Page 196 - Video Coding for Mobile Communications Efficiency, Complexity, and Resilience

Section 7.9. Discussion 173

7.9 Discussion

Processing digital video requires a signi)cant amount of computational power.
This represents one of the main challenges for real-time mobile video com-
munication, where processing power and battery life are scarce resources.
In this chapter, the computational complexity of a typical video codec was
investigated. It was found that this complexity is due mainly to the motion
estimation process. In fact, it was found that the computational complexity of
this process is greater than that of all the remaining encoding steps combined.
It was concluded, therefore, that reducing the complexity of this process is the
best way to reduce the overall complexity of the codec. The chapter reviewed
the main categories of reduced-complexity BMME techniques. The chapter
then presented the results of a study comparing the di-erent categories. It
was found that hierarchical techniques and techniques based on a reduced
set of motion vector candidates, in general, provide the highest reduction in
computational complexity.