Bad case of dithering with ION, HDMI and HDTV

[madmalkav]

The situation is as follow:

Ubuntu 64 bits running on Packer Bell Mini -rebranded Acer Revo-, last stable Nvidia driver.

VGA conection to HDTV gives good 1080p image. HDMI conection to HDTV gives annoyingly big dithering. Other HDMI source, XBOX 360, with the same HDMI cable works ok. The PC conected to a PC monitor through HDMI doesn't have the same problem.

I'm totally at lost here, any idea will be welcome. Thanks for reading.

[danix]

Try disabling dithering by adding the following line to xorg.conf in the "Device" section:

Option "RegistryDwords" "DitherAlgo8=3; DitherAlgo6=3"

[madmalkav]

Didn't work

I have been paying more attention and the dither happens from the very PC boot time. I didn't had that problem some weeks ago, I moved the PC to other room and used on a PC monitor for that weeks, and wasn't aware of the problem until I put it back on TV. As I said before, it works ok on a PC monitor through HDMI, also I don't have this problem with other HDMI sources. Resolution is the display native. Really weird.

[madmalkav]

For what I have been reading on some forums and websites, this probably can be caused by graphic card detecting it is connected to a TV through the EDID information and trying to optimize the image for that kind of display. Some people have made an EDID dump and modified it to avoid the issue, but that seems to disable HDMI audio and I cannot afford that. Any idea if that "TV Mode" can be disabled anyway in the config?

[madmalkav]

Little bump to this.