Inconsistent playback, stuttering

[ohshitgorillas]

I am a recently Jellyfin convert after discovering that both Plex and Emby want money to enable hardware transcoding.

I am running Jellyfin inside Docker on an Ubuntu Server, with an Intel i5-10600KF CPU and Nvidia GTX 1660 Ti GPU... plenty of power to go around for a media server. The endpoints are a Google Chromecast 4K and my <1yr old Samsung tablet. 

I am currently traveling in a country with restricted internet, so everything goes through my WireGuard VPN, the server for which is located on the same machine as Jellyfin. I have never had any problems streaming content from Netflix, Hulu, etc. so it's not a hotel bandwidth problem or a VPN limitation. My home internet has gigabit speeds and I am the only person streaming from this server; there are other processes on the server but none that would consume significant bandwidth (i.e. only very minor BitTorrent traffic).

The problem I'm having is very inconsistent performance. I have gotten 4K videos to stream perfectly smoothly (with hardware transcoding), while others stutter so badly it becomes unwatchable (same source, same format, also with hw transcoding). I have even seen SD videos stutter. I have also been watching seasons of a show and had the first two episodes work without issue and without transcoding whereas the third one stutters frequently (all downloaded from the same source and in the same format). This appears to happen on an episode-by-episode basis since I haven't seen the problem start mid-episode (yet).

I assume the problem is related to transcoding since all other variables suggest that this isn't a bandwidth problem, however, I'm open to the idea that I'm wrong.

Since I'm new to this kind of troubleshooting, please let me know what kind of logs or data you all want to see. I'm hesitant to dump a bunch of info into the first post since a) I don't know what is useful and what isn't, and b) I don't want the first post to become an unreadable labyrinth of logs that may not even be relevant.

I will say that I have Nvidia NVENC enabled for all formats, including enhanced decoding. When the GPU does kick in, it rarely goes above 20% total power. I use a Grafana dashboard to check on the GPU when watching videos.

What's even stranger is that hardware transcoding seems to be enabled inconsistently as well, as I'm trying to stream a 4K video right now that isn't using the GPU... when another video from the same website, in the same format, does use the GPU. Both stuttered.

[TheDreadPirate]

When you setup your jellyfin, did you have it bind to a specific IP? Or did you leave that field blank so it binds to all IPs?

[ohshitgorillas]

I left the bind address blank. Should I set it to something specific? Thanks!

[TheDreadPirate]

No. It should be blank.

Can you share your logs with us?

[ohshitgorillas]

Sure, I've attached a few logs here. No idea why my tablet renamed them all "log" but one is the main log and the other two are transcoding/direct stream logs. I hope this is helpful.

I should note that the Beavis and Butthead episode in SD didn't stutter, but An Idiot Abroad has never played smoothly.

[TheDreadPirate]

From the ffmpeg logs, the transcode is happening more than fast enough. Nothing out of the ordinary in the jellyfin log. Without more network testing, we can't rule that out. Packet loss? Is your VPN setup to only route LAN traffic through the VPN? Or all traffic? I know with OpenVPN you have to specify. If your VPN was only routing your LAN traffic for jellyfin but not the streaming services you might have been streaming netflix from a local CDN edge server. And Jellyfin from however far away you were from home.

But I don't know what country you were in or how restrictive their Internet is. We would need to do more testing to figure it out, but it isn't anything wrong with Jellyfin.

[ohshitgorillas]

Thanks for checking, although it's a bit disappointing that nothing obvious is wrong.

I am in China, and the VPN is set up to route all internet traffic. The idea is that my internet activity will appear encrypted to China, but on the outgoing end it should look like honest-to-god American home internet traffic, which is how I'm able to access streaming services. Access to local services is a bonus.

Tonight, I experienced the same pattern as last night: I watched two episodes of Always Sunny, but the third one kept freezing. All 1080p or larger videos I watch now are stuttering. Hard to believe it's a coincidence at this point, but I believe you when you say that it doesn't appear to be a Jellyfin issue.