search

TUM-Dev / gocast

TUMs lecture streaming service.
https://tum.live
MIT License
190 stars 43 forks source link

Camera Stream & Slide Stream out of sync after using different playback rates in Split View #878

Open Saydemr opened 1 year ago

Saydemr commented 1 year ago

Describe the bug In the lecture recordings, the camera and and slides go out of sync when the playback rate is set to something other than default. If rate is greater than 1.0, camera falls behind and/or slides & sounds arrive early.

To Reproduce

  1. Go to TUM-Live
  2. Open a lecture VoD
  3. Choose combined-view from viewing options
  4. Set playback rate to 2x
  5. Leave the video playing for 10 to 20 minutes.
  6. If there is a professor, you will see that hand-gestures and lip sync is out of sync.

Expected behavior Camera recording and slideshow should be displayed at the exact time even when the playback rate is different than 1x

Screenshots I can share a sample recording upon request and share privately.

Desktop (please complete the following information):

Additional context

Saydemr commented 1 year ago

Issue still persists and it is annoying. Do you consider to work on it or does it have a lower priority?

Thanks

MatthiasReumann commented 1 year ago

Issue still persists and it is annoying. Do you consider to work on it or does it have a lower priority?

Thanks

Hey! First of all, thanks for pointing out the issue. As of now, I unfortunately can't figure out what exactly causes this. It is also kind of time consuming to test since the video does indeed need to play for quite a while to notice the bug. Sometimes I also can't reproduce the bug altogether and the playback works just fine.

For the time being it would be probably best to not use the SplitView with playback rate > 1. Maybe a "resync" once every 10-15 minutes (Stop → Play) could also circumvent this problem. 😬

Saydemr commented 1 year ago

This problem also occurs when "seek back" & "seek forward" is used multiple times regardless of the playback rate.