Brief skipping / pause on first 4K UHD playback

[Darrenrwood]

Im very new to all this and have found it a steep but rather enjoyable learning curve. Still ripping my 4K discs to a synology drive running plex.
Played my first film at the weekend from plex (on Nvidia Shield) , from the synology NAS which is connected to my Denon AMP and then into my projector within a few feet of each other, so no long wire runs and no wifi issues ( as Im not relying on it).
The convenience of having them all on plex was great and the quality was amazing.
However 3 or 4 times during the movie it seemed to skip or pause for the briefest of second, and flashed up with the spinning yellow circle.
Any ideas what would have caused this given that the network is not used for anything else, so i cant imagine it was overloaded. Is it possible that during the ripping process the odd scene could have been missed ?
Is there any way to compare the ripped version to the original 4k disc version to check the size/number of frames ?

Any ideas of things I could test would be greatly appreicated.
I dont really want ot be in the position of showing people the set up and then having that happen again while watching a film so if there is anything I can do to "check" the files then that would be great
Thank you

[dcoke22]

Generally speaking, if MakeMKV produces a file, it is a good copy of what's on the disc. MakeMKV does not produce a file if there was a problem during the copy. Blu-rays and UHDs have something called Content Hash Tables that can be used to verify that what was read off the disc matches what is on the disc and MakeMKV makes use of these for this purpose while it rips.

Personally, I use mediainfo a lot to know the details of what's in a .mkv file. If you wanted to count the number of frames or some other details like that, you'd probably have to use ffprobe or something similar.

Is your Synology directly connected to your Denon? If so, how? And how is your Nvidia Shield connected? I think you can have local storage connected to a Shield for Plex but I don't have any direct experience with an Nvidia Shield.

I don't use a Synology, but I do use a Plex server running on a NAS that is connected to my network via 10gb ethernet. My client at the TV is an AppleTV 4K, also connected to my network via gigabit ethernet. I can watch 4K movies on this setup without any hiccups like you describe.

[Woodstock]

Generally speaking, a Synology server will play (at least) 4K content without pauses, even while handling other tasks. My pair are both sources and sinks for my network, in general, so the primary one is handling video in from 11 cameras, while hosting playback streams for those cameras AND watching video, while ripping up to two BD disks, and handling encoding of one file via handbrake. That's with 1gb networking on one port. The only time I've seen slowdowns is when the network port is screwed up (10mb just won't cut it, 100mb struggles while ripping, but 1gb smokes right along.

Where things can slow down is if you're having the Synology doing more than just providing data services. I have not tested mine as a Plex server (where the server is doing data manipulation such as converting MKV file to MP4 for display on a less-capable player) recently. Plex can do "just a little" or "a hell of a lot" of processing, depending on your needs. The Synology version of it will use the hardware encoder built into the CPU most of the time, but not always, especially if you try to play more than one stream to a less-capable player. Delays can be seen, especially if you're encoding a subtitle stream into the video. All of my players now handle subtitles themselves, but I stopped using Plex a long time ago.

[dcoke22]

All of my players now handle subtitles themselves, but I stopped using Plex a long time ago.

Out of curiosity, what do you use now?

[Woodstock]

what do you use now?

My computers just need to be pointed at the directory, and play using VLC. On some of the TVs, I have (old) Amazon FireTV modules and use ViMu more than VLC.

One thing I have to do with the FireTVs is to make sure the subtitles are tagged correctly. The default configuration for most videos will either have NO subtitles, or play the wrong set (full vs forced-only "just signs"). I have a script that I run after handbrake to turn on both the forced and default flags. Once tagged, they'll display the forced-only by default, and full can be switched on. Without it, nothing gets displayed by default.

[Darrenrwood]

Generally speaking, if MakeMKV produces a file, it is a good copy of what's on the disc. MakeMKV does not produce a file if there was a problem during the copy. Blu-rays and UHDs have something called Content Hash Tables that can be used to verify that what was read off the disc matches what is on the disc and MakeMKV makes use of these for this purpose while it rips.

Personally, I use mediainfo a lot to know the details of what's in a .mkv file. If you wanted to count the number of frames or some other details like that, you'd probably have to use ffprobe or something similar.

Is your Synology directly connected to your Denon? If so, how? And how is your Nvidia Shield connected? I think you can have local storage connected to a Shield for Plex but I don't have any direct experience with an Nvidia Shield.

I don't use a Synology, but I do use a Plex server running on a NAS that is connected to my network via 10gb ethernet. My client at the TV is an AppleTV 4K, also connected to my network via gigabit ethernet. I can watch 4K movies on this setup without any hiccups like you describe.

Hi - just checked and the synology Nas goes into my broadband router. Into that router is also plugged the Denon Amp and the Nvidia Shield. All of the equipment is within a meter of each other.

[Woodstock]

My suspicion would be the broadband router, depending on how it operates. Some do a lot of processing on signals, others only handle what is deliberately routed through them.

For me, anything attached to "internet" is separate from regular network stuff. A 24-port gigabit switch talks to everything, and cables run from it to the internet equipment (I have multiple internet connections).

But, I've still had cables screw things up. Last two times that was, the link between the switch and the server was "just" 10mb, which screwed things up royally, but was only obvious when you looked at the switch and saw the incorrect light color. Failing would have been too obvious. Change the cable, and it jumped back to gigabit speeds.

Anything that processes the signal can slow it down. A typical test is to eliminate things one at a time, which is hard when the "joint" is also something that needs testing. Checking speed lights, and possibly using a different network switch temporarily, are quick things to check.

[dcoke22]

I wouldn't expect your Plex server to be transcoding, but maybe it is. It is worth checking to see if Plex is transcoding while you play a 4K file. You can see this on the Plex dashboard.

Plex Support: Direct Play, Direct Stream, Transcoding Overview

[Darrenrwood]

I wouldn't expect your Plex server to be transcoding, but maybe it is. It is worth checking to see if Plex is transcoding while you play a 4K file. You can see this on the Plex dashboard.

Plex Support: Direct Play, Direct Stream, Transcoding Overview

Thank you - I will run a test at the weekend

[Darrenrwood]

My suspicion would be the broadband router, depending on how it operates. Some do a lot of processing on signals, others only handle what is deliberately routed through them.

For me, anything attached to "internet" is separate from regular network stuff. A 24-port gigabit switch talks to everything, and cables run from it to the internet equipment (I have multiple internet connections).

But, I've still had cables screw things up. Last two times that was, the link between the switch and the server was "just" 10mb, which screwed things up royally, but was only obvious when you looked at the switch and saw the incorrect light color. Failing would have been too obvious. Change the cable, and it jumped back to gigabit speeds.

Anything that processes the signal can slow it down. A typical test is to eliminate things one at a time, which is hard when the "joint" is also something that needs testing. Checking speed lights, and possibly using a different network switch temporarily, are quick things to check.

Ta - I might get a proper switch in that case and also swap out a couple of the cheaper/older network cables - thank you

[daveyboyNo1]

Darrenwood, the answer will be what coke said - Synology nas are not fast enough.
Ive got a synology and it will rarely ever play any UHD without stutter as it transcodes. Synology are not powerful to transcode.

Use handbrake to convert to something easier and store that copy.
Keep the original for when you get a plex server with some power.
I'm in the same boat as you. My plan is to purchase a mini pc. but funds are tight right now.

My main PC proved the issue was the synolgy as I set it up as a temp plex server. I also checked the CPU on the synology both when it was the plex server to when it wasn't.

[Billycar11]

Why not just direct play why transcode live every time?