Research Of Fast Mode Selection Algorithms In H.264/AVC

In H.264/AVC, many new coding techniques are adopted. For example, multiple reference frames, variable block size motion estimation and rate distortion optimization technique. These coding techniques improve compression efficiency of H.264/AVC video coding standard but also greatly increase the computing complexity. How to guarantee the compression efficiency at the same time reduce the encoding complexity has important research value. Mode selection is the quite time-consuming process in H.264/AVC. This paper makes an intensive study of intra mode selection and inter mode selection.This paper studies two representative algorithms which narrow the scope of the choice of prediction modes for mode selection and tests standard sequences with different resolution and different texture complexity under the two algorithms respectively, proves the effectiveness of the algorithm from the rate-distortion curve of RD and subjective quality of the decoded image. This paper introduces the traversing interframe mode selection algorithm in H.264/AVC, then researches a fast inter mode decision methods in P frames. The algorithm makes use of the relationship between macroblock modes and avgJmotion, classifies candidates search block modes according to the range of Jmotion(i6×16), then inactivates many modes in advance according to the temporal correlation and the relationship between optimal mode and sub-optimal mode and thus decreases candidate patterns range,reduces the computational complexity of RDO process.