Very Odd Issue in Red Channel on HDTV over DVI->HDMI

jamonterrell · 03-26-07, 02:32 AM

Hi,

The problem appears to be limited to my software/settings/drivers under linux. The same hardware functions properly under Windows. Imagine a gradient in red from 0 to 255. The gradient appears correct from values 0-15. Once you hit value 16, it's observed to be the same color as somewhere around value 8. This phenomenon continues repeating itself at every 16 shade segment all the way to pure bright red. This is only observed in the Red Channel, Green and Blue are both perfectly normal. In addition, this only occurs on my HDTV, which, as I mentioned before, works perfectly fine in Windows over the same DVI->HDMI cable. I've attached some shots of the same gradient taken with my Digital camera on both my LCD and my HDTV. Please forgive the bad shots, it's very difficult to take pictures of display devices. Though the blue looks slightly wonky in the photograph, it appears fine in person. The Red effect is actually more obvious in person than the photograph displays.

I've also attached my Xorg log and my Xorg.conf files. I've tried many things for the Xorg.conf, which is why i have so many strange settings on it now... all settings have the same effect.

Thanks for any help you can provide,
Jamon Terrell

xorg.conf.txt

Xorg.0.log.txt

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jamonterrell · 03-26-07, 06:31 PM

attaching Nvidia Bug Report, sorry for leaving that off the first post.
nvidia-bug-report.log.zip

netllama · 03-26-07, 06:43 PM

1.0-9631 is no longer supported for your GPU. Does this problem persist with 1.0-9755?

Also, is this problem not present with the 'vesa' or 'nv' X drivers?

thanks,
Lonni

jamonterrell · 03-27-07, 08:15 PM

Thanks for the reply, I'll try the three suggestions you made and let you know what I find.

jamonterrell · 04-06-07, 06:07 PM

I think either I have a bad DVI port or it's just not working under linux. It doesnt' seem to work at all when my LCD is hooked up to it. It used to work when I ran windows a few months ago, so either the port went bad between then and now, or it's just not working at all in linux. I'll install windows on another disk and give it a try sometime.

Thanks for all your input.

Jamon

03-26-07, 02:32 AM	#1
jamonterrell Registered User Join Date: Mar 2007 Posts: 4	Very Odd Issue in Red Channel on HDTV over DVI->HDMI Hi, The problem appears to be limited to my software/settings/drivers under linux. The same hardware functions properly under Windows. Imagine a gradient in red from 0 to 255. The gradient appears correct from values 0-15. Once you hit value 16, it's observed to be the same color as somewhere around value 8. This phenomenon continues repeating itself at every 16 shade segment all the way to pure bright red. This is only observed in the Red Channel, Green and Blue are both perfectly normal. In addition, this only occurs on my HDTV, which, as I mentioned before, works perfectly fine in Windows over the same DVI->HDMI cable. I've attached some shots of the same gradient taken with my Digital camera on both my LCD and my HDTV. Please forgive the bad shots, it's very difficult to take pictures of display devices. Though the blue looks slightly wonky in the photograph, it appears fine in person. The Red effect is actually more obvious in person than the photograph displays. I've also attached my Xorg log and my Xorg.conf files. I've tried many things for the Xorg.conf, which is why i have so many strange settings on it now... all settings have the same effect. Thanks for any help you can provide, Jamon Terrell xorg.conf.txt Xorg.0.log.txt

03-26-07, 06:31 PM	#2
jamonterrell Registered User Join Date: Mar 2007 Posts: 4	Re: Very Odd Issue in Red Channel on HDTV over DVI->HDMI attaching Nvidia Bug Report, sorry for leaving that off the first post. nvidia-bug-report.log.zip

03-26-07, 06:43 PM	#3
netllama NVIDIA Corporation Join Date: Dec 2004 Posts: 8,763	Re: Very Odd Issue in Red Channel on HDTV over DVI->HDMI 1.0-9631 is no longer supported for your GPU. Does this problem persist with 1.0-9755? Also, is this problem not present with the 'vesa' or 'nv' X drivers? thanks, Lonni

03-27-07, 08:15 PM	#4
jamonterrell Registered User Join Date: Mar 2007 Posts: 4	Re: Very Odd Issue in Red Channel on HDTV over DVI->HDMI Thanks for the reply, I'll try the three suggestions you made and let you know what I find.

04-06-07, 06:07 PM	#5
jamonterrell Registered User Join Date: Mar 2007 Posts: 4	Re: Very Odd Issue in Red Channel on HDTV over DVI->HDMI I think either I have a bad DVI port or it's just not working under linux. It doesnt' seem to work at all when my LCD is hooked up to it. It used to work when I ran windows a few months ago, so either the port went bad between then and now, or it's just not working at all in linux. I'll install windows on another disk and give it a try sometime. Thanks for all your input. Jamon