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Quote:
Originally Posted by thepoohcontinuum /forum/post/19572613


Refer to this post for running a 4:4:4 test - link . Here are two 4:4:4 results: this one passes 4:4:4, and this one fails 4:4:4 (it does 4:2:2 instead).

Is a test of this caliber even necessary to determine if the TV has 4:4:4? I just take Windows paint, fill the image with black for the background, and then draw a one pixel wide circle in full 255 red. If I see the color fade out in the vertical sections of the circle relative to the horizontal sections (blending with black background), I know it doesn't support 4:4:4.


Michael
 

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There is no need for specialised test patterns. My method is to open MS Paint, paint a blue background, then use the pencil tool to draw a 1-pixel-thin red scribble. You can tell instantly what the chroma bandwidth situation is.
 

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Quote:
Originally Posted by Michael2000 /forum/post/19577805


Is a test of this caliber even necessary to determine if the TV has 4:4:4? I just take Windows paint, fill the image with black for the background, and then draw a one pixel wide circle in full 255 red. If I see the color fade out in the vertical sections of the circle relative to the horizontal sections (blending with black background), I know it doesn't support 4:4:4.


Michael
Quote:
Originally Posted by lyris /forum/post/19577822


There is no need for specialised test patterns. My method is to open MS Paint, paint a blue background, then use the pencil tool to draw a 1-pixel-thin red scribble. You can tell instantly what the chroma bandwidth situation is.

I dunno, Colmino seems to be the ultra expert in regards to 4:4:4, so I just use his method. Seems pretty "scientific" and its an easy way to get pics for proof. Pictures are worth a million times more than words.
 

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Well, I suppose it prevents forum debates like this one, even if it's not necessary.
 

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Quote:
Originally Posted by lyris /forum/post/19578706


Well, I suppose it prevents forum debates like this one, even if it's not necessary.

I wasn't implying yours or Michael2000's method was bad. But sometimes having proof to back up assertions brings a quick end to meaningless back and forth squabble; which happens quite often on this forum.
 

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Agreed ^
 

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I think the problem with the test chart is people don't know what they are looking for. I've seen at least one case, where someone had to post it for "the expert" to review it.


I do agree it is nice to have a standardized test, though, and a big thanks goes to Colmino for bringing up this issue and creating the test. He explained why I wasn't satisfied with the picture I was getting from most HDTVs used with computers.


Michael
 

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Quote:
Originally Posted by Michael2000 /forum/post/19579570


I think the problem with the test chart is people don't know what they are looking for. I've seen at least one case, where someone had to post it for "the expert" to review it.

That was most likely me
. I pretty much understood the results and had a theoretical understanding of 4:4:4, but needed a seasoned expert like Colmino to verify my results. Its the nature of peer review.


But even to the average Joe, I think the results should be pretty intuitive -- you have a picture of vertical lines of red/black/red/black, but then it shows up as red/semi-black/semi-red/black; most people should know that's obviously not right.
 

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I wonder then how an uncompressed 4:4:4 video looks on decent and big size panel. Too much detail strike the eyes?
 

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Hell no, it looks gorgeous. There's no way a fairly low resolution like 1920x1080 would be overwhelming to the human eye.


Unless the monitor was in torch mode, that is...
 

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Discussion Starter #51
First of all, thanks to all of you that have helped me...I posted this original thread and learned a lot in the meantime, and ended up buying the LG 42LD450. I was excited to get it yesterday and see that it was labeled 42LD450-UA.CUSWLH, so I knew it had the IPS panel. I took it out and configured the HDMI1 input using thepoohcontinuum's settings and connected it to my laptop. I pulled up colmino's 4:4:4 color chart post and expected to see results like thepoohcontinuum got . Instead, I saw:




And as I scrolled the image by one pixel, the filled in part between where there are supposed to be 5 vertical lines shifted like:




so based on what I read, this isn't doing 4:4:4 chroma correctly. I thought, am I doing this correct? Is it possible that they updated the firmware on the LD450 and now it isn't working? (mine was manufactured Oct 2010). I clicked the info button on the TV and it showed 1080p, and I'm running Windows Vista on the laptop.


So next I tried booting up the same laptop, connected in the same way to the same cable, with an Ubuntu 10.04 Boot CD. I didn't expect anything to be different, but I was pleased and surprised to see:




Looks perfect as far as I can tell, I zoomed in a lot and it is very crisp!


So it looks like the HDTV does 4:4:4 properly, but either my computer is not sending it properly or it is not negotiating into the correct mode?


The laptop's video is just the built in Intel 965 series chipset, HDMI port out. I also tried a similar test on my desktop computer which has a NVIDIA 210 card: HDMI output, if I used the Ubuntu boot CD which just has some generic NVIDIA-compatible driver, it works great, but if I booted up the computer to my normal Ubuntu install, which uses the actual NVIDIA 260.19.06 driver, it fails 4:4:4.


I realize that not everyone uses Linux, but does anyone at least know what could be going on and how to fix it in Windows (then I can figure out how to do the same thing in Linux)? Its weird that I have two different video cards (one Intel and one NVIDIA) on two different machines, and they both fail when handled by one set of drivers and succeed when handled by another set. What is the one drivers doing differently that is causing 4:4:4 to work? Thanks for any assistance.
 

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Quote:
Originally Posted by DarkNovaNick /forum/post/19583590


I realize that not everyone uses Linux, but does anyone at least know what could be going on and how to fix it in Windows (then I can figure out how to do the same thing in Linux)? Its weird that I have two different video cards (one Intel and one NVIDIA) on two different machines, and they both fail when handled by one set of drivers and succeed when handled by another set. What is the one drivers doing differently that is causing 4:4:4 to work? Thanks for any assistance.

nuker43 experienced some very poor picture quality with a nvidia and LD450 (w/ S-IPS) combination. He even went as far as to buy an ATI card for testing and he said it solved his PQ problems. So there's definitely something fishy with the nvidia drivers. (note: my 4:4:4 test result is from an ATI card). Fortunately he came up with an "EDID fix" that seemed to solve his nvidia problems. So give it a try and see if it helps you out. link
 

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Discussion Starter #53

Quote:
Originally Posted by thepoohcontinuum /forum/post/19583965


nuker43 experienced some very poor picture quality with a nvidia and LD450 (w/ S-IPS) combination. He even went as far as to buy an ATI card for testing and he said it solved his PQ problems. So there's definitely something fishy with the nvidia drivers. (note: my 4:4:4 test result is from an ATI card). Fortunately he came up with an "EDID fix" that seemed to solve his nvidia problems. So give it a try and see if it helps you out. link

Thanks for the link. I was able to follow what people were doing under Windows and find someone who did the same thing in Linux. If anyone else finds this post and has the same problem, visit http://analogbit.com/node/23 . It was quite easy: I just used the NVIDIA driver utility to grab the EDID data from the TV and then used this guy's edid_disable_exts program to strip out the attributes, and added
Code:
Code:
Option "CustomEDID" "DFP-1:/etc/X11/LG-42LD450-fixed.edid"
to /etc/X11/xorg.conf under the "Device" section. Rebooted, then the display was great!


After going through all this, and seeing it happen with both NVIDIA and Intel drivers (not sure if there is even a fix for the Intel drivers), I'm wondering if there might be more 4:4:4 capable HDTVs out that people have dismissed because of driver problems? I know that if I had just bought this TV without knowing that others were successful with 4:4:4 and had done the test myself and seen it fail, I probably would have just taken it back and assumed it wouldn't work. I definitely wouldn't have thought to hack the driver to replace the EDID info.
 

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Quote:
Originally Posted by DarkNovaNick /forum/post/19588350


Thanks for the link. I was able to follow what people were doing under Windows and find someone who did the same thing in Linux. If anyone else finds this post and has the same problem, visit http://analogbit.com/node/23 . It was quite easy: I just used the NVIDIA driver utility to grab the EDID data from the TV and then used this guy's edid_disable_exts program to strip out the attributes, and added
Code:
Code:
Option "CustomEDID" "DFP-1:/etc/X11/LG-42LD450-fixed.edid"
to /etc/X11/xorg.conf under the "Device" section. Rebooted, then the display was great!


After going through all this, and seeing it happen with both NVIDIA and Intel drivers (not sure if there is even a fix for the Intel drivers), I'm wondering if there might be more 4:4:4 capable HDTVs out that people have dismissed because of driver problems? I know that if I had just bought this TV without knowing that others were successful with 4:4:4 and had done the test myself and seen it fail, I probably would have just taken it back and assumed it wouldn't work. I definitely wouldn't have thought to hack the driver to replace the EDID info.

Great stuff! Thanks for posting.


I had to modify the monitor.inf file one time to edit the EDID.


Michael
 

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If I'm watching a movie through my pc like a video file or a bluray disk does 4:4:4 matter? Does the computer upconvert all of the color so everything will look bad even movies that aren't 4:4:4? Or does the chroma mainly affect the text and other normal computer work?


I guess what I'm saying is, is everything going to look worse through a PC on a 4:4:2 hdmi tv then it would normally or is it just the computer tasks that will look worse? Is Toy Story 3, for example, going to look just as good from my PC on hdmi input 1 as it would from my Bluray player on Hdmi 2?
 

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LG 60pk550 supports RGB/4:4:4


Works on Nvidia and ATI drivers, haven't tried Linux

In ubuntu to test using the Nvidia driver make sure DFP-0 (or whatever your screen is) is set for RGB in color space controls
 

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For all those wanting to use an LCD TV as a PC monitor I recommend the Philips xxPFL5405.


- Uses an AS-IPS panel from LG (check my pic posted in Page 8 of the "Lcd Matrices" thread on the UK equivalent of this forum)

- It has 4:4:4 full chroma support (using the Bell-Nuit Test chart I confirmed this)

- Very low input lag (17ms on average) in PC Mode, can display pics if anyone wants.


I have read on several forums, notably this one, people saying that the LG xxLD450 is the best tv for PC use.

I disagree, that model uses an S-IPS panel which produces a much weaker contrast ratio and weaker blacks than the AS-IPS panel.

The input lag on the LD450 is the same as on the PFL5405 and the Philips has 100 Hz!

The xxLD450 can also reproduce full 4:4:4 chroma but only after installing the EDID override fix.

The Philips reproduces full 4:4:4 right out of the box!

All the advantages of the xxLD450 + a better panel + more uniform CCFL backlighting (in my case anyway, Philips have always been great with their backlighting) + 100 Hz!


PFL5405 = Superior for PC use IMO.
 

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It appears to my novice eyes that I have found a sub $300. TV that both accepts 1920x1080 over VGA, and does 4:4:4 chroma over DVI-HDMI. The TV is a Westinghouse VR-3225 and I am quite pleased with it. Until I came across this thread, I was puzzled as to why VGA text looked so sharp and straight HDMI driven text appeared blurry.


Viola.....in short, when driven with a DVI-HDMI cable, text became sharp & clear.
 

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Quote:
Originally Posted by dlipter /forum/post/21112923


It appears to my novice eyes that I have found a sub $300. TV that both accepts 1920x1080 over VGA, and does 4:4:4 chroma over DVI-HDMI. The TV is a Westinghouse VR-3225 and I am quite pleased with it. Until I came across this thread, I was puzzled as to why VGA text looked so sharp and straight HDMI driven text appeared blurry.


Viola.....in short, when driven with a DVI-HDMI cable, text became sharp & clear.

Interesting find dlipter, any updates?


TIA
 
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