[M4IF Technotes] b-vop with quarter pel

[jeansonh admtek.com.tw]

Hi, all
I got one question about b-vops with quarter-pel, and wish somebody may
give me a hint. :)
In the reference code, if B-VOPs with Backward, Forward, or Bi-directional
prediction, the quarter-pel interpolation will be done on 16x16 pixels,
while
with Direct mode prediction it will be on 4 8x8 pixel blocks. Is this
correct?
I think in standard section 7.6.9.5.3, it remarks that the result will be
totally
different on those two different interpolation processes. But when decoding
B-VOPs with quarterpel bitstreams generated by DivX 5, 16x16 interpolation
will result in blocky images, while 8x8 will 'look' fine...
Is this the problem of DivX or it changed in later amendant?My standard
version is 14496-2:1999/Amd.1:2000
Thanks in advance!
--
Jeanson Hung
BU2, ADMtek Inc.
Phone: +886-3-5788879-521