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fe22d21e93
Add support to the YUV formats bellow: - NV12/NV16/NV24 - NV21/NV61/NV42 - YUV420/YUV422/YUV444 - YVU420/YVU422/YVU444 The conversion from yuv to rgb is done with fixed-point arithmetic, using 32.32 fixed-point numbers and the drm_fixed helpers. To do the conversion, a specific matrix must be used for each color range (DRM_COLOR_*_RANGE) and encoding (DRM_COLOR_*). This matrix is stored in the `conversion_matrix` struct, along with the specific y_offset needed. This matrix is queried only once, in `vkms_plane_atomic_update` and stored in a `vkms_plane_state`. Those conversion matrices of each encoding and range were obtained by rounding the values of the original conversion matrices multiplied by 2^32. This is done to avoid the use of floating point operations. The same reading function is used for YUV and YVU formats. As the only difference between those two category of formats is the order of field, a simple swap in conversion matrix columns allows using the same function. [Louis Chauvet: - Adapted Arthur's work - Implemented the read_line_t callbacks for yuv - add struct conversion_matrix - store the whole conversion_matrix in the plane state - remove struct pixel_yuv_u8 - update the commit message - Merge the modifications from Arthur] Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net> Acked-by: Maxime Ripard <mripard@kernel.org> Link: https://lore.kernel.org/r/20250415-yuv-v18-2-f2918f71ec4b@bootlin.com Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.