Created attachment 133959 [details] Media information SUMMARY I have a vide in mov format recorded from a Canon DSLR (EOS 550D), that can't be played with phonon (neither gstreamer nor vlc), in both cases when playing the file (with either dragon or gwenview) I only get a black screen with no sound. On the console there are several of these messages: WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded WARNING: Phonon::createPath: Cannot connect Phonon::MediaObject ( no objectName ) to Phonon::VideoWidget ( no objectName ). STEPS TO REPRODUCE 1. Remove phonon-backend-gstreamer 2. Try to play mov file in any program using phonon 3. Black screen with no sound 4. Install again phonon-backend-gstreamer and remove phonon-backend-vlc 5. Try to play mov file in any program using phonon 6. Black screen with no sound The same file can be played both without problemes with: - gst-launch-1.0 filesrc location=MVI_6781.mov ! queue ! decodebin ! autovideosink - vlc MVI_6781.mov SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE Frameworks Version: Frameworks 5.76.0 Qt Version: Qt 5.15.1 Plasma Neon