Hello there. I expect this to be one of the first posts that I will continue to update. Mostly for my one reference. I have been in the process of converting some old video files for better support for Chromecast/DLNA and generally for my own streaming purposes.
Some of the first problems I found were combining old files without re-encoding them. So I looked at the old trusty ffmpeg to do the job. Below I will over time add lists of ffmpeg one-liners:
Combine two .avi files and copy codecs:
ffmpeg -i "concat:part1.avi|part2.avi" -c copy complete.avi