UV subsampling is also specified in the enum value names using J:a:b notation (e.g. 4:2:0 is
1/2 horizontal and 1/2 vertical resolution for U and V). If alpha is present it is not sub-
sampled. Note that Subsampling values other than k444 are only valid with PlaneConfig values
that have U and V in different planes than Y (and A, if present).
Given image dimensions, a planer configuration, subsampling, and origin, determine the expected
size of each plane. Returns the expected planes. The input image dimensions are as displayed
(after the planes have been transformed to the intended display orientation). The plane
dimensions are output as the planes are stored in memory (may be rotated from image dimensions).
SubsamplingFactors(Subsampling) if plane_index refers to a U/V plane and otherwise (1, 1)
if inputs are valid. Invalid inputs consist of incompatible PlaneConfigSubsamplingplane_index combinations. (0, 0) is returned for invalid inputs.
Specifies the structure of planes for a YUV image with optional alpha. The actual planar data
is not part of this structure and depending on usage is in external textures or pixmaps.