Arris Enterprises LLC

General Instrument Corporation

Google Inc.

Nokia Technologies Oy

Motorola Mobility LLC

Motorola Corporation

General Instrument Corporation of Delaware

Google Technology Holdings LLC

Krit Panusopone

Limin Wang

Yue Yu

Seungwook Hong

Ajay K Luthra

Koohyar Minoo

Rajeev Gandhi

David M Baylon

Jian Lou

Xue Hai Fang

Xuemin Chen

Robert Owen Eifrig

Yinqing Zhao

Jian Zhou

Wei-Ying Kung

Weiyao Lin

Miska Matias Hannuksela

Chanchal Chatterjee

Fan Ling

Jae Hoon Kim

Robert O Elfrig

Xue Fang

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 child node represented by a leaf node into two child coding units of unequal size, representing the two child coding units as leaf nodes in a binary tree branching from the parent leaf node and coding the child coding units represented by final leaf nodes of the binary tree with JVET. Disclosed is a generalized method of partitioning a block, either square or rectangular, which leads to more flexible block sizes with possible higher coding efficiency.

General block partitioning method

A method, apparatus, and computer program product provide for improving prediction accuracy of a geometric partitioning merge mode. In the context of a method, the method accesses a coding unit partitioned into a first partition and a second partition. The method also determines whether an enabling value associated with the coding unit is indicative of additional motion vector refinement and, in accordance with a determination that the enabling value associated with the coding unit is indicative of additional motion vector refinement, determines at least one motion vector difference value for at least one partition of the first partition and the second partition. The method additionally applies a prediction of the coding unit in accordance with the at least one motion vector difference value.

Geometric partitioning merge mode with merge mode with motion vector difference

A method, apparatus, and computer program product provide for management of luma mapping with chroma scaling (LMCS) processes for Gradual Decoding Refresh (GDR) pictures. In the context of a method, the method accesses a picture to be decoded and determines whether the picture is a GDR picture. The method can also prevent a LMCS decoding process from being applied to the GDR picture. Another method can determine whether a virtual boundary is within a current coding tree unit of the gradual decoding refresh picture and if so, prevent a chroma residual scaling decoding process associated with LMCS from being applied to one or more coding units within a clean area. Another method can pad a neighboring pixel area from one or more reconstructed pixels in a clean area for a chroma residual scaling decoding process associated with LMCS.

Luma mapping with chroma scaling for gradual decoding refresh

A method, apparatus, and computer program product provide for management of luma mapping with chroma scaling (LMCS) processes for Gradual Decoding Refresh (GDR) pictures. In the context of a method, the method accesses a picture to be decoded and determines whether the picture is within a GDR period. The method can also prevent a LMCS decoding process from being applied to the picture within the GDR period. Another method can determine whether a virtual boundary is within a current coding tree unit of a picture with a GDR period and if so, prevent a chroma residual scaling decoding process associated with LMCS from being applied to one or more coding units within a clean area. Another method can pad a neighboring pixel area from one or more reconstructed pixels in a clean area for a chroma residual scaling decoding process associated with LMCS.

A method of decoding JVET video includes receiving a bitstream indicating how a coding tree unit was partitioned into coding units, and parsing said bitstream to generate at least one predictor based on an intra prediction mode signaled in the bitstream. The predictor may be generated by interpolating neighboring pixels for each pixel within a coding block. The computation may be more accurate by deriving a value for a bottom right neighboring pixel.

Video bitstream coding

A method of decoding JVET video includes receiving a bitstream that includes encoded video data that includes encoded video data. From the encoded data, a horizontal predictor and a vertical predictor for a pixel in the current coding block may be interpolated. A coding block size may be identified to determine whether to use equal weight or unequal weights to apply to each of the horizontal and vertical predictors for calculating a final planar prediction value P(x,y) by comparing the coding block size to a coding block size threshold.

Adaptive unequal weight planar prediction

A method is provided for inter-coding video in which transmission bandwidth requirements associated with second motion vectors for bi-directional temporal prediction is reduced. In the method, vector information for one of motion vectors for multi-directional temporal prediction can be transmitted together with information on how to derive or construct the second motion vectors. Thus, rather than sending express information regarding each of the plurality of motion vectors, express information related to only one motion vector along with information related to reconstruction/derivation of the second motion vectors is transmitted, thus reducing bandwidth requirements and increasing coding efficiency.

Reducing overhead for multiple-hypothesis temporal prediction

A method for inter-coding video is provided in which transmission bandwidth requirements associated with second motion vectors for bi-directional temporal prediction is reduced. In the method motion vector information for only one of the two motion vectors for bi-directional temporal prediction can be transmitted together with information on how to derive or construct the second motion vector. Thus, rather than sending express information regarding two motion vectors, express information related to only one motion vector along with information related to reconstruction/derivation of the second motion vector is transmitted, thus reducing bandwidth requirements and increasing coding efficiency.

Reducing motion vector information transmission in bi-directional temporal prediction

A method and apparatus for decoding JVET video, including receiving a bitstream, and parsing said bitstream to identify a syntax element indicating an intra direction mode to use for generating at least one predictor. The intra direction mode is a first intra direction mode in a plurality of intra direction modes that includes at least one weighted intra direction mode that corresponds to a non-weighted intra direction mode. The syntax element may identify whether to use a non-weighted or weighted intra direction mode to generate the at least one predictor. Thus, the coding unit may be coded in accordance with the at least one generated predictor associated with the selected intra direction mode.

Coding weighted angular prediction for intra coding

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.

Unequal weight planar motion vector derivation

A method of decoding JVET video, 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 according to a partitioning technique. An intra direction mode for a coding unit may be selected, as well as one or more of the plurality of reference lines to generate at least one predictor for the intra direction mode. A predictor may be generated from reference samples within each selected reference line by combining predicted pixel values based on a projected position on a main reference line in combination with predicted pixel values based on a projected position on a side reference line. The predicted pixel values are weighted according to a weight parameter, wherein the weight parameter is determined based on a shift conversion factor.

Weighted angular prediction for intra coding

A method of decoding JVET video that includes receiving a bitstream indicating how a coding tree unit was partitioned into coding units, and parsing said bitstream to generate at least one predictor based on an intra prediction mode signaled in the bitstream, the intra prediction mode selected from a plurality of intra prediction modes for calculating a prediction pixel P[x,y] at coordinate x,y for the coding unit. A number of intra prediction modes available for coding the coding unit are reduced by replacing two or more non-weighted intra prediction modes by a weighted intra prediction mode.

Weighted angular prediction coding for intra coding

A method, apparatus, and computer program product provide for management of history-based motion vector prediction (HMVP) processes for Gradual Decoding Refresh (GDR) pictures, as well as efficient implementations of mode selection within a GDR period and tuning of coding tools such as in-loop filters and Luma Mapping with Chroma Scaling (LMCS) such that current coding units within a clean area avoid use of coding information within a dirty area of a picture. In the context of a method, the method accesses a current coding unit of a picture. The method also accesses information associated with coding unit references each associated with a respective inter-coded coding unit. The method also determines at least one candidate coding unit reference based at least upon a comparison of an associated index value to a dirty index, and assigns at least one coding unit to a candidate list for selection in a coding process.

History-based motion vector prediction and mode selection for gradual decoding refresh

A system and method of defining a plane for planar coding in JVET in which first and second lines can be defined based upon pixels in left-adjacent and top-adjacent coding units. In some embodiments, the least squares method can be employed to define the relevant lines. One point along each of the lines can then be identified and the y-intercepts of the two lines can be averaged to obtain a third point. The three points can then be used to identify and define a plane for planar coding in JVET.

System and method for constructing a plane for planar prediction

A second level intra prediction mode can be combined with one or more of sixty-seven JVET intra prediction modes during encoding of a coding unit in a video bitstream. Embodiments include making a position dependent intra prediction combination (PDPC) mode available as the second level intra prediction mode. In embodiments, when a PDPC (position dependent intra prediction combination) mode is enabled, the second level intra prediction is combined with one of the 67 selected intra predictor modes. In embodiments, the PDPC mode is only enabled or available for a predetermined subset of intra prediction modes (out of 67 possible modes), in order to reduce encoder complexity and potentially improve coding efficiency. The PDPC mode may be identifies as enabled or available by a list of modes or signaling in the video bitstream.

Growing community of inventors

San Diego, CA, United States of America

Krit Panusopone