Abstract: The H.264/AVC video coding standard adopts the Context-based Adaptive Variable Length Code (CAVLC) in order to get high data compression. Because of the large number of code tables and variable code words, the decoding process is very complex.A new design for MPEG-4 AVC/H.264 CAVLC decoding is presented to improve the efficiency of decoding, which is based on the number of zeros (m) followed by the first 1. In the proposed design, the length of the code word and the value of the syntax element can be obtained easily.

Key words: H.264, CAVLC, Coeff-token, reorder of code table

摘要： H.264 标准中采用了基于内容自适应得变长编码CAVLC，提高了编码的效率。但由于采用了多个码表，码字的长度也不固定，使解码算法的复杂度很高。本文通过分析码表的结构特点，提出了一种基于码流中第一个1的位置，即1前面连续0的个数m的方法，来重建码表，快速判断码长和确定码字。这种新型解码器设计，将大大提高解码的速度。

关键词: H.264, CAVLC, 系数标志符, 码表重组