As implimented by Gigabyte , GA-EG45M-DS2H
http://my.ocworkbench.com/2008/gigabyte/GA-EG45M-DS2H/g1.htm
While the specs says it decodes H.264 the reailty not quite here.
http://software.intel.com/en-us/articles/quick-reference-guide-to-intel-integrated-graphics/
PowerDVD even says it supports it.
http://www.cyberlink.com/eng/press_room/view_1723.html
I could not easily get it working on xp or vista.
This poster had more success.
http://www.geekzone.co.nz/forums.asp?forumid=83&topicid=25244
Read more about it here
http://www.geekzone.co.nz/forums.asp?ForumId=83&TopicId=30062