avidemux is a program that offers a GUI to cut videos on Linux. To install it, you need to either have the readymade .deb for your distro of Ubuntu, or compile it from source yourself. This post tells you how to compile and install avidemux for Ubuntu 16.10 (and other versions)
You need to first compile and install avidemux:
Download it from here, extract it.
tar xf avidemux_2.6.12.tar.gz cd avidemux_2.6.12
Install all dependencies:
sudo apt-get install gcc g++ make cmake pkg-config libpng12-dev fakeroot yasm libsqlite3-dev build-essential qttools5-dev-tools qtbase5-dev libaften-dev libmp3lame-dev libx264-dev libfaad-dev libfaac-dev libqt4-dev
Compile and install:
bash bootStrap.bash --deb
Now install the compiled debs:
sudo dpkg -i debs/*deb
If you want to split a video file without using avidemux, use avconv.