For video coding, {HEAD ~ the described architecture} uses {TAIL ~ block based comparisons}, e.g., to support for motion estimation and motion compensation 
uses
For video coding , { HEAD ~ the described architecture } uses { TAIL ~ block based comparisons } , e.g. , to support for motion estimation and motion compensation
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH