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Originally Posted by e-t172
you're basically telling us that there is no way to know for sure which gamut to use based on information in the source? Meaning we can never be sure that we're using the right gamut and getting the right color?
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There clearly isn't any way to automatically "guess" the gamut that was used during mastering...the same way there is no way to "guess" whether 25fps is genuine PAL or sped up cinema NTSC.
You can detect the decoding matrix(601/709) if it was added to video stream headers, but no can do about the gamut being used during mastering.
Ideally(and I made this feature request to madshi a while back), we'd need some automatic rules like:
-23.976: SMPTE-C(that you could always change to EBU using a hotkey if it was mastered in Europe)
-25: EBU(it could also be HDTV, so you could always swap it if need be)
-29.97: SMPTE-C(it's most likely SD VIDEO NTSC, but it could also be HDTV if it's HD)
You'll find some food for thoughts in this thread:
http://www.avsforum.com/avs-vb/showthread.php?t=1038602
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Tom Stites has stated that almost all material is mastered on SMPTE-C monitors and that Rec 709 monitors are rarely used.
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It's a fact that the hero of CARS will be never as deep red in the movie as he is on the movie poster...the video industry went cheap and decided to use the royalties-free SMPTE-C gamut, and orangey red is part of the kludge
The CEO of the french ISF used to keep a BD list on his website as to whether you should use EBU or SMPTE-C..but it basically boiled down to: mastered in the US: SMPTE-C / mastered in Europe: EBU. The ISF takes care of the (free) calibration worldwide on those high-end Samsung DLP projectors(that were blessed by Joe Kane). You even get direct access buttons on their remote to map gamuts on the fly, goodness gracious!
Some mastering houses are said to use a 3DLUT at the very very last stage to map SMPTE-C to HDTV....but IRL, most bluray's don't go through this stage apparently.
All I can say is that IME european BD's look washed out in SMPTE-C(the smallest gamut ever) and US/JAP BD's look oversaturated in EBU/HDTV...I'd even dare saying that using the right gamut seems to increase the subjective CR, because the colors are simply as accurate as the mastering engineer saw them...they don't "overlap" each other anymore, so to speak
Another testimonial of gamut mapping goodness:
http://www.avsforum.com/avs-vb/showp...4&postcount=90
The first time I watched a US HD movie in SMPTE-C on my DLP projector will always remain deeply imprinted in my brain...wow, proper colors! yay, about ******* time \o/
It's like Reclock, once you've seen the light...you're doomed
This said, I'm very pleased to see that mVR is finally diving into the colorimetry nitty gritty
