H.264/AVC Video Codec Technology for High-Image-Quality and Low-Power Applications

To make use of the high coding performance of the international standard H.264/AVC to achieve high image quality, a massive amount of computation and accompanying reference to many pieces of image data are required. These processes involve a trade-off with reducing power consumption. Fujitsu has developed H.264/AVC codec technology capable of achieving industry-leading levels of high-image-quality and low-power-consumption performance based on its proprietary image analysis technology, and applied it to many LSIs for imaging devices. This paper outlines the technology to reduce power consumption with the focus on data transfer with external memory, which occurs when there is internal computation processing. First, it describes a lossless image compression technique optimized for video codec processing. Then, it gives an explanation about technology called "lossless compression prefetch memory," which is applied to read ahead and retain the data likely to be used repeatedly, thereby significantly reducing the amount of data transfer. The technology presented in this paper, and the H.264/AVC codec technology, which achieves both high image quality and lower power consumption, can be applied to devices for which there is a high demand for power consumption reduction.