http://lists.freedesktop.org/archives/dri-devel/2013-January/033572.html
Dear All,
Please, never do pointless stuff like that.
I don't know what exactly are written in the "CEA guidelines" mentioned in the above posts (AFAIK one cannot get a copy of them for free legally), but no one should follow some "guidelines" like that when it make zero sense.
Unlike colorspace, literally it's impossible to detect what RGB ranges can a monitor takes, so having an "Automatic" mechanism for it is very likely to be insane. Worsestill, using modes to determine the range is absurd.
What does that imply? It implies within a same product line of monitors, models with different physical size (which is likely to have different optimal resolutions) should use different rgb ranges, and the range should also varies when we switch resolution ourselves.
The only reason I can think of for those guidelines to exists is, it makes consumer products send limited range signal when it's likely video playback (coz that's how most video is stored), and full range for other usage (such as gameplay). But this mechanism could hardly apply to PC.
IMO keeping Full as a default and allow Limited as an option is the only sane way for PC, especially when better HDTV nowadays is starting to accept full RGB range signal. But if you guys think that, people with some cheaper HDTV or some awkward PC monitors which doesn't even do what's aka "PC Level" should get more care, just make Limited as default then.
But please, don't deceive users with some fake Automatic option/fix like that. It sucks.
Regards, Tom Yan
P.S. I am not a programmer or tech expert here, if there's anything wrong in this mail, I'm glad that you point it out to me.