VirtualDub2 behaves strangely with this AviSynth+ script:
Code:
blankclip(pixel_type="rgbaps")
invert
converttoyv12
It seems to paint nothing in the panes (redrawing problems are evident if you drag the panes around, plus they darken when the window loses focus).
If you change converttoyv12 to converttoy8, you get colourful garbage, which may indicate an AviSynth+ problem but I'm not sure (since I can't read the output of "info" to determine what colourspace I've ended up with), but the redrawing issue with converttoyv12 indicates
some kind of trouble with VirtualDub2 not sensibly handling unexpected data.
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Edit: confusion abounds because converttoyv12/y8 don't actually change the bit depth, so the problem is just that VirtualDub2 doesn't display (or throw an error for) float data.