HDR encoding

[mparade]

Had a quick look at did some adjustments, color matrix should now be detected correctly.
DebugLog shows that DGSource was used, so that seems to work,..

I am testing. Until then could you please help because still do not understand:

# adjusting output color from: YUV420P16 to YUV420P8

clip = core.resize.Bicubic(clip=clip, format=vs.YUV420P8)

Why adjusting output color to 8 bit and feed that to the encoder which will use 10 bit? (I am a bit confused)

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Preview window still not working. "Interesting": after pushing crop window icon Hybrid start indexing for a few minutes, after indexing crop window doesn't show up but a Windows 10 bug report on the tray is displayed for just a few seconds directly after indexing.