Block Partitioning Structure in the VVC Standard
Block Partitioning Structure in the VVC Standard
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DOI：
10.1109/tcsvt.2021.3088134
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发表时间：
2021-10-01
影响因子：
8.4
通讯作者：
Chubach, Olena
中科院分区：
文献类型：
--
作者：
Huang, Yu-Wen;An, Jicheng;Chubach, Olena
通用视频编码（VVC）是由ITU-T VCEG和ISO/IEC MPEG联合制定的最新视频编码标准。本文提供了 VVC 块划分结构的技术细节和实验结果。在VVC的所有新技术方面中，块划分结构被认为是相对于之前的视频编码标准最实质性的变化之一，并提供了最显着的编码增益。新的分区结构采用更灵活的方案设计。每个编码树单元（CTU）要么被视为一个编码单元，要么被一个或多个递归四元树分区分割成多个编码单元，随后是一个或多个递归多类型树分割。后者可以是水平二叉树分裂、垂直二叉树分裂、水平三叉树分裂或垂直三叉树分裂。在新的块分区结构之上描述了用于帧内编码切片的CTU双树，允许针对亮度和色度使用单独的编码树。此外，还提出了一种处理图片边界的新方法。此外，为了降低硬件解码器的复杂性，引入了虚拟管道数据单元约束，这禁止某些多类型树分割。最后，描述了局部二元树，其减少了小色度帧内块的数量。
Versatile Video Coding (VVC) is the latest video coding standard jointly developed by ITU-T VCEG and ISO/IEC MPEG. In this paper, technical details and experimental results for the VVC block partitioning structure are provided. Among all the new technical aspects of VVC, the block partitioning structure is identified as one of the most substantial changes relative to the previous video coding standards and provides the most significant coding gains. The new partitioning structure is designed using a more flexible scheme. Each coding tree unit (CTU) is either treated as one coding unit or split into multiple coding units by one or more recursive quaternary tree partitions followed by one or more recursive multi-type tree splits. The latter can be horizontal binary tree split, vertical binary tree split, horizontal ternary tree split, or vertical ternary tree split. A CTU dual tree for intra-coded slices is described on top of the new block partitioning structure, allowing separate coding trees for luma and chroma. Also, a new way of handling picture boundaries is presented. Additionally, to reduce hardware decoder complexity, virtual pipeline data unit constraints are introduced, which forbid certain multi-type tree splits. Finally, a local dual tree is described, which reduces the number of small chroma intra blocks.