摘要
提出了一种改进的H.264视频编码方案。针对H.264中具有7种不同块模式运动估值的特点,在帧间预测过程中使用一种扩展的变换编码概念——自适应块变换,把运动估值的块大小和变换块大小联系起来,通过限制最大的变换块尺寸对自适应块变换做了简化,以适应实际应用的需要;通过扩展帧内预测的块模式,将简化的自适应块变换也应用到帧内预测编码中;鉴于不同块尺寸的变换系数矩阵的概率分布不同,提出在熵编码过程中采用自适应通用变长编码对码表进行动态重组,以进一步提高编码效率。比较了与现有H.264视频编码方案的性能差异。
An improved H.264 video coding scheme is brought forward. According to the seven block modes of motion estimation in H.264, this new scheme applies an extending concept of transform coding called adaptive block transform (ABT) to inter prediction which associates the block size of motion estimation with that of the transform. As the high complexity being taken into account, the original ABT is simplified and adapted to meet the practical situation by restricting the maximal transform size. Meanwhile, intra pre- diction is also adjusted to accommodate the simplified ABT. In terms of the different probability distributions corresponding to the trans- formed coefficients of different block size, an adaptive universal variable length coding method with dynamic code table remapping is adopted to further improve the coding efficiency. The detailed description of the scheme is presented with the performance compared to current H.264. As a result of the simulation, the proposed scheme has significant capability at high bitrates, where maximal 2dB PNSR gain can be achieved.
出处
《计算机工程与设计》
CSCD
北大核心
2005年第5期1161-1163,共3页
Computer Engineering and Design
基金
国家自然科学基金项目(60172050)
