Whats the deal with Quicktime X Colour Management?

[onedog]

So Im on a MacPro running Snow Leopard. I just cant work out why my clips look completely different in QT7 to QTX.

Any ideas what this is about?

Thanks for your help.

Cheers
Glenn

http://dl.dropbox.com/u/4891596/Screen%20shot%202010-05-05%20at%2011.20.29%20AM.png

 

[Demistate]

This was a huge topic of Discussion at NAB 2010 PPW. Here is what I gathered from it:


Don't trust Quicktime Player. What you see in FCP is what you will get when you deliver.

If your clients are using Quicktime player to review, explain to them that it won't be accurate, but when you go to tape/filmout it will be.

Try to get your clients to use a different player if they are on PC. Windows Media Player in Windows 7 will handle h.264 files correctly. You can avoid a lot of color shift issues by just packaging your content in a .mp4 container (since there are only 2 ways to handle gamma/colorspace in .mp4, and more than likely the player will choose correctly). h.264 is not a delivery medium for pro video since it's only 4:2:0 (You're probably shooting 4:2:2 or higher) If you deliver in h.264 your clients can download free players like vlc and Media player classic to review the files with some good accuracy (assuming their player is configured properly for 16-235 video levels)

Oon Quicktime 7 player, you'll want to enable the "Final Cut Pro Compatibility" to see what you are seeing in FCP if you must give .mov container deliverables.

If you are delivering Quicktime files to Adobe CS4 or less, make sure you give them a screenshot of how it's supposed to look. Premiere Pro CS4 handles the gamma incorrectly in almost every quicktime format, and unless the editor on the other end knows how to color manage it in After Effects, they will output the wrong colors.

Blame Apple for making this so damn difficult. Their own framework doesn't have a consistent way of determining colorspace/gamma/etc.

 

[JeganRX]

(assuming their player is configured properly for 16-235 video levels)....Their own framework doesn't have a consistent way of determining colorspace/gamma/etc.

I was under the impression that, despite Apple severely messing up gamma handling in QT (which is baffling considering the standard to which Apple likes to portray its color accuracy), that the erroneously displayed levels were 16-235, instead of proper 0-255.

Unless you mean that the files are encoded in 16-235 (Also confusing and pointless in this day and age), and QT fails to stretch them to 0-255?

 

[Demistate]

Unless you mean that the files are encoded in 16-235 (Also confusing and pointless in this day and age), and QT fails to stretch them to 0-255?

Yes, Quicktime fails to stretch YUV(16-235) levels back to RGB(0-255). Ironically if you rename the file with a .3gpp extention, the black stretch does occur.

I know for a fact that Mainconcept's h.264 encoder squeezes your video into a 16-235 range even if you give it a 0-255 signal.

It might have to do with the fact that TV's still assume that the signal is 16-235

http://avisynth.org/mediawiki/ConvertBackToYUY2

According to avisynth rec.709 defaults to "TV Range" wich is 16-235 You can encode a full 0-255 signal in rec.709, but many devices would not play it back correctly, as the flag for full range isn't always adhered to properly.

On the XBOX 360, setting your output to REC.709 will clamp the signal to 16-235. Even though post people tell you that 16-235 clamp is not necessary anymore, it still happens...just automatically for you

 

[JeganRX]

On the XBOX 360, setting your output to REC.709 will clamp the signal to 16-235. Even though post people tell you that 16-235 clamp is not necessary anymore, it still happens...just automatically for you

All in the name of l-l-l-l-legacy support...

And yeah, I'm not even sure why 709 is 16-235 by default, since it was supposed to be the then-future format (as opposed to 601). You'd think in prep for HDTVs and higher performance CRTs, they'd have thought ahead on that one.... though not like digital video "standards" have ever made much sense.