JVET quadtree plus binary tree (QTBT) structure with multiple asymmetrical partitioning
A method of partitioning in video coding for JVET, comprising representing a JVET coding tree unit as a root node in a quadtree plus binary tree (QTBT) structure that can have quadtree or binary partitioning of the root node and quadtree or binary trees branching from each of the leaf nodes. The partitioning at any depth can use asymmetric binary partitioning to split a node represented by a leaf node into two child nodes of unequal size, representing the two child nodes as leaf nodes in a binary tree branching from the parent leaf node and coding the child nodes represented by final leaf nodes of the binary tree with JVET, wherein further partitioning of child nodes split from leaf nodes via asymmetric binary partitioning is allowed recursively along the same branch in any order with symmetric partitioning.
1 . A method of decoding a bitstream, the method comprising:
receiving a bitstream indicating how a coding tree unit was partitioned into coding units according to a partitioning structure that allows nodes to be split with at least one of quaternary tree partitioning, symmetric binary tree partitioning, and/or asymmetric tree partitioning;
parsing said bitstream to determine if at least one of asymmetric tree partitioning and/or symmetric binary tree partitioning splits a parent node into child nodes, wherein symmetric binary tree partitioning splits a parent node into a plurality of child nodes of equal size each of which are rectangular in shape, and asymmetric tree partitioning splits a parent node into a plurality of child nodes of unequal size each of which are rectangular in shape;
identifying each of the child nodes within each respective parent unit, wherein a node can be recursively partitioned into smaller rectangular nodes;
wherein the partitioning structure allows both asymmetric tree partitioning and symmetric binary tree partitioning to occur in either order during recursive partitioning;
wherein the partitioning structure allows further partitioning of rectangular child nodes that are produced from asymmetric tree partitioning of at least one parent node;
wherein said asymmetric tree partitioning produces child nodes having a size ratio that is anything other than 1;
wherein at least one node is asymmetrically partitioned including two child nodes of unequal sizes, where a larger child node is two times as large as a smaller child node for a size ratio of 2:1; and
decoding the identified coding units using an intra decoding process.
2 . A method of encoding a bitstream, the method comprising:
providing an encoded bitstream indicating how a coding tree unit was partitioned into coding units according to a partitioning structure that allows nodes to be split with at least one of quaternary tree partitioning, symmetric binary tree partitioning, and/or asymmetric tree partitioning;
wherein said bitstream is configured for a decoder for parsing said bitstream to determine if at least one of asymmetric tree partitioning and/or symmetric binary tree partitioning splits a parent node into child nodes, wherein symmetric binary tree partitioning splits a parent node into a plurality of child nodes of equal size each of which are rectangular in shape, and asymmetric tree partitioning splits a parent node into a plurality of child nodes of unequal size each of which are rectangular in shape;
wherein said bitstream is configured for a decoder to identify each of the child nodes within each respective parent unit, wherein a node can be recursively partitioned into smaller rectangular nodes;
wherein the partitioning structure allows both asymmetric tree partitioning and symmetric binary tree partitioning to occur in either order during recursive partitioning;
wherein the partitioning structure allows further partitioning of rectangular child nodes that are produced from asymmetric tree partitioning of at least one parent node;
wherein said asymmetric tree partitioning produces child nodes having a size ratio that is anything other than 1;
wherein at least one node is asymmetrically partitioned including two child nodes of unequal sizes, where a larger child node is two times as large as a smaller child node for a size ratio of 2:1; and
encoding the identified coding units within said bitstream in a manner to be decoded using an intra decoding process.