3.3.8.3.1 Color Conversion
The forward transformation from ARGB to AYUV is based on full-range BT.709 ([ITU-BT.709-5] section 4) and is described by the following two formulas:
A = A
The resultant Y, U, and V components MUST be clamped to the range 0...255 inclusive.
The reverse transformation from AYUV to ARGB is described by the following two formulas:
A = A
The resultant R, G, and B components MUST be clamped to the range 0...255 inclusive.