I have installed kde 5.5.3 on kubuntu 15.10 via ppa:kubuntu-ppa/backports-landing After that, vlc doesn't work correctly: it takes unusually long to start (more than 10 seconds) and also that long to shutdown. When i play video, it is cropped, only top left corner is shown. Please see picture: http://s71.photobucket.com/user/nbelavic/media/vlc-553-problem_zpsd1lo0dya.png.html?sort=3&o=0 When i switch from "native stile" to "custom skin" in vlc preferences, everything works OK. It was working ok with 5.4.3, an vlc wasn't updated recently. Reproducible: Always Steps to Reproduce: 1. open any video in vlc with "native style" Actual Results: vlc opens extremly slow, and video is cropped Expected Results: vlc opens fast, whole video is shown
I've been having a similar problem (with the cropped video, not sure about the performance degradation) these last few days, also since installing Kubuntu backports (the bug has been reported through Debian and OpenSUSE channels too). After some searching around it looks like the bug was introduced in Qt 5.5, https://bugreports.qt.io/browse/QTBUG-48321. I'm not sure about the development processes but from what I can tell in the report a fix has been merged into the Qt code, but only for the 5.6 release. Until that gets released we will have to work around the issue.
The Qt 5.6 release candidate is available. Please check if this fixes the issue. If not please add a comment here or to the Qt bug link above.
Not sure what's changed in the Kubuntu release yesterday but the issue seems to have gone away for me. KDE 5.5.4 (haven't yet got 5.5.5 from the backports), Qt 5.5.1. How intrusive would it be to try the Qt 5.6 RC?