[Mp4-tech] Differences between MPEG4 & WMA

[Ravi Bulusu]

Hi All,
Can someone please tell me (if and) what the differences are in video compression algorithms, specifically related to motion compensation (if such thing exists in WMA), for MPEG4 & WMA video compression techniques? 
More precisely, if I were to design a motion compensation block for MPEG2/MPEG4, would it also be useful/applicable for WMA?
Any pointers/material would be really helpful. 
thx, 
Ravi