FFmpeg: How to Join Video Files

Problem:
I have 2 .mp4 video files, and I want to combine them into a single video file. How can I do that with FFmpeg?


Solution:
Follow the instructions in FFmpeg's FAQ:
http://www.ffmpeg.org/faq.html#SEC27

For Windows folks, remember to set the /b flag to perform a binary copy, e.g.
copy /b video1.mpg + video2.mpg combined.mpg