Variety download size restriction seems not HiDPI aware

[Forge64]

On a fresh reinstall of Ubuntu 19.04 on my laptop, added Variety from the Universe repo, (0.7.1). Configured Variety to download only landscape and only 80% or greater of screen resolution. Screen is 3840x2160, set for 200% scaling, and Variety is downloading ~1920x1080 wallpapers, even when higher resolutions are available. This seems to affect all the download source locations.

Please let me know how to get more information for you to use.

[peterlevi]

Let's check this, what does this command return on your machine?
python3 -c "from gi.repository import Gdk; s = Gdk.Screen.get_default(); print(s.get_width(), s.get_height())"

But even if this check behaves correctly, the size restriction is automatically relaxed if Variety cannot find enough images meeting the criteria, and 80% of your resolution is actually really huge - most wallpapers available in Variety's sources are not that big, so it will almost certainly be downloading whatever bigger images are available, fullhd being a very common resolution.

With Wallhaven specifically, and to some extent Flickr and Reddit you could add some hand-crafted custom sources which contain only images in the proper resolution. The default sources of Variety are not tailored for this.

[Forge64]

I apologize, I didn't see the notification of comment. Results below seem to indicate the screen is seen as FHD, but it is UHD with 200% scaling;

forge@Zbookbuntu:~$ python3 -c "from gi.repository import Gdk; s = Gdk.Screen.get_default(); print(s.get_width(), s.get_height())"
-c:1: PyGIWarning: Gdk was imported without specifying a version first. Use gi.require_version('Gdk', '3.0') before import to ensure that the right version gets loaded.
-c:1: DeprecationWarning: Gdk.Screen.get_width is deprecated
-c:1: DeprecationWarning: Gdk.Screen.get_height is deprecated
1920 1080
forge@Zbookbuntu:~$ 

[Forge64]

forge@Zbookbuntu:~$ inxi -G
Graphics:  Device-1: Intel HD Graphics 530 driver: i915 v: kernel 
           Device-2: NVIDIA GM107GLM [Quadro M1000M] driver: N/A 
           Display: x11 server: X.Org 1.20.5 driver: modesetting,nvidia unloaded: fbdev,nouveau,vesa 
           resolution: 3840x2160~60Hz 
           OpenGL: renderer: Mesa DRI Intel HD Graphics 530 (Skylake GT2) v: 4.5 Mesa 19.1.6 
forge@Zbookbuntu:~$ 

[bmn001]

I'm seeing this same behavior. I've set Variety to download "100% of the screen resolution" images.

I'm running a 3840x2160 4k monitor (at 100% scale), yet Variety keeps grabbing 1920x1280 and similar images and blowing them up.

The result is some very pixellated/blurry wallpapers on this 43" monitor.

A bit frustrating, and it defeats the purpose of using Variety as a low-effort way to showcase this 4k display. :)

[Tamas-Toth-ebola]

Hi!

I can confirm a same like behaviour. On Ubuntu 21.04 (with Ubuntu's stock Gnome) and Variety 0.8.5 with my 24" 4k monitor which scaled at 200%, the unsplash.com downloaded wallpapers are however not exactly 1920px width, but constant 2304px width which is fram from the required minimum 3840px what is the native resolution of the monitor.

Sadly the mentioned Python command give back wrong results at least not clearly DPI awareness:

$ python3 -c "from gi.repository import Gdk; s = Gdk.Screen.get_default(); print(s.get_width(), s.get_height())"
<string>:1: PyGIWarning: Gdk was imported without specifying a version first. Use gi.require_version('Gdk', '3.0') before import to ensure that the right version gets loaded.
<string>:1: DeprecationWarning: Gdk.Screen.get_width is deprecated
<string>:1: DeprecationWarning: Gdk.Screen.get_height is deprecated
1920 1080

While the physical resolution is really 4k:

$ xrandr | grep "primary"
DP-2 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 525mm x 295mm

Because of the problem, all the Variety handled wallpapers are blurry on HDPI screens.

Can anybody help on it please?

This is somehow relevant (wrong target resolutions in Variety with HDPI screens) to this another HDPI problem: #429
where I can confirm also the same. If I set my screen scale to 100% the resulted images will be 3840*2160, but if I set to scale to 200%, the result will be 'low res' images with blurry clock, and quotes. Check the following examples in full res:

[Tamas-Toth-ebola]

Hi!

Are there anybody with a clue/competence to fix it?

[Tamas-Toth-ebola]

With the help of the screeninfo Python package we can get correct values:

from screeninfo import get_monitors
 
for monitor in get_monitors():
    width = monitor.width
    height = monitor.height
 
    print(str(width) + '×' + str(height))

Result (on a 4k monitor with HDPI/2× screen scale):

3840×2160

Is it possible to change Variety's corresponding query to something similar above?

[Tamas-Toth-ebola]

Ok!

After a bit digging:

• Seems that the Gdk.Screen.get_default().get_width() function gives us wrong screen width results on HDPI monitors, used in variety/Util.py.
  • (At least in my case the variety/plugins/builtin/downloaders/UnsplashDownloader.py uses indirectly that function (through the internal get_screen_with() function), and becase its processed result (int(Util.get_screen_width() * 1.2)) of that call is 2304, all my download images are 2304px width.)
• So the function call in the 'downloader' refer the following function in Util.py:

  def get_screen_width():
    return Gdk.Screen.get_default().get_width()

• Beyond that we have problems with the results, we also got a warning with it: Gdk.Screen.get_width is deprecated
• Let's check, what happens with constant but good value for get_screen_with() function...

  def get_screen_width():
      return 3840

  ...and the result... I wonder it for some minutes as I did not get downloaded images for a first try, and because of it - before any further debugging - I started to think of a resolution limitation with the applied API key... but after some minutes my images started to download... aaaaand?! Tudum... in a good size (in 4608px).

For now, for me it's enough, as I have no more time for it now. But in the next cycle we just need to change that function call to something better (maybe to what I refered before).

[Tamas-Toth-ebola]

@nlpsuge hello. As I'm very far from know anything about Python could you please help in my digging above?

Maybe as a 'latest' contributor and releaser of the project you could change all the Gdk.Screen.* calls in the app, to the screeninfo method that I mentioned?

With that we could jump over the 'deprecatid' problems and could handle the HDPI screens (platform independently).

Lot of thanks for your efforts in advance!

[nlpsuge]

@Tamas-Toth-ebola
Really sorry for the late response. I've been busy recently.

My contribution to this project was two years ago at the beginning of the Covid-19 pandemic actually. And the author modified and merged it to the main branch recently.

We can use Gdk.Display.get_default().get_monitor(0).get_geometry().width in Gtk 3 instead of the deprecated Gdk.Screen.get_default().get_width().

variety/variety/plugins/builtin/downloaders/UnsplashDownloader.py

Lines 99 to 101 in 45b22b0

	image_url = item["urls"]["full"] + "&w={}".format(
	max(1980, int(Util.get_screen_width() * 1.2))
	)

Looks we should take into account the scale factor, right? Is it enough that modify the line 100 to something like this:

max(1980, int(Util.get_screen_width() * screen_factor * 1.2))

in which the screen_factor should be 2 in your case. So it is equivalent to max(1980, 1920 * 2 * 1.2), the final result is 4608. Is this right for you?

P.S. I don't have HDPI screens, so I can't test this issue precisely. I'm not sure I can really help with this issue. :)