On Mon, 16 Jun 2025 11:30:23 +0000 "Borah, Chaitanya Kumar" <chaitanya.kumar.bo...@intel.com> wrote:
> > -----Original Message----- > > From: Alex Hung <alex.h...@amd.com> > > Sent: Wednesday, April 30, 2025 6:41 AM > > To: dri-de...@lists.freedesktop.org; amd-...@lists.freedesktop.org > > Cc: wayland-devel@lists.freedesktop.org; harry.wentl...@amd.com; > > alex.h...@amd.com; leo....@amd.com; ville.syrj...@linux.intel.com; > > pekka.paala...@collabora.com; cont...@emersion.fr; m...@igalia.com; > > jad...@redhat.com; sebastian.w...@redhat.com; > > shashank.sha...@amd.com; ago...@nvidia.com; jos...@froggi.es; > > mdaen...@redhat.com; aleix...@kde.org; xaver.h...@gmail.com; > > victo...@system76.com; dan...@ffwll.ch; Shankar, Uma > > <uma.shan...@intel.com>; quic_nas...@quicinc.com; > > quic_cbr...@quicinc.com; quic_abhin...@quicinc.com; mar...@marcan.st; > > liviu.du...@arm.com; sashamcint...@google.com; Borah, Chaitanya > > Kumar <chaitanya.kumar.bo...@intel.com>; louis.chau...@bootlin.com; > > Daniel Stone <dani...@collabora.com> > > Subject: [PATCH V9 16/43] drm/colorop: Add 3x4 CTM type > > > > From: Harry Wentland <harry.wentl...@amd.com> > > > > This type is used to support a 3x4 matrix in colorops. A 3x4 matrix uses the > > last column as a "bias" column. Some HW exposes support for 3x4. The > > calculation looks like: > > > > out matrix in > > |R| |0 1 2 3 | | R | > > |G| = |4 5 6 7 | x | G | > > |B| |8 9 10 11| | B | > > |1.0| > > > > This is also the first colorop where we need a blob property to program the > > property. For that we'll introduce a new DATA property that can be used by > > all > > colorop TYPEs requiring a blob. The way a DATA blob is read depends on the > > TYPE of the colorop. > > > > We only create the DATA property for property types that need it. > > Is there any value to adding pre-offsets [1] in the uapi? > > |R/Cr| | c0 c1 c2 | ( |R/Cr| |preoff0| ) |postoff0| > |G/Y | = | c3 c4 c5 | x ( |G/Y | + |preoff1| ) + |postoff1| > |B/Cb| | c6 c7 c8 | ( |B/Cb| |preoff2| ) |postoff2| > > Handling limited range values is one use case that I can think of. Hi, in the mathematical sense, no. A pre-offset can always be converted into a post-offset by multiplying it with the 3x3 matrix (and adding to the existing post-offset). This can be pre-computed, no need to do it separately for every pixel. For hardware reasons, I have no idea. > [1] > https://cgit.freedesktop.org/drm-tip/tree/drivers/gpu/drm/i915/display/intel_color.c#n112 > Thanks, pq
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