DAV1D_MC_IDENTITY requires DAV1D_PIXEL_LAYOUT_I444
Section 6.4.2 (Color config semantics) of the AV1 spec says: If matrix_coefficients is equal to MC_IDENTITY, it is a requirement of bitstream conformance that subsampling_x is equal to 0 and subsampling_y is equal to 0.
Superseeds: !1063 (closed). CC @lynne & @wtc
Edited by Ronald S. Bultje