A sub-mW MPEG-4 motion estimation processor core for mobile video application

This paper describes a sub-mW motion estimation processor core for MPEG-4 video encoding. It features a Gradient Descent Search algorithm whose computation power is only 7 % of the conventional 1:4-subsampling search, producing higher picture quality. Another feature is an optimized SIMD datapath architecture to decrease a clock frequency and an operating voltage. It has been fabricated with CMOS 5-metal 0.18 um technology. The measured power consumption to process a QCIF 15 fps video is 0.4 mW under 0.85 MHz@1.0 V