MKVToolNix, is a set of tools (e.g. mkvmerge gui, mkvinfo) to create, alter and inspect Matroska files under Linux.
As both Matroska and MKVToolNix are under heavy development here’s how to install the latest release from its official repository and keep it up-to-date through Software Updater.
1. Add MKVToolNix repository
MKVToolNix repository so far supports Ubuntu 12.04, Ubuntu 14.04, Linux Mint 17, and Ubuntu 14.10.
To add it, open Software & Updates -> Other Software tab. Click on Add button and input below line in pop-up dialog:
deb http://www.bunkus.org/ubuntu/trusty/ ./
You may replace trusty with utopic or precise for Ubuntu 14.10 or 12.04.
2. Download and import the key
Open terminal from the Dash, Application Menu, or by pressing Ctrl+Alt+T. When it opens, run below command to get the keyring:
wget --no-check-certificate http://www.bunkus.org/gpg-pub-moritzbunkus.txt -O - | sudo apt-key add -
3. Install/Upgrade MKVToolNix:
Finally you can install the tool via Ubuntu Software Center and upgrade it as part of system updates through Software Updater:
That’s it. Enjoy!