I have some .mpg files on my computer that do not play correctly in Quicktime, vlc, or MPlayer. What happens in QT is I will play the file but it will only play a fraction of the movie and it will end ...

Is there any free, easy, reliable way of concatenating multiple video .mpg or .avi files into a single file? This are all of the same type--I don't need to concatenate files of differing types, so ...