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I bought the generic 24" 1080P LCD Best Buy had on sale on Black Friday this year. I bought it intending to use it as a decent 1080p monitor and overall, it's not bad for $80. however there seems to be an annoying limitation on the HDMI ports.


When I connect my computer to it using VGA, it displays content perfectly fine. However, when I use the HDMI port connection (which is connected to my 9800GT via a DVI to HDMI cable), there is noticeable color bleeding left and right on text, particularly any white text. I've tried to compensate for it by playing around with the Microsoft ClearType settings, but it doesn't help. Even with ClearType disabled, there's color bleeding. Particularly, the yellow and blue don't line up right and provides ghosting to the left and right of any text.


I think that the HDMI port may be downsampling the chroma to 4:2:2 whereas VGA is 4:4:4. Does this sound about right? Is there a reason why VGA can output fine whereas DVI/HDMI, a digital signal, is being downsampled? I've tried to play around with the menu settings to correct this, but there doesn't seem to be any way to fix it. Changing the label from HDMI to COMPUTER does nothing.



Could it be that the graphics card is outputting the DVI port at 4:2:2? Or should the graphics card spit out 4:4:4 by default?


Honestly, VGA isn't a problem for me, but it is rather annoying that I cannot use HDCP-compliant video unless I live with the color bleed. Thankfully, I haven't used anything on the computer that requires HDCP compliance, but I was hoping to future-proof myself.
 

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Some sets have way of labeling HDMI input as PC/game, otherwise TV has no way of knowing PC is attached, tried that? If not, your color is probably limited to 16-235, not 0-255 computers use, as well. Also your video driver should have settings like YCBR 4 4 4 and RGB 4 4 4 and maybe few others, you could play with that too. If the colors bleed on black and white screen, it could be something else besides chroma: in theory luma should be sent pixel for pixel, so black font on white screen should have 1:1 mapping, it's only when you have blue or red font, with color mapped to 2 pixels at the time, you should see that type of 1 pixel bleed.
 

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I found the solution to this annoying Color Bleeding.

Make sure scaling is off on TV, just to make sure you are using exact display fit. If you mess with scaling through your Graphics card (AMD's CCC or Nvidia properties) You will notice the bleeding is reduce. However that is not the fix I found.


Originally the computer was set to YCbCr 4:4:4 pixel format. As soon as I changed it to YCbCr 4:2:2 Pixel Format, the Color bleeding Disappeared.

Now the Dynex works flawlessly as a monitor
.
 

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Weird. Are you sure you got this one right? In theory it should be opposite: 4 4 4 should mean 1:1 color mapping, 4 2 2 always meant color is subsampled with every 2 pixels assigned one color value and therefore above mentioned color bleeding, unless TV can't do 4 4 4 at all and subsampling on the computer works better, than subsampling it inside TV, but that still would not solve problem of not having full RGB info for each pixel.
 

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Before the beginning of the night, I had no idea what this chroma down sampling is. XBgamer's deductions seems to make sense. I have adjust the Pixel format from 4:4:4 where it was by default to 4:2:2 and it seems to work.


The Doesn't seem to be able to handle 4:4:4.

Unfortunately that was in Bootcamp win 7 installation with AMD CCC. but in MAc OSX, I'm only offered basic display profiles like HD 709-A, SD 170M-A, Color LCD, Generic RGB Profile. The HD 709-A and the rest seem to be all sampling at 4:4:4 which seems to be the standard.


NVidia doesn't seem to allow any option to change down to YCbCr 4.2.2 downsampling.

Google : where is the Ycbcr 4:2:2 Option


I found this Detailed Manual for this TV, and It doesn't specify whether it supports 4:2:2 sub-sampling. but it mentions the E-EDID standard which seems to have issues with NVIDIA. Also it says that DVI is allowed through HDMI 1 port only.

hxxp:// www.dynexproducts.com/cms/documents/Manuals/DX-24L200A12_11-0584_MAN_EN_V1_Final_lr.pdf
 

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Before the beginning of the night, I had no idea what this chroma down sampling is. XBgamer's deductions seems to make sense. I have adjust the Pixel format from 4:4:4 where it was by default to 4:2:2 and it seems to work.


The Doesn't seem to be able to handle 4:4:4.

Unfortunately that was in Bootcamp win 7 installation with AMD CCC. but in MAc OSX, I'm only offered basic display profiles like HD 709-A, SD 170M-A, Color LCD, Generic RGB Profile. The HD 709-A and the rest seem to be all sampling at 4:4:4 which seems to be the standard.


NVidia doesn't seem to allow any option to change down to YCbCr 4.2.2 downsampling.

Google : where is the Ycbcr 4:2:2 Option


I found this Detailed Manual for this TV, and It doesn't specify whether it supports 4:2:2 sub-sampling. but it mentions the E-EDID standard which seems to have issues with NVIDIA. Also it says that DVI is allowed through HDMI 1 port only.

Google Dynexproducts and search the model DX-24L200A12


Here is an Email I sent their support team, hopefully I get a response:


When I plug the TV with the computer via HDMI port (tried two computers) and after I set the resolution to 1080P. I noticed something wrong with the text. like MS word text or web browser text. It seems that it bleeds colors. the black text appears Red or blue Blue in many places across the screen.

Now The TV has nothing wrong with it; it displays PS3, TV and PC content fairly fine. but when it comes to using it as a monitor where fine small text quality matters; it becomes very distracting.

I have researched this issue, and it seems it is called Chroma Subsampling.

And the two subsampling methods in question are YCbCr 4:4:4 and YCbCr 4:2:2.

I have two computers, one has AMD graphics, the other Has Nvidia. AMD Graphics Catalyst Control Center has an option called Pixel Format. By default, it was set to YCbCr 4:4:4. I tried the option YCbCr 4:2:2 and the red and blue color bleeding disappeared, And the picture was perfect.


My Question is, Does this mean that the TV can Only do YCbCr 4:2:2 subsampling. when Using HDMI? And if yes, Is there a work around or a firmware update in the works?


The other computer with Nvidia, doesn't have the option to change the subsampling to 4:2:2. and I have also tried a Mac with AMD graphics (but Without AMD Catalyst Control Center since it's not available for MAC OS), and IT seems that It doesn't have the option to change the subsampling to 4:2:2 either, leaving me stuck without a fix for these two other cases.
 

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I have found this tool called Monitor Asset Manager and it gave me the following:



Monitor

Model name............... DX-24L200A12

Manufacturer............. BBY

Plug and Play ID......... XXXXXXX

Serial number............ XX

Manufacture date......... 2011, ISO week 31

Filter driver............ None

-------------------------
EDID revision............ 1.3

Input signal type........ Digital

Color bit depth.......... Undefined
Display type............. RGB color

Screen size.............. 520 x 290 mm (23.4 in)

Power management......... Not supported
Extension blocs.......... 1 (CEA-EXT)

-------------------------

DDC/CI................... Not supported


Color characteristics

Default color space...... Non-sRGB

Display gamma............ 2.20
Red chromaticity......... Rx 0.625 - Ry 0.340

Green chromaticity....... Gx 0.277 - Gy 0.595

Blue chromaticity........ Bx 0.155 - By 0.070

White point (default).... Wx 0.297 - Wy 0.298


Additional descriptors... None


Timing characteristics

Horizontal scan range.... 14-68kHz

Vertical scan range...... 48-62Hz

Video bandwidth.......... 150MHz

CVT standard............. Not supported

GTF standard............. Not supported

Additional descriptors... None

Preferred timing......... Yes

Native/preferred timing.. 1920x1080p at 60Hz (16:9)

Modeline............... "1920x1080" 148.500 1920 2008 2052 2200 1080 1084 1090 1125 +hsync +vsync

Detailed timing #1....... 1280x720p at 61Hz (16:9)

Modeline............... "1280x720" 75.000 1280 1390 1430 1650 720 725 730 750 +hsync +vsync


Standard timings supported

640 x 480p at 60Hz - IBM VGA

800 x 600p at 60Hz - VESA

1024 x 768p at 60Hz - VESA

640 x 480p at 60Hz - VESA STD

800 x 600p at 60Hz - VESA STD

1024 x 768p at 60Hz - VESA STD

1280 x 1024p at 60Hz - VESA STD


EIA/CEA-861 Information

Revision number.......... 3

IT underscan............. Not supported

Basic audio.............. Supported
YCbCr 4:4:4.............. Supported

YCbCr 4:2:2.............. Supported


Native formats........... 0

Detailed timing #1....... 1920x1080i at 50Hz (16:9)

Modeline............... "1920x1080" 74.250 1920 2448 2492 2640 1080 1084 1094 1124 interlace +hsync +vsync

Detailed timing #2....... 1920x1080i at 60Hz (16:9)

Modeline............... "1920x1080" 74.250 1920 2008 2052 2200 1080 1084 1094 1124 interlace -hsync -vsync

Detailed timing #3....... 1280x720p at 50Hz (16:9)

Modeline............... "1280x720" 74.250 1280 1720 1760 1980 720 725 730 750 +hsync +vsync

Detailed timing #4....... 1920x1080p at 50Hz (16:9)

Modeline............... "1920x1080" 148.500 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync

Detailed timing #5....... 1920x1080p at 60Hz (16:9)

Modeline............... "1920x1080" 148.500 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync


CE video identifiers (VICs) - timing/formats supported

640 x 480p at 60Hz - Default (4:3, 1:1)

720 x 480p at 60Hz - EDTV (4:3, 8:9)

720 x 480p at 60Hz - EDTV (16:9, 32:27)

1280 x 720p at 60Hz - HDTV (16:9, 1:1)

1920 x 1080i at 60Hz - HDTV (16:9, 1:1)

720 x 576p at 50Hz - EDTV (4:3, 16:15)

720 x 576p at 50Hz - EDTV (16:9, 64:45)

1280 x 720p at 50Hz - HDTV (16:9, 1:1)

1920 x 1080i at 50Hz - HDTV (16:9, 1:1)

1920 x 1080p at 50Hz - HDTV (16:9, 1:1)

1920 x 1080p at 24Hz - HDTV (16:9, 1:1)

1920 x 1080p at 25Hz - HDTV (16:9, 1:1)

1920 x 1080p at 30Hz - HDTV (16:9, 1:1)

720 x 480i at 60Hz - Doublescan (4:3, 8:9)

720 x 480i at 60Hz - Doublescan (16:9, 32:27)

1920 x 1080p at 60Hz - HDTV (16:9, 1:1) [Native]

NB: NTSC refresh rate = (Hz*1000)/1001


CE audio data (formats supported)

LPCM 2-channel, 16/20/24 bit depths at 32/44/48 kHz


CE speaker allocation data

Channel configuration.... 2.0

Front left/right......... Yes

Front LFE................ No

Front center............. No

Rear left/right.......... No

Rear center.............. No

Front left/right center.. No

Rear left/right center... No

Rear LFE................. No


CE vendor specific data (VSDB)

IEEE registration number. 0x000C03

CEC physical address..... 2.0.0.0

Supports AI (ACP, ISRC).. Yes

Supports 48bpp........... No

Supports 36bpp........... Yes

Supports 30bpp........... Yes
Supports YCbCr 4:4:4..... Yes

Supports dual-link DVI... No

Maximum TMDS clock....... 225MHz
 
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