Parameters that describe how pixels are packed.
If the format has 1 or 2 components, then luma is 0.
If the format has 3 or 4 components:
if the RGB flag is set then 0 is red, 1 is green and 2 is blue;
otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V.
If present, the Alpha channel is always the last component.
Parameters that describe how pixels are packed. If the format has 1 or 2 components, then luma is 0. If the format has 3 or 4 components: if the RGB flag is set then 0 is red, 1 is green and 2 is blue; otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V.
If present, the Alpha channel is always the last component.