Remove bars top and bottom

[If there is a tutorial/doc on this, please point me to it. I haven’t found anything here or in the documentation.]

I’m not exactly sure what I need to do to accomplish my goal. So, I’ll explain what I’m seeing. NOTE: When testing converted videos, I use VLC but generally I watch videos from my media server which runs Plex.

I have a video that, by default, displays as 4:3. It is actually formatted as 2.35:1 so when it displays it has black bars at the top and bottom. In VLC, if I select “Video > Crop > 2.35:1” it displays correctly and the bars are removed.

What options can I set in MKVToolNix so that it defaults to correctly displaying as 2.35:1? I haven’t found any setting that allows me to alter the default aspect ratio. I’ve read articles that talk about using “Video display width/height” do alter this but I have tried playing with those and with “Video pixel width/height” but have not been successful getting it to be formatted.