Re: [RFC][PATCH 0/5] Introduce drm scaling filter property

From: Pekka Paalanen
Date: Fri Mar 13 2020 - 06:35:38 EST


On Thu, 12 Mar 2020 18:01:12 +0200
Ville SyrjÃlà <ville.syrjala@xxxxxxxxxxxxxxx> wrote:

> On Thu, Mar 12, 2020 at 03:37:03PM +0000, Laxminarayan Bharadiya, Pankaj wrote:
> >
> >
> > > -----Original Message-----
> > > From: Ville SyrjÃlà <ville.syrjala@xxxxxxxxxxxxxxx>
> > > Sent: 12 March 2020 19:35
> > > To: Laxminarayan Bharadiya, Pankaj
> > > <pankaj.laxminarayan.bharadiya@xxxxxxxxx>
> > > Cc: jani.nikula@xxxxxxxxxxxxxxx; daniel@xxxxxxxx; intel-
> > > gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; airlied@xxxxxxxx;
> > > maarten.lankhorst@xxxxxxxxxxxxxxx; tzimmermann@xxxxxxx;
> > > mripard@xxxxxxxxxx; mihail.atanassov@xxxxxxx; linux-
> > > kernel@xxxxxxxxxxxxxxx; Nautiyal, Ankit K <ankit.k.nautiyal@xxxxxxxxx>
> > > Subject: Re: [RFC][PATCH 0/5] Introduce drm scaling filter property
> > >
> > > On Tue, Feb 25, 2020 at 12:35:40PM +0530, Pankaj Bharadiya wrote:
> > > > Integer scaling (IS) is a nearest-neighbor upscaling technique that
> > > > simply scales up the existing pixels by an integer (i.e., whole
> > > > number) multiplier. Nearest-neighbor (NN) interpolation works by
> > > > filling in the missing color values in the upscaled image with that of
> > > > the coordinate-mapped nearest source pixel value.
> > > >
> > > > Both IS and NN preserve the clarity of the original image. In
> > > > contrast, traditional upscaling algorithms, such as bilinear or
> > > > bicubic interpolation, result in blurry upscaled images because they
> > > > employ interpolation techniques that smooth out the transition from
> > > > one pixel to another. Therefore, integer scaling is particularly
> > > > useful for pixel art games that rely on sharp, blocky images to
> > > > deliver their distinctive look.
> > > >
> > > > Many gaming communities have been asking for integer-mode scaling
> > > > support, some links and background:
> > > >
> > > > https://software.intel.com/en-us/articles/integer-scaling-support-on-i
> > > > ntel-graphics http://tanalin.com/en/articles/lossless-scaling/
> > > > https://community.amd.com/thread/209107
> > > > https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/1002
> > > > /feature-request-nonblurry-upscaling-at-integer-rat/
> > > >
> > > > This patch series -
> > > > - Introduces new scaling filter property to allow userspace to
> > > > select the driver's default scaling filter or Nearest-neighbor(NN)
> > > > filter for scaling operations on crtc/plane.
> > > > - Implements and enable integer scaling for i915
> > > >
> > > > Userspace patch series link: TBD.
> > >
> > > That needs to be done or this will go nowhere.
> >
> > Yes, Sameer is working on enabling this feature in Kodi.
> > Sameer, please share link here once you post patches.
>
> And who is doing it for other stuff? I think this would be most useful
> for games/emulators and such so IMO we should find a way to get it to
> the hands of users doing those things.
>

Hi,

FWIW, being able to tell KMS to use nearest-neighbor filtering could be
useful for
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/394
as a follow-up.


Thanks,
pq

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