基于时空相关的H.264多参考帧快速选择算法

Fast Multiple Reference Frame Selection Algorithm for H.264 Based on Temporal and Spatial Correlation

H.264/AVC视频编码标准采用的多参考帧技术改善了视频质量,但同时也增加了编码复杂度。为避免搜索多余的参考帧,提高H.264编码器的编码效率,基于视频序列帧间具有较强时间相关性、相邻宏块具有较强时空相关性,提出了一种多参考帧选择算法。该算法根据视频序列的帧间时间相关程度确定参考帧个数;由相邻宏块的时空相关性自适应确定当前宏块的编码模式及其最佳参考帧。实验结果表明,与校验模型JM16.2相比,该算法在编码质量几乎不变的情况下,平均可节约60%的编码时间。

The multi-reference frames technique is employed in H. 264/AVC, which ameliorates video quality greatly, but also increases the complexity of coding. In order to avoid searching redundant reference frame and increase the effi- ciency of the H. 264 encoder, a fast multi-reference frames selection algorithm was proposed according to the temporal correlation between inter frames, and the temporal and spatial correlation among the adjacent macro blocks. The number of reference frames was determimed according to the degree of the temporal correlation between inter frames, and the coding mode and the best reference frame of the current macro block were detemined by the degree of temporal and spa- tial correlation between its adjacent macro blocks adaptively. Experimental results show that the proposed algorithm can save about 60% of encoding time with the encoding quality almost unchanged in comparison with JM16.2.