New features and enhancements

• all: added new scalable (SVG) application icons for all applications, replacing the existing pixmap (PNG, ICO) icons. Icons from Sarreq Teryx. Implements #6253.
• mkvmerge: MP4 reader: track names are now read from the track's user-data atoms (trak → udta → name) if present. Implements #6274.
• MKVToolNix GUI: executing actions configuration, type "play audio file": added a slider to make configuration more intuitive. Implemented by #6267.
• MKVToolNix GUI: executing actions: macOS only: the GUI will now use bundled audio files for "play audio file" actions that Qt can play instead of using macOS's system sounds. Implemented by #6268. Fixes #6264.
• MKVToolNix GUI: executing actions: Windows only: added a new type: executing a PowerShell script. Either an existing script file can be selected or custom PowerShell script code entered in a small editor. The executed script has access to all MTX_… variables through the environment, e.g. $env:MTX_DESTINATION_FILE_BASE_NAME. Workaround for the problems talked about in #6254.
• MKVToolNix GUI: job queue: added a context menu for opening copies of the selected queue jobs in the multiplexer as new settings there without removing the queue jobs. Implements #6255.
• MKVToolNix GUI: job queue: added a search functionality for jobs that searches in job descriptions, outputs, warnings & errors. Implements #6256.

Bug fixes

• command-line tools: Windows: switched to Boost's UTF-8 code-conversion facet (boost::locale::utf8_codecvt) from std::utf8_codecvt included in MingW. This seems to fix an issue with converting certain high code point from wchar_t to char (from UTF-32/16 to UTF-8), preventing interesting exceptions from being thrown. Fixes #6257.
• mkvmerge: AAC: fixed mis-detection of ADTS streams not starting on a frame boundary. Fixes regression starting with v87 when fixing AAC LATM config not being parsed if it wasn't present in the first AAC frame. Patch by Corticalcode. Fixes #6196.
• mkvmerge: MPEG TS reader: under certain rare conditions mkvmerge was skipping a certain amount of content at the start of the main M2TS file when reading MPLS playlists. The amount of content skipped proportional to the probe range percentage. This only happened when the source Blu-ray contains HDMV TextST subtitles. Fixes #6269.
• MKVToolNix GUI: executing actions configuration, type "play audio file": fixed audio volume not working since switching to Qt 6 due to its interface taking a float in range 0.0–1.0 instead of the old interface taking an int in range 0–100. Implemented by #6267. Fixes #6266.
• MKVToolNix GUI: executing actions: fix backslash handling when parsing a Unix-shell escaped string into separate arguments. The user-visible fix is that the command-line in the "executing actions" dialog will not have the quoting changed in wrong ways by the GUI when the GUI adds another variable upon user request, a regression introduced in v99. Fixes #6253.

Build system changes

• all: when building for Windows the programs ImageMagick (executable magick) & Inkscape (executable inkscape) are required in order to build ICOs from SVGs.
• macOS: include the app's supported platform(s) in Info.plist to correctly resolve the app's Kind as Apple Silicon in System Information. Detected during discussion of #6260.
• macOS: updated Qt to 6.11.1. The patch that made building Qt from source possible on macOS 26.4 (by Touchstone64) has been removed as Qt 6.11.1 includes the fix upstream. See #6276.