Joining multiple mp4 files

I'm not going to claim to know anything about video codecs and the such, so I'm pretty much at the mercy of google when it comes to modifying video files. Having found part of the answer but not all of it, I figured I'd post the exact command line here for the lazy like me...

A forum hinted me to the software MP4Box, which I was able to install by installing the gpac bundle. From there, it was simply a matter of...

MP4Box a.mp4 -cat b.mp4 -out result.mp4

a is input, with -cat saying that we should concatenate b to the end of a.

This worked well enough for me, but since the video codec world is strange and mysterious, your results may vary.