mkvtoolnix  62.0.0
About: MKVToolNix is a set of tools to create, alter and inspect Matroska files (the open standard audio/video multimedia container format).
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mkvtoolnix Documentation

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MKVToolNix 62.0.0

Table of contents

  1. Introduction
  2. Installation
    1. Requirements
      1. Hard requirements
      2. Requirements with bundled fallbacks
    2. Optional components
    3. Building libEBML and libMatroska
    4. Building MKVToolNix
      1. Getting and building a development snapshot
      2. Configuration and compilation
    5. Notes for compilation on (Open)Solaris
    6. Unit tests
  3. Reporting bugs & getting support
    1. Reporting bugs
    2. Getting support
  4. Test suite and continuous integration tests
  5. Code of Conduct
  6. Included third-party components and their licenses
    1. avilib
    2. libEBML
    3. libMatroska
    4. librmff
    5. nlohmann's JSON
    6. pugixml
    7. utf8-cpp
    8. Oxygen icons and sound files
    9. MKVToolNix icons
    10. QtWaitingSpinner
    11. Fancy tab widget
    12. fmt

1. Introduction

With these tools one can get information about (via mkvinfo) Matroska files, extract tracks/data from (via mkvextract) Matroska files and create (via mkvmerge) Matroska files from other media files. Matroska is a new multimedia file format aiming to become THE new container format for the future. You can find more information about it and its underlying technology, the Extensible Binary Meta Language (EBML), at

The full documentation for each command is now maintained in its man page only. Type mkvmerge -h to get you started.

This code comes under the GPL v2 (see or the file COPYING). Modify as needed.

The icons are based on the work of Alexandr Grigorcea and modified by Eduard Geier. They're licensed under the terms of the Creative Commons Attribution 3.0 Unported license.

The newest version can always be found at

Moritz Bunkus

2. Installation

If you want to compile the tools yourself, you must first decide if you want to use a 'proper' release version or the current development version. As both Matroska and MKVToolNix are under heavy development, there might be features available in the git repository that are not available in the releases. On the other hand the git repository version might not even compile.

2.1. Requirements

2.1.1. Hard requirements

In order to compile MKVToolNix, you need a couple of libraries. Most of them should be available pre-compiled for your distribution. The programs and libraries you absolutely need are:

  • A C++ compiler that supports several features of the C++11, C++14 and C++17 standards: initializer lists, range-based for loops, right angle brackets, the auto keyword, lambda functions, the nullptr keyword, tuples, alias declarations, std::make_unique(), digit separators, binary literals, generic lambdas, user-defined literals for std::string, [[maybe_unused]] attribute, nested namespace definition, structured bindings, std::optional, std::regex. Others may be needed, too. For GCC this means at least v8; for clang v7 or later.

  • libOgg and libVorbis for access to Ogg/OGM files and Vorbis support

  • zlib — a compression library

  • Boost — Several of Boost's libraries are used, e.g. operators, multi-precision. At least v1.66.0 is required.

  • libxslt's xsltproc binary and DocBook XSL stylesheets — for creating man pages from XML documents

You also need the rake or drake build program. I suggest rake v10.0.0 or newer (this is included with Ruby 2.1) as it offers parallel builds out of the box. If you only have an earlier version of rake, you can install and use the drake gem for the same gain.

2.1.2. Requirements with bundled fallbacks

Several required libraries might not be available for your distribution. Therefore they're bundled with the MKVToolNix source code. The configure script will look for those libraries and use existing versions if present. If not, the bundled versions are used instead.

It is highly recommended to install the versions provided by your distribution instead of relying on the bundled versions.

These libraries are:

  • fmt — a small, safe and fast formatting library. Version 6.1.0 or later is required.

  • libEBML v1.4.2 or later and libMatroska v1.6.3 or later for low-level access to Matroska files. Instructions on how to compile them are a bit further down in this file.

  • librmff — a library for accessing RealMedia files

  • nlohmann's JSON — JSON for Modern C++

  • Qt v5.9.0 or newer — a cross-platform library including a UI toolkit. The library is needed for all programs, even if you decide not to build MKVToolNix GUI.

  • pugixml — light-weight, simple and fast XML parser for C++ with XPath support

  • utf8-cpp — UTF-8 with C++ in a Portable Way

2.2. Optional components

Other libraries are optional and only limit the features that are built. These include:

  • cmark — the CommonMark parsing and rendering library in C is required when building MKVToolNix GUI.

  • libFLAC for FLAC support (Free Lossless Audio Codec)

  • po4a for building the translated man pages

2.3. Building libEBML and libMatroska

This is optional as MKVToolNix comes with its own set of the libraries. It will use them if no version is found on the system.

Start by either downloading the latest releases of libEBML and libMatroska or by getting fresh copies from their git repositories:

git clone
git clone

First build and install libEBML according to the included instructions. Afterwards do the same for libMatroska.

2.4. Building MKVToolNix

Either download the current release from the MKVToolNix home page and unpack it or get a development snapshot from my Git repository.

2.4.1. Getting and building a development snapshot

You can ignore this subsection if you want to build from a release tarball.

All you need for Git repository access is to download a Git client from the Git homepage at There are clients for both Unix/Linux and Windows.

First clone my Git repository with this command:

git clone

Now change to the MKVToolNix directory with cd mkvtoolnix and run ./ which will generate the "configure" script. You need the GNU "autoconf" utility for this step.

2.4.2. Configuration and compilation

If you have run make install for both libraries, then configure should automatically find the libraries' position. Otherwise you need to tell configure where the libEBML and libMatroska include and library files are:

./configure \
  --with-extra-includes=/where/i/put/libebml\;/where/i/put/libmatroska \

Now run rake and, as "root", rake install.

2.4.3. If things go wrong

By default the commands executed by the build system aren't output. You can change that by adding V=1 as an argument to the rake command.

If rake executes too many processes at once, then you've stumbled across a known bug in rake. In that case you should install the drake Ruby gem and use the command drake instead of rake. drake supports parallelism properly and doesn't try to execute all jobs at once.

2.5. Notes for compilation on (Open)Solaris

You can compile MKVToolNix with Sun's sunstudio compiler, but you need additional options for configure:

./configure --prefix=/usr \
  CXX="/opt/sunstudio12.1/bin/CC -library=stlport4" \
  --with-extra-includes=/where/i/put/libebml\;/where/i/put/libmatroska \

2.6. Unit tests

Building and running unit tests is completely optional. If you want to do this, you have to follow these steps:

  1. Download the "googletest" framework from (at the time of writing the file to download was "googletest-release-1.8.0.tar.gz")

  2. Extract the archive somewhere and create a symbolic link to its googletest-release-1.8.0/googletest sub-directory inside MKVToolNix' lib directory and call it gtest, e.g. like this:

    ln -s /path/to/googletest-release-1.8.0/googletest lib/gtest

  3. Configure MKVToolNix normally.

  4. Build the unit test executable and run it with

     rake tests:run_unit

3. Reporting bugs & getting support

3.1. Reporting bugs

If you're sure you've found a bug — e.g. if one of my programs crashes with an obscur error message, or if the resulting file is missing part of the original data, then by all means submit a bug report.

I use GitLab's issue system as my bug database. You can submit your bug reports there. Please be as verbose as possible — e.g. include the command line, if you use Windows or Linux etc.pp.

If at all possible, please include sample files as well so that I can reproduce the issue. If they are larger than 1 MB, please upload them somewhere and post a link in the issue. You can also upload them to my FTP server. Details on how to connect can be found in the MKVToolNix FAQ.

3.2. Getting support

The issue tracker above is not meant for general support which you can find in the following places:

  • The MKVToolNix sub-Reddit is suitable for all kinds of questions.
  • The MKVToolNix thread on Doom9's forum is more suited for in-depth technical questions.
  • There's also the IRC channel #matroska on the Freenode IRC network where we hang out. The main MKVToolNix author Moritz Bunkus is known as "mosu" there.

4. Test suite and continuous integration tests

MKVToolNix contains a lot of test cases in order to detect regressions before they're released. Regressions include both compilation issues as well as changes from expected program behavior.

As mentioned in section 2.6., MKVToolNix comes with a set of unit tests based on the Google Test library in the tests/unit sub-directory that you can run yourself. These cover only a small amount of code, and any effort to extend them would be most welcome.

A second test suite exists that targets the program behavior, e.g. the output generated by mkvmerge when specific options are used with specific input files. These are the test cases in the tests directory itself. Unfortunately the files they run on often contain copyrighted material that I cannot distribute. Therefore you cannot run them yourself.

A third pillar of the testing effort is the continuous integration tests run on a Buildbot instance. These are run automatically for each commit made to the git repository. The tests include:

  • building of all the packages for Linux distributions that I normally provide for download myself in both 32-bit and 64-bit variants
  • building of the Windows installer and portable packages in both 32-bit and 64-bit variants
  • building with both g++ and clang++
  • building and running the unit tests
  • building and running the test file test suite
  • building with all optional features disabled

5. Code of Conduct

Please note that this project is released with a Code of Conduct. By participating in this project you agree to abide by its terms.

6. Included third-party components and their licenses

MKVToolNix includes and uses the following libraries & artwork:

6.1. avilib

Reading and writing AVI files. Originally part of the transcode package.

  • Copyright: 1999 Rainer Johanni
  • License: GNU General Public License v2 or later
  • URL: the transcode project doesn't seem to have a home page anymore
  • Corresponding files: lib/avilib-0.6.10/*

6.2. libEBML

A C++ library to parse EBML files

  • Copyright: 2002-2021 Steve Lhomme et. al.
  • License: GNU Lesser General Public License v2.1 or later (see doc/licenses/LGPL-2.1.txt)
  • URL:
  • Corresponding files: lib/libebml/*

6.3. libMatroska

A C++ library to parse Matroska files

  • Copyright: 2002-2020 Steve Lhomme et. al.
  • License: GNU Lesser General Public License v2.1 or later (see doc/licenses/LGPL-2.1.txt)
  • URL:
  • Corresponding files: lib/libmatroska/*

6.4. librmff

librmff is short for 'RealMedia file format access library'. It aims at providing the programmer an easy way to read and write RealMedia files.

6.5. nlohmann's JSON

JSON for Modern C++

  • Copyright: 2013-2019 Niels Lohmann
  • License: MIT (see doc/licenses/nlohmann-json-MIT.txt)
  • URL:
  • Corresponding files: lib/nlohmann-json/*

6.6. pugixml

An XML processing library

6.7. utf8-cpp

UTF-8 with C++ in a Portable Way

  • Copyright: 2006 Nemanja Trifunovic
  • License: custom (see doc/licenses/utf8-cpp-custom.txt)
  • URL:
  • Corresponding files: lib/utf8-cpp/*

6.8. Oxygen icons and sound files

Most of the icons included in this package originate from the Oxygen Project. These include all files in the share/icons sub-directory safe for those whose name starts with mkv.

The preferred form of modification are the SVG icons. These are not part of the binary distribution of MKVToolNix, but they are contained in the source code in the icons/scalable sub-directory. You can obtain the source code from the MKVToolNix website.

All of the sound files in the share/sounds sub-directory originate from the Oxygen project.

  • License: GNU Lesser General Public License v3 (see doc/licenses/LGPL-3.0.txt)
  • URL:
  • Corresponding files:
    • share/icons/* (except for share/icons/*/mkv*)
    • share/sounds/*

6.9. MKVToolNix icons

  • Copyright:
  • License: Creative Commons Attribution 3.0 Unported (CC BY 3.0) (see doc/licenses/CC-BY-3.0.txt)
  • Corresponding files: share/icons/*/mkv*

6.10. QtWaitingSpinner

A highly configurable, custom Qt widget for showing "waiting" or "loading" spinner icons in Qt applications

  • Copyright:
    • 2012–2014 by Alexander Turkin
    • 2014 by William Hallatt
    • 2015 by Jacob Dawid
  • License: MIT (see doc/licenses/QtWaitingSpinner-MIT.txt)
  • URL:
  • Corresponding files: src/mkvtoolnix-gui/util/waiting_spinning_widget.{h,cpp}

6.11. Fancy tab widget

A beefed-up tab widget class for Qt extracted from the Qt Creator project

  • Copyright: 2011 Nokia Corporation and/or its subsidiary(-ies).
  • License: GNU General Public License v2 (see COPYING)
  • Corresponding files: src/mkvtoolnix-gui/util/fancy_tab_widget.{h,cpp}

6.12. fmt

Small, safe and fast formatting library

  • Copyright: 2012–present by Victor Zverovich
  • License: BSD (see doc/licenses/fmt-BSD.txt)
  • URL:
  • Corresponding files: lib/fmt/*