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2 commits

Author SHA1 Message Date
Laurent Pinchart
4baaecb4ff utils: rkisp1: gen-csc-table: Specify coefficients with full precision
The Rec01, Rec709, Rec2020 and SMTPE 240M standards specify the Cb and
Cr coefficients of the RGB to Y'CbCr conversion matrix using a quotient
of two values. Use the exact same formulas instead of hardcoding the
division results with a lower precision.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Florian Sylvestre <fsylvestre@baylibre.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
2022-08-30 15:25:35 +03:00
Laurent Pinchart
3fad116f89 utils: rkisp1: Add script to generate CSC coefficients
This script generates fixed-point integer coefficients for the YCbCr
encoding 3x3 matrix. The encoding, quantization and fixed-point
precision can be selected through command line arguments.

The main purpose of the script is to generate coefficient tables to
extend the rkisp1 driver with support for additional YCbCr encodings,
but it may be useful for other purposes as well given that the rounding
isn't trivial.

The Rec. 601 full and limited range coefficients have been verified to
match the values currently used by the rkisp1 driver.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2022-08-26 15:42:09 +03:00