[M4IF Technotes] Stuffing bytes in MPEG-4 version 2

[Paulo Nunes]

Dear all,
	in MPEG-4 Part2:Visual, the mechanism of inserting stuffing bytes (1
stuffing_start_code + n stuffing_bytes) for proper VBV operation is only
allowed for B- and S-VOPs for rectangular VOLs, while for
non-rectangular VOLs it is allowed for all VOP types.
	I would very much appreciate if someone could point me the reason, if
there is one, why this mechanism can not be used for I and P rectangular
VOPs.
Thanks in advance for your help,
	Paulo Nunes