SAD or SATD? How the Distortion Metric Impacts a Fractional Motion Estimation VLSI Architecture
Ismael Seidel, Vanio Rodrigues Filho, Mateus Grellert, Luciano Volcan Agostini, José Luís Güntzel · 2021
Video coding systems have to deal with a number of tradeoffs. The decision of adopting a specific distortion metric in the Fractional Motion Estimation (FME) step, for instance, presents a designer with a tradeoff between energy and coding efficiency. This paper analyzes such a tradeoff considering two of the most known and used distortion metrics, the Sum of Absolute Differences (SAD) and the Sum of Absolute Transformed Differences (SATD), within a High Efficiency Video Coding (HEVC)-compatible FME hardware architecture. We show that the SATD-based FME architecture is 1.94 times larger than the SAD-based one and consumes 2.07 times more energy.