Once upon a time, I was searching the Internet for a way to combine video files. There are quite a few free and paid for software programs to accomplish this task. However, most of them require you to run these files through an encoder.
This can be extremely time consuming. I found a Linux tool called MP4Box. I love Linux for exactly this reason.
You will need to install this software via apt-get Advanced Packaging Tool on Debian distributions such as Ubuntu and Yellow Updater Modified on Redhat linux distributions ie. Fedora. Also, you can install this manually via source, but that is another more technical discussion. MP4Box actually comes with gpac.
You will need to install gpac to then use MP4Box. You can type following command on a Debian distribution to install. You will need root privileges to install this software.
apt-get install gpac
Now that you have it installed you can start combining video files. This package was case sensitive when I use it with Ubuntu. What this means is you need to spell it out correctly including upper or lower case characters when you run this command.
Also, I found out that you have to specify a temporary folder when running this command. On my Ubuntu Linux distributions I run the following command to concatenate multiple video files into one file.
MP4Box -tmp /mnt/c/Users/USER/Videos -cat x.mp4 -cat x.mp4 -new xxx.mp4
Remember MP4Box command is case sensitive. Specifying -tmp with a path tells this program where to save any temp file(s). You want to choose a directory that is writeable.
I choose the same folder that I store and save video files for convenience. You can set this to any folder that has write permissions. Finally, in the above example the -cat variable tells this program to concatenate these files which means to combine them sequentially.
The entire second file gets added after the first file so that when you play it back it is one file. Each time you specify a file you want combined you must preface it with the -cat variable. Also, the -new variable tells this MP4Box tool to create a new file that combines two or more video files.
x.mp4 is name of your video file(s) you want combined. xxx.mp4 is name of your new file. This saves me a ton of time waiting for a video encoder to process this project. This program is supposed to support AVI, MP4, MPG, TS, and 3GP video formats.
I have only used this program with MP4 video files.