[M4IF Technotes] CBPC and CBPY

[Bart Lehane]

Hello,
In a rectangular I frame, is it possible to have values of cbpy (coded
block pattern for luminance) that do not equal '1111', or values of cbpc
(cbp for chrominance) that do not equal '11'??
If true, would this give a pattern code not equal to '111111' which
would mean that there would be no DCT coefficients for a particular
block?? (i.e if pattern_code[5] = 0, then the second chrominance block
would have no dct coefficients)
First of all is this scenario possible, where an intra macroblock
contains a block with no (AC) DCT coefficients? If it is possible, what
values would go into that block?
Thanks in advance,
Bart