A Chroma subsampling
These enumerate the available chroma subsampling options supported by the theora format. See Section 4.4 of the specification for exact definitions.
Chroma subsampling by 2 in each direction (4:2:0)
Horizonatal chroma subsampling by 2 (4:2:2)
No chroma subsampling at all (4:4:4)
Definition at line 91 of file theora.h.