Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Official Blue ray options - Denon, Arcam, Pioneer, etc.

Stacey:

Very much appreciated...only thing os interest is 1080p24 as:

i) Lumagen RadianceXE will handle 1080i60 issues for DVD;
ii) Meridian 800 will handle DVD-A; and
iii) SACD not an issue.

Thanks so much,


Joel

OK, so I've been looking into the chroma issue, with reference to the Panny players, and found the following on AVS Forum:

"Pixel Processing Gets Better
--------------------------
A solution is provided in Panasonic HD/DVD players:
The Panasonic Hollywood Laboratories PHL Reference Chroma Processor studies and improves restoration, color correction, compression and digital conversion, then up-samples (4:2:0 to 4:2:2) the color information in decoded video signals. The unique PHL Reference Chroma Processor Plus expresses the fine details and nuances of movie scenes by reproducing clearer color boundaries, providing all the qualities that a Blu-ray (and DVD) disc has to offer."

Looking at Panny's own documentation on the subject we read such things as:

"To get the best high definition images from a Blu-ray disc, you need a player that renders high-quality progressive images, expresses motion smoothly, and draws sharp diagonal lines. The Panasonic-unique P4HD technology processes more than 15 billion pixels per second, generating each pixel correctly according to information obtained from up to 60 surrounding pixels, and applies the optimum processing to every pixel in the video data on the disc. The result is images with exceptional resolution."

In other words the Panasonic players are interpolating the source data in a number of ways. If this is correct then I'm not interested. Interpolation at the same resolution as the source data leads to obfuscation of original information and a LOSS of image fidelity.

No thanks.

Mark

I thought all players had to interpolate to get 4:2:0 to 4:2:2, and that you can't restore the chroma resolution without doing so. Wikipedia has a decent article on the encodings: http://en.wikipedia.org/wiki/4:2:2

As far as I remember, chroma subsampling is lossy. The idea is that we're less sensitive to red and blue light and so rather than sampling every pixel for it's chroma value, an average is taken, and when the average is displayed over adjacent pixels we will tend not to notice the error (as long as the number of pixels averaged is small of course...) But there's no way to correctly get back what has been lost. I guess you can make a good guess, and with certain images, eg test patterns, maybe even get it right, but you are also going to get it wrong as well, particularly in complex images (ie non test patterns) and so I'd personally rather not interpolate at all and simply display what has actually been sampled as that will more often that not be the more accurate image.

I'd love to proven wrong.

Mark

Mark,

The Panasonic stuff is marketing speak.

There are two issues at work.

1. The type of filter used for the upscaling. Most are probably using bilinear. Panasonic is using something better.
2. Most are using a horizontal low pass filter based on some outdated spec, to ensure they are down some dB by Nyquist. Panasonic is much smarter here.

I can assure you that what you get from the Panasonic is what the pattern(s) on my disc are supposed to look like.

Besides the 2nd row, last burst on the right, you can also look at the chroma zone plate. The left and right half of the image get dimmer on everything but the Panasonic. My original pattern was not dim on the edges.

Whay they are doing for video is no different than what Meridian is doing for audio with their apodizing filters. Its all about getting back to the original.

Its far easier to demo the loss of chroma on video than it is to demo 96 kHz audio vs. 48 kHz audio.


That is not possible. Chroma is co-sited with luma in the horizontal direction and interstitial in the vertical direction. If you don't properly scale (aka filter), you will end up with an uwatchable image.

They do. You can't watch a 4:2:0 image.

The reason the burst is blue and red is the phase of Cb and Cr to each other. I could have easily made it green and the results would be the same. This occurs with all colors, not just blue and red.

I just happen to like the look of red and blue on black. This is a chroma only pattern, the colors you see are not important, its the amplitude that counts when looking at the channels on a WFM. If I were to change luma from 16 to another value, you would see different colors, but the dim burst would not change.

Stacey
Where and when can we read your Pioneer 09 review? How does it compare to the Panasonics and Oppo for 1080p24 video and SD DVD upconverting playback?
Thanks
Joe

+1

Stacey, thanks for the input. Food for thought!

Mark

Mark,

When we get to our color space article, I will include a waveform showing what happens when it gets dim. That may help. Images usually begin and end as RGB. The YCbCr is just for transport. A lot of filter occurs on both sides and its up to the content creation and playback to do it however they like. Really wish someone would have spec'd how to do it. Some are doing it so poorly it is shocking!

As far as 09, it should be in an upcoming issue of WSR. It uses the Marvell Qdeo 2710, which I believe is what Meridian is using in the box that drives their projector.

I look forward to reading the article. Its stuff like that which helps to expand the consumer's knowledge of the formats we are using.


This is a discussion we've already had here. Video *decoding* should be deterministic, so all players, as a minimum (assuming no gross errors), should be capable of delivering the same image from the same source encoding. This is why I was sceptical about your Panny claims (and indeed any such claims that a particular player has a better image than it's competitors). To me it means that Panasonic are breaking the rules, backed up by your comment that other manufacturers are filtering to stay within the Nyquist sampling limits. On the other hand, we've all seen the benefit of breaking this rule with SDI for DVD (typically a sharper image with less filtering - although in that case it's more likely an argument for digital delivery vs analogue). But one can argue that correctly mastered DVD video should not have information above the Nyquist limit for the format anyway, so there shouldn't really be any benefit to breaking the rules. Is this not the same for Blu? In other words is your test pattern supplying chroma frequencies above the spec for Bluray video encoding and that such frequencies are generally not found in Blu material? Or is it really that other manufacturers are filtering too aggressively and losing genuine chroma detail?

Have you done A/B tests with movie material on the chroma issue? Are improvements easily visible? The Panny players are cheap enough that I'm tempted to buy one to see for myself but it seems a waste if the video material doesn't contain the information the Panny is capable of displaying?

Many thanks,

Mark