| H.264 is the newest international video coding standard. The standard has greatlyenhanced coding performance relative to the traditional video coding standards, becauseit has adopted many fire-new coding technologies. Inter-frame encoding technology isthe key technology of video coding standard, it accounts for about 50 to 80 percent ofthe whole encoding computation,so it is the most challenging research topic in videoencoding.In this thesis, firstly the encoding principle of H.264 and its main function modulesand new technologies being adopted are introduced. Secondly the inter-frame encodingalgorithm is discussed, and many kinds of classical motion estimation algorithms arediscussed and summarized.Then, a new fast algorithm for inter-frame encoding called cocktail inter-frameencoding algorithm is proposed. This new algorithm takes advantages of prioralgorithms proposed in the literature. By not only holding the original benefit but alsoconstructively improving the existing drawbacks, the algorithm can provide the betterperformance and require less computational costs than others.The algorithm optimizes the flow of inter mode of macro-block decision algorithm.Initially, every fixed-size 4×4 small blocks in the macro-block being coded are used forthe motion estimation using diamond search. Motion vectors from the neighboringsmall blocks are used to determine the search window where the matching motionvector of the merged block (we suppose the two neighboring small blocks have beenmerged) is searched. Then the rate-distortion(RD) optimization is used to determinedthat if the two blocks could be merge into other predefined block types or not. Duringthis process, a new all-zero block decision algorithm is used to determine inter modes ofsome macro-blocks in advance. The simulation results show that the performance of thissimple algorithm is close to H.264 video encoder JM7.3 with all block modes areenabled while the computational complexity is significantly reduced.
|
PDF Full Text Request