Blurry image when "HDMI Support" Data Block is enabled

[a_netanel]

This is a years old problem that I have, and only now found the incentive to dig deeper and attempt to solve.

I have a GA-MA78GM-SH2 motherboard, with ATI 3200 onboard GPU. It is connected to a Samsung Plasma TV (PS42A450) by HDMI cable. In BIOS it is possible to configure the output to be either DSUB/HDMI, or DSUB/DVI. When HDMI mode is selected, audio is delivered to the screen and Windows shows that the HDMI audio device is plugged in and working. When DVI mode is selected, audio is not working - as expected. Of course in both settings I'm using the same HDMI cable.

The problem is that when using the HDMI setting, the image is a bit blurry. Whereas in DVI mode it is razor sharp.
I double and triple checked that the problem is not in the TV's setting and I can almost 100% guarantee that it is not the TV's fault.

Upon diving a bit deeper with CRU, I noticed that I can get sharp image in HDMI mode as well, as long as the extension block does NOT contain the "HDMI Support" Data Block. But, that also disables audio and Windows shows the HDMI Audio Device as unplugged. Once this Data Block is added, no matter what settings inside it I tried, the image becomes blurry, but I get audio back...

I would really appreciate any help.
Thanks!

[ToastyX]

(08-17-2016 09:16 PM)a_netanel Wrote:  The problem is that when using the HDMI setting, the image is a bit blurry. Whereas in DVI mode it is razor sharp.
I double and triple checked that the problem is not in the TV's setting and I can almost 100% guarantee that it is not the TV's fault.

Upon diving a bit deeper with CRU, I noticed that I can get sharp image in HDMI mode as well, as long as the extension block does NOT contain the "HDMI Support" Data Block. But, that also disables audio and Windows shows the HDMI Audio Device as unplugged. Once this Data Block is added, no matter what settings inside it I tried, the image becomes blurry, but I get audio back...

It definitely sounds like the TV handles HDMI and DVI signals differently. First, try the different pixel formats in the AMD/Catalyst Control Center. You'll need YCbCr 4:4:4 or RGB 4:4:4 for the sharpest picture, and the TV may treat them differently. Also, check the scaling options and make sure it's set to 0% overscan, and make sure overscan is disabled in the TV as well.

If that doesn't work, try adding a detailed resolution with the "LCD reduced" timing option and make sure the same resolution doesn't appear anywhere else. Some TVs will treat that as a PC resolution and turn off image processing. If that doesn't help, there's nothing you can do. This is a limitation of the TV.

[a_netanel]

(08-18-2016 02:08 AM)ToastyX Wrote:  It definitely sounds like the TV handles HDMI and DVI signals differently. First, try the different pixel formats in the AMD/Catalyst Control Center. You'll need YCbCr 4:4:4 or RGB 4:4:4 for the sharpest picture, and the TV may treat them differently. Also, check the scaling options and make sure it's set to 0% overscan, and make sure overscan is disabled in the TV as well.

If that doesn't work, try adding a detailed resolution with the "LCD reduced" timing option and make sure the same resolution doesn't appear anywhere else. Some TVs will treat that as a PC resolution and turn off image processing. If that doesn't help, there's nothing you can do. This is a limitation of the TV.

Thank you for you reply!

Sadly, the driver is already set on RGB 4:4:4 and no scaling or overscan whatsoever.
The TV detects the 1:1 pixel ratio. The TV manual says to connect computers to a specific HDMI port, and when a computer resolution is detected, most of the image processing is disabled.

I tried to use the LCD reduced template, which does make the image sharp, but disables audio, and in CCC it looks like it is detected as DVI.