Huawei Technologies Co., Limited

Future Wei Technologies, Inc.

University of Science and Technology of China

Xiang Ma

Haitao Yang

Jianle Chen

Huanbang Chen

Shan Liu

Lian Zhang

Yin Zhao

Fan Mu

Vasily Alexeevich Rufitskiy

Alexey Konstantinovich Filippov

Sergey Yurievich Ikonin

Li Li

Roman Igorevich Chernyak

Sriram Sethuraman

Jiali Fu

Shan Gao

Houqiang Li

Yuqun Fan

Jeeva Raj A

Victor Alexeevich Stepin

Sagar Kotecha

Igor Igorevich Pasechnik

Igor Pasechnik

Roman Chernyak

An encoding or decoding method implemented by a video coding device is provided. In an encoding method, the video coding device determines a value of a reference line index of a coding unit, and determines an intra-prediction mode from a list of most probable modes when the value of the reference line index indicates an additional reference line. The video coding device also encodes coding unit into a bitstream based on the intra-prediction mode, and stores the bitstream in a memory of the video coding device. In example decoding method, the video coding device receives a bitstream, determines a value of a reference line index of a coding unit, and determines an intra-prediction mode from a list of most probable modes when a value of the reference line index indicates an additional reference line. The video coding device also decodes the coding unit based on the intra-prediction mode.

Intra-prediction with multiple refence lines

A video coding mechanism is disclosed. The mechanism includes receiving a video signal partitioned into a chroma block and a first neighboring luma block. The mechanism also includes encoding prediction information for chroma samples of the chroma block into a bitstream. The prediction information for the chroma samples is determined via intra-prediction based on down-sampled neighboring luma samples. The down-sampled neighboring luma samples are generated from a single row of luma samples from the first neighboring luma block. A bitstream including the prediction information for the chroma samples is transmitted to support decoding and display of the chroma samples.

Intra-prediction using a cross-component linear model in video coding

Disclosed are an inter prediction method based on an affine prediction mode and a related apparatus. The method includes: obtaining a predicted pixel value of a current affine block; obtaining an LIC flag of the current affine block, where the LIC flag is used to indicate whether local illumination compensation LIC is applied to the current affine block; and when the LIC flag indicates that LIC is applied to the current affine block, updating the predicted pixel value of the current affine block based on an update coefficient for LIC, to obtain an updated predicted pixel value of the current affine block.

Inter prediction method and related apparatus

The inter prediction method is provided, which includes: obtaining a predicted sample value of a current affine block; determining one or more luminance compensation blocks based on motion vectors of one or more subblocks of the current affine block; determining a linear model coefficient based on a first sample set and a second sample set, where the first sample set includes at least one reconstructed sample neighboring to an edge of the current affine block, the second sample set includes at least one reconstructed sample neighboring to an edge of the one or more luminance compensation blocks, and the sample in the first sample set is in a one-to-one correspondence with the sample in the second sample set; and updating the predicted sample value of the current affine block based on the linear model coefficient, to obtain an updated predicted sample value of the current affine block.

Inter prediction method and apparatus

This application provides a chroma block prediction method and apparatus. The method includes: obtaining chroma values of chroma samples; obtaining, luma values of luma samples corresponding to the chroma samples; obtaining, from the luma values, a first luma set and a second luma set; grouping the chroma values into a first chroma set and a second chroma set; determining a scaling coefficient in a linear model based on an average value of luma values in the first luma set, an average value of luma values in the second luma set, an average value of chroma values in the first chroma set, and an average value of chroma values in the second chroma set; determining, based on the scaling coefficient, an offset factor in the linear model; and determining prediction information of the chroma block based on the scaling coefficient and the offset factor.

Chroma block prediction method and apparatus

Apparatuses and methods for encoding and decoding are provided. The method for intra predicting a chroma sample of a block by applying cross-component linear model includes: obtaining reconstructed luma samples; determining maximum and minimum luma sample values based on the reconstructed luma samples; obtaining a difference of the maximum and minimum luma sample values. The method also includes: fetching a value out of a lookup table (LUT) by using a set of bits as an index, the set of bits following a position of the most-significant bit; obtaining linear model parameters based on the fetched value; and calculating a predicted chroma sample value by using the obtained linear model parameters. The efficiency to fetch the value out of the LUT is increased.

Method and apparatus of cross-component linear modeling for intra prediction

A method of determining one or more candidate prediction modes, the method comprises deriving, by a processor, a first indicator by parsing a bitstream, wherein the first indicator specifies whether any affine model is a candidate motion model for an image block in a preset area; determining, by the processor, that the first indicator is set to 1; deriving, by the processor and based on the determination that the first indicator is set to 1, a second indicator by parsing the bitstream, wherein the second indicator specifies whether a 6-parameter affine model is a candidate motion model for the image block; and determining, by the processor, one or more candidate prediction modes for the image block based on the first indicator and the second indicator.

Motion model signaling

A video coding device receives a bitstream including video data. The device determines an intra-prediction mode subset. The intra-prediction mode subset include intra-prediction modes that correlate to a plurality of reference lines for a current image block and excludes intra-prediction modes that correlate to a primary reference line for the current image block. When a first intra-prediction mode is included in the intra-prediction mode subset, the device decodes the first intra-prediction mode by an alternative intra-prediction mode index. When the first intra-prediction mode is not included in the intra-prediction mode subset, the device decodes the first intra-prediction mode by an intra-prediction mode index. The device presents video data including an image block decoded based on the first intra-prediction mode.

Intra-prediction with multiple reference lines

This application discloses a picture display order determining method which includes: obtaining a decoding order index value of a current picture and a decoding order index value of a previous picture that is adjacent to the current picture according to a decoding order; adding 1 to a cycle identifier value when the decoding order index value of the current picture is less than the decoding order index value of the previous picture; and determining a display order index value of the current picture based on a sum of the decoding order index value of the current picture and a preset positive integer multiple of the cycle identifier value. In this application, the display order index value of the current picture progressively increases based on a display order index value of a picture that is located before the current picture according to the decoding order.

Picture display order determining method and apparatus, and video coding device

An intra prediction method by using cross component liner prediction mode (CCLM), includes: determining a luma block corresponding to a current chroma block; obtaining luma reference samples of the luma block based on determining L available chroma reference samples of the current chroma block, wherein the obtained luma reference samples of the luma block are down-sampled luma reference samples; calculating linear model coefficients based on the luma reference samples and chroma reference samples that correspond to the luma reference samples; and obtaining a prediction for the current chroma block based on the linear model coefficients and values of a down-sampled luma block of the luma block.

Intra prediction method and device

This application provides video picture prediction methods and apparatuses. In an implementation, a method for encoding of video picture comprises generating a bitstream for video signals, the bitstream comprises a plurality of syntax elements, wherein the plurality of syntax elements comprises a first identifier indicating that an affine motion model based motion compensation is enabled for a video sequence including a picture block to be processed, wherein a second identifier is conditionally signaled at least based on a value of the first identifier, wherein a false value of the second identifier indicates that a 6-parameter affine motion model based motion compensation is disabled for the video sequence, and wherein a true value of the second identifier indicates that the 6-parameter affine motion model based motion compensation is enabled for the video sequence.

Video picture prediction method and apparatus

This application provides an example inter prediction method and a related example apparatus. One example method includes parsing a bitstream to determine prediction information of a to-be-processed picture block, where the prediction information indicates that a prediction direction of the to-be-processed picture block is bidirectional prediction, where the bitstream does not include target identification information, and where the target identification information indicates to perform local illumination compensation (LIC) on the to-be-processed picture block; and obtaining a prediction value of the to-be-processed picture block based on the prediction information.

This application provides a chroma block prediction method and apparatus. The method includes: obtaining a maximum luma value and a minimum luma value based on luma samples corresponding to neighboring samples of a target chroma block, and calculating a first difference between the maximum luma value and the minimum luma value; if the first difference is not equal to 0, processing the first difference based on a quantity of significant bits of the first difference and a first preset bit depth to obtain a second difference; and determining, based on a first chroma value, a second chroma value, and the second difference, an intra prediction model parameter corresponding to the target chroma block, and determining prediction information of the target chroma block based on the intra prediction model parameter and luma reconstruction information corresponding to the target chroma block.

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Shenzhen, China

Xiang Ma