Create and Edit Matroska Video Files on Linux with MKVToolNix

MKVToolnix is a suite of applications to work with Matroska video and audio files. The latest version, v8.1.0, released 27 Jun 2015, comes under the most respectable name of “Psychedelic Postcard.” It includes tools to edit Matroska files, extract information from them, or package many other video formats into an Matroska container.

Matroska is an “extensible, open source, open standard Multimedia container. Matroska is usually found as .MKV files (Matroska video), .MKA files (Matroska audio), .MKS files (subtitles) and .MK3D files (stereoscopic/3D video). It is also the basis for .webm (WebM) files.” Matroska aims to become a single multimedia standard.

Matroska files are not just video files (or compression formats or codecs) but containers that can store many different video and audio files and seven subtitle streams, so that a complete movie can live in one container. It is very useful if you have a different audio track ripped from a DVD or subtitles in different languages.

By design, Matroska files offer:

  • Fast seeking in the file
  • Chapter entries
  • Full metadata (tags) support
  • Selectable subtitle/audio/video streams
  • Modularly expandable
  • Error resilience (can recover playback even when the stream is damaged)
  • Streaming over the Internet and local networks (HTTP, CIFS, FTP, etc)
  • “Menus” (like DVDs have)


Among the software compatible with Matroska, MKVToolNix offers probably the most complete package. It comes as different command-line applications that are bundled together in a single GUI, allowing you to create, modify and inspect Matroska files with relative ease.


Packages are provided for 14.04 or newer Ubuntu versions.

First you need to get the developer’s GPG public key with

sudo nano /etc/apt/sources list

and append the following lines to the end, depending on your Ubuntu version.

15.04 “Vivid Vervet”

deb ./
deb-src ./

14.10 “Utopic Unicorn”

deb ./
deb-src ./

14.04 “Trusty Tahr”

deb ./
deb-src ./

Next, import the GPG key.

wget -q -O - | sudo apt-key add -

Update your package list.

sudo apt-get update

then install MKVToolNix.

sudo apt-get install mkvtoolnix mkvtoolnix-gui

For instructions on installing MKVToolNix on a different distribution, please refer to the developer’s website

When you open the GUI you will find yourself on the “Merge” tool that allows you to create Matroska files from different sources. You can specify your sources by pressing the “Add Sources” button. The list of supported file types is extensive.


If you add a video file, MKVToolNix will automatically find the different streams and make them selectable and individually editable in the Properties section.


You can also specify an output file name, although the field will be automatically populated. If you want finer control over the output file, you can adjust various settings under the “Output tab.”


You can also add attachments to your file. Pressing the “Start Muxing” button will send the files into the job queue and begin processing. If you want to specify a longer queue you can use the “Add to job queue” button. To see the progress, switch to the “Job Output” window.


Due to no encoding necessary (it only packages the already compressed and encoded tracks), the process is rather fast. When it is done you can edit the various attributes of your file by switching to the “Edit Headers” tab and opening the file.


You will find information about the Segments and different tracks contained in your file, all (or most) of which you can modify.


Working with chapters is equally simple. You will need to create a chapters file (that you can later even merge into the Matroska file) first on the chapters window, or if your Matroska file contains chapters you can open it from here.


To manipulate chapters, you will need to use the right click context menu.


From there you can add chapters and subchapters, and edit various properties of each entry.


To save the new chapter you have two options. You can save it as an XLM or add it directly into an Existing Matroska container, e.g. the one you’ve just created (The “Save” menu is only active is you’ve opened a Matroska file that already has chapters).


If you only wish to read more about Matroska files you can use the MKVInfo tool, which is also part of the package. Simply open your Matroska file in it, and you can read very detailed information about its contents.


MKVToolNix offers easy-to-use and versatile GUI tools for creating, editing and inspecting Matroska audio and video files, including stereoscopic 3D videos. With it, creating and manipulating Matroska files is a simple and intuitive process, although to learn all the possible settings and options could be time consuming. You can find more help regarding the use of MKVToolNix tools on the developer’s website, and learn more about the Matroska format on