'Buffering' for no apparent reason

[Toby Hogg]

I am having an issue with Jellyfin where I am getting buffering whilst direct streaming or transcoding. This occurs even when using Jellyfin on the same device that hosts the server so is not a network related issue.

I'm not well versed in the FFMPEG or Jellyfin logs but nothing jumps out at me. Attached for anyone who knows enough to spot any issues.

HDD sits at about 30-60MBPS depending on what I'm playing. Media is stored on a HDD but transcodes etc etc should be stored on an m.2 SSD

GPU for the server(and in this case the client) for Direct Play sits at less than 10%. The GPU cuts to 0 on Decode every time it freezes if that means anything

And if transcoding it sits at 98% and transcodes at ~450FPS according to the playback info

Can answer any Questions and provide any info that might be needed

[TheDreadPirate]

Does this happen with every video or only some videos?

[Toby Hogg]

I've checked a few files, a mix of movies and tv shows in varying quality and file sizes, it happens on every one
If it helps, the issue happens on Firefox as well as chrome so doesn't seem to be browser based.
All videos play fine in VLC.

[TheDreadPirate]

When you are accessing it from the same machine running the server, are you using "localhost" or "127.0.0.1"? Or are you using a domain name?

[Toby Hogg]

Interesting and something I didn't think of. I've been using the domain name rather than localhost/my local IP. If I use localhost the issue vanishes completely.

In that is the issue potentially with Caddy? The Caddy file is a standard reverse proxy so I can't think of a reason why it would cause this. Nothing exciting in the Caddy logs either

[TheDreadPirate]

The issue is that your router is not keeping the traffic local.  The traffic is going out to the Internet only for it to come back.

There are a couple ways to prevent that.  Some routers have a setting you can enable called "NAT loopback" or "NAT hairpin".  When that is enabled when the router sees that the DNS request resolves to itself it will keep the traffic local instead of sending it to the Internet.

Your other option, if your router doesn't have NAT loopback/hairpin, is to setup local DNS entries for your domain.  You'd set the IP address for your domain to be 192.168.1.42.  You'd also need to ensure that your server always gets this IP assignment from your router.

   

[Toby Hogg]

Thank you, that's solved it, at least for local connections