AviSynth 2.6.0 RC1 [Jan 14th, 2015]

[real.finder]

Originally Posted by StainlessS

Not sure what you are saying there but I'll take a guess.
I'm guessing that you have only just tried out v2.6 for the first time.
v2.5 filters (compiled with v2.5 Avisynth.h version 3) cannot tell the difference between YV12 and other planar formats.
If processing eg YV24 then the header used would give chroma rowsize and height as if for YV12, and the returned
chroma might appear only in the Top Left Hand side quarter of the frame, the rest of the frame may contain garbage.
You can only use v2.6 compatible plugins with Avisynth v2.6 additional colorspaces.

I see

I used 2.6 (SEt mt) for a years but with yv12 all the time, but now I deal with a yv411 source and just note that