Skipping Algorithm Based On H.264 Intra Prediction And Rate Control

H.264 video coding standard has been approved in May, 2003 by Joint VideoTeam which was jointly by the ITU-T and ISO/IEC. The elements common to allvideo coding standards are present in the H.264. The basic theory of this codingalgorithm is, using the time-related statistics to develop inter-frame predictionalgorithm, using projected residual transform coding to develop to space statisticalrelevance. And some new techniques, such as spatial prediction in intra-coding,adaptive block size motion compensation, 4×4 integer transformation, multiplereference pictures and content adaptive binary arithmetic coding (CABAC) are usedin this standard. As a result, H.264 has achieved a significant improvement incompression performance and a "network-friendly" representation relative to allexisting standards. So this standard obtains much attention from academic andindustrial fields.On the aspect of improving video coding efficiency, it is not a single algorithmmake special contributions to, but the results of a lot of small improvementalgorithm. In order to achieve high compress performance, H.264 use a robustrate-distortion optimization (RDO) technique to select the best coding mode andreference frame for each macroblock. As H.264 use brute force-searching algorithm,its computational burden is far more than any existing video coding algorithm. As aresult, this standard can not be used to real time video communication, itscomputational needs to optimize.The intra coding is an important part of H.264.It has many prediction modes.And all these modes are needed to calculated in I,P and B frames, so that the fastalgorithm can significantly reduce the overall complexity. Based on the thoroughresearch of the classic Full Search algorithm and the fast algorithm based on edgedirection histogram, an improved fast algorithm based on edge direction histogram isproposed and to be implemented on x.264.The experimental results have proved thatthis proposed algorithm has more coding performance on coding time and bit rateexcept that PNSR littele lower than that of the fast algorithm based on edge direction histogram.The target of rate control is to regulate the coded bit stream to satisfy thechannel condition and improve the reconstructed video quality. Based on theresearch of key technology and typical algorithms of rate control, especially theframe skipping algorithms of rate control, a new frame skipping algorithm of ratecontrol for H.264 based on the motion complexity is proposed and to beimplemented on x.264.The experimental results have shown that our method hasmore precise rate control performance than that of H.264. The proposed algorithmcan make the usage of the buffer much smoother, and it also can output bit streammore steadily.