Long delay before subtitles appear (jellyfin-web)

[scott]

Hi folks, first post here.

I'm getting a 10-20 second delay before embedded subtitles appear when I start playback in jellyfin-web, usually subs embedded in .mkv files. This is **without** any fetching additional data indicator, and regardless of whether I have on the fly subtitle extraction on or off in Playback. I also don't have any issue like this when using a client other than jellyfin-web such as Infuse.

My logs show entries like this:

[INF] [37] MediaBrowser.MediaEncoding.Attachments.AttachmentExtractor: ffmpeg attachment extraction completed for "/config/data/data/attachments/0/00d98a57-5d1d-2b2c-0dbd-b32d6f9884a9" to "/config/data/data/attachments/0/00d98a57-5d1d-2b2c-0dbd-b32d6f9884a9"

which I'm guessing must be the sub extraction, and multiple of these entries show up *before* subs appear. Really weird.

I've searched for the issue and wonder if this open issue is still relevant, one comment maybe suggests that the delay is the time it takes to extract the full subs file from the video file? But why would it still happen if I disable subtitle extraction and presumably force burning them in in that case? Confused on how to tackle troubleshooting this.

My setup is v10.8.13, in Docker on Debian 12. I have Intel QuickSync hardware accleration turned on and the /config/data directory is on SSD while the media is on HDD. Let me know what other info I can provide, thanks!

[TheDreadPirate]

This is on-the-fly subtitle extractuon.
This provides better subtitle compatibility for clients that can't play embedded subs. Depending on the performance of your setup it may not be completing the extraction until well after the video starts

You can try the Subtitle Extract plugin which pre-extracts your subs and stores them. You would need to run the scheduled task for this plugin from the dashboard.