An Optimization for CAVLC Code Table Lookup Algorithm in H. 264 Decoder

Abstract

The computational complexity of H.264 video coding standard is two or three times higher than that of H.263 and MPEG-4. Especially, the operation of the entropy coding is one of the most time-consuming parts in the decoder. According to the characteristics of two-dimensional code table for CAVLC, a fast algorithm was proposed in H.264 decoder implementation, which enable different strategies to be made respectively based on the Variable Length Codes and the Fixed Length Codes existing in two-dimensional code table for CAVLC. The computer simulation results indicate that the decoding time of the entropy decode algorithm can be decreased by 75.1%-82.7% than the original algorithm in the H.264 reference software.