# Version 49.0.0 "Sick Of Losing Soulmates" 2020-08-02
## New features and enhancements
* mkvmerge: added support for copying the new track header elements
`BlockAddIDName`, `BlockAddIDType`, `BlockAddIDValue` and
`BlockAddIDExtraData` from Matroska files if they exist. Part of the
implementation of #2887.
* mkvinfo: added support for the new track header elements
`BlockAdditionMapping`, `BlockAddIDName`, BlockAddIDType`, `BlockAddIDValue`
and `BlockAddIDExtraData`. Part of the implementation of #2887.
* MKVToolNix GUI: multiplexer: the list of recent directories can now be
edited in the preferences > "Multiplexer" > "Destination file
name". Implements #2861.
* MKVToolNix GUI: preferences: the values in the various "predefined values"
lists can now be re-ordered freely by dragging & dropping.
## Bug fixes
* mkvmerge: Matroska reader: when reading tracks (e.g. a subtitle track) from
Matroska files with their `default track` flag set to `yes`, and when
overwriting those via the command line to `no`, `mkvmerge` would not promote
additional tracks of the same type from other files (e.g. another subtitle
track from an SRT file). Fixes #2863.
* mkvmerge: SRT reader: empty lines inside entries were doubled. Fixes #2888.
* mkvmerge: subtitles: when calculating the rounded duration of each entry the
error from rounding the corresponding timestamp will be taken into
account. Fixes #2890.
* mkvextract: SSA/ASS extraction: mkvextract is no longer inserting empty
lines before the `Dialogue:` lines. Fixes #2876.
* mkvextract: USF subtitles: start & end timestamps were too high by a factor
of 1.000.000. Fixes #2875.
* MKVToolNix: info tool: when saving to a text file the checkbox "Save as
default for saving output to text files" did nothing. Fixes #2869.
* MKVToolNix: info tool: when saving to a text file in "all elements in a
tree-like structure" mode, the GUI always stopped at the first cluster
regardless of the setting of the "verbosity" option.
* MKVToolNix GUI: preferences: when tooltips were disabled the dialogs for
adding new entries to the various "predefined values" lists were missing
* Windows installer: the images are shown again. Fixes #2868.
* configure: fixed detection of QtDBus. Fixes #2886.
## Build system changes
* libMatroska v1.6.1 is now required. The bundled version has been updated to
• MKVToolNix v49.0.0 released: