Add border to the bottom of an mkv

[naszdom]

I want to add a border to the bottom of an MKV to display subtitles in. Handbrake is good at taking the black bits out but I want to somehow negatively crop.

OK when posting I noticed the "Similar Threads" below. I am now trying Avidemux. However if anyone knows a way of using handbrake for this...

[Baldrick]

Nope. YOu can't use handbrake to add any black borders.

[naszdom]

Thanks - as I thought

[naszdom]

Having added a black boarder (to take soft subtitles) I have tried hard coding subtitles above it. However with avidemux 2.6.8 (windows version) all it does is increase the size of the black border and puts the subtitles there. Increase the subtitle bottom margin and it just increases the size of the black border. It does not move the subtitles. Even if you do not want a black border it insists on giving you one and putting the subtitles there. Attached is a scene from an xvid 704 X 288 converted into an mkv 704 X 448. That is 288 + border 100 + subtitle bottom margin 60. How do I get the subtitles burnt into the film and not in a black box of its own.