MKVToolNix 18.0.0 (32-bit)

What's new in this version:

New features and enhancement:
- build system: when building with clang v3.8.0 or newer, `configure` will no longer restrict optimization flags to `-O1` and use `-O3` again (older versions of clang suffered from excessive memory usage with higher optimization levels)
- build system: when building with mingw 7.2.0 or newer, `configure` will no longer restrict optimization flags to `-O2` and use `-O3` again (older versions of mingw suffered from bugs such as segmentation faults with higher optimization levels)
- build system: stack protection is enabled when building with clang 3.5.0 or newer on all platforms
- mkvmerge: AVC & HEVC ES parsers: performance improvements by copying much less memory around
- mkvmerge: tags: reintroduced a workaround for non-compliant files with tags
- that do not contain the mandatory `SimpleTag` element. This workaround was removed during code refactoring in release v15.0.0.
- GUI: multiplexer: the "AAC is SBR/HE-AAC/AAC+" checkbox in the "audio properties" section will be disabled if the functionality is not implemented for the selected track's codec & container
- GUI: multiplexer: the "reduce to core" checkbox in the "audio properties" section will be disabled if the functionality is not implemented for the selected track's codec

Bug fixes:
- mkvmerge: AAC ADTS parser: fixed interpretation of the `channel_configuration` header element for ADTS files that do not contain a program configuration element: value 7 means 7.1 channels
- mkvmerge: Matroska identification: the `date_local` and `date_utc`attributes will only be output if the identified Matroska file actually contains the "date" header field
- mkvmerge: WebVTT: mkvmerge did not recognize timestamp lines if the hours components were absent mkvpropedit, GUI's header editor: the `date` header field won't be added automatically anymore whenever the segment info section is edited and the `date` element is either deleted or not present in the first place