Need to resize an MKV file

[factor3]

I have a video on an MKV file that, when displayed on TV or any video player (including VLC Player!) shows a very small screen and is surrounded by thick black borders. I would like to resize the video display so that it will be the proper size for TV or any video players without the borders.

There seem to be a lot of converters (free and otherwise), but none of the ones I found will actually resize a video. There are plenty of tools that apparently let you shrink a video so that it will work with mobile devices and screw around with aspect ratios, but what I need to do is to increase the size of my video so that it will actually fit the screen(s) that I play it on.

Can someone point me to a tool that will do this?

Thanks in advance for any suggestions.

[johns0]

Load the video into vidcoder,it should detect the black borders and remove them when you re-encode the video.

[jan5678]

In mkvtoolnixgui you can change the aspect ratio of the movie?

[Selur]

iirc VLC also supports mkvs cropping flags, see: https://forum.videohelp.com/threads/346278-MKVToolnix-cropping-or-changing-display-width-height

[johns0]

Upload a short(10sec)sample of the video here so we can see if the video has the black bars baked in or just flagged that way.

[ProWo]

As johns0 wrote, we need your support.
Load your mkv into Avidemux, cut after 30 seconds, save to a new mkv and post this new file here.
So we will take a look.