MKVToolNix
Set of tools to work with Matroska files - GUI frontend
MKVToolNix is a set of tools to create, alter and inspect Matroska files under Linux, other Unices and Windows.
Matroska is a new multimedia container format, based on EBML (Extensible Binary Meta Language), which is a kind of binary XML. . The mmg tool is a graphical user interface for the mkvmerge program, which allow one to create Matroska files from other formats. . This package also contains a graphical version of the mkvinfo tool, which allow one to get information about a Matroska file.
How to install MKVToolNix in Ubuntu
If you are on a supported distro, you can install the application through software center by clicking the below link.
If the above link not working, run the below command in terminal to install mkvtoolnix-gui in Ubuntu
sudo apt install mkvtoolnix-gui