Energy-efficient motion estimation with approximate arithmetic

Roger Porto, Luciano Agostini, Bruno Zatt, Marcelo Porto, Nuno Roma, Leonel Sousa
2017 2017 IEEE 19th International Workshop on Multimedia Signal Processing (MMSP)  
Energy efficiency has become a primary concern in the design of multimedia digital systems, particularly when targeting mobile devices. Approximate computing is a highly promising approach to address this challenge. This paper presents an architectural exploration in a variable block size motion estimation (VBSME) architecture using imprecise Lower-Part-OR Adders (LOA). These adders were applied to Sum of Absolute Differences units (SAD) in order to reduce the energy consumption while
more » ... g a minimum impact on the coding efficiency. Three VBSME architectures with LOA operators were developed by considering different imprecision levels. The conducted evaluations, performed using the High-Efficiency Video Coding standard (HEVC) reference software, showed that this technique introduces a negligible impact on the coding efficiency (between 0.6% and 2.5% increase of the BD-Rate). Nevertheless, when the designed architectures were synthesized for a 45nm standard cells technology, significant power savings were observed (between 7% and 11.5%, depending on the used LOA version), demonstrating the viability and significant gains of the proposed approach.
doi:10.1109/mmsp.2017.8122248 dblp:conf/mmsp/PortoAZPRS17 fatcat:ifvj3wigwzfc7ke5iv7fd24pbm