Re: [radeonhd] [PATCH] Correct colour scaling for r6xx-r7xx Xv

On Feb 13, 09 09:29:45 -0800, Yang Zhao wrote:

2009/2/13 Matthias Hopf :

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I don't understand this, Alex. You are changing *both* the color conversion matrix *and* introducing scaling functions?!?

The change to the conversion matrix is actually to make it follow BT.709 instead of BT.601. The former seemed like a better default, as

Ah, I see. Then everything makes sense. Alex, Yang, sorry that I apparently mixed you both up.

it's what's used in HD media, and the difference between the two is claimed to be mostly negligible.

Which is interesting, because the coefficients are actually pretty different.

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The scaling can be perfectly embedded in the color matrix.

My linear algebra is a little rusty, so I wasn't sure if was possible to fold the 2 sets scaling multiplier and offset into the conversion matrix when I made the patch. I can give this another look-over.

;-) It's possible with 4x4 matrices, and input vectors (read: color) with a 1.0 in the forth component. Analogous to homogeneous coordinates. Matthias -- Matthias Hopf __ __ __ Maxfeldstr. 5 / 90409 Nuernberg (_ | | (_ |__ mat@mshopf.de Phone +49-911-74053-715 __) |_| __) |__ R & D www.mshopf.de -- To unsubscribe, e-mail: radeonhd+unsubscribe@opensuse.org For additional commands, e-mail: radeonhd+help@opensuse.org