A method of decoding a bitstream by a decoder, comprising: (a) receiving said bitstream indicating how a coding tree unit was partitioned into coding units according to a quad tree plus binary tree, QTBT, structure, wherein the QTBT structure allows a square parent block to be split with a quaternary tree partitioning that splits said square parent block in half in both horizontal and vertical directions to define four equally sized square blocks, wherein said QTBT structure allows one of said four equally sized square blocks to be split based upon one selected from a group consisting of: (i) a symmetric binary tree partitioning that splits one of said four equally sized square blocks in half in either a horizontal direction or a vertical direction resulting in two blocks that are the same size, and (ii) an asymmetric binary tree partitioning that splits one of said four equally sized square blocks in either a horizontal direction or a vertical direction resulting in two blocks that are different sizes; (b) wherein said two blocks as a result of said symmetric binary tree partitioning are allowed to be further partitioned by said symmetric binary tree partitioning; (c) wherein said two blocks as a result of said asymmetric binary tree partitioning are not permitted to be further partitioned; (d) identifying final coding units to be decoded based on the QTBT structure; and (e) decoding the identified final coding units using an intra decoding process, wherein syntax is coded in the bitstream, the syntax indicating which blocks were split with quaternary tree partitioning, which blocks were split with symmetric binary tree partitioning, and which blocks were split with asymmetric binary tree partitioning. (a) receiving said bitstream indicating how a coding tree unit was partitioned into coding units according to a quad tree plus binary tree, QTBT, structure, wherein the QTBT structure allows a square parent block to be split with a quaternary tree partitioning that splits said square parent block in half in both horizontal and vertical directions to define four equally sized square blocks, wherein said QTBT structure allows one of said four equally sized square blocks to be split based upon one selected from a group consisting of: (i) a symmetric binary tree partitioning that splits one of said four equally sized square blocks in half in either a horizontal direction or a vertical direction resulting in two blocks that are the same size, and (ii) an asymmetric binary tree partitioning that splits one of said four equally sized square blocks in either a horizontal direction or a vertical direction resulting in two blocks that are different sizes; (i) a symmetric binary tree partitioning that splits one of said four equally sized square blocks in half in either a horizontal direction or a vertical direction resulting in two blocks that are the same size, and (ii) an asymmetric binary tree partitioning that splits one of said four equally sized square blocks in either a horizontal direction or a vertical direction resulting in two blocks that are different sizes; (b) wherein said two blocks as a result of said symmetric binary tree partitioning are allowed to be further partitioned by said symmetric binary tree partitioning; (c) wherein said two blocks as a result of said asymmetric binary tree partitioning are not permitted to be further partitioned; (d) identifying final coding units to be decoded based on the QTBT structure; and (e) decoding the identified final coding units using an intra decoding process,