VapourSynth Editor R19-mod-6.6

Major changes since mod-6.5:

• Fixed regression since mod-6.4 that makes the previewer refuse to work.
• Support all recent VapourSynth versions with API4. This should include VS-C.
• Add an option to periodically (per 0.5s) sync script in editor from disk (when unmodified inside the editor).
• Add info text in frame property panel for certain reserved frame properties.
• Mark on the title of preview dialog if script text is changed after preview evaluation.

About this release:

• A recent VapourSynth version with API4 on Windows 10 or later is required. If you are with earlier VS or Windows versions, please check the mod-5.x releases (built with Qt 5) or the master branch.
• A blank vsedit.config is included in the portable package.
• Runtime dependencies: Microsoft Visual C++ Redistributable X64.