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4:4:4 Chroma Sampling - Questions

post #1 of 22
Thread Starter 
Hey :-)

I recently purchased the 'LD460' LG LCD. It's mainly used for HD Movies (720p or 1080p) and Video Games.

The forum have a post here about the fact 4:4:4 sampling will not work on HDMI to HDMI connection due to a driver bug in both ATI and Nvidia. I'm guessing that the Playstation 3 (or the Wii for that matter) using some sort of ATI or Nvidia chipset (I'm not aware to any other graphical chip set companies) , so it will also won't display a real 4:4:4. Also - as far as I understand, there is no 'option' to turn on 4:4:4 on the TV Set - it just displays it if the video displayed is 4:4:4 right?

I tried to have a look just for the research. According to the post above, I can test is using two ways:

1. Using this file, I should be able to read the 'Red' easily. I wasn't at the start - but playing around with the LCD Settings (Dynamic Contract and Black Level) made is look crisp and clear. As far as I know - 4:4:4 should not be a subject to color settings so I'm guessing this is not it?

2. Using this chart . See the attached picture. The 'blue' in the middle seems to point the 4:4:4 does not work?

Why is the difference between the two tests?

If I'm summing it up - There is no way to enjoy 4:4:4 on my Console at the moment right? Unless somehow ATI/Nvidia will fix this HDMI Bug and sony will push a new system update?
For the PC, I know there is an option to find an DVI to HDMI Cable, or use a fix that disables sound on the HdMI?

Thanks!
LL
post #2 of 22
On my set (Westinghouse VR-3225) I have tested it two ways:

1) VGA native resolution 1920x1080.

The color text chart is clear & sharp.
The modified Bell-Nuit chart shows red pixel columns with SOME left & right pixel spill.
Normal text is sharp & clear.

2) DVI-HDMI 1920x1080

The color text chart is sharp & clear.
The modified Bell-Nuit chart shows well defined 'one pixel wide' red columns with NO left & right pixel spill.
Normal text is sharp & clear.

You could argue that test 1 fails Bell-Nuit and thus fails 444, but it passes the color text chart and displays normal computer text sharp & clear. The color text chart might not be a definitive 444 test.

Your Bell-Nuit chart suggests your TV is not doing 444, there seems to be too many red pixel columns. I get clean sharp well defined 'one pixel wide' red columns on mine. In other words, the red columns have a width of only ONE pixel.
post #3 of 22
Thread Starter 
I see.

Well, since the Playstation 3 don't have any DVI Output, is it safe to say nothing I will do make 4:4:4 work on Playstation 3?
Even more then that, according to that : NO ONE else that owns playstation 3 can make 4:4:4 work at the moment?
post #4 of 22
I'm not a gamer.......

You'll have to wait for more experienced users for PlayStation 3 info.

P.S. I'm not sure 444 is important for gaming. For me it's very important for clear computer text, but for gaming, it might be a non-issue.
post #5 of 22
Thread Starter 
Well, someone mentioned 4:4:4 is 'useful' for Consoles and PCs. Some console games have a lot of reading going in the game, and it's just another source that don't use pre-rendered stuff.

Will wait for more comments. Thanks :-)
post #6 of 22
To expand on my point....

Video like movies and TV shows is usually 4:4:3 which might be what your PlayStation is outputting.

The text that 4:4:4 is needed for is small text like from emails and this message.
post #7 of 22
Thread Starter 
Ermm, I'm wondering - this bug only happens on HDMI to HDMI when it carries the sound data. If I'll connect the PS3 to a Receiver, Does the HDMI will no longer carry the sound data (which will allow it to do a 4:4:4?)?
post #8 of 22
Use your Bell-Nuit chart and play around.

Look for sharp single pixel wide columns.

I use a 5x loupe (10x or 20x would be better).

A Hastings Triplet would be great for this (I think).
post #9 of 22
Thread Starter 
I think i'll try picking an SPDIF cable. Out from the Playstation 3 and in into the TV (as I don't have a receiver). This might work, as the Playstation 3 have an option to pick the sound output (HDMI or SPDIF).
post #10 of 22
The Radeon 6000 series don't have a problem with chroma sampling. Some of the 4000 and 5000 series did which requires the EDID fix.

I've been using a 32" Insignia for over a year as a computer monitor, first with a Nvidia 9600GT (DVI-HDMI through a Denon AVR-1508) and in March I bought a Radeon 6970. I still used the DVI-HDMI cable as my Denon AVR-1508 didn't support HDMI audio. Last month I upgraded to a Denon AVR-1712 and a HDMI cable for true 6 channel audio.

My Denon AVR will display HDMI signal information. This is what I can output from my Radeon.
DVI:
8 bit 4:4:4 RGB
10 bit 4:4:4 RGB
HDMI:
8bit 4:4:4 RGB 16-235 white
8bit 4:4:4 RGB 0-255 white
10bit 4:4:4 RGB 16-235 white
10bit 4:4:4 RGB 0-255 white
8bit 4:2:2 YCbCr
10bit 4:2:2 YCbCr
8bit 4:4:4 YCbCr
10bit 4:4:4 YCbCr

However my Denon Blu Ray BDP-1610 will output 12bit 4:4:4 YCbCr. I assume it could do other settings but I haven't messed with Deep Color and RGB settings.
post #11 of 22
Thread Starter 
I did some more research. After tweaking my TV abit, I manage to get to the attached picture.

I only photoed 1 Red Column (zoomed it).
Can anyone confirm this is indeed 4:4:4?

By the way Dlipter, I saw some one Column only 4:4:4 screenshot (for example this: http://img213.imageshack.us/img213/5999/proper444.jpg). Perhaps it's an old Bell Chart? Does you also get 'one' column using the chart on the first message?

Thanks
post #12 of 22
Quote:
Originally Posted by Tall-Guy View Post

I did some more research. After tweaking my TV abit, I manage to get to the attached picture.

I only photoed 1 Red Column (zoomed it).
Can anyone confirm this is indeed 4:4:4?

By the way Dlipter, I saw some one Column only 4:4:4 screenshot (for example this: http://img213.imageshack.us/img213/5999/proper444.jpg). Perhaps it's an old Bell Chart? Does you also get 'one' column using the chart on the first message?

Thanks

i don't see your attached picture, unless you meant the imageshack link?
post #13 of 22
Thread Starter 
Ermm, It didnt attach it on the first time. Trying again :-)
LL
post #14 of 22
If the PS3 outputs RGB you are getting 4:4:4. By definiton RGB is 4:4:4 (no chroma subsampling to save space). YCbCr only comes in various "flavors". (4:4:4, 4:2:2, 4:2:0)

larry
post #15 of 22
Quote:
Originally Posted by 51dueller View Post

The Radeon 6000 series don't have a problem with chroma sampling. Some of the 4000 and 5000 series did which requires the EDID fix.

I've been using a 32" Insignia for over a year as a computer monitor, first with a Nvidia 9600GT (DVI-HDMI through a Denon AVR-1508) and in March I bought a Radeon 6970. I still used the DVI-HDMI cable as my Denon AVR-1508 didn't support HDMI audio. Last month I upgraded to a Denon AVR-1712 and a HDMI cable for true 6 channel audio.

My Denon AVR will display HDMI signal information. This is what I can output from my Radeon.
DVI:
8 bit 4:4:4 RGB
10 bit 4:4:4 RGB
HDMI:
8bit 4:4:4 RGB 16-235 white
8bit 4:4:4 RGB 0-255 white
10bit 4:4:4 RGB 16-235 white
10bit 4:4:4 RGB 0-255 white
8bit 4:2:2 YCbCr
10bit 4:2:2 YCbCr
8bit 4:4:4 YCbCr
10bit 4:4:4 YCbCr

However my Denon Blu Ray BDP-1610 will output 12bit 4:4:4 YCbCr. I assume it could do other settings but I haven't messed with Deep Color and RGB settings.

From what I remember, until HDMI supported deep color, 8bit RGB and YCbCr 4:4:4 were the only "uncompressed" color spaces supported. You could do 10 and 12bit YCbCr 4:2:2.

larry
post #16 of 22
Thread Starter 
Ermm, I'm not sure if the Playstation 3 is RGB or not really :-(
Maybe you can identify 4:4:4 based on the picture above?
post #17 of 22
If the ps3 will let you output a RGB signal, you will get 4:4:4 as I highly doubt your tv would convert that to YCbCr 4:2:2 or 4:2:0

Quote:
Originally Posted by PooperScooper View Post

From what I remember, until HDMI supported deep color, 8bit RGB and YCbCr 4:4:4 were the only "uncompressed" color spaces supported. You could do 10 and 12bit YCbCr 4:2:2.

Most people will only see 12 or 16 bit from there blu ray player as the only way to get that from a pc is to have a workstation videocard. Then your also converting from display port to hdmi. Kind of a moot point since workstation cards aren't good for gaming and tvs aren't good for high colour playback.
post #18 of 22
Thread Starter 
Well, the more I read about 4:4:4, the more the picture I posted above looks right. Cheers for the help guys :-)
post #19 of 22
Quote:
Originally Posted by Tall-Guy View Post

Hey :-)

I recently purchased the 'LD460' LG LCD. It's mainly used for HD Movies (720p or 1080p) and Video Games.

The forum have a post here about the fact 4:4:4 sampling will not work on HDMI to HDMI connection due to a driver bug in both ATI and Nvidia. I'm guessing that the Playstation 3 (or the Wii for that matter) using some sort of ATI or Nvidia chipset (I'm not aware to any other graphical chip set companies) , so it will also won't display a real 4:4:4. Also - as far as I understand, there is no 'option' to turn on 4:4:4 on the TV Set - it just displays it if the video displayed is 4:4:4 right?

I tried to have a look just for the research. According to the post above, I can test is using two ways:

1. Using this file, I should be able to read the 'Red' easily. I wasn't at the start - but playing around with the LCD Settings (Dynamic Contract and Black Level) made is look crisp and clear. As far as I know - 4:4:4 should not be a subject to color settings so I'm guessing this is not it?

2. Using this chart . See the attached picture. The 'blue' in the middle seems to point the 4:4:4 does not work?

Why is the difference between the two tests?

If I'm summing it up - There is no way to enjoy 4:4:4 on my Console at the moment right? Unless somehow ATI/Nvidia will fix this HDMI Bug and sony will push a new system update?
For the PC, I know there is an option to find an DVI to HDMI Cable, or use a fix that disables sound on the HdMI?

Thanks!

It's not a driver bug AFAIK. On my samsung HDTV it seems to turn off 4:4:4 itself unless you label and input PC mode and then 4:4:4 works (but sadly PC mode also disables most of the calibration controls )
post #20 of 22
Thread Starter 
Yep, Annoying. It seems like the bug mentioned on the LD450 thread, it fixed with ATI Driver at least. I heard some old Nvidia drivers still have tons issues.

And those TV specific issues like you have with the Samsung :-)
post #21 of 22
Quote:
Originally Posted by PooperScooper View Post

YCbCr only comes in various "flavors". (4:4:4, 4:2:2, 4:2:0)

Do you happen to know which of those three the PS3 uses for YCbCr output while playing DVDs and BDs?
post #22 of 22
Quote:
Originally Posted by skibum5000 View Post

It's not a driver bug AFAIK. On my samsung HDTV it seems to turn off 4:4:4 itself unless you label and input PC mode and then 4:4:4 works (but sadly PC mode also disables most of the calibration controls )

So even if you send YCbCr 4:4:4 to the Samsung TV, it converts it into something lower?
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