Many times resolution of video is greater than that of the windows or operating system's default or customized resolution, so VLC scales the video resolution to the window resolution and fits display to window and this is the default option selected when VLC is installed i.e. "always fit window" under Video menu.
This reduces video quality by transforming video to fit window using Transformation and Translation algorithms. So many users like me don't like reduced quality and disable "fit window" option, but problem is that when we start VLC again it is re-enabled automatically. There is a solution to prevent VLC automatically enabling "always fit window" option, which is described below.
- Goto tools menu and select Preferences or press "ctrl+p"
- From preference dialog box, select All under show settings menu at bottom-left corner.
- Now from the listed options scroll to Video option and select it
- Now under the right side options scroll to "general video settings"
- Form available options uncheck "video auto scaling" option
- Press save.
This will stop VLC from auto fitting video to window when you restart the VLC.