A Fast Software-Only H.263 Video Codec

摘要

H.263[l] is one of the most efficient video compression standards available today. It is expected that H.263 will replace H.261 [2] in many applications. This paper analyzes the computational complexity of H.263 and presents a set of methods for maximizing the performance of this codec based on 64-bit Digital's Alpha processor. The optimization problem is approached from two directions: algorithmic enhancement and efficient software implementation. Performance comparisons are evaluated for the default mode and full-option mode (including syntax-based arithmetic mode, PB-frames mode, advanced prediction mode, and unrestricted motion vector mode). Finally, this paper provides a brief description of multimedia instructions supported by a new generation of Alpha CPU, which is designed to provide the most cost-effective solution for software-only video compression and other multimedia applications.