YUV-to-RGB Conversion

DstMode.YUV2RGB treats source color as YCbCr/YUV and converts it to RGB in the blend unit. Normal blend and fog functions cannot be used at the same time.

Set FogColor to (r,g,b) = (128,YUVBlack,128). The green byte becomes an unsigned YUV black-level value; 16 is the nominal MPEG value. YUVContrast is unsigned eight-bit and resets to 41. Raising YUVBlack darkens pixels; raising YUVContrast increases contrast.

sY = (YUVContrast + 256) * (Y - YUVBlack) + 128
R = floor((sY + 407 * (Cr - 128)) / 255)
G = floor((sY - 207 * (Cr - 128) - 100 * (Cb - 128)) / 255)
B = floor((sY + 515 * (Cb - 128)) / 255)

These are the equations printed in the specification, including the divisor 255.

SrcFmt 0xD supplies Y0CrY1Cb, with Y0 for even U and Y1 for odd U. SrcBGR swaps the chroma component placement. Other source formats map Cr to the red field, Y to green and Cb to blue when conversion is enabled.

YUVContrast · FogColor / YUVBlack · Video capture

Source: Technical Spec, p.37