On Thu, 25 Nov 2021 20:43:19 +0000 "Shankar, Uma" <uma.shankar@xxxxxxxxx> wrote: > > -----Original Message----- > > From: Harry Wentland <harry.wentland@xxxxxxx> > > Sent: Tuesday, November 23, 2021 8:35 PM > > To: Shankar, Uma <uma.shankar@xxxxxxxxx>; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; dri- > > devel@xxxxxxxxxxxxxxxxxxxxx > > Cc: ville.syrjala@xxxxxxxxxxxxxxx; ppaalanen@xxxxxxxxx; brian.starkey@xxxxxxx; > > sebastian@xxxxxxxxxxxxxxxxx; Shashank.Sharma@xxxxxxx > > Subject: Re: [RFC v2 01/22] drm: RFC for Plane Color Hardware Pipeline > > > > > > > > On 2021-09-06 17:38, Uma Shankar wrote: > > > This is a RFC proposal for plane color hardware blocks. > > > It exposes the property interface to userspace and calls out the > > > details or interfaces created and the intended purpose. > > > > > > Credits: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > Signed-off-by: Uma Shankar <uma.shankar@xxxxxxxxx> > > > --- > > > Documentation/gpu/rfc/drm_color_pipeline.rst | 167 > > > +++++++++++++++++++ > > > 1 file changed, 167 insertions(+) > > > create mode 100644 Documentation/gpu/rfc/drm_color_pipeline.rst > > > > > > diff --git a/Documentation/gpu/rfc/drm_color_pipeline.rst > > > b/Documentation/gpu/rfc/drm_color_pipeline.rst > > > new file mode 100644 > > > index 000000000000..0d1ca858783b > > > --- /dev/null > > > +++ b/Documentation/gpu/rfc/drm_color_pipeline.rst > > > @@ -0,0 +1,167 @@ > > > +================================================== > > > +Display Color Pipeline: Proposed DRM Properties > > > +================================================== > > > + > > > +This is how a typical display color hardware pipeline looks like: > > > + +-------------------------------------------+ > > > + | RAM | > > > + | +------+ +---------+ +---------+ | > > > + | | FB 1 | | FB 2 | | FB N | | > > > + | +------+ +---------+ +---------+ | > > > + +-------------------------------------------+ > > > + | Plane Color Hardware Block | > > > + +--------------------------------------------+ > > > + | +---v-----+ +---v-------+ +---v------+ | > > > + | | Plane A | | Plane B | | Plane N | | > > > + | | DeGamma | | Degamma | | Degamma | | > > > + | +---+-----+ +---+-------+ +---+------+ | > > > + | | | | | > > > + | +---v-----+ +---v-------+ +---v------+ | > > > + | |Plane A | | Plane B | | Plane N | | > > > + | |CSC/CTM | | CSC/CTM | | CSC/CTM | | > > > + | +---+-----+ +----+------+ +----+-----+ | > > > + | | | | | > > > + | +---v-----+ +----v------+ +----v-----+ | > > > + | | Plane A | | Plane B | | Plane N | | > > > + | | Gamma | | Gamma | | Gamma | | > > > + | +---+-----+ +----+------+ +----+-----+ | > > > + | | | | | > > > + +--------------------------------------------+ > > > ++------v--------------v---------------v-------| > > > +|| || > > > +|| Pipe Blender || > > > ++--------------------+------------------------+ > > > +| | | > > > +| +-----------v----------+ | > > > +| | Pipe DeGamma | | > > > +| | | | > > > +| +-----------+----------+ | > > > +| | Pipe Color | > > > +| +-----------v----------+ Hardware | > > > +| | Pipe CSC/CTM | | > > > +| | | | > > > +| +-----------+----------+ | > > > +| | | > > > +| +-----------v----------+ | > > > +| | Pipe Gamma | | > > > +| | | | > > > +| +-----------+----------+ | > > > +| | | > > > ++---------------------------------------------+ > > > + | > > > + v > > > + Pipe Output > > > + > > > > This diagram defines what happens before and after the blending space but did > > where does scaling fit into it? Scaling can look different when performed in linear or > > non-linear space so I think it is important to define where in the pipeline it sits. > > > > In my view scaling would happen between plane degamma and plane CSC. > > Yeah we can add scaling as well to make it clear. Scaling ideally should happen after > Degamma. In intel's case it is after the CSC. Btw. are you aware that if a plane has an alpha channel which is used for pixel coverage (i.e. shape anti-aliasing), then non-nearest sampling and therefore also scaling must operate on alpha pre-multiplied optical (linear) values? For the best results, of course. So after degamma indeed, but you cannot degamma with pre-multiplied alpha, yet scaling should use pre-multiplied alpha. Thanks, pq
Attachment:
pgpX_2KU_LdIc.pgp
Description: OpenPGP digital signature
