I don't know exactly how to describe this, but here it is Amarok is running, playing MP3 files just fine. Then I open MKV files (AVC, AAC) in VLC, they play normally. When I go back to Amarok to continue the playback, it plays a millisecond then moves on the next and does the same, until it goes through all the playlist (as if the files are corrupt). I have to quit VLC for Amarok to go back to playing normally. I'd like to point out that it weren't always like that (a regression) Amarok is 2.8.0-8, phonon-qt5-vlc 0.8.2-4, VLC 2.2.2-3
you should not be using phonon-qt5-vlc for amarok 2.8.0 which is Qt4 based, please use the phonon-backend-vlc based on Qt4
I also have phonon-qt4-vlc, in fact I have all the Phonon backends installed $ pacman -Ss phonon extra/phonon-qt4 4.8.3-6 [installed] The multimedia framework for KDE4 extra/phonon-qt4-gstreamer 4.8.2-4 [installed] Phonon GStreamer backend for Qt4 extra/phonon-qt4-vlc 0.8.2-4 [installed] Phonon VLC backend for Qt4 extra/phonon-qt5 4.8.3-6 [installed] The multimedia framework for KF5 extra/phonon-qt5-gstreamer 4.8.2-4 [installed] Phonon GStreamer backend for Qt5 extra/phonon-qt5-vlc 0.8.2-4 [installed] Phonon VLC backend for Qt5 In Amarok I have Phonon VLC selected, the version says 0.8.2. However, there's no v4.8.3 (Qt4) visible to select
I strongly suggest you check with your distribution, as we do not provide packaging for neither Qt, nor VLC, nor Phonon or its backends. Since Amarok doesn't use VLC, but the phonon backend which in turn is compiled with libvlc, an independent library, playing something in VLC has zero influence over how Amarok plays something, Those packages are totally independent of each other (VLC doesn't use Phonon for playback for instance).