Emby Theatre laggy at 4096x2160 with 1080 video

[Robnaeyaert 10]

Dear Emby

Sorry might be a very stupid issue but here goes.

I just purchased my first 4K Samsung TV running off my Intel NUC5i5RYH  - the screen was an upgrade from my 1080p Samsung which worked perfectly with Theatre.

When I set my resolution to 4096x2160 in Theatre all my videos lag and the synch is way out and look choppy. 

When I get my resolution back to 1920x1080 Theater plays perfectly.

So I reset my resolution back to 4096x2160 and played my videos directly from the server "browse library" in the browser and they all played perfectly at the higher resolution.

These videos are not 4k encoded - they are bog standard 720p, 1080 videos which all play perfectly when i set my resolution to 1080.

It's like Theater has an incorrect setting and I cant work it out.  I tried setting the resolution in "auto" and also to 1080 etc but nothing worked.

It seems a shame to have a 4k TV set to 1080 just to get this to work.

Could someone please point me in the right direction as I'd like to continue using Theater as I use my remote from my sofa to drive it.

Cheers guys appreciate the help

[lorac 100]

Check to see if the videos play properly outside of emby using VLC or MPC-HC as a test.

If so then check out the various hardware acceleration modes (auto, d3d, etc). I forget what the section above hardware acceleration is but it can be set to GPU / Auto so test with those to see if it makes a difference.

Another thing to consider is the framerate (ie. 60 or 30hz) which could make a difference as well.

I'm sure others will have thoughts but hopefully this gives you something to work with.

[generiq 113]

Your resolution should be 3840x2160, and as mentioned above, (assuming you're using the desktop app) the renderer should be set to GPU and hardware acceleration set to auto. Also, check your audio configuration. Many people don't realize that audio issues can also cause this effect.

Edited August 31, 2021 by generiq

[Robnaeyaert 10]

Hey guys - thanks for the advice - this seemed to do the trick so greatly appreciated.

Just for my education - why should the resolution be 3840x2160?  I just assumed being a 4k TV that it should be cranked up to the max.  Is there a reson for 3840x2160?

Also, last question - on the playback settings I note you can select low quality all the way up to 4k - 80mbs etc etc.  What is the optimum setting for that please?

 

Cheers again

 

Edited September 1, 2021 by Robnaeyaert

[generiq 113]

47 minutes ago, Robnaeyaert said:

Hey guys - thanks for the advice - this seemed to do the trick so greatly appreciated.

Just for my education - what should the resolution be 3840x2160?  I just assumed being a 4k TV that it should be cranked up to the max.  Is there a reson for 3840x2160?

The whole '4k' thing is kinda silly, and can be confusing. When it comes to resolution, think of multiples. It's also commonly defined by height moreover than width. So when we say 1080, we refer to vertical height (1920(w)x1080(h)). Using '4k' is a departure, as it's referring to width being 4096 (more than 4000, k=kilo, meaning thousand). But when talking about media, it's actually double 1080 HD (1920x2=3840, 1080x2=2160), which is not actually 4000 ('4k'). So setting your display/GPU to wider than the actual video frame, can sometimes cause issues, as it needs to be scaled up (lots of processing). This is why they use the term UHD (Ultra High Definition).

59 minutes ago, Robnaeyaert said:

Also, last question - on the playback settings I note you can select low quality all the way up to 4k - 80mbs etc etc.  What is the optimum setting for that please?

If you're in your LAN, just set it to the highest. Mine is always set 120Mb/s.

[Robnaeyaert 10]

Thanks generiq - that makes perfect sense and thanks for talking the time to explain it to me.  Cheers