Aspect Ratio Support Within The Linux Kernel's DRM Code Revised

[phoronix]

Phoronix: Aspect Ratio Support Within The Linux Kernel's DRM Code Revised

Intel open-source developer Ankit Nautiyal has restarted work on adding picture aspect ratio support to the Linux kernel's Direct Rendering Manager (DRM) layer...

http://www.phoronix.com/scan.php?page=news_item&px=DRM-Aspect-Ratio-Revised

[duby229]

Does this mean that if I have two different monitors plugged in with different native resolutions, that each monitor will display the console framebuffer at the correct resolution for that screen?

[hjahre]

Does this mean that if I have two different monitors plugged in with different native resolutions, that each monitor will display the console framebuffer at the correct resolution for that screen?

Probably not. This is support for correctly supporting aspect ratios. Some years ago TV's and monitors had non square pixels with the same aspect as the monitor, even though the resolution was the same for 4:3 and 16:9. If you viewed a 4:3 image on a 16:9 screen, the image would be stretched. Similarly, an 16:9 image on a 4:3 screen, would result in a squashed image as opposed to the black borders at top and bottom.

I guess it is software (like xrandr) that handles image aspects in Linux today, not hardware (as the TV or monitor). But this I do not know for certain

[caligula]

Does this mean that if I have two different monitors plugged in with different native resolutions, that each monitor will display the console framebuffer at the correct resolution for that screen?

Console framebuffer can already use any correct resolution, e.g. the native full resolution. What is the correct resolution? How does the machine determine it?

[dungeon]

Does this mean that if I have two different monitors plugged in with different native resolutions, that each monitor will display the console framebuffer at the correct resolution for that screen?

It means this, from abandonware FGRX for example... currently on opensource drivers you are always stretched or use display, this is to use GPU and give you option to maintain (keep) aspect, to stretch image (that is only what you have now) or centered - that is to use original res just in fullscreen. Point is to keep original image aspect whatever your display is, does not matter black bars on sides, up-down or all around.

[duby229]

Probably not. This is support for correctly supporting aspect ratios. Some years ago TV's and monitors had non square pixels with the same aspect as the monitor, even though the resolution was the same for 4:3 and 16:9. If you viewed a 4:3 image on a 16:9 screen, the image would be stretched. Similarly, an 16:9 image on a 4:3 screen, would result in a squashed image as opposed to the black borders at top and bottom.

I guess it is software (like xrandr) that handles image aspects in Linux today, not hardware (as the TV or monitor). But this I do not know for certain

Ah ok, that makes sense. TY.

[duby229]

Console framebuffer can already use any correct resolution, e.g. the native full resolution. What is the correct resolution? How does the machine determine it?

Well, right now it seems like the console framebuffer uses both monitors native resolution, but the splash screen will only use the lower of the two resolutions. So the screen with the lower resolution appears correct, but the screen with the higher resolution appears wrong. I never found any configuration anywhere to fix it. But it appears that this thread is not related to that problem.