Lag and flickering with complex subtitles

Summary

I'm having trouble playing video's with complex subtitles. The video starts flickering when subtitles are just a little more than text and if the subtitles are too complex the video just freezes.

Minimal project and steps to reproduce

I've created a video sample that causes some slight flickering for me: http://77.162.107.82/SubtitleTests/normal_test.mkv

I also created a sample that freezes for me: http://77.162.107.82/SubtitleTests/subtitle_testing_complex.mkv

What is the current bug behavior?

Freezes and flickering happening for a lot of videos with subtitles

What is the expected correct behavior?

Normal playback

Does it work on other platforms? Does it work with the official VLC apps?

Tested in VLC 3.0.16 without problems.

Lag with VLC nightly.

Lag and flickering with vlc-unity

Relevant logs and/or screenshots

No errors but a lot of these:

Environment

• OS: Windows 10
• Version 20H2
• Graphic GTX 970
• VLC Unity plugin version 0.1.3