I have a video file that has multiple subtitle tracks. I want to convert it as it is nearly 4GB and it will convert to 500MB. Sadly when I converted it all the subtitles disappeared. I only want one of them but they are embedded in the video (mkv). I see lots of help on how to ADD a subtitle track using a .srt file but I don't have a .srt file.

1) How can I convert this file and keep 1 specific subtitle or all the subtitles?

or

2) Is it possible to use VSDC to strip out the subtitle I want to an srt file and then use that to convert the original file with that srt file?