FFmpeg

Documentation: ffmpeg.org

Concatenate: ffmpeg.org

Example:

ffmpeg -f concat -i mylist.txt -c copy out.mp4

mylist.txt:

file 'GOPR3733.MP4'
file 'GP013733.MP4'
file 'GP023733.MP4'
file 'GP033733.MP4'
file 'GP043733.MP4'
file 'GP053733.MP4'
file 'GP063733.MP4'
file 'GP073733.MP4'

Rate limit: ffmpeg.org

Example:

ffmpeg -i out.mp4 -b:v 4000k -bufsize 4000k -strict -2 out2.mp4