基于H.264的CABAC解码算法改进研究

An Improved Decoding Algorithm Research of CABAC Based on H.264

针对H.264 Main profile中采用的CABAC解码算法,分别从逆二进制化数据查表、常规解码器归一化过程查找表和子区间定位查找表三个方面进行改进,避免了之前表格查找及分支判断耗费大量的时间,并在一定程度上减少了存储空间的使用,降低了解码时间。经过测试,改进后的算法在速度上提高了45%左右,有一定的实用价值。

CABAC is one of the entropy coding scheme that H.264 uses for main profile.This paper improves the scheme by reverse binary data look-up table,normal decoder normalization process and subinterval location look-up table etc.Based on the principles above,the proposed methods can avoid the branch table lookup and judgment’s time consuming,partly reduce the use of storage space,and reduce the decoding time.After the test,the improved algorithms in speed increase by around 45 % and it has certain practical value.