If you have a movie which is in many parts,you can join them to make one file using the avimerge command in Ubuntu.
You need to install the transcode package to use the avimerge tool
to Install Transcode
sudo apt-get install transcode at Terminal
To merge avi files use the avimerge command.
avimerge -i part1.avi part2.avi -o mergedavifile.avi
The above command merges part1.avi and part2.avi into a single file called mergedavifile.avi
The following video will make things clear.
In this video I am joining the parts of the movie 1920.
