A video decoding method, comprising: parsing coding tree split information from a bitstream to obtain a current node obtaining a split mode of the current node, wherein the split mode comprises binary split, BT, mode, ternary split, TT, mode or quad-tree, QT, split mode according to Quad Tree plus Multi-Type Tree, QT-MTT, partitioning; determining, based on a depth N of the current node, coordinates of an upper-left corner of a region covered by a current quantization group; wherein if the depth N of the current node is equal to a second threshold T2 minus 1, and the split mode of the current node is a ternary split mode, determining that the coordinates of the upper-left corner of the region covered by the current quantization group are coordinates of an upper-left corner of a region covered by the current node; obtaining a quantization parameter, QP, delta of a current coding unit, CU, in the region covered by the current quantization group; and obtaining a reconstructed picture of the current CU based on the QP delta of the current CU wherein the depth N of the current node is determined based on a QT depth of the current node and a binary depth Db of the current node; wherein if the current node is an MTT root node, the binary depth Db of the current node is 0; wherein if the current node is an MTT node and is not an MTT root node, and the current node is a child node obtained in the binary split mode, the binary depth Db of the current node is a binary depth of a direct parent node of the current node plus 1, wherein an MTT split refers to one of a binary split or a ternary split; if the current node is an MTT node and is not an MTT root node, and the current node is a middle child node obtained in the ternary split mode, the binary depth Db of the current node is a binary depth of a direct parent node of the current node plus 1; if the current node is an MTT node and is not an MTT root node, and the current node is a non-middle child node obtained in the ternary split mode, the binary depth Db of the current node is a binary depth of a direct parent node of the current node plus 2. parsing coding tree split information from a bitstream to obtain a current node obtaining a split mode of the current node, wherein the split mode comprises binary split, BT, mode, ternary split, TT, mode or quad-tree, QT, split mode according to Quad Tree plus Multi-Type Tree, QT-MTT, partitioning; determining, based on a depth N of the current node, coordinates of an upper-left corner of a region covered by a current quantization group; wherein if the depth N of the current node is equal to a second threshold T2 minus 1, and the split mode of the current node is a ternary split mode, determining that the coordinates of the upper-left corner of the region covered by the current quantization group are coordinates of an upper-left corner of a region covered by the current node; obtaining a quantization parameter, QP, delta of a current coding unit, CU, in the region covered by the current quantization group; and obtaining a reconstructed picture of the current CU based on the QP delta of the current CU wherein the depth N of the current node is determined based on a QT depth of the current node and a binary depth Db of the current node; wherein if the current node is an MTT root node, the binary depth Db of the current node is 0; wherein if the current node is an MTT node and is not an MTT root node, and the current node is a child node obtained in the binary split mode, the binary depth Db of the current node is a binary depth of a direct parent node of the current node plus 1, wherein an MTT split refers to one of a binary split or a ternary split; if the current node is an MTT node and is not an MTT root node, and the current node is a middle child node obtained in the ternary split mode, the binary depth Db of the current node is a binary depth of a direct parent node of the current node plus 1; if the current node is an MTT node and is not an MTT root node, and the current node is a non-middle child node obtained in the ternary split mode, the binary depth Db of the current node is a binary depth of a direct parent node of the current node plus 2.