I am trying to cut out a part of an MKV file. For example, the MKV is 3 hours long, but I only want to keep 1 hour and 12 minutes. I have been trying to use mkvMerge under the global tab and setting the "split after duration" setting to the time I want to file to end. But this doesn't seem to work. It just produces a exact copy of the original MKV file.