dri, gbm: Add support for importing/exporting [AX]BGR_16161616 DMABUFs
This MR makes it possible to import/export DMABUFs with formats equal to DRM_FORMAT_ABGR16161616
or DRM_FORMAT_XBGR16161616
, resolving #5785 (closed) .
What are these formats good for?
-
Sharing high bit depth image data between processes (e.g., a Wayland client and compositor). Note that ABGR16161616 is the simplest non-float format with >= 10 bits for the RGB channels and more than 2 bits of alpha.
-
Some AMD GPUs allow DRM planes to use these formats, so having this format, AFAIK, makes it easier to create such buffers using GBM.
See comment ( !14580 (comment 1285554) ) below for ways to test this.