JVET第十次会议正式定义了VVC Test Model 1(VTM1),最初版本的VTM1仅仅包含了binary/ternary/quanternary(二叉/三叉/四叉)编码树。
图1:General block diagram of VTM1 encoder
图2:The binary/ternary/quaternary-treepartitions: (a) no splitting (b) quaternary partitioning (c) horizontal binarypartitioning (d) vertical binary partitioning (e) horizontal ternarypartitioning (e) vertical ternary partitioning
图3:QTBTTT划分标志
CTU首先进行QT划分,然后进行BT/TT划分(flag1:是否划分,flag2:划分方向,flag3:BT还是TT)
划分过程由以下5个参数控制:
4:2:0图像
l CTU size: the root node size of a quaternary tree(128x128)
l MinQTSize: the minimum allowed quaternary tree leaf node size(16x16)
l MaxBTTSize: the maximum allowed binary and ternary tree root nodesize(64x64)
l MaxBTTDepth: the maximum allowed binary and ternary tree depth(4)
l MinBTTSize: the minimum allowed binary and ternary tree leaf nodesize(4x4)
128x128的CTU首先进行四叉树划分;
四叉树节点进行二叉树划分时,则该节点是二叉/三叉树的根节点,且二叉/三叉树深度为0;