[RFC PATCH v4 00/42] Color Pipeline API w/ VKMS
Melissa Wen
mwen at igalia.com
Wed Jun 5 10:04:52 UTC 2024
On 02/26, Harry Wentland wrote:
> This is an RFC set for a color pipeline API, along with a sample
> implementation in VKMS. All the key API bits are here. VKMS now
> supports two named transfer function colorops and two matrix
> colorops. We have IGT tests that check all four of these colorops
> with a pixel-by-pixel comparison that checks that these colorops
> do what we expect them to do with a +/- 1 8 bpc code point margin.
>
> The big new change with v4 is the addition of an amdgpu color
> pipeline, for all AMD GPUs with DCN 3 and newer. Amdgpu now support
> the following:
>
> 1. 1D Curve EOTF
> 2. 3x4 CTM
> 3. Multiplier
> 4. 1D Curve Inverse EOTF
> 5. 1D LUT
> 6. 1D Curve EOTF
> 7. 1D LUT
>
> The supported curves for the 1D Curve type are:
> - sRGB EOTF and its inverse
> - PQ EOTF, scaled to [0.0, 125.0] and its inverse
> - BT.2020/BT.709 OETF and its inverse
So, as we talked in the 2024 Linux Display Next Hackfest, I hacked
`drm_info` to show the KMS color pipeline properties. You can find the
experimental-and-ugly code here:
- https://gitlab.freedesktop.org/mwen/drm_info/-/merge_requests/1
It depends on updating libdrm [1] and you will only see something if you
use a custom kernel with this series applied.
After checking the output, I missed a kind of Default or "Identity"
curve for the `CURVE_1D_TYPE` enum. I understand that if the color
operation is set bypass, we can ignore all property values, but I didn't
find a similar approach on plane properties, so it looks weird to me:
└───"CURVE_1D_TYPE" (atomic): enum {sRGB Inverse EOTF, BT.2020 OETF, PQ 125 Inverse EOTF} = invalid (0)
Another thing that caught my attention was the size property for 1D
Curve Custom LUT, that I expected a similar setup to CRTC 1D LUTs:
└───"GAMMA_LUT_SIZE" (immutable): range [0, UINT32_MAX] = 4096
But I got:
├───"SIZE" (atomic): range [4096, 4096] = 4096
Any thoughts?
Anyway, see below an example of `drm_info` output on AMD DCN301 for a
given Overlay/Primary plane without userspace usage of the properties:
│ └───"COLOR_PIPELINE" (atomic): enum {Bypass, Color Pipeline 265} = Bypass
│ ├───Bypass
│ └───Color Pipeline 265
│ ├───Color Operation 265
│ │ ├───"TYPE" (immutable): enum {1D Curve, 1D Curve Custom LUT, 3x4 Matrix, Multiplier} = 1D Curve
│ │ ├───"BYPASS" (atomic): range [0, 1] = 1
│ │ └───"CURVE_1D_TYPE" (atomic): enum {sRGB EOTF, BT.2020 Inverse OETF, PQ 125 EOTF} = sRGB EOTF
│ ├───Color Operation 270
│ │ ├───"TYPE" (immutable): enum {1D Curve, 1D Curve Custom LUT, 3x4 Matrix, Multiplier} = 3x4 Matrix
│ │ ├───"BYPASS" (atomic): range [0, 1] = 1
│ │ └───"DATA" (atomic): blob = 0
│ ├───Color Operation 275
│ │ ├───"TYPE" (immutable): enum {1D Curve, 1D Curve Custom LUT, 3x4 Matrix, Multiplier} = Multiplier
│ │ ├───"BYPASS" (atomic): range [0, 1] = 1
│ │ └───"MULTIPLIER" (atomic): range [0, UINT64_MAX] = 0
│ ├───Color Operation 280
│ │ ├───"TYPE" (immutable): enum {1D Curve, 1D Curve Custom LUT, 3x4 Matrix, Multiplier} = 1D Curve
│ │ ├───"BYPASS" (atomic): range [0, 1] = 1
│ │ └───"CURVE_1D_TYPE" (atomic): enum {sRGB Inverse EOTF, BT.2020 OETF, PQ 125 Inverse EOTF} = invalid (0)
│ ├───Color Operation 285
│ │ ├───"TYPE" (immutable): enum {1D Curve, 1D Curve Custom LUT, 3x4 Matrix, Multiplier} = 1D Curve Custom LUT
│ │ ├───"BYPASS" (atomic): range [0, 1] = 1
│ │ ├───"SIZE" (atomic): range [4096, 4096] = 4096
│ │ └───"DATA" (atomic): blob = 0
│ ├───Color Operation 291
│ │ ├───"TYPE" (immutable): enum {1D Curve, 1D Curve Custom LUT, 3x4 Matrix, Multiplier} = 1D Curve
│ │ ├───"BYPASS" (atomic): range [0, 1] = 1
│ │ └───"CURVE_1D_TYPE" (atomic): enum {sRGB EOTF, BT.2020 Inverse OETF, PQ 125 EOTF} = sRGB EOTF
│ └───Color Operation 296
│ ├───"TYPE" (immutable): enum {1D Curve, 1D Curve Custom LUT, 3x4 Matrix, Multiplier} = 1D Curve Custom LUT
│ ├───"BYPASS" (atomic): range [0, 1] = 1
│ ├───"SIZE" (atomic): range [4096, 4096] = 4096
│ └───"DATA" (atomic): blob = 0
It's a WIP and the output still needs to be reviewed. So feel free to
point out any mistake.
BR,
Melissa
>
> Note that the 1st and 5th colorops take the EOTF or Inverse
> OETF while the 3rd colorop takes the Inverse EOTF or OETF.
>
> We are working on two more ops for amdgpu, the HDR multiplier
> and the 3DLUT, which will give us this:
>
> 1. 1D Curve EOTF
> 2. 3x4 CTM
> 3. HDR Multiplier
> 4. 1D Curve Inverse EOTF
> 5. 1D LUT
> 6. 3D LUT
> 7. 1D Curve EOTF
> 8. 1D LUT
>
> This, essentially mirrors the color pipeline used by gamescope
> and presented by Melissa Wen, with the exception of the DEGAM
> LUT, which is not currently used. See
> [1] https://indico.freedesktop.org/event/4/contributions/186/attachments/138/218/xdc2023-TheRainbowTreasureMap-MelissaWen.pdf
>
> After this we'd like to also add the following ops:
> - Scaler (Informational only)
> - Color Encoding, to replace drm_plane's COLOR_ENCODING
> - Color Range, to replace drm_plane's COLOR_RANGE
>
> This patchset is grouped as follows:
> - Patches 1-3: couple general patches/fixes
> - Patches 4-7: introduce kunit to VKMS
> - Patch 7: description of motivation and details behind the
> Color Pipeline API. If you're reading nothing else
> but are interested in the topic I highly recommend
> you take a look at this.
> - Patches 7-27: DRM core and VKMS changes for color pipeline API
> - Patches 28-40: DRM core and amdgpu changes for color pipeline API
>
> VKMS patches could still be improved in a few ways, though the
> payoff might be limited and I would rather focus on other work
> at the moment. The most obvious thing to improve would be to
> eliminate the hard-coded LUTs for identity, and sRGB, and replace
> them with fixed-point math instead.
>
> There are plenty of things that I would like to see here but
> haven't had a chance to look at. These will (hopefully) be
> addressed in future iterations, either in VKMS or amdgpu:
> - Clear documentation for each drm_colorop_type
> - Add custom LUT colorops to VKMS
> - Add pre-blending 3DLUT
> - How to support HW which can't bypass entire pipeline?
> - Add ability to create colorops that don't have BYPASS
> - Can we do a LOAD / COMMIT model for LUTs (and other properties)?
> - read-only scaling colorop which defines scaling taps and position
> - read-only color format colorop to define supported color formats
> for a pipeline
> - named matrices, for things like converting YUV to RGB
>
> IGT tests can be found at
> https://gitlab.freedesktop.org/hwentland/igt-gpu-tools/-/merge_requests/1
>
> IGT patches are also being sent to the igt-dev mailing list.
>
> If you prefer a gitlab MR for review you can find it at
> https://gitlab.freedesktop.org/hwentland/linux/-/merge_requests/5
>
> v4:
> - Add amdgpu color pipeline (WIP)
> - Don't block setting of deprecated properties, instead pass client cap
> to atomic check so drivers can ignore these props
> - Drop IOCTL definitions (Pekka)
> - Use enum property for colorop TYPE (Pekka)
> - A few cleanups to the docs (Pekka)
> - Rework the TYPE enum to name relation to avoid code duplication (Pekka)
> - Add missing function declarations (Chaitanya Kumar Borah)
> - Allow setting of NEXT property to NULL in _set_ function (Chaitanya Kumar Borah)
> - Add helper for creation of pipeline drm_plane property (Pekka)
> - Always create Bypass pipeline (Pekka)
> - A bunch of changes to VKMS kunit tests (Pekka)
> - Fix index in CTM doc (Pekka)
>
> v3:
> - Abandon IOCTLs and discover colorops as clients iterate the pipeline
> - Remove need for libdrm
> - Add color_pipeline client cap and make mutually exclusive with
> COLOR_RANGE and COLOR_ENCODING properties
> - add CTM colorop to VKMS
> - Use include way for kunit testing static functions (Arthur)
> - Make TYPE a range property
> - Move enum drm_colorop_type to uapi header
> - and a bunch of smaller bits that are highlighted in the relevant commit
> description
>
> v2:
> - Rebased on drm-misc-next
> - Introduce a VKMS Kunit so we can test LUT functionality in vkms_composer
> - Incorporate feedback in color_pipeline.rst doc
> - Add support for sRGB inverse EOTF
> - Add 2nd enumerated TF colorop to VKMS
> - Fix LUTs and some issues with applying LUTs in VKMS
>
> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> Cc: Pekka Paalanen <pekka.paalanen at collabora.com>
> Cc: Simon Ser <contact at emersion.fr>
> Cc: Harry Wentland <harry.wentland at amd.com>
> Cc: Melissa Wen <mwen at igalia.com>
> Cc: Jonas Ådahl <jadahl at redhat.com>
> Cc: Sebastian Wick <sebastian.wick at redhat.com>
> Cc: Shashank Sharma <shashank.sharma at amd.com>
> Cc: Alexander Goins <agoins at nvidia.com>
> Cc: Joshua Ashton <joshua at froggi.es>
> Cc: Michel Dänzer <mdaenzer at redhat.com>
> Cc: Aleix Pol <aleixpol at kde.org>
> Cc: Xaver Hugl <xaver.hugl at gmail.com>
> Cc: Victoria Brekenfeld <victoria at system76.com>
> Cc: Sima <daniel at ffwll.ch>
> Cc: Uma Shankar <uma.shankar at intel.com>
> Cc: Naseer Ahmed <quic_naseer at quicinc.com>
> Cc: Christopher Braga <quic_cbraga at quicinc.com>
> Cc: Abhinav Kumar <quic_abhinavk at quicinc.com>
> Cc: Arthur Grillo <arthurgrillo at riseup.net>
> Cc: Hector Martin <marcan at marcan.st>
> Cc: Liviu Dudau <Liviu.Dudau at arm.com>
> Cc: Sasha McIntosh <sashamcintosh at google.com>
> Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah at intel.com>
>
> Alex Hung (10):
> drm/colorop: define a new macro for_each_new_colorop_in_state
> drm/amd/display: Skip color pipeline initialization for cursor plane
> drm/amd/display: Add support for sRGB EOTF in DEGAM block
> drm/amd/display: Add support for sRGB Inverse EOTF in SHAPER block
> drm/amd/display: Add support for sRGB EOTF in BLND block
> drm/colorop: Add 1D Curve Custom LUT type
> drm/amd/display: add shaper and blend colorops for 1D Curve Custom LUT
> drm/amd/display: add 3x4 matrix colorop
> drm/colorop: Add mutliplier type
> drm/amd/display: add multiplier colorop
>
> Harry Wentland (32):
> drm: Don't treat 0 as -1 in drm_fixp2int_ceil
> drm: Add helper for conversion from signed-magnitude
> drm: Correctly round for fixp2int_round
> drm/vkms: Round fixp2int conversion in lerp_u16
> drm/vkms: Create separate Kconfig file for VKMS
> drm/vkms: Add kunit tests for VKMS LUT handling
> drm/vkms: Avoid reading beyond LUT array
> drm/doc/rfc: Describe why prescriptive color pipeline is needed
> drm/colorop: Introduce new drm_colorop mode object
> drm/colorop: Add TYPE property
> drm/colorop: Add 1D Curve subtype
> drm/colorop: Add BYPASS property
> drm/colorop: Add NEXT property
> drm/colorop: Add atomic state print for drm_colorop
> drm/plane: Add COLOR PIPELINE property
> drm/colorop: Add NEXT to colorop state print
> drm/vkms: Add enumerated 1D curve colorop
> drm/vkms: Add kunit tests for linear and sRGB LUTs
> drm/colorop: Introduce DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE
> drm/colorop: Add 3x4 CTM type
> drm/vkms: Pull apply_colorop out of pre_blend_color_transform
> drm/vkms: Use s32 for internal color pipeline precision
> drm/vkms: add 3x4 matrix in color pipeline
> drm/tests: Add a few tests around drm_fixed.h
> drm/vkms: Add tests for CTM handling
> drm/colorop: pass plane_color_pipeline client cap to atomic check
> drm/amd/display: Ignore deprecated props when plane_color_pipeline set
> drm/amd/display: Add bypass COLOR PIPELINE
> drm/colorop: Add PQ 125 EOTF and its inverse
> drm/amd/display: Enable support for PQ 125 EOTF and Inverse
> drm/colorop: add BT2020/BT709 OETF and Inverse OETF
> drm/amd/display: Add support for BT.709 and BT.2020 TFs
>
> Documentation/gpu/rfc/color_pipeline.rst | 360 ++++++++
> drivers/gpu/drm/Kconfig | 14 +-
> drivers/gpu/drm/Makefile | 1 +
> .../gpu/drm/amd/display/amdgpu_dm/Makefile | 3 +-
> .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 +
> .../amd/display/amdgpu_dm/amdgpu_dm_color.c | 352 ++++++++
> .../amd/display/amdgpu_dm/amdgpu_dm_colorop.c | 160 ++++
> .../amd/display/amdgpu_dm/amdgpu_dm_colorop.h | 36 +
> .../amd/display/amdgpu_dm/amdgpu_dm_plane.c | 32 +
> drivers/gpu/drm/drm_atomic.c | 161 +++-
> drivers/gpu/drm/drm_atomic_helper.c | 12 +
> drivers/gpu/drm/drm_atomic_state_helper.c | 5 +
> drivers/gpu/drm/drm_atomic_uapi.c | 158 ++++
> drivers/gpu/drm/drm_colorop.c | 411 +++++++++
> drivers/gpu/drm/drm_ioctl.c | 7 +
> drivers/gpu/drm/drm_mode_config.c | 7 +
> drivers/gpu/drm/drm_plane.c | 52 ++
> drivers/gpu/drm/tests/Makefile | 3 +-
> drivers/gpu/drm/tests/drm_fixp_test.c | 69 ++
> drivers/gpu/drm/vkms/Kconfig | 20 +
> drivers/gpu/drm/vkms/Makefile | 4 +-
> drivers/gpu/drm/vkms/tests/.kunitconfig | 4 +
> drivers/gpu/drm/vkms/tests/vkms_color_tests.c | 449 ++++++++++
> drivers/gpu/drm/vkms/vkms_colorop.c | 100 +++
> drivers/gpu/drm/vkms/vkms_composer.c | 135 ++-
> drivers/gpu/drm/vkms/vkms_drv.h | 8 +
> drivers/gpu/drm/vkms/vkms_luts.c | 802 ++++++++++++++++++
> drivers/gpu/drm/vkms/vkms_luts.h | 12 +
> drivers/gpu/drm/vkms/vkms_plane.c | 2 +
> include/drm/drm_atomic.h | 122 +++
> include/drm/drm_atomic_uapi.h | 3 +
> include/drm/drm_colorop.h | 301 +++++++
> include/drm/drm_file.h | 7 +
> include/drm/drm_fixed.h | 35 +-
> include/drm/drm_mode_config.h | 18 +
> include/drm/drm_plane.h | 13 +
> include/uapi/drm/drm.h | 16 +
> include/uapi/drm/drm_mode.h | 14 +
> 38 files changed, 3882 insertions(+), 30 deletions(-)
> create mode 100644 Documentation/gpu/rfc/color_pipeline.rst
> create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_colorop.c
> create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_colorop.h
> create mode 100644 drivers/gpu/drm/drm_colorop.c
> create mode 100644 drivers/gpu/drm/tests/drm_fixp_test.c
> create mode 100644 drivers/gpu/drm/vkms/Kconfig
> create mode 100644 drivers/gpu/drm/vkms/tests/.kunitconfig
> create mode 100644 drivers/gpu/drm/vkms/tests/vkms_color_tests.c
> create mode 100644 drivers/gpu/drm/vkms/vkms_colorop.c
> create mode 100644 drivers/gpu/drm/vkms/vkms_luts.c
> create mode 100644 drivers/gpu/drm/vkms/vkms_luts.h
> create mode 100644 include/drm/drm_colorop.h
>
> --
> 2.44.0
>
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