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Old 17th August 2019, 02:14   #87  |  Link
jpsdr
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Join Date: Oct 2002
Location: France
Posts: 2,308
Neither my dictionnary, google trad or me understand "borked"...

There is no XYZ colorspace in avisynth, so, it's tagged RGB. So, the system (avs, Windows, Video card drivers, monitor) diplays (linear) XYZ data, thinking it's non-linear RGB. Not so suprise result is odd... But basicaly, you'll see darker colors than original. Effect even worse (a lot darker) with HDR data.
If you haven't, read the pdf document i've put with the filter, i've tried to explain how things work (at least, what i've understood).
Maybe it will help you.

I've put the two rec.601 because there was two in the spec, so, i made them both avaible.
After, colorimetry is not realy my best field, so, i would suggest you to follow StvG advice.

After, i'm not sure there is realy need to go through XYZ (neither Linear RGB) for 601 <-> 709. Colorimetry parameters are almost identical, this is why people always do the convertion staying in the standard non-linear space, so, just by a simple matrix translation.
After, if you want perfect accuracy...

For 2020 <-> 709/601, you need to go through XYZ, because colorimetry parameters are different, and so it's only through XYZ that you can do it. Only Linear RGB is not enough and will produce improper results. Described in R-REC-BT.2087-0-201510-I!!PDF-E.

So, it's 3 am for me, time to bed...
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