DVE: HD BASICS (Blu-ray)

[crackinhedz]

Hey guys, just wanted to get a thread up about the new DVE: HD Basics disc calibration that is due out in a few days...mines already shipped from amazon!!!

Anyways, I e-mailed Mr. Joe Kane on his thoughts of using the Bluray version over just using the standard definition version to calibrate your HDTV.

Here is Mr. Kane's response:

Thanks for your interest in what we are trying to accomplish at JKP. You asked for a brief statement saying why someone might want to purchase DVE: HD Basics, even if they already own DVE on DVD.

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In today's HD market there are a lot of devices that pretend to be HD. True HD materials are needed to properly test for a true HD capability.

Digital Video Essentials was originally produced in 1080p. It was then down converted to standard definition to create the DVD. It took many more years than we anticipated before we could get it out on an HD consumer disc.

In the mean time HD everything else was continuing to grow. We saw things happening we didn't think were good for the format so we decided to update DVE before bringing it out in HD. The theme of the program became HD Basics. It explains our current expectations of the system in addition to telling consumers how to check for it.

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We have some additional information you may find useful in answering questions that will come up in playing the discs.

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The program itself was put together to fill the void of knowledge of what high definition television is supposed to be in terms of a communications system. The consumer world seems to be caught in marketing hype about things that are detrimental to the high definition television system. DVE: HD Basics is a tutorial about what it takes to properly reproduce a high definition image. It points out what we see going wrong and how we believe the errors are being justified by equipment manufacturers. The disc also partially tests HD player capabilities.

In setting a goal for menu interaction, we decided a minimum threshold would be based on what we accomplished in a prior disc in the HD DVD format. We set a goal of simplifying the menu system and added a bookmark capability. We found most Blu-ray players don't have the internal memory required to support bookmarks so left those off the disc.

We designed the BD-J menu to challenge the specified capability of a Profile 1.1 player. There is no BD-MV or movie mode menu system. What you get when you play the disc will be partially dependent on the player. Here's a look at what we've noticed in our QC of the disc on various Blu-ray players.

Menu System

The largest differences in player performance appears to come in how each handles the disc's menu system.

1. Displaying fonts

The Blu-ray format has the capability to populate menu graphics with words from text files. In the old days of DVD, the text had to be imbedded in the menu graphics. If you wanted to create a menu in a different language, you had to create a completely new set of graphics. If you wanted to have multiple languages in menus on a disc, you had to create parallel menu systems. In the HD optical formats you can load the menu graphics and text files into the player and ask the player to build the menus for you. This allows multiple languages in menus with just the addition of a font and text file for each language. Such a system would also allow you to down load and store additional text files in your player once the program had been released. You could add languages to the menu as the market expanded for your product.

What we found is some early players didn't have the horsepower to render the fonts properly. The text you see on screen looks like the typewriter ribbon is running out of ink. Does anyone remember what that looks like? Sections of individual letters are not as bright and clear as other parts of the letter.

We found one player that could do a good job of rendering text in the outer layers of the menu but couldn't fill the text on the inner layers of the menu. You could see right through the letters to the background graphics.

Another player displayed dark gray text instead of white text. It was more difficult to read against the gray background in the menu.

2. Speed at which the menu graphics change

Parts of the foreground in the menu system are animated. When the menu first comes up, after the usual wait for the player to load the program, you'll see the menu options entering from the left side followed by the background popping on. In some players you'll see it coming in from the left in slow motion. In other players the animation will appear to be good.

We did find a correlation between the amount of time it took to load the program and the amount of time it took to complete the animation steps in the menu. In some players the animation speed seemed to slow down as you got deeper into the menu structure.

We've already discussed the player's ability to render fonts. Some of the slowest players to bring up menu options did a good job of displaying the fonts and conversely some of the faster players in bringing up menu options did a poor job of rendering fonts. Then there were players doing a good job of both.

3. Menu system luminance levels

If you look closely at the menus in HD Basics you'll see multiple layers in the images. There is the background of a home theater screen, with the Blu-ray logo and then there is the multilayered foreground of the menu items.

On at least one Blu-ray player the luminance level of the foreground layers was about 20% of the level measured in other players. The video level of the background matched all of the other players. The menu is still visible and functions properly, but just isn't as bright as we intended.

4. Some times the menu didn't come up at all

In every case where we encountered this situation a firmware upgrade to the player made the disc playable.


Video

We’d like to open the discussion of video quality by pointing out there were a large number of players that didn't convert Y Cr Cb to RGB properly at the HDMI output. This is a general problem in the HD consumer industry and is detailed in the tutorial sections of DVE: HD Basics. The errors we're seeing are improper color decoding of Y Cr Cb to RGB and not providing video levels for the RGB output. It provides PC levels.

We expected differences in the video performance of individual players beyond the Y Cr Cb to RGB issues, but were surprised where the largest difference occurred.

1. Our biggest surprise was none of the Blu-ray players tested could properly handle 720p playback in conjunctions with a Java script in the menu system.

Considering the wildly different experiences we've had with various Blu-ray players at 720p we believe the majority of their manufacturers are not testing for that HD rate. Some of the problems were minor, as in not being able to play 720p/24 as 720p/24 or 1080p/24. (Keep in mind Blu-ray is the original 24 Hz format.)

At least one player down converts 720p to 480p instead of up converting it to the 1080p set as the desired output rate. When returning to the menu system from the first 720p video selected, the player only displayed a 480p section of the menu. Only the top left corner of the menu shows up on screen. When we set the player for a 720p output it would play the 720p material as 720p but the 24 frame material was converted to 60 frames and only a section of the menu showed up on screen when we went back to the menu.

We should mention that particular player could play 720p properly prior to the latest software upgrade.

Here's the most unexpected 720p change in functionality we found in one player. The amount of delay time in menu navigation goes up by at a factor of at least four times once you start a 720p video. The slower rate of menu operation remains even if you go back to 1080p content. The only way to reset the interaction time is to start the disc over again. Pressing the “Top Menu” key will do that for you.

2. Ringing in the chroma

You may know that in a Y Cr Cb signal the bandwidth of Cr Cb is half that of the Y channel. We were therefore initially surprised to find ringing in the chroma where there wasn't any in the Y signal. You can see the ringing in transitions in the color bars, or at least in the green/cyan transition.

How can you build a clean Y channel, which has twice the bandwidth of a color channel and still get the color channels wrong? Our best guess is the circuit is taking 4:2:0 that is on the disc and processing it up to 4:4:4, then converting it back down to 4:2:2 for the Y Cr Cb output.

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We hope this helps.

Joe Kane

I highly recommend everyone to pick up a copy. Your TV will thank you.