Gwenview used to play back mp4 video, but after 20.04 Ubuntu upgrade videos are no longer playing.
I tried installing these dependencies based on the info found here, but got E: Unable to locate package phonon-gstreamer-4.8.2-x86_64-1
What is missing? How can I get Gwenview to play mp4 files again? (VLC Video player works)
I just found Gwenview Version 19.12.3, and there the video is working.
I found this post looking for a way to solve that same issue, and finally solved by installing
phonon4qt5-backend-vlc
Dropping this here in case someone needs it :)