基于帧内/帧间模式选择相关性的H.264/AVC快速帧内模式选择算法

A Fast Intra Mode Decision Algorithm for H.264/AVC Encoder Based on Intra/inter Correlation

对高清视频序列而言,H.264/AVC视频编码器性能优异,但同时其计算复杂度也较高。帧间和帧内预测模式的选择是H.264/AVC待优化的主要技术。鉴于此,根据选定的帧间预测模式和帧内模式选择之间存在的相关性,提出了基于最佳帧间预测模式的H.264高清基本档次编码器的快速帧内模式选择算法。对该算法的评估是基于率失真、峰值信噪比(PSNR)的改变量、执行时间以及所跳过的intra4×4和intra16×16模式占全搜索算法的百分比进行的。经720p(1280×720)和1080p(1920×1088)高清视频序列测试,在不损失PSNR、不增加码率的前提下,该算法能节省60%的帧内预测计算时间,并对16×16宏块和4×4子块帧捏模式选择部分的跳过率分别达到了16%和83%。

Although H. 264/AVC has an excellent performance, it also induces a high complexity in computation, the case is more obvious to HD video sequence. The inter and intra mode decision module is one of the main features of H. 264/AVC needing improvement. Therefore, based on the correlation between inter and intra mode decision, an algorithm based on the best inter decision mode of H. 264/AVC HD baseline profile is proposed. Evaluation of this algorithm is based on the variation of rate distortion and PSNR, together with execution time and the percentage of skipping intra4 4 and intra16 16 . we test the algorithm on 720p and 1080p HD video sequence. The experimental results show that without reducing PSNR and increasing bit-rate, this algorithm can bring 16% and 83% percentage reducing for intra16 16 and intra4 4.