SOLVED: Hang when starting video or seeking

[TastefulRegent]

When playing any video through Jellyfin on my Firestick, there's a long hang/pause, for maybe about 10 seconds, when the video first starts and whenever I seek to a new point in the video (e.g. when trying to skip a show's opening). However, there is no such hang if I seek to a position I've previously "seeked" to. In other words, after the initial hang when starting a video, if I skip ahead (and then wait for the hang of seeking to a new point to finish), and then skip back to the beginning, the video will start from the beginning without a hang. In other other words, it will only hang for any point in the video a single time. If I never try to seek to or skip any part of a video, the video will play just fine (after the initial hang of starting it).

This issue only affects my Firestick. From my PC, if I try to play a video through Jellyfin on my web browser, everything is instant without any hangs/pauses. Additionally, this issue only affects Jelllyfin. I've previously watched local media via Kodi on this same Firestick, accessing the media on the network without any server software at all, and it had no hanging or pausing issues like this.

Things I've tried:

• Restarting the Firestick (no effect)
  
• Disabling transcoding for the user (resulted in videos not playing at all)
  
• Enabling hardware acceleration for transcoding (Intel QSV) (no effect)
  
• Moving the transcode cache directory to a fast SSD instead of the onboard eMMC storage (no effect)
  

Is there anything else I can try, or more information I should provide? Logs (truncated to around the most recent time I tested starting a video) are attached. I don't know if it logs at the debug level by default, but I'm not able to find an option to enable debug-level logging, so guidance would be appreciated. Thank you for your time!

Server info:
Hardware: Evolve III Maestro (N3450 processor)
OS: Xubuntu (Ubuntu 24.04 LTS)
Jellyfin version: 10.9.8

Client: androidtv 0.17.4

[TheDreadPirate]

You are transcoding, and not very quickly. When you skip ahead it has to build up a buffer since it is not really "getting ahead". When you skip back to where you've already watched, its because the transcode from that point is still on the disk.

The N3450 just isn't a super fast transcoder, especially when you are burning in the subtitles. Without subtitles it would probably transcode quite a bit faster, but subtitle burn-in involves the CPU and not just the GPU.

The reason only the Firestick is transcoding is due to exoplayer not fully supporting ASS subtitles. It supports basic, un-styled, ASS subtitles. Most browsers fully support ASS subs, as does Kodi.

[TastefulRegent]

The media I watch will pretty much always have subtitles, so that's unfortunate to hear. Any suggestions, aside from maybe going back to Kodi but with a Jellyfin plugin?

[TheDreadPirate]

Your options are to upgrade the server or use a more capable client (Kodi + jellyfin plugin).

[TastefulRegent]

Not the answer I was hoping to hear, but that's clear and concise, and it's not within your power to suddenly change how these things work. I really adore Jellyfin's UI, but I guess it's back to Kodi for me. Thanks for your help!