Research On Intra-Prediction Mode Decision Algorithm For H.264

H.264 is the lastest standard for video compression issued jointly by Video Coding Experts Group of the International Telecommunication Standardisation Sector and Moving Picture Experts Group of the International Organisation for Standardization and the Internation Electrotechnical Commission. It aims to provide enhanced coding efficiency as well as ensuring its suitability for transmission over various kinds of networks. However, the high efficiency of H.264 is at the expanse of its complexity, because of its high operations, it's hard to be used widely.In order to reduce the complexity of H.264 video coding algorithm, the main process of H.264 is introduced firstly, and then researches in this paper focus on intra-prediction algorithms for H.264. Based on the analysis of the algorithm complexity, two fast intra-prediction mode decision algorithms for H.264 are present in this paper, in which maily complete the following work:1. On the basis of large number of experiments and in-depth study, the correlation of the macroblock and the characteristics of the differences between the neighbouring pixcels of the macroblock is analyzed. Then macroblock type pre-decision algorithm for intra-prediction is proposed and the algorithm is implemented on H.264 test model JM90. Experimental results show that the pre-decision algorithm save about 23.47% of the encoding time with negligible loss of the quality.2. An improved Pan algorithm based on edge direction histogram is present. Experimental results show that the improved Pan algorithm save about 62.32% of the encoding time with acceptable loss of the quality. Then we implement both improved Pan algorithm and the pre-decision algorithm on H.264 test model JM90. Experimental results show the combinative algorithm save about 72.49% of the encoding time when ensuring the capability of the rate distortion and the Bits rate.