deband grain has input video resolution size

[kokoko3k]

Important Information

• mpv version: mpv 0.34.1-dirty
• Linux Distribution and Version: Archlinux/rolling
• Source of the mpv binary: Archlinux package
• Window Manager and version: kwin_x11 5.22.5
• GPU driver and version: nvidia-495.46
• Possible screenshot or video of visual glitches:
  

Reproduction steps

Try to play a video which is lower than resolution of your screen with debanding active:
mpv https://0x0.st/ooiM.png --image-display-duration=inf --deband --deband-grain=4096 --fs

See how dither behaves better:
mpv https://0x0.st/ooiM.png --image-display-duration=inf --dither-depth=2 --fs

OFC playing screen resolution videos (or prescaling to screen size) works ok with debanding:
mpv https://0x0.st/ooiM.png --image-display-duration=inf --vf=scale=1920:-1 --deband --deband-grain=4096 --fs

Expected behavior

Debanding grain should have screen pixel size.

Actual behavior

Debanding grain has input video pixel size.

Log file

https://0x0.st/ooiB.txt

Sample files

256x122 BW gradient: https://0x0.st/ooiM.png

[haasn]

This is expected and by design. If you would prefer to have grain at screen resolution, I would recommend disabling --deband-grain and using a shader like this one. (Change LUMA to SCALED)

[kokoko3k]

Ok thanks.