Fast Algorithm Of The Inter Mode Decision For H.264/AVC

The main object of video coding is to indicate image video information by less bit rate under the instance of stated channel and limited transfers bit and ensuring define restructure quality. Marcroblock coding of H.264/AVC which is up-to-date standard of video coding fully searched many coding modes to obtain the best coding efficiency by the rate-distortion optimization(RDO) algorithm. However, it also made the computation complexity increase with germination. So it is significance for the clipping selection study of inter predictive coding mode of H.264/AVC in order to reduce computation complexity.In this thesis, it was clear that MB types of P frame or B frame all existed very strong relativity in temporal and spatial for various QCIF test sequences from the extensive experiment results of H.264/AVC. In order to more analyze the relativity of MB types, the mean absolute difference (MAD) and the mean of absolute frame difference (MAFD) are introduced to measure the relativity of MB types in P and B frame in temporal and spatial. And rules of MB types SKIP/DIRECT mode selection inter frames were set down according to the experiments. Then a quick selection algorithm of the SKIP/DERICT modes was put forward in accordance with these rules. Meanwhile, an self-adaptive selection algorithm for the inter modes was put forward according to the disadvantage of the algorithm on the base of the frontal algorithm. The algorithm would prospectively judge the mode of current MB types to reduce the quantity of inter MB mode selection according as current MB types had pre-adopted the MAD value of SKIP/DIRECT mode or 16×16 MB mode. The extensive experimental results of validating model JM7.6 showed that first algorithm reduced about 30 percent coding time and the second reduced near 50 percent coding time for videosequences having no too much smart change and the latter algorithm saved on more 10 percent coding time under the instance of not only almost invariability of image coding quality also no more increase of video coding bit rate. Accordingly, the disadvantage of RDO algorithm was fetched up so that the work efficiency of encoder was improved effectively.