A LOW-POWER VIDEO RECORDING SYSTEM WITH H.264/AVC AND LIGHT-WEIGHT COMPRESSION

초록

The increasing demand for mobile video recording systems makes it important to reduce the power consumption and to extend the lifetime of the battery. The H.264/AVC compression is widely used for most video recording systems because of its high compression efficiency. However, a complex coding structure of H.264/AVC requires a large amount of computation and also large power consumption as well. Meanwhile, a light weight video compression (LWC) based on DWT and SPIHT consumes less power than H.264/AVC thanks to its relatively simple coding structure although its compression efficiency is lower than that of H.264/AVC. This paper proposes a low-power video recording system that combines both H.264/AVC and LWC. LWC is used to compress video data temporarily. When the temporal data are turned out to be meaningful, they are compressed by the H.264/AVC to be stored permanently. The use of LWC for temporal storage contributes to power saving because LWC consumes less power than H.264/AVC does. For additional power saving, a NAND flash memory instead of an SDRAM is used for temporal storage of video data compressed by LWC. The estimation of power consumption shows that a power reduction of 73.7% is achieved compared to the conventional video recording system which uses only H.264/AVC.