[M4IF Technotes] Doubt on Padding of VOP

[Mithun N]

Hi..
I have a certain doubt on the process of padding
followed for MPEG4.
After the horizontal and repetitive padding has
been completed, we
continue with the extended padding...which pads
all the macroblocks
inside the bounding rectangle of the VOP.(as
stated in ISO 14496-2)
Assuming this is the case and the search range is
very small(f code =1 )
and the object has moved considerably between 2
time instants,and the
reference vop falls outside the search range, and
unrestricted motion vector is disabled ,how do we
form the error macroblock???
Is it taken as ... error macroblock = current
macroblock - zero(reference is zero since there is
no search range ) ????????
Or is it that the whole frame has to be padded?
If so how do we proceed with the padding of the
macroblocks outside the VOP (between
the bounding rectangle and the frame boundary)????
Please explain in detail....the reference
microsoft decoder seems to pad the macroblocks
outside the VOP.
But there is no unrestricted motion vector
parameter setting in the Microsoft encoder
parameter file..
Thanks n Regards,
Mithun Nayak