Intel Posts Patches For Plane Color Pipeline Support On Linux - Jiving With AMD's Design

As part of the AMD color management and HDR efforts worked on by AMD Linux engineers along with Valve and other stakeholders like Igalia developers, Intel engineers have posted their plane color pipeline implementation that follows the cross-vendor API proposal.

AMD and other parties have been working on this color pipeline API for months and also implementing it in the VKMS DRM driver for reference purposes. On Tuesday the Intel patches were posted for implementing this compatible plane color pipeline API support for Intel platforms. The DRM core changes for the color pipeline support still need to be merged while now havinfg this Intel implementation available should help in seeing consensus as well as getting the desktop/compositor developers to make use of the user-space API.

As a refresher on the Linux Color Pipeline API:

"We would like to support pre-, and post-blending complex color transformations in display controller hardware in order to allow for HW-supported HDR use-cases, as well as to provide support to color-managed applications, such as video or image editors.

It is possible to support an HDR output on HW supporting the Colorspace and HDR Metadata drm_connector properties, but that requires the compositor or application to render and compose the content into one final buffer intended for display. Doing so is costly.

Most modern display HW offers various 1D LUTs, 3D LUTs, matrices, and other operations to support color transformations. These operations are often implemented in fixed-function HW and therefore much more power efficient than performing similar operations via shaders or CPU.

We would like to make use of this HW functionality to support complex color transformations with no, or minimal CPU or shader load."

Currently the Intel implementation is 27 patches and can be found out for review on the dri-devel mailing list.

Thanks to the AMD-based Steam Deck (OLED) there's been a lot of upstream color/HDR work happening.

Hopefully this year the Linux Color Pipeline API support -- and more broadly the HDR efforts for the Linux desktop -- pan out and see mainline status.