MKVToolNix v20.0.0 released

Well, hello everyone!

The holidays are always a nice time for coding as the world seems to turn just a tad slower than usual and people are that tiny bit more relaxed. I took the opportunity to work on my backlog and fix quite a number of bugs in mkvmerge. I’ve also removed those options and features that I had deprecated a year ago.

Another huge change was the near complete rewrite of mkvinfo’s internals. The goal is to include its GUI into MKVToolNix GUI in the next release. It won’t be a 1:1 copy; instead, the new GUI will have more features. A result is that the output generated by the command-line utility has changed in several ways. See the corresponding NEWS entry below for more details.

An important change for package maintainers is the new requirement for the cmark library. Fedora/CentOS/openSUSE already contain the necessary package (cmark-devel), whereas Debian/Ubuntu don’t just yet (there’s the cmark package, but that only contains the binary, whereas MKVToolNix needs the library & header files).

You can download the source code or one of the binaries. The Windows and macOS binaries are available already. The Linux binaries are stil being built and will be available of the course of the next couple of hours.

Here are the NEWS since the previous release:

Important notes

  • Feature removal: several deprecated features have been removed:
    • mkvmerge: the deprecated options --identify-verbose (and its counterpart
      -I), --identify-for-gui, --identify-for-mmg and
      --identification-format verbose-text
    • all command line tools: support for the deprecated, old, proprietary format
      used for option files
    • all command line tools: support for passing command line options via the
      deprecated environment variables MKVTOOLNIX_OPTIONS, MKVEXTRACT_OPTIONS,
  • mkvinfo: most of its code was re-written in order to lay the groundwork for
    including its functionality in MKVToolNix GUI but with more features than
    the existing mkvinfo GUI. The result is that a lot of its output has been
    changed slightly while keeping the basic layout. Changes include but aren’t
    limited to:

    • Several element names are a bit clearer (e.g. Maximum cache instead of
    • All timestamps and durations are now output as nanoseconds in formatted
      form (e.g. 01:23:45.67890123). All additional formats (e.g. floating
      point numbers output in seconds or milliseconds) were removed.
    • Element names for chapters and tags are now translated if a translation is
    • Elements located in wrong positions within the Matroska document are
      handled better.
      While mkvinfo’s output is mostly kept very stable, it is not designed to be
      parsed by other utilities. Even though I’ve tried hard to cram all changes
      and cleanups into this version, additional changes may be made in the next
      couple of releases depending on user feedback and bug reports.

New features and enhancements

  • mkvmerge: AVC/h.264 packetizer (framed): access unit delimiter NALUs will
    now be removed. Implements #2173.

Bug fixes

  • mkvmerge: AVC/h.264 parser: when fixing the bitstream timing information
    mkvmerge will now use exact representations of the desired field duration if
    possible. For example, when indicating 50 fields/second num_units_in_tick
    is set to 1 and time_scale to 50 instead of 5368709 and 268435456. Part of
    the fix for #1673.
  • mkvmerge: AVC/h.264 parser: mkvmerge no longer assumes that encountering
    sequence parameter set or picture parameter set NALUs signal the start of a
    new frame. Fixes #2179.
  • mkvmerge: AVC/h.264 packetizer (framed): when mkvmerge is told to fix the
    bitstream timing information, it will now update all SPS NALUs, not just the
    ones in the AVCC. Part of the fix for #1673.
  • mkvmerge: MPEG TS reader: TS packet payloads will only be treated as PES
    packets if the payload actually starts with a PES start code. The prior
    behavior led to wrong timestamps and potentially broken frame data. Fixes
  • mkvmerge: MPEG TS reader: mkvmerge will now drop incomplete PES packets as
    soon as an error is detected in the transport stream instead of passing the
    incomplete frame to the packetizer. An error is assumed either if the
    transport_error_indicator flag is set or if the value of the
    continuity_counter header field doesn’t match the expected value. Fixes
  • mkvmerge: Opus: when re-muxing Opus from Matroska mkvmerge will now write
    "block duration" elements for all block groups where a "discard padding" is
    set, too. Fixes #2188.
  • mkvmerge: SRT reader: mkvmerge can now handle SRT files with timestamps
    without decimal places (e.g. 00:01:15 instead of 00:01:15.000).
  • mkvmerge: read buffer I/O class: the class could get out of sync regarding
    the file position of the underlying file I/O class causing wrong data to be
    returned on subsequent read operations. One result was that trying to
    identifying MPLS files that refer to very short M2TS files caused mkvmerge
    to segfault.
  • mkvmerge: multiplexer core: if there’s a gap in audio timestamps, a new
    block group/lace will be started for the first frame after each gap. Before
    the fix the frame after the gap was often stored in the previous block group
    causing the gap to be in the wrong place: at the end of that block
    group. Fixes #1700.
  • mkvextract: AVC/h.264: if two consecutive IDR frames with the same
    idr_pic_id parameter and no access unit delimiters are found between them,
    mkvextract will insert an access unit delimiter in order to signal the start
    of a new access unit. Fixes #1704.
  • MKVToolNix GUI: update check dialog: Markdown links will now be converted to
    clickable links. Fixes #2176.
  • build system: fixed a race condition when creating new directories if rake
    is run with -jN in newer versions of Ruby/rake. Fixes #2194.

Build system changes

  • cmark, the CommonMark parsing and
    rendering library in C, is now required when building the GUIs.

Have fun :)

10 thoughts on “MKVToolNix v20.0.0 released

  1. whcqq

    I installed the MKVToolNix v20.0.0, but I found MKVExtractGUI2.exe doesn’t work, no tracks are displayed. Please fix it, thanks.

  2. Drak

    Since version 20, mkvmerge is not working with Popcorn audio converter anymore. Up to 19 was working fine. I know it’s an old tool, but still the best to convert audio tracks witin a mkv container. So I will have to stick to 19 from now I guess. :(

    1. mosu Post author

      You could also notify the developers of that application so that maybe, just maybe, they’ll update their application.

  3. Venelin Dimitrov

    Congratulations for the good job but there is a big con:
    Every new version performs slower and slower…
    In the versions before (10,11 etc) 2GB MKV was rendered in a couple of seconds. Now it takes longer and longer. Same system…

  4. Jalba

    Hi, first thanks a lot for this nice tool.
    Got a question please, i use those switches to remove some of the metadata :
    –no-date –disable-track-statistics-tags –engage no_variable_data

    In mediaInfo this leaves :
    Writing application: no_variable_data
    Writing library : no_variable_data

    Can then be removed with MkvPropEdit :
    mkvpropedit “file.mkv” –set “writing-application=” –set “muxing-application=”

    Would like to know if it is possible to achieve this directly during the first step, during the muxing, before the file is create and without mkvpropedit.exe please.

    Thanks again.

      1. Jalba

        Thanks for the quick reply,
        I guess nothing can be done to change this and i’ll always have to do it in 2 steps with mkvpropedit.exe once the mkv is created then.
        Well not a big deal,
        thank you very much for the answer and those nice tools.


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