why is my apple dvd player saying not permitted

WHY IS MY APPLE DVD PLAYER SAYING NOT PERMITTED HOW TO

It should be 'xvYCC testing'.Ī display saying that it 'supports' xvYCC doesn't tell you much. So I guess the title of the thread's wrong. I'd also like to see some A/B comparison animations - image with xvYCC, image without. Calibration will be best performed with normal 709 data. Display gamut could be probed with a colorimeter, and that information could be reported by reviewers. The point won't be so much to calibrate the xvYCC space, as to confirm that it's working, and to see how wide a gamut your display has. I'd guess it's embedded in the H.264 video stream, but we need to find out how that's done and whether the encoding tools available can do that. That implies that there must be some way of encoding the gamut in AVCHD so it can be passed out through HDMI, and we have to do it. My calculations say that we'd need to use 70% colour bars for those primaries.Īnother test would just be an encode of that CIE diagram - alternating between normal and extended-gamut renditions.īut one issue is that HDMI xvYCC requires that the gamut be signalled by the source. The catch is that although xvYCC can reach basically any colour in the CIE diagram, its luminance is more limited the further out it gets. The diamonds are the new primaries and secondaries, and we produce test bars with different saturations of those - a few steps along the radial lines. (Diagram borrowed from Wikipedia, and scribbled on). I suggest maybe selecting a new set of monochromatic primaries - maybe 630nm, 540nm and 450nm, which I've seen suggested for laser display systems, and producing a set of saturation test bars that gradually approach those colours - starting with the best that standard Rec.709 can do, and working outwards: Not sure of the best way to approach this - just doing 95%, 100%, 105%, 110% saturation of the standard primaries isn't going to be terribly effective, as that'll just hit the limits of the CIE colour space pretty fast. The next step is to test increased saturation - actually producing new colours outside the standard Rec.709 gamut. I would be inclined to have one more step, and smaller increments - say 95%, 100%, 105%, 109/110%. Some displays may conceivably collapse that overbright yellow to white, but that would be part of the test. And likewise, I'd be inclined to make the top white bar be maximum too (254=109%). I don't think there's any reason to limit yellow for a test pattern - Y' is allowed to go beyond 235. That's testing higher intensities of the standard primaries, yes? To some extent, that's not really exercising the new facilities in xvYCC, it's been kind-of-unofficially been something that people have quietly done in standard YCbCr - RGB values outside the 16-235 range convert to those values.īut as xvYCC formally endorses that practice, lets do it. 'New' Extended-gamut Color Space for Video Applications xvYCC (IEC6) Other formats like AVCHD that support it are in use now, so get them tested, and distinguish marketing spiel from good kit.

WHY IS MY APPLE DVD PLAYER SAYING NOT PERMITTED HOW TO

But we need tests to confirm that it's being done properly, and we're waiting for Blu-ray to figure out how to add it in a backwards-compatible way. There is a sound technical reason for it, and it's a good idea.

In particular I want someone who knows about AVCHD.Īnd a final note - xvYCC isn't just marketing snake-oil. But I'd like work with someone from the AVS HD 709 team to do the final encode and authoring. Is anyone interested in working with me on this? I can help with the colour theory, getting hold of the IEC 6 standard, and the maths to produce the underlying YCbCr data for encode. I'd be very interested to see the results, and test it on a colorimeter. We should be able to produce fully-legal xvYCC test patterns for the AVCHD version of the AVS HD 709 disc, and dodgy ones for the Blu-ray version.

Why is my apple dvd player saying not permitted