Nxg-501-engsub Convert03-00-18 Min · Complete

This appears to be a to convert a specific time range.

Assuming you have NXG-501-engsub.mp4 (or .mkv) and want to extract 03:00 to 21:00 , here is the professional method using (free, command-line tool). NXG-501-engsub convert03-00-18 Min