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

[willymilkytron]

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.

[willymilkytron]

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.