The VideoLAN Forums

If I lighten a dar video (tools > Effects & filters > video effects >(ip Brightness and Contrast) > close, I get the "##_cut.mov" .
But when I input it into Video Dub (to trim it), it shows the original, dark version.

How can I make the filtered result permanent?

You need to transcode (convert) video together with chosen video filters.
Adjust Brightness and Contranst the way you already do it in video effects dialog box.
Then Media > Stream... where you include "vfilter=adjust" in your transcoding chain.

https://forum.videolan.org/viewtopic.ph ... 47#p381148
Or enable the "adjust" video filter for transoding in VLC prefererences:
Tools > Preferences > ( Show settings = All ) >
> Stream output \ Sout stream \ Transcode: [v] Image properties filter
Save changes, restart VLC.
Then Media > Convert / Save...

New VLC-2.1
Media > Convert / Save...
...
Profile: "Edit selected profile" button or "Create a new profile" button > "Video codec" tab > "Filters" tab: [v] Image properties filter
...