Sunday, December 14, 2008

5020 and 6020 have a 3D Y/C comb filter

A Y/C comb filter separates the luma (Y) and the chroma (C) signals from a composite source such as laser disc or an OTA NTSC broadcast. Digital sources already have their luminance and color components separated but for analog composite sources, the video signal quality is highly dependent on the technology of the Y/C comb filter. Pioneer's documentation mentions that the Elite Kuro models have four settings of (Off / High / Mid / Low) for a video processing 3DYC feature. The documentation for the non-Elite Kuro mention that they have no 3DYC feature. So I decided to determine what type of Y/C comb filter Pioneer decided to put in the PDP-5020FD and PDP-6020FD Kuro plasma displays.

I did some testing with a couple of video test patterns, a Pioneer Elite CLD-99 laser disc player, and a Pioneer Kuro PDP-6020FD plasma display. In the late 90's the CLD-99 laser disc player was the first consumer electronics device to have a 3D Y/C comb filter. It was based on a digital 3 line comb filter design and it added a digital frame buffer to compare with the previous frame. This added time as a dimension, hence the 3D label. It was amazing new technology that was expensive, and it was only in the CLD-99. A couple years later 3D Y/C comb filters became more common place and were introduced in some higher-end RPTV's.

The S-video port of the CLD-99 laser disc player uses the 3D Y/C comb filter while the composite port has the combined Y/C signal straight from the optical disc which means that the comb filter in the display is used. This allowed for the comparison of the CLD-99's 3D Y/C comb filter to the comb filter in the non-Elite Kuro.

Static Test
First a color bar test pattern from a laser disc was viewed. The sharp transitions between the different colors is a good test of the separation quality of a Y/C comb filter. Lessor comb filters have an active noise shimmering-like effect between the colors. A 3D Y/C comb filter stabilizes the shimmering but it does have some video artifacts. On a PDP-6020FD display the CLD-99 S-video output looked about the same as the composite output.

Motion Test
For the second test the Snell & Wilcox zone plate from a laser disc was viewed. The zone plate has a fresnel ball that bounces around the middle square section. This motion causes all sorts of problems for Y/C comb filters and the result is chroma flashing. The zone plate also has a couple boxes with vertical and diagonal lines near the top that tend to have a lot of chroma noise with non 3D Y/C comb filters. The comparison of the S-video and the composite signals showed roughly the same image. The CLD-99 had slightly less flashing chroma noise with the moving ball than the Kuro did. The static vertical and diagonal lines in the boxes had slightly less luma noise with the Kuro but increasing the 3DYC slider control from the default value with the CLD-99 equaled and then improved that noise aspect.

The performance of the comb filter in the PDP-6020FD roughly equaled that of the 3D Y/C comb filter in the Pioneer CLD-99 laser disc player. So Pioneer's specifications are incorrect, the PDP-5020FD and PDP-6020FD both have 3D Y/C comb filters. The non-Elite Kuro just lack 3DYC configuration controls.

The CLD-99 had a slightly better Y/C separation than the Kuro but the results were close. This advantage is probably due the CLD-99 being optimized for the laser disc formats 425 lines of resolution while the Kuro's 3D Y/C comb filter is designed to work well with a resolution range from VHS (220 lines) to D1 (480 lines).

The Kuro's 3D Y/C comb filter default also have a bit more Y and C noise reduction (NR) than the standard default in the CLD-99 player. The CLD-99 standard default setting is 50% for Y NR, C NR, 3DYC, and Sharpness controls. Increasing the CLD-99 players Y NR, C NR, and 3DYC settings by a couple ticks to about 75% equaled the image effect of the Kuro's default. It is unknown if this is equal to the 3DYC Med or the High setting of an Elite Kuro display.

Sunday, December 7, 2008

is a source running at 24 fps?

The PureCinema film mode can reverse telecine 24 fps (frame per second) film material and display it at a native 72 Hz. A Blu-ray player can transmit a movie over HDMI at its original 24 fps and have a Kuro display this at 72 Hz. This is great and it eliminates the effect of 3:2 pull-down induced film judder. So how can it be determined if a Kuro is being fed a source at a 24 fps rate?

The Sony BDP-S350 Blu-ray player has a "24P" blue LED that lights up when 24 fps material is being output. This is a great feature since it is rather tricky to correctly configure the S350 for 24P output. Unfortunately there is not an easy way to query a Kuro's refresh rate. Other than observing the smoothness of motion and pans, there is no way to tell if PureCinema is actively performing reverse telecine. Switching an HDMI source to be a PC input is a trick that will report the input frame rate.

Here are the steps to check the refresh rate of an HDMI source:
  1. Select HDMI input
  2. Press Home Menu
  3. Enter Setup
  4. Enter Option
  5. Enter HDMI Input
  6. Select PC from the Signal Type submenu
  7. Exit menu
  8. Press Display to see the refresh rate
  9. go back to step #1 and change Signal Type back to Video
Unless your source is a PC you probably won't want to keep your HDMI in PC mode since it has a number of picture ramifications that are not good for general TV and film viewing. It would be a really nice feature if Pioneer gave the Kuro a special control panel screen that displayed internal information like frame rate, 720p or 1080i resolution, MPEG2 bit rate, AC3 channels and bit rate, and full PSIP information.

Tuesday, December 2, 2008

PDP-5020FD vs. PRO-111FD

The Pioneer Kuro PDP-5020FD and PRO-111FD are 50" versions of the 60" PDP-6020FD and PRO-151FD plasma displays. The 50" Kuro panels are smaller, about 45 pounds lighter, and consume less energy than their 60" counterparts. The feature differences between the Elite and non-Elite models are exactly the same. See the PDP-6020FD vs. PRO-151FD comparison report for details.

  • PDP-5020FD 50" - $3500
  • PDP-6020FD 60" - $5500
  • PRO-111FD 50" Elite - $4500
  • PRO-151FD 60" Elite - $6500

The step up from a 50" to a 60" panel costs +$2000. The step up to an Elite model costs +$1000.

For current street prices check out the Pioneer Kuro 9G store.

Monday, December 1, 2008

Firmware Version

Below are the software firmware and hardware version numbers from a July 2008 build PDP-6020FD:

  • Software Version: 0901-0201
  • Hardware Version: 0x351
  • HMG Version: 02.00

Recently built Pioneer Kuro have been reported to be using the same versions. This means as of December 2008 no firmware bugs have been fixed. The Kuro 8G had a mid production firmware fix but since the Kuro 9G hasn't had one yet and its operation is fairly solid a future firmware update is unlikely.

In any case, the Kuro firmware is not user upgradeable and must be done by a certified technician.

Other than minor cosmetic items and the speaker positions, the only difference between the Elite and the non-Elite Kuro is believed to be firmware. So, theoretically a non-Elite Kuro could be upgraded to be an Elite Kuro simply via a firmware update. This would likely require some special equipment and the chances of Pioneer offering this are near zero.

Since the Kuro 9G runs Linux it is unfortunate that the interface isn't more open in a manner that would allow users to get inside and tweak their displays. The potential is enormous. I'm sure some amazing things could be done by creative users but such an open architecture would create a major support headache for Pioneer and it could reveal many proprietary secrets to how the Kuro operates. So, again, the chances of this happening are near zero.