# US 2020/0404306 A1 · Method and apparatus for video coding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0404306 A1 - Document ID: US20200404306A1 - Status: Published application - Kind: A1 - Application number: 16/908,504 - Filed: 2020-06-22 - Published: 2020-12-24 - Earliest claimed: 2019-06-24 - Assignees: Tencent America LLC - Applicants: Tencent America LLC - Inventors: Cheung AUYEUNG; Xiang LI; Shan LIU - Web page: https://patentgrep.com/patent/US20200404306A1 ## CPC - H04N 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder - H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction - H04N 19/13: Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] - H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Aspects of the disclosure provide a method and an apparatus for video coding. In some examples, an apparatus includes processing circuitry that receives a bit stream that includes coded information representing a bin of a syntax element for a current block in a picture. The bin of the syntax element indicates whether a local illumination compensation (LIC) process is applied to code the current block. The processing circuitry selects a context model from multiple candidate context models applicable to coding of the syntax element, according to at least a coding characteristic of a region neighboring the current block, and decodes the coded information according to the selected context model to obtain the bin of the syntax element. The processing circuitry reconstructs the current block in response to the bin of the syntax element. ## Claims ### Claim 1 A method of video decoding, comprising: receiving a bit stream that includes coded information representing a bin of a syntax element for a current block in a picture, the bin of the syntax element indicating whether a local illumination compensation (LIC) process is applied to code the current block; selecting, by processing circuitry, a context model from multiple candidate context models applicable to coding of the syntax element, according to at least a coding characteristic of a region neighboring the current block; decoding, by the processing circuitry, the coded information according to the selected context model to obtain the bin of the syntax element; reconstructing the current block with the LIC process, in response to the bin indicating that the LIC process is applied to code the current block; and reconstructing the current block without the LIC process, in response to the bin indicating that the LIC process is not applied to code the current block. ### Claim 2 (depends on 1) The method of claim 1, wherein the selecting the context model from the multiple candidate context models comprises: determining whether at least one of top row sub-blocks or left column sub-blocks of the current block meet one or more conditions for applying the LIC process; selecting a first one of the multiple candidate context models as the selected context model in response to the at least one of the top row sub-blocks or the left column sub-blocks being determined to meet the one or more conditions; and selecting a second one of the multiple candidate context models as the selected context model in response to none of the top row sub-blocks and the left column sub-blocks being determined to meet the one or more conditions. ### Claim 3 (depends on 2) The method of claim 2, wherein the first one of the multiple candidate context models corresponds to a first probability of the bin indicating that a probability of applying the LIC process is higher than a probability of not applying the LIC process, and the second one of the multiple candidate context models corresponds to a second probability of the bin indicating that the probability of not applying the LIC process is higher than the probability of applying the LIC process. ### Claim 4 (depends on 2) The method of claim 2, wherein each one of the multiple candidate context models is associated with a corresponding context incremental index, the first one of the multiple candidate context models is associated with a first context incremental index having a value of one of 0 and 1, and the second one of the multiple candidate context models is associated with a second context incremental index having a value of the other one of 0 and 1. ### Claim 5 (depends on 2) The method of claim 2, wherein the one or more conditions comprises: for a first sub-block that is one of the top row sub-blocks, an above block neighboring an upper side of the first sub-block being coded according to an inter prediction with no residue, and for a second sub-block that is one of the left column sub-blocks, a left block neighboring a left side of the second sub-block coded according to the inter prediction with no residue. ### Claim 6 (depends on 2) The method of claim 2, wherein the one or more conditions comprises: for a first sub-block that is one of the top row sub-blocks, an above block neighboring an upper side of the first sub-block being coded with root coded block flag (CBF) not zero, the above block being coded according to an inter prediction, and the above block not being coded according to a combined intra and inter prediction (CIIP), and for a second sub-block that is one of the left column sub-blocks, a left block neighboring a left side of the second sub-block being coded with the root CBF not zero, the left block being coded according to the inter prediction, and the left block not being coded according to the CIIP. ### Claim 7 (depends on 2) The method of claim 2, wherein the top row sub-blocks and the left column sub-blocks of the current block are within an upper left 16×16 sample region of the current block in a case that the current block has a size greater than 16×16 samples. ### Claim 8 An apparatus, comprising: processing circuitry configured to: receive a bit stream that includes coded information representing a bin of a syntax element for a current block in a picture, the bin of the syntax element indicating whether a local illumination compensation (LIC) process is applied to code the current block; select a context model from multiple candidate context models applicable to coding of the syntax element, according to at least a coding characteristic of a region neighboring the current block; decode the coded information according to the selected context model to obtain the bin of the syntax element; reconstruct the current block with the LIC process, in response to the bin indicating that the LIC process is applied to code the current block; and reconstruct the current block without the LIC process, in response to the bin indicating that the LIC process is not applied to code the current block. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the processing circuitry is further configured to: determine whether at least one of top row sub-blocks or left column sub-blocks of the current block meet one or more conditions for applying the LIC process; select a first one of the multiple candidate context models as the selected context model in response to the at least one of the top row sub-blocks or the left column sub-blocks being determined to meet the one or more conditions; and select a second one of the multiple candidate context models as the selected context model in response to none of the top row sub-blocks and the left column sub-blocks being determined to meet the one or more conditions. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the first one of the multiple candidate context models corresponds to a first probability of the bin indicating that a probability of applying the LIC process is higher than a probability of not applying the LIC process, and the second one of the multiple candidate context models corresponds to a second probability of the bin indicating that a probability of not applying the LIC process is higher than the probability of applying the LIC process. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein each one of the multiple candidate context models is associated with a corresponding context incremental index, the first one of the multiple candidate context models is associated with a first context incremental index having a value of one of 0 and 1, and the second one of the multiple candidate context models is associated with a second context incremental index having a value of the other one of 0 and 1. ### Claim 12 (depends on 9) The apparatus of claim 9, wherein the one or more conditions comprises: for a first sub-block that is one of the top row sub-blocks, an above block neighboring an upper side of the first sub-block being coded according to an inter prediction with no residue, and for a second sub-block that is one of the left column sub-blocks, a left block neighboring a left side of the second sub-block being coded according to the inter prediction with no residue. ### Claim 13 (depends on 9) The apparatus of claim 9, wherein the one or more conditions comprises: for a first sub-block that is one of the top row sub-blocks, an above block neighboring an upper side of the first sub-block being coded with root coded block flag (CBF) not zero, the above block being coded according to an inter prediction, and the above block not being coded according to a combined intra and inter prediction (CIIP), and for a second sub-block that is one of the left column sub-blocks, a left block neighboring a left side of the second sub-block being coded with the root CBF not zero, the left block being coded according to the inter prediction, and the left block not being coded according to the CIIP. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein the top row sub-blocks and the left column sub-blocks of the current block are within an upper left 16×16 sample region of the current block in a case that the current block has a size greater than 16×16 samples. ### Claim 15 A non-transitory computer-readable medium storing instructions which when executed by a computer for video decoding cause the computer to perform: receiving a bit stream that includes coded information representing a bin of a syntax element for a current block in a picture, the bin of the syntax element indicating whether a local illumination compensation (LIC) process is applied to code the current block; selecting a context model from multiple candidate context models applicable to coding of the syntax element, according to at least a coding characteristic of a region neighboring the current block; decoding the coded information according to the selected context model to obtain the bin of the syntax element; reconstructing the current block with the LIC process, in response to the bin indicating that the LIC process is applied to code the current block; and reconstructing the current block without the LIC process, in response to the bin indicating that the LIC process is not applied to code the current block. ### Claim 16 (depends on 15) The non-transitory computer-readable medium of claim 15, wherein the selecting the context model from the multiple candidate context models comprises: determining whether at least one of top row sub-blocks or left column sub-blocks of the current block meet one or more conditions for applying the LIC process; selecting a first one of the multiple candidate context models as the selected context model in response to the at least one of the top row sub-blocks or the left column sub-blocks being determined to meet the one or more conditions; and selecting a second one of the multiple candidate context models as the selected context model in response to none of the top row sub-blocks and the left column sub-blocks being determined to meet the one or more conditions. ### Claim 17 (depends on 16) The non-transitory computer-readable medium of claim 16, wherein the first one of the multiple candidate context models corresponds to a first probability of the bin indicating that a probability of applying the applying LIC process is higher than a probability of not applying the LIC process, and the second one of the multiple candidate context models corresponds to a second probability of the bin indicating that the probability of not applying the LIC process is higher than the probability of applying the LIC process. ### Claim 18 (depends on 16) The non-transitory computer-readable medium of claim 16, wherein each one of the multiple candidate context models is associated with a corresponding context incremental index, the first one of the multiple candidate context models is associated with a first context incremental index having a value of one of 0 and 1, and the second one of the multiple candidate context models is associated with a second context incremental index having a value of the other one of 0 and 1. ### Claim 19 (depends on 16) The non-transitory computer-readable medium of claim 16, wherein for a first sub-block that is one of the top row sub-blocks, an above block neighboring an upper side of the first sub-block being coded with root coded block flag (CBF) not zero, the above block being coded according to an inter prediction, and the above block not being coded according to a combined intra and inter prediction (CIIP), and for a second sub-block that is one of the left column sub-blocks, a left block neighboring a left side of the second sub-block being coded with the root CBF not zero, the left block being coded according to the inter prediction, and the left block not being coded according to the CIIP. ### Claim 20 (depends on 16) The non-transitory computer-readable medium of claim 16, wherein the top row sub-blocks and the left column sub-blocks of the current block are within an upper left 16×16 sample region of the current block in a case that the current block has a size greater than 16×16 samples.