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[csswg-drafts] [css-color] colorspace for video

From: Chris Lilley via GitHub <sysbot+gh@w3.org>
Date: Sun, 10 Jul 2016 07:40:53 +0000
To: public-css-archive@w3.org
Message-ID: <issues.opened-164704217-1468136451-sysbot+gh@w3.org>
svgeesus has just created a new issue for 
https://github.com/w3c/csswg-drafts:

== [css-color] colorspace for video ==
https://drafts.csswg.org/css-color/#sRGB

> Note that this rule does not apply to videos, since untagged video 
should be presumed to be in CCIR 601.

> Really? Isn’t HD video in Rec.709? Shouldn’t video be consistent 
with images? Or do implementations really do this differently?

Different issue to 3286 because video is typically not explicitly 
tagged; the colorspace is out of band for broadcast video, and absent 
for web video.

Presuming untagged video to be CCIR 601 is incorrect for video 
originating from PAL/SECAM systems, incorrect for HD video, and 
incorrect for 4k video. It is also probably incorrect for video from 
SLRs and phones. So CCIR 601 is a poor choice as a default here.

Rec.709 is sufficiently close to sRGB (same primaries, very similar 
transfer curve) that it may be best to assume sRGB. However, it also 
depends on what existing implementations do and what colorspace 
conversions are done by hardware video acceleration in current 
graphics cards. 


Please view or discuss this issue at 
https://github.com/w3c/csswg-drafts/issues/287 using your GitHub 
account
Received on Sunday, 10 July 2016 07:41:08 UTC

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