In Kubuntu you can use Dragon Player to play both
video and audio files. To play video files:
Procedure 1. Open Files From The File Manager
Open the Dolphin file manager.
Navigate to the video file.
Click on the file name to open it with the default video player
(Dragon Player).
Procedure 2. Open Files From Within Dragon Player
Open Dragon Player; → → →
Click on the Play File button or press
Ctrl+O
Navigate to the selected video file, and click
Open