Huawei Technologies Co., Limited

Huawei Technoloiges Co., Ltd.

Spectraquest, Inc.

Alexander Alexandrovich Karabutov

Sergey Yurievich Ikonin

Roman Igorevich Chernyak

Timofey Mikhailovich Solovyev

Elena Alexandrovna Alshina

Jianle Chen

Maxim Borisovitch Sychev

Haitao Yang

Huanbang Chen

Alexey Konstantinovich Filippov

Vasily Alexeevich Rufitskiy

Anand Meher Kotra

Victor Alexeevich Stepin

Shan Liu

Semih Esenlik

Han Gao

Yin Zhao

Biao Wang

Alexis Decurninge

Dmitry Yurievich Kuryshev

Dimitrios Tsilimantos

Stefan Valentin

Mikhail Vyacheslavovich Sosulnikov

Mikhail Lyamshev

Vladislav Mikhalevich

Manomohan Subudhl

Upendra Rohatgl

A method for coding a video implemented in an encoder or a decoder including the enhanced interpolation filter, EIF, for motion compensation, the method comprising: i) determining control point motion vectors, CPMVs, for a block according to affine inter-prediction, the block being an affine block or a sub-block of the affine block; ii) for a predefined sub-block size determining a reference area for a sub-block with the predefined sub-block size according to values of the CPMVs; iii) comparing the determined reference area with a predefined threshold; iv) applying EIF for motion compensation, comprising deriving the pixel-based motion vector field for the block; wherein if the determined reference area is larger than the threshold, deriving the pixel-based motion vector field for the block further comprises motion vector clipping, wherein motion vector clipping range is determined based on motion model of the block and the size of the block.

Affine motion model restrictions for memory bandwidth reduction of enhanced interpolation filter

A method of obtaining a chrominance quantization parameter (QP) for chrominance components based on a luminance QP for a luminance component, wherein the method is performed by a decoder, and comprises parsing a received bitstream comprising a sequence parameter set (SPS) to obtain the luminance QP and information of a mapping function (ƒ) which associates a QP index (QPi) to a chrominance QP (QPc), wherein the chroma QP mapping table is signaled in the SPS; obtaining the QPi based at least in part on the luminance QP; obtaining the mapping function based on the obtained information of the mapping function; and obtaining a QPc based on the obtained mapping function and the obtained QPi.

Method and apparatus for signaling of mapping function of chroma quantization parameter

A method for inverse quantization of a current block of a picture, the method comprising: receiving a bitstream; obtaining a joint chrominance component residual, JCCR, control flag from the bitstream; obtaining a chrominance mapping information from the bitstream based on the JCCR control flag; obtaining at least one chrominance quantization parameter, QP, offset from the bitstream based on the JCCR control flag; obtaining a QP value for the current chrominance block based on the obtained chrominance mapping information and the at least one obtained chrominance QP offset; performing inverse quantization on the current chrominance block by using the obtained QP value.

Method and apparatus for chrominance quantization parameters signalling

Methods and apparatuses are provided for estimating motion vectors of a dense motion field based on subsampled sparse motion field. The sparse motion field includes two or more motion vectors with their respective start positions. For each of the motion vectors, a transformation is derived which transforms the motion vector from its start point into a target point. The transformed motion vectors then contribute to the estimated motion vector on the target position. The contribution of each motion vector is weighted. Such motion estimation may be readily used for video encoding and decoding.

Motion compensation with a sparse optical flow representation

A method of obtaining a chrominance quantization parameter (QP) for chrominance components based on a luminance QP for luminance component, wherein the method is performed by a decoder, comprising parsing a received bitstream to obtain the luminance QP and information of a mapping function (ƒ) which associates a QP index (QPi) to the chrominance QP (QPc); obtaining the QPi based at least in a part on the luminance QP; obtaining the mapping function based on the obtained information; and obtaining a QPc based on the obtained mapping function and the obtained QPi.

A method for inverse quantization of a current block of a picture or a frame, where the method is performed by a decoder, and includes obtaining, by a decoder, from a bitstream, a joint chrominance residual (JCCR) mode for a current block of a picture or a frame, obtaining one or more quantization parameter (QP) offset values for chrominance components from the bitstream, determining at least one QP value for the current block depending on the JCCR mode, and performing an inverse quantization process on a chrominance component of the current block using the determined QP value.

Method and apparatus for chrominance QP offsets tables signaling and derivation

A method related to adaptive usage of pixel-based and block-based affine motion compensation and includes performing sub-block-based affine transform prediction on an affine block with a first sub-block size if the first sub-block size is greater than or equal to a first sub-block size threshold. If the first sub-block size is less than the first sub-block size threshold, it is determined whether a pixel-based motion vector field is not applied for performing motion compensation for the affine block. If the motion vector field is not applied, a sub-block-based affine motion prediction is performed with a second sub-block size that is based on the first sub-block size. If the pixel-based motion vector field is applied, motion compensation is performed for a sub-block of the affine block using the pixel-based motion vector field.

Usage of DCT based interpolation filter and enhanced bilinear interpolation filter in affine motion compensation

A filter, to an encoder and a decoder using the filter, to a filtering method and a corresponding program, as well as to encoding and decoding using the filtering method or the filter. The method includes obtaining of an extended reconstructed block by extending the current reconstructed block to include at least padding samples from the current reconstructed block. After padding, a current pixel of the extended reconstructed block and its neighboring pixels are loaded into a linear buffer and transformed with a one-dimensional (1D) transform. The method is performed in frequency domain using a look-up table and the filtered pixels are transformed back.

Apparatus and method for filtering in video coding

Reference picture management scheme is provided in the context of video coding. A method of decoding an encoded video sequence, comprising obtaining a value of a reference picture list (RPL) syntax element from a bitstream of the encoded video sequence, the RPL syntax element specifying whether syntax elements related to reference picture lists are present in the bitstream, when the RPL syntax element specifies that the syntax elements related to the reference picture lists are present in the bitstream, obtaining, from the bitstream, values of the syntax elements related to the reference picture lists; and constructing at least one reference picture list for inter prediction using the obtained values of the syntax elements related to the reference picture lists.

Reference picture management methods for video coding

A method of coding implemented by a decoding/encoding device for coding video data includes for a block coded in affine mode, determining control point motion vectors (CPMVs); determining a reference area in a reference picture corresponding to a sub-block of the affine coded block based on the CPMVs; setting a variable clipMVX equal to TRUE if a size of the reference area is greater than a predefined threshold, otherwise setting a variable clipMVX equal to FALSE; deriving a pixel-based motion vector field for the affine coded block; wherein, if the variable clipMVX is equal to TRUE, the deriving the pixel-based motion vector field further comprises motion vector clipping based on a first clipping range, wherein the first clipping range is determined based on the determined CPMVs and a size of the affine coded block.

Usage of DCT based interpolation filter

A method of obtaining a chrominance quantization parameter (QP) for chrominance components based on a luminance QP for a luminance component, wherein the method is performed by a decoder, and comprises parsing a received bitstream to obtain the luminance QP and information of a mapping function (ƒ) which associates a QP index (QPi) to a chrominance QP (QPc); obtaining the QPi based at least in part on the luminance QP; obtaining the mapping function based on the obtained information of the mapping function; and obtaining a QPc based on the obtained mapping function and the obtained QPi.

An apparatus for inter prediction of a sample value of a current full-integer pixel of a plurality of pixels associated with a current block of a current frame of a video signal is disclosed. The apparatus is configured to: determine a motion vector of the current full-integer pixel based on a motion compensation model; determine for the current full-integer pixel a corresponding sub-integer pixel in a reference frame; determine positions of a set of corresponding filter support pixels in the reference frame; obtain a respective sample value of the corresponding sub-integer pixel of the current full-integer pixel and the corresponding filter support pixels in the reference frame by applying a bilinear interpolation; and determine the inter predicted sample value of the current full-integer pixel.

Interpolation filter for an inter prediction apparatus and method for video coding

A method for coding video data is disclosed. The method comprises: obtaining a center motion vector of a coding block; deriving a first motion vector range for the coding block based on the center motion vector and a motion vector spread, wherein the motion vector spread depends on a size of the coding block; if the first motion vector range is at least partially pointing outside a first area including a reference picture, updating the first motion vector range to point within the first area, such that a minimum value or a maximum value of the updated first motion vector range is pointing at a boundary of the first area.

Motion vector range derivation for enhanced interpolation filter

A method for decoding of a video bitstream implemented by a decoding device, wherein the video bitstream includes data representing one or more sequence parameter set, SPS, flags, the method comprising: for an SPS flag of the one or more SPS flags, obtaining two variables of the SPS flag, respectively, by parsing the video bitstream, wherein the value of one variable of the two variables is the minimum allowed value of the SPS flag, and wherein the value of the other variable of the two variables is the maximum allowed value of the SPS flag; obtaining the SPS flag, by parsing the video bitstream; evaluating whether the value of the SPS flag is valid based on the values of the two variables; and in case that the value of the SPS flag is valid, decoding the video bitstream according to the value of the SPS flag.

Encoder, a decoder and corresponding methods of flexible profile configuration

A method for deriving motion information for a current block includes: determining whether the current block and a top neighboring block of the current block are in a same coding tree unit (CTU) or not; obtaining a position of a spatial motion information candidate for the current block; obtaining motion information corresponding to the position of the spatial motion information candidate, depending on the result of whether the current block and top neighboring block of the current block are in the same CTU; adding the obtained motion information to a motion information candidate list for the current block; obtaining a value of a first index of a motion information candidate; and deriving motion information of the current block based on the motion information candidate list and the value of the first index.

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Moscow, Russia

Alexander Alexandrovich Karabutov