为了提高编码速度, 针对H.264/AVC中运算量较大的P帧模式选择部分, 提出了一种新的快速选择算法。该算法依次通过Jmode值单调性检测、基于子块运动向量(MV)的水平与垂直方向选择, 这两个步骤逐步缩小候选帧间模式检测范围, 同时提出了基于最佳帧间模式的帧内模式选择方法, 选择性地检测帧内模式, 从而有效避免不必要的模式检测过程。实验结果表明, 相对JM中模式全搜索算法, 改进算法平均减小了约63.80%的编码时间, 而只带来了微小的编码性能损失。

In order to speed up video encoding, a new fast algorithm is proposed, on P-frame mode decision which has high complexity in H.264/AVC. In the proposed algorithm, the check range of candidate inter modes are reduced gradually through the following two steps: the monotonicity check of Jmode and the selection of horizontal or vertical orientation based on sub-blocks′ motion vector (MV). Meanwhile, an intra mode checking method based on the best inter mode is proposed, which check intra modes selectively. Thus, it is avoided effectively that checking unnecessary modes. The experiment results show that, compared with exhaustive mode decision algorithm in the JM, the proposed algorithm reduced the encoding time about by 63.80% on average, while brought negligible performance degradation.