Unequal weight planar motion vector derivation
A system and method of planar motion vector derivation which, in some embodiments can employ an unequal weighted combination of adjacent motion vectors. In some embodiments, motion vector information associated with a bottom right pixel or block adjacent to a current coding unit can be derived from motion information associated with a top row or top neighboring row of a current coding unit and motion information associated with a left column or left neighboring column of a current coding unit. Weighted or non-weighted combinations of such values can be combined in a planar mode prediction model to derive associated motion information for bottom and/or right adjacent pixels or blocks.
1 . A method of decoding a video included in a bitstream by a decoder, comprising:
(a) receiving said bitstream, where said bitstream includes at least one slice, indicating how a coding tree unit was partitioned into coding units according to a quad tree plus multi tree structure that allows a square parent node to be split with a quaternary tree partitioning that splits said square parent node in half in both horizontal and vertical directions to define leaf nodes that are square in shape each of which are the same size, wherein said quad tree plus multi tree structure allows one of said leaf nodes to be split based upon one selected from a group consisting of,
(i) a symmetric binary tree partitioning that splits one of said leaf nodes of said quaternary tree partitioning in half in either a horizontal direction or a vertical direction resulting in two blocks that are the same size as leaf nodes, and
(ii) an asymmetric tree partitioning that splits one of said leaf nodes of said quaternary tree partitioning in either a horizontal direction or a vertical direction resulting in three blocks two of which are different in size than a third one of said three blocks as leaf nodes;
(b) identifying final coding units to be decoded represented by leaf nodes of the quad tree plus multi tree structure where a plurality of said final coding units are rectangular coding units, where none of said plurality of rectangular coding units is a prediction unit, where none of said plurality of rectangular coding units is a transform unit, where each of said rectangular coding units are each a decision point whether to perform inter-picture or intra-picture prediction, where said bitstream does not support prediction units as a decision point whether to perform inter-picture or intra-picture prediction, where said bitstream does not support transform units as a decision point whether to perform inter-picture or intra-picture prediction;
(c) receiving both (1) a first motion vector associated with a rectangular coding unit of a B-slice of a current frame of said video, where one of said final coding units is said rectangular coding unit included in a bi-predictive slice of said current frame of said video, referencing a temporally previous reference slice of a temporally previous reference frame relative to said current frame of said rectangular coding unit, and a (2) a second motion vector associated with said rectangular coding unit of said B-slice of said current frame of said video referencing a temporally future reference slice of a temporally future frame relative to said current frame of said rectangular coding unit;
(d) wherein said rectangular coding unit of said B-slice of said current frame of said video has a top neighboring row, a left neighboring column, a bottom neighboring row and a right neighboring column, each of said top neighboring row, left neighboring column, bottom neighboring row, and right neighboring column in the said current frame;
(e) applying an optical flow between said temporally future reference slice and said temporally previous reference slice to perform modification based upon at least one of said second motion vector and said first motion vector;
(f) decoding said rectangular coding unit based upon said sample based motion modification as a result of said applying said optical flow between said temporally previous reference slice and said temporally future reference slice.
2 . A method of encoding a video included in a bitstream by an encoder, comprising:
(a) providing said bitstream, where said bitstream includes at least one slice, indicating how a coding tree unit was partitioned into coding units according to a quad tree plus multi tree structure that allows a square parent node to be split with a quaternary tree partitioning that splits said square parent node in half in both horizontal and vertical directions to define leaf nodes that are square in shape each of which are the same size, wherein said quad tree plus multi tree structure allows one of said leaf nodes to be split based upon one selected from a group consisting of,
(i) a symmetric binary tree partitioning that splits one of said leaf nodes of said quaternary tree partitioning in half in either a horizontal direction or a vertical direction resulting in two blocks that are the same size as leaf nodes, and
(ii) an asymmetric tree partitioning that splits one of said leaf nodes of said quaternary tree partitioning in either a horizontal direction or a vertical direction resulting in three blocks two of which are different in size than a third one of said three blocks as leaf nodes;
(b) wherein said bitstream is configured for identifying final coding units to be decoded represented by leaf nodes of the quad tree plus multi tree structure where a plurality of said final coding units are rectangular coding units, where none of said plurality of rectangular coding units is a prediction unit, where none of said plurality of rectangular coding units is a transform unit, where each of said rectangular coding units are each a decision point whether to perform inter-picture or intra-picture prediction, where said bitstream does not support prediction units as a decision point whether to perform inter-picture or intra-picture prediction, where said bitstream does not support transform units as a decision point whether to perform inter-picture or intra-picture prediction;
(c) providing both (1) a first motion vector associated with a rectangular coding unit of a B-slice of a current frame of said video, where one of said final coding units is said rectangular coding unit included in a bi-predictive slice of said current frame of said video, referencing a temporally previous reference slice of a temporally previous reference frame relative to said current frame of said rectangular coding unit, and a (2) a second motion vector associated with said rectangular coding unit of said B-slice of said current frame of said video referencing a temporally future reference slice of a temporally future frame relative to said current frame of said rectangular coding unit;
(d) wherein said rectangular coding unit of said B-slice of said current frame of said video has a top neighboring row, a left neighboring column, a bottom neighboring row and a right neighboring column, each of said top neighboring row, left neighboring column, bottom neighboring row, and right neighboring column in the said current frame;
(e) wherein said bitstream is configured for applying an optical flow between said temporally future reference slice and said temporally previous reference slice to perform modification based upon at least one of said second motion vector and said first motion vector;
(f) encoding said rectangular coding unit based upon said sample based motion modification as a result of said applying said optical flow between said temporally previous reference slice and said temporally future reference slice.
3 . A bitstream of compressed video data for decoding by a decoder, including a computer readable storage medium storing the compressed video data, the bitstream comprising:
(a) said bitstream, where said bitstream includes at least one slice, containing data indicating how a coding tree unit was partitioned into coding units according to a quad tree plus multi tree structure that allows a square parent node to be split with a quaternary tree partitioning that splits said square parent node in half in both horizontal and vertical directions to define leaf nodes that are square in shape each of which are the same size, wherein said quad tree plus multi tree structure allows one of said leaf nodes to be split based upon one selected from a group consisting of,
(i) a symmetric binary tree partitioning that splits one of said leaf nodes of said quaternary tree partitioning in half in either a horizontal direction or a vertical direction resulting in two blocks that are the same size as leaf nodes, and
(ii) an asymmetric tree partitioning that splits one of said leaf nodes of said quaternary tree partitioning in either a horizontal direction or a vertical direction resulting in three blocks two of which are different in size than a third one of said three blocks as leaf nodes;
(b) wherein said bitstream is configured for identifying final coding units to be decoded represented by leaf nodes of the quad tree plus multi tree structure where a plurality of said final coding units are rectangular coding units, where none of said plurality of rectangular coding units is a prediction unit, where none of said plurality of rectangular coding units is a transform unit, where each of said rectangular coding units are each a decision point whether to perform inter-picture or intra-picture prediction, where said bitstream does not support prediction units as a decision point whether to perform inter-picture or intra-picture prediction, where said bitstream does not support transform units as a decision point whether to perform inter-picture or intra-picture prediction;
(c) wherein said bitstream is configured for receiving both (1) a first motion vector associated with a rectangular coding unit of a B-slice of a current frame of said video, where one of said final coding units is said rectangular coding unit included in a bi-predictive slice of said current frame of said video, referencing a temporally previous reference slice of a temporally previous reference frame relative to said current frame of said rectangular coding unit, and a (2) a second motion vector associated with said rectangular coding unit of said B-slice of said current frame of said video referencing a temporally future reference slice of a temporally future frame relative to said current frame of said rectangular coding unit;
(d) wherein said rectangular coding unit of said B-slice of said current frame of said video has a top neighboring row, a left neighboring column, a bottom neighboring row and a right neighboring column, each of said top neighboring row, left neighboring column, bottom neighboring row, and right neighboring column in the said current frame;
(e) wherein said bitstream is configured for applying an optical flow between said temporally future reference slice and said temporally previous reference slice to perform modification based upon at least one of said second motion vector and said first motion vector;
(f) wherein said bitstream is configured for decoding said rectangular coding unit based upon said sample based motion modification as a result of said applying said optical flow between said temporally previous reference slice and said temporally future reference slice.