ray protection hasn’t been cracked. So how to get the movies off the physical disk?

This is not something we should discuss here, but yes, the protection has been broken.