intel / intel/vpl-gpu-rt

Incorrect clipping for high dynamic range mastering display color volume metadata

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Description

https://github.com/intel/vpl-gpu-rt/blob/e6a12d5090489e89a8f6dda8ff2842c734ceec54/_studio/mfx_lib/encode_hw/av1/agnostic/base/av1ehw_base_hdr.cpp#L42-L57

The implemented clipping of primary_chromaticity/display_primaries parameters is incorrect as it limits primary_chromaticity_y to the value of 0.762940, but it must be the 0.840000 (according to the range derived from AVC/HEVC/VVC specs).
To meet this requirement the upper limit of DisplayPrimariesY must be at least 55050.

Related specs:
https://aomediacodec.github.io/av1-spec/#metadata-high-dynamic-range-mastering-display-color-volume-semantics
D.2.29 of Rec. ITU-T H.264 (V15) (08/2024), [dl link](https://www.itu.int/rec/T-REC-H.264-202408-I/en)

BTW, AV1 specification does not set limits for HDR MDCV values (other than those determined by syntax).

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