[M4IF Technotes] Range of Motion vectors.

[Biju Ravindran]

Hi,
     Could anybody explain in detail about how the
range of motion vetcors is definied?
In Mpeg-2 the range is given as
[-8:+7.5],[-16:+15.5],[-32:+31.5],[-64:+63.5],....[-2048:+2047.5].
Normally if we take a 16x16 macro block the motion
vectors will be in the range [-8:+7.5] in half pel
res.
       + . + . + . + . + . +
                -1 0 1 2 3 4     
       where,
            + integer pel position.
            . half-pel position.
What would be the search radius for other ranges such
a 16,32,64...2048? What could be the size of
macroblock in these cases and how the ME is found?
=====
ciao,
-biju
__________________________________________________
Do You Yahoo!?
Check out Yahoo! Shopping and Yahoo! Auctions for all of
your unique holiday gifts! Buy at http://shopping.yahoo.com
or bid at http://auctions.yahoo.com