The Default Player Problem
When you double-click an MP4, MKV, or AVI video file in Ubuntu’s file manager, the operating system relies on its default application handler to open it. In a standard Ubuntu installation (using the GNOME desktop), this default handler is usually “Videos” (technically known as the Totem movie player). While Totem is a functional, basic player, it often lacks the necessary codecs to play complex video formats or properly render subtitles, leading to stuttering playback or blank screens. For power users who prefer robust, codec-heavy media players like VLC or MPV, automatically launching Totem is a frustrating interruption.
Reassigning the Default Handler
To ensure your media plays smoothly in your preferred software and stop Ubuntu from automatically opening videos in the default Totem player, you must reassign the file associations.
First, ensure your preferred video player (like VLC) is installed on your system. Next, click the system menu in the top-right corner and open Settings. In the left-hand navigation sidebar, scroll down and click on Default Applications. Look for the dropdown menu labelled Video. Click this menu; it will display a list of all installed media players capable of handling video. Select your preferred application (e.g., VLC media player) from the list. From this point forward, double-clicking any standard video file across the entire operating system will instantly launch it in VLC, completely bypassing the default Totem player.