Gene, LOL this does the Opposite of Making MKV files... it is a FFMPEG GUI with input format restricted to a subset of the MKV container spec ... the output can be anything that FFMPEG can produce provided you manually fix the default output profile settings as they all have poorly considered and non-adaptive bitrates that will produce massive video output file size.

If you got the previous giveaway of Dimo VideoMate 4.6.1 a few months back then you have everything this does and support for the rest of the other video input containers and codecs.

Olaf,

No.
A video converter re-encodes video to a new frame size &/or bit rate &/or format. CC can be embedded in some video formats like mpg2 & AVC, though not every player will decode & display it. You'd use something like ccextractor to write embedded CC to a .srt format text file, that when named the same as a video file, and stored in the same folder, will be displayed by very many players. Subtitles for a Blu-ray or DVD movie are in a stream separate from the video file but in the same container, e.g. VOB, .m2ts, or less often, MKV. That stream can be taken out of a .m2ts file for example, and put with the video in a MKV container file, or it can be used with OCR [e.g. using Subtitle Edit] to get a .srt file. When a video converter does handle subtitles that usually means that it will encode the video with the text from an .srt file overlaid on top of the video, so the subtitles are a permanent part of the picture.