Low energy optimization for MPEG-4 video encoder on ARM-based mobile phones

Most compiler optimization techniques concern most about speed. In this paper, we present two high-level power/energy optimization methods for ARM-based battery-powered embedded multimedia systems, e.g. mobile phones, pocket PCs, personal multimedia systems, etc. The experiments using MPEG-4 simple profile level 0 (SP@L0) video encoder on ARM920T with two QCIF video sequences 15 fps, 24 kbps show that the proposed techniques can complement the existing speed-oriented ones to achieve lower energy/power consumption up to 5.7% relative to all ARM C++ optimization levels despite the 16-KB instruction and 16-KB data caches of ARM 920T core.