Web player: Subtitles out of sync occasionally/random offset when seeking

[ghost]

Sometimes when seeking the video the subtitles track becomes "out of sync" and starts displaying dialogue from a random offset (usually less than 10 seconds). This is really annoying, and the only workaround is to restart the video from offset 0.

[Maxr1998]

This is likely an upstream issue related to a combination of the web client and (mobile) browser, there's more information about this here: https://github.com/jellyfin/jellyfin/issues/2547

The best option would be to use the native player implementation, if it supports the video and subtitle formats. At least .srt worked very well in my tests.

[ghost]

Confirming the native player doesn't seem to trigger this issue :+1:

[redactedscribe]

I'm also experiencing this. First time using the app.

Input #0, matroska,webm, from '.\video.mkv':
…
Stream #0:0(und): Video: h264 (High), yuv420p(progressive), 1920x1080, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
…
Stream #0:1(und): Audio: flac, 48000 Hz, stereo, s16 (default)
…
Stream #0:2(und): Subtitle: ass (default)

Seems to happen when I seek. Somewhat related: the subtitle offset feature steps in too large increments to accurately compensate for the delay. Seeking some more can help knock the subtitle delay around, making it align with a degree of selected offset. Also, I recall having to manually select the subtitle each time I started the video, even though the subtitle already had a tick next to it (toggling the subtitle to Off and back again). Haven't tested whether this still happens with an external subtitle.

Another observation I made was that, when testing SyncPlay, I noticed the subtitles on my Android seemed to always stay in time with the ones being shown on my PC. I'm new to Jellyfin so I don't know what level of synchronisation to expect from SyncPlay, but the two videos seemed out by a couple seconds, but as I said, the subtitles were in synch. Might not necessarily be a clue, but I thought I'd mention it regardless.

• App version: 2.0.0-rc.5
• Android version: Android 9
• Jellyfin server version: 10.6.4
• The type of video player implementation used: Web player

Originally posted by @redactedscribe in https://github.com/jellyfin/jellyfin-android/issues/137#issuecomment-696472915

[TKFRvisionOfficial]

This is still a big issue. again it is only on mobile. if i try to use an external player ("vlc for android" for example) i can only use mp4 stored movies not mkv ones wich really sucks because vlc actually supports that

[yalanyali]

Can confirm, still an issue.

[SadmanTariq]

This is still an issue. As a temporary solution, I wrote this script to automate burning subs for an entire directory. Only works on Linux but can be easily modified for Windows. Be aware that it can take a long time to finish depending on computer specs.

[daniel-smartners]

I can confirm this is still an issue, using Jellyfin for android TV seems be a solution for now.

[jellyfin-bot]

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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.

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[dannymichel]

Don't stale.

I think this issue keeps getting closed and popping back up

[Maxr1998]

It shouldn't since I added the confirmed tag.

[YodaQ]

I have this issue as well and Im running the latest stable version of both the server (10.7.7) and the client (2.4.4). It doesn't occur using the exo player but that has other issues regarding subtitles.

[dannymichel]

I have this issue as well and Im running the latest stable version of both the server (10.7.7) and the client (2.4.4). It doesn't occur using the exo player but that has other issues regarding subtitles.

I think myself and several other people are trying to fix this. I'd say the is one of the top three jellyfin bugs to be fixed.

[karlseven]

still a problem in 10.8.9

[0x0ade]

I've tested manually applying the htmlMediaHelper change from https://github.com/jellyfin/jellyfin-web/commit/baf1b55a0cb83d4cb63a18968fc93493ce785498 on my Jellyfin instance, and it seems like using hls.js on Android fixes any desyncs / seeking problems I've had.