[Mp4-tech] Mpeg4 Visual Conformance standard Query

[Mohit Agarwal]

Hi,
The Conformance  standard for Mpeg4 Visual section 4.4 of ISO 14496-4 
states that
compliant decoder shall reconstruct I ,P B VOPs within +/-1 pixel 
diference compared
with that by the reference decoder.How does one measure this +/- 1 pixel 
difference
.After IDCT(before IDCT) we get a set of matrixes ,so this computation 
is done on
that matrix or there is some other way to do it.
If anybody could clear my doubts I would be greatful..
Regards
Mohit