PyJoin is a software that can be used to join multiple MPEG files into one MPEG file.
When program is startet, go to preferences -> directories and enter the standard-directories for input- and outputfiles.
In preferences -> language you can modify the language. Default is english. If you change the language, you must restart the program.
Now select your files. A popup will open, where you must enter the new filename. Default is the first filename of your mpg-files. If you don't change this filename, this file will be replaced.
Now click on OK.