subtitle out of sync when transcoding

[shinobiii163]

This issue respects the following points:

• This issue is not already reported on GitHub (I've searched it).
• I agree to follow Jellyfin's Code of Conduct.
• This report addresses only a single issue; If you encounter multiple issues, kindly create separate reports for each one.

Describe the bug

1. video name: Squid.Game.S02E01.2021.2160p.NF.WEB-DL.DDP5.1.Atmos.DV.HDR.H.265-HHWEB.mkv
2. subtitle out of sync when transcoding play
3. the issue happens both on androidtv app and web.
4. On the web, if I set "Always burn in subtitle when transcoding", the issue solved.
5. But androidtv app doesn't have this option，the issue can't be avoided.

Logs

No response

Application version

0.18.3

Where did you install the app from?

None

Device information

Xiaomi TV，HK1 RBOX X4，X96X10pro

Android version

Android9，Android 11

Jellyfin server version

10.10.3

Other sources

No response

[GertSallaerts]

From what I understand, subtitle sync issues during transcoding are a problem that's not easy to solve and a new option was introduced in Jellyfin 10.10 to help out people who are affected. (1, 2).

Subtitles often have synchronization issues after video transcoding. This option allows the client to opt-in to always burn in all subtitles, preventing out-of-sync subtitles at the cost of transcoding performance.

The option is already implemented in jellyfin-web where I tested it out and (for me at least) it solved the sync issues I was seeing when transcoding. Would it be a good idea to add the same "Always burn in subtitle when transcoding" option in this project?

I was browsing around the code a bit to see if I could whip up a quick PR for it as it sounded like an easy one (looking at the changes that were required on web) but -- unless I'm mistaken -- it's a bit more complicated as that part of the code is currently using an older Jellyfin SDK that's no longer being updated and to make this change a significant part of the code should be migrated to the modern SDK. Again, that's just what I gleaned from scanning the code and some issues, please do correct me if I'm wrong about that and there is an easier way. Edit: I see the old Jellyfin SDK was just removed completely 🎉

(While this comment is mainly about finding a solution, I am also affected by this issue, if I can help out by providing more details, do let me know.)

[Nezteb]

I've been having a similar issue, especially after seeking during playback.

Recently I disabled this setting:

So far, things seem better? Still, I look forward to testing out #4459! 😄

[jellyfin-bot]

This issue has gone 120 days without comment. To avoid abandoned issues, it will be closed in 21 days if there are no new comments.

If you're the original submitter of this issue, please comment confirming if this issue still affects you in the latest release or master branch, or close the issue if it has been fixed. If you're another user also affected by this bug, please comment confirming so. Either action will remove the stale label.

This bot exists to prevent issues from becoming stale and forgotten. Jellyfin is always moving forward, and bugs are often fixed as side effects of other changes. We therefore ask that bug report authors remain vigilant about their issues to ensure they are closed if fixed, or re-confirmed - perhaps with fresh logs or reproduction examples - regularly. If you have any questions you can reach us on Matrix or Social Media.

[GertSallaerts]

This issue is still present

[PilotFlying]

Resetting the 120d comment cutoff. This issue is keeping Jellyfin from being perfect 🙂

off-topic

What brought me to Jellyfin from Plex was the ability to do audio downmix at the server, with options on which algorithm to pick. This is the transcoding that is triggering the issue (video is not being transcoded). Would be great to one day have a "custom" option, passing the actual parameter to ffmpeg.

[jellyfin-bot]

This issue has gone 120 days without comment. To avoid abandoned issues, it will be closed in 21 days if there are no new comments.

If you're the original submitter of this issue, please comment confirming if this issue still affects you in the latest release or master branch, or close the issue if it has been fixed. If you're another user also affected by this bug, please comment confirming so. Either action will remove the stale label.

This bot exists to prevent issues from becoming stale and forgotten. Jellyfin is always moving forward, and bugs are often fixed as side effects of other changes. We therefore ask that bug report authors remain vigilant about their issues to ensure they are closed if fixed, or re-confirmed - perhaps with fresh logs or reproduction examples - regularly. If you have any questions you can reach us on Matrix or Social Media.