Resolution has a wrong aspect ratio (16:9 squashed into 4:3)
by tauro_kpo from LinuxQuestions.org on (#6G5E7)
I'm trying to set up a custom resolution (1024x576) on the old IGP Unichrome (Openchrome X.Org driver), running on Debian Squeeze.
I add the gtf or cvt Modeline to the xorg.conf, but when I set it, my screen displays it in a 4:3 aspect ratio and with very poor definition, it looks squashed. I can stretch it by changing the settings in the monitor itself, but it's the same low quality image, only that now it's stretched. It looks horrible. The monitor detects it as 720x576 60Hz, so it's really 5:4.
Interestingly, I took a screen capture and when I opened it later (on a normal resolution) it looks fine.
I tried to do this on a few other computers to see what would happen. One (I think it was nvidia) also showed the image with a bad aspect ratio but the third one (Intel IGP) showed the correct aspect ratio after adding the option "ModeValidation" "AllowNonEdidModes" to the xorg.conf.
So, what's going on here?
Is this a limitation of the driver or maybe there's something I'm not configuring correctly? There's a lot I ignore about what goes down under the hood when you change a resolution. I would appreciate any help to fix this or just to understand what's going on.
By the way, I'm using an LCD display with a VGA standard cable on the Unichrome. The Openchrome driver is capable of displaying 1280x720 or 1920x1080 resolutions perfectly, albeit not as fast as 1024x576 would be.
I add the gtf or cvt Modeline to the xorg.conf, but when I set it, my screen displays it in a 4:3 aspect ratio and with very poor definition, it looks squashed. I can stretch it by changing the settings in the monitor itself, but it's the same low quality image, only that now it's stretched. It looks horrible. The monitor detects it as 720x576 60Hz, so it's really 5:4.
Interestingly, I took a screen capture and when I opened it later (on a normal resolution) it looks fine.
I tried to do this on a few other computers to see what would happen. One (I think it was nvidia) also showed the image with a bad aspect ratio but the third one (Intel IGP) showed the correct aspect ratio after adding the option "ModeValidation" "AllowNonEdidModes" to the xorg.conf.
So, what's going on here?
Is this a limitation of the driver or maybe there's something I'm not configuring correctly? There's a lot I ignore about what goes down under the hood when you change a resolution. I would appreciate any help to fix this or just to understand what's going on.
By the way, I'm using an LCD display with a VGA standard cable on the Unichrome. The Openchrome driver is capable of displaying 1280x720 or 1920x1080 resolutions perfectly, albeit not as fast as 1024x576 would be.