MKVToolNix 54.0.0 (64-bit)

What's new in this version:

New features and enhancements:
- mkvmerge: added support for using ISO 639-3 language codes in IETF BF47 language tags
- mkvmerge: AC-3 parser: added support for byte-swapped AC-3 data
- mkvmerge: Matroska reader: for audio tracks that have the bit depth track header set mkvmerge will now keep that header even for codecs that don't require it for decoding
- mkvmerge: MPEG transport stream reader, PCM audio tracks: mkvmerge will now re-order the channels for 5.1, 7.0 and 7.1 channel tracks from the Blu-ray layout to the WAVEFORMATEXTENSIBLE layout expected in Matroska. Patch by Tom Yan
- mkvmerge, mkvinfo, mkvpropedit, MKVToolNix GUI: added support for the following new track header elements: "hearing impaired" flag, "visual impaired" flag, "text descriptions" flag, "original" flag, "commentary"flag
- MKVToolNix GUI: added support for using ISO 639-3 language codes in IETF BF47 language tags. As there are several thousand of them, they're deactivated by default and must be activated in the preferences ("GUI" ? "Often used selections" ? "Languages"). Part of the implementation of #3007.
- MKVToolNix GUI: multiplexer: when adding Blu-rays the user can select multiple playlists to add simultaneously in the "select playlist to add" dialog
- MKVToolNix GUI: multiplexer: the file name extensions "eb3" and "ec3" were added for Dolby Digital Plus & "mpl" for Dolby TrueHD in the file dialogs
- MKVToolNix GUI: multiplexer: when adding multiple files the dialog asking the user what to do with them has gained a new checkbox. If enabled, all files containing at least one video track will always be placed in newly created multiplex setting
- MKVToolNix GUI: multiplexer: added a menu entry in the "Multiplexer" for adding all files that are currently in the clipboard

Bug-fixes:
- all: Windows: fixed compatibility with gettext 0.21 and newer on mingw.
- all: Windows: fixed several of the programs having problems with certain
- Unicode characters (primarily emojis) in file names (e.g. mkvextract wrongfully complaining about an "invalid mode" or the GUI not being able to find parts of Blu-ray file structures).
- mkvextract: AAC: fixed wrong channel mask field in the ADTS headers for 7.1 channel layouts
- mkvextract: h.265/HEVC extraction: if the first frame starts with the parameter sets (SPS, PPS & VPS), the ones from CodecPrivate aren't written and the ones from the first frame are kept
- mkvmerge: fixed the calculation of chapter timestamps read from NTSC DVDs. Fix by Tom Yan.
- MKVToolNix GUI: IETF BCP 47 language widget: the language combo box will now always contain the language code the user enters in the free-form field, even if it isn't in the list of often-used languages the user configured in the preferences.
- MKVToolNix GUI: multiplexer: when browsing for the destination file name the default directory is now chosen according to the preferences regarding how the destination file name should be formed. For example, if the policy is set to "fixed output directory" then that output directory will be the one initially set when the directory selection dialog is opened
- MKVToolNix GUI: multiplexer: fixed the removal of appended source files if the "delete source files" end-of-job action is enabled
- MKVToolNix GUI: chapter editor: when importing chapters from DVDs the IETF BCP 47 language elements will be set, too, not just the legacy language elements

Build system changes:
- libEBML v1.4.2 and libMatroska v1.6.3 are now required. The optional, bundled copies of both libraries have been updated to those versions. This bump in requirements fixes several heap overflow bugs in libEBML.
- MKVToolNix is now using the C++17 library feature "file system library" instead of Boost's "file system" and "system" libraries. For the GNU Compiler Collection (gcc) libstdc++ this means v8 or newer is required; for clang's libc++ it means v7 or newer. For macOS this means that provided disk image will only run on 10.15 "Catalina" or newer.