Picture data encoding method and apparatus and picture data decoding method and apparatus

A method of picture data encoding, comprising:

• determining a coding tree unit (CTU) corresponding to a to-be-encoded picture block, wherein the size of the CTU is 128×128;
• splitting the CTU in a node split mode corresponding to a first-level coding tree, to obtain a sub-node of the first-level coding tree, wherein a root node of the first-level coding tree corresponds to the CTU, wherein the node split mode corresponding to a first-level coding tree is a quadtree split mode;
• splitting a first node of a second-level coding tree into three child nodes using a horizontal ternary split mode or a vertical ternary split mode, wherein a root node of the second-level coding tree is the sub-node of the first-level coding tree;
• determining a split mode of a first child node of the first node from a candidate-split-mode set that does not comprise a horizontal binary split mode when the first node of the second-level coding tree is split by the horizontal ternary split mode, or does not comprise a vertical binary split mode when the first node of the second-level coding tree is split by the vertical ternary split mode;
• splitting the first child node into at least two sub-child nodes using the split mode of the first child node;
• and
• encoding a coding unit corresponding to a sub-child node from the at least two sub-child nodes, when the sub-child node needs no further splitting.

A decoder device, comprising:

• a non-transitory memory coupled to a processor to store instructions, which when executed by the processor, cause the processor to perform operations, the operations including:
• obtaining a bitstream comprising picture data;
• parsing the bitstream to obtain node split mode information of a first-level coding tree, wherein a root node of the first-level coding tree corresponds to a coding tree unit (CTU), and the size of the CTU is 128×128, and a sub-node of the first-level coding tree is defined by using the root node of the first-level coding tree and a node split mode corresponding to the node split mode information of the first-level coding tree, wherein the node split mode information of the first-level coding tree indicates a quadtree split mode;
• parsing the bitstream to obtain node split mode information of a second-level coding tree, wherein the node split mode information of the second-level coding tree indicates a horizontal ternary split mode or a vertical ternary split mode used to split a first node of the second-level coding tree, and a root node of the second-level coding tree is the sub-node of the first-level coding tree;
• splitting the first node of the second-level coding tree into three child nodes using the horizontal ternary split mode or the vertical ternary split mode;
• parsing the bitstream to obtain node split mode information of a first child node of the first node, wherein a split mode of the first child node, indicated by the node split mode information of the first child node, is not a horizontal binary split mode when the first node of the second-level coding tree is split by the horizontal ternary split mode, or is not a vertical binary split mode when the first node of the second-level coding tree is split by the vertical ternary split mode;
• splitting the first child node into at least two sub-child nodes using the split mode of the first child node;
• and
• decoding a coding unit corresponding to a sub-child node from the at least two sub-child nodes, based on encoding information of the at least two sub-child nodes to obtain a picture corresponding to the picture data, when the sub-child node needs no further splitting.

An encoder device, comprising:

• a non-transitory memory coupled to a processor to store instructions, which when executed by the processor, cause the processor to perform operations, the operations including:
• determining a coding tree unit (CTU) corresponding to a to-be-encoded picture block, wherein the size of the CTU is 128×128;
• splitting the CTU in a node split mode corresponding to a first-level coding tree, to obtain a sub-node of the first-level coding tree, wherein a root node of the first-level coding tree corresponds to the CTU, wherein the node split mode corresponding to a first-level coding tree is a quadtree split mode;
• splitting a first node of a second-level coding tree into three child nodes using a horizontal ternary split mode or a vertical ternary split mode, wherein a root node of the second-level coding tree is the sub-node of the first-level coding tree;
• determining a split mode of a first child node of the first node from a candidate-split-mode set that does not comprise a horizontal binary split mode when the first node of the second-level coding tree is split by the horizontal ternary split mode, or does not comprise a vertical binary split mode when the first node of the second-level coding tree is split by the vertical ternary split mode;
• splitting the first child node into at least two sub-child nodes using the split mode of the first child node;
• and
• encoding a coding unit corresponding to a sub-child node from the at least two sub-child nodes, when the sub-child node needs no further splitting.