mkvtoolnix v4.2.0 released

I’ve released mkvtoolnix v4.2.0. It contains a lot of bug fixes and a few enhancements but no major new features.

There are no changes for package maintainers in this release.

Here are the usual links: the home page, the source code and the Windows installer and 7zip archive.

All binaries that I provide myself have already been uploaded.

Here’s the full ChangeLog since release 4.1.1:

  • 2010-07-28 Moritz Bunkus <>
    • Released v4.2.0.
    • mkvmerge: bug fix: mkvmerge was accessing invalid memory In certain cases, e.g. when appending Matroska files that use compression while turning compression off.
  • 2010-07-27 Moritz Bunkus <>
    • mkvmerge: bug fix: Splitting output files by size was basing its decision when to create a new file on an uninitialized variable. This caused effects like a lot of small files being created with sizes much smaller than the intended split size.
  • 2010-07-19 Moritz Bunkus <>
    • mkvmerge: bug fix: The speed with which mkvmerge skips garbage in DTS tracks has been greatly improved.
  • 2010-07-18 Moritz Bunkus <>
    • mkvmerge: enhancement: Reading Matroska files: DisplayWidth & DisplayHeight values that are obviously not meant to represent pixels but only to be used for aspect ratio calculation (e.g. 16×9) are converted into proper ranges based on the track’s PixelWidth & PixelHeight values and the quotient of DisplayWidth / DisplayHeight.
  • 2010-07-12 Moritz Bunkus <>
    • mkvmerge: enhancement: Attachments will be rendered at the end of the file instead of at the beginning. The attachments will be placed after the cues but before the chapters. Fix for bug 516.
    • mkvmerge: enhancement: Header removal compression has been enabled by default for MPEG-4 part 10 (AVC/h.264) video tracks with a NALU size field length of four bytes.
    • mkvmerge: bug fix: Header removal compression has been deactivated for MPEG-4 part 2 (aka DivX/Xvid) video tracks due to incompatibility with packed bitstreams.
  • 2010-07-10 Moritz Bunkus <>
    • mmg: enhancement: The taskbar progress is reset as soon as mkvmerge finishes/as soon as all jobs are done (Windows 7).
  • 2010-07-06 Moritz Bunkus <>
    • mkvmerge: bug fix: Fixed reading AVC/h.264 tracks from AVI files if they’re stored without NALUs inside the AVI. Was broken by a fix for handling AVC/h.264 in NALUs inside AVI.
    • mkvmerge: bug fix: All readers that only handled file formats which do not contain more than one track did not respect the “–no-audio / –no-video / –no-subtitles” options. This applied to the following readers: AAC, AC3, AVC/h.264, CorePicture, Dirac, DTS, FLAC, IVF, MP3, MPEG ES, PGS/SUP, SRT, SSA, TrueHD, TTA, VC1, WAV and WavPack.
  • 2010-07-05 Moritz Bunkus <>
    • mkvmerge: enhancement: Improved reading text files that use mixed end-of-line styles (DOS & Unix mixed).
  • 2010-07-04 Moritz Bunkus <>
    • mkvmerge: bug fix: Fixed invalid memory access in the PCM packetizer. Fix for bug 510.
    • mmg: bug fix: When mmg starts it will check the entries in the file and chapter menu’s list of recently used files and remove those entries that no longer exist. Fix for bug 509.
    • mkvmerge: bug fix: Fixed a crash when reading Matroska files that were damaged in a certain way.

Have fun.

17 thoughts on “mkvtoolnix v4.2.0 released

  1. bastik

    Thank you. Another version of the best toolkit for creating and modifying matroska files.

  2. Koichi

    lastest version (4.2.0) has problems muxing .ass (it doesn’t work for me, at least) on windows.

  3. Guitarboy

    Enhancement request – as you’re probably aware, newer versions of mkvmerge turn on header removal compression by default. While I understand that this is a part of the spec that implementers should support, many don’t. Consequently, those of us using those players are forced to remux with the feature turned off, which can take quite some time on larger files. Is it possible to turn header removal compression OFF by default in mkvmerge?

      1. Mediauser

        Thank you for rendering Millions of players useless (no audio on WD TV Live anymore, for instance) because of your new useless feature. Really shaking my head about that. Hope fully you get back on the ground of reality.

  4. SkinArt

    Thank you very much, this version is the best, because works very quickly during separation of MKV’s faster than previous versions. Sincerely thanks.

  5. Globulus

    First I want to say thank you for your work, and for all people complaining remember he’s doing this for FREE, if you are not happy go do it yourself!
    Since version 4.0.0 when we setup English language on an audio track or subtitle track this information disappear (even with mkvinfo). It’s working fine for other language. I didn’t find a bug for this on Bugzilla.
    You can check here:
    Above line 40 normally “language” must be present as line 51/52. This is with version 4.0.0 but it’s the same with last one.
    If your already aware about this I hope you plan to fix it on future release.

      1. Globulus

        Seems I need to search more carefully next time.
        Thanks for quick feedback and sorry for disturbing.

  6. arcus84

    When I use v4.2.0 to mux x264, DTS and srt tracks and set “Default track flag” to “yes” for each of them, the mkv file will not play on LG BD390 player and when I open such a muxed mkv file in v3.3.0 it says that each of tracks has “Default track flag” set to “no”. What’s the problem with a new version?

  7. arcus84

    OK, but what with the other thing? >>When I use v4.2.0 to mux x264, DTS and srt tracks and set “Default track flag” to “yes” for each of them (…) and when I open such a muxed mkv file in v3.3.0 it says that each of tracks has “Default track flag” set to “no”.<<

      1. arcus84

        Buggy or not, it is the only version I can use to make mkv compatibile with my player. More flexibility would be appreciated. Nevertheless thank you for a great job.

  8. djm

    Just thought that I should point out that Trend Micro Internet Security recently (last month, I think) has classified your web site as dangerous and is blocking it.

    Therefore, users of Trend Micro Internet Security are not able to access your web site.

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