Log Message:
mkvtoolnix: updated to 28.0.0

Version 28.0.0 "Voice In My Head":

New features and enhancements
* mkvmerge: AV1 parser: updated the code for the finalized AV1 bitstream
  specification.
* mkvmerge: AV1 packetizer: updated the code for the finalized AV1-in-Matroska
  & WebM mapping specification.
* mkvmerge: AV1 support: the `--engage enable_av1` option has been removed
  again.
* mkvmerge: MP4 reader: added support for AV1.
* mkvmerge: DTS: implemented dialog normalization gain removal for extension
  substreams.
* mkvmerge, mkvextract: simple text subtitles: added a workaround for simple
  text subtitle tracks that don't contain a duration.
* mkvextract: added support for extracting AV1 to IVF.
* mkvextract: IVF extractor (AV1, VP8, VP9): precise values will be used for
  the frame rate numerator & denominator header fields for certain well-known
  values of the track's default duration.
* mkvmerge: VP9: mkvmerge will now create codec private data according to the
  VP9 codec mapping described in the WebM specifications.
* MKVToolNix GUI: automatic scaling for high DPI displays is activated if the
  GUI is compiled with Qt ≥ 5.6.0.
* MKVToolNix GUI: added a menu item ("Help" → "System \ 
information") for
  displaying information about the system MKVToolNix is running on in order to
  make debugging easier.
* MKVToolNix GUI: multiplexer, header editor: the user can enter a list of
  predefined track names in the preferences. She can later select from them in
  "track name" combo box.

Bug fixes
* mkvmerge: JSON identification: fixed a bug when removing invalid UTF-8 data
  from strings before they're output as JSON.
* mkvmerge: MP4/QuickTime reader: fixed handling of PCM audio with FourCC
  `in24`.
* mkvmerge: MPEG transport stream reader, teletext subtitles: the decision
  whether or not to keep frames around in order to potentially merge them with
  the following frame is made sooner. That avoids problems if there are large
  gaps between teletext subtitle frames which could lead to frames being
  interleaved too late.
* mkvextract: IVF extractor (AV1, VP8, VP8): the frame rate header fields
  weren't clamped to 16 bits properly causing wrong frame rates to be written
  in certain situations.
* mkvpropedit, MKVToolNix GUI's header editor: fixed file corruption when a
  one-byte space must be covered with a new EBML void element but all
  surrounding elements have a "size length" field that's eight bytes long
  already.