# US 11,451,811 B2 · 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 11,451,811 B2 - Document ID: US11451811B2 - Status: Granted - Kind: B2 - Application number: 17/220,672 - Filed: 2021-04-01 - Published: 2021-10-07 - Granted: 2022-09-20 - Earliest claimed: 2020-04-05 - Assignees: Tencent America LLC - Applicants: Tencent America LLC - Inventors: Byeongdoo Choi; Shan Liu; Stephan Wenger - Web page: https://patentgrep.com/patent/US11451811B2 ## CPC - H04N 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N 19/93: Run-length coding - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. An apparatus includes processing circuitry that obtains a gate flag for each of at least one constraint information group in constraint information signaled in a coded video bitstream. Each gate flag indicates whether a constraint information group of the at least one constraint information group corresponding to the respective gate flag is present in the constraint information. The constraint information is for a subset of coding blocks in the coded video bitstream. Whether the constraint information group of the gate flag is present in the constraint information is determined based on the gate flag. The constraint information group includes at least one constraint flag for the subset of coding blocks. Prediction information for the subset of coding blocks is determined based on whether the constraint information group of the gate flag is present in the constraint information. ## Claims ### Claim 1 A method of video decoding in a decoder, comprising: obtaining a gate flag for each of at least one constraint information group in constraint information in a syntax structure signaled in a coded video bitstream, each gate flag indicating whether a constraint information group of the at least one constraint information group corresponding to the respective gate flag is present in the constraint information, the constraint information being for a subset of coding blocks in the coded video bitstream, and the constraint information group of the gate flag including a plurality of constraint flags for the subset of coding blocks, wherein the gate flag for each of the at least one constraint information group is signaled in the constraint information in the syntax structure and each gate flag indicates whether the plurality of constraint flags for the subset of coding blocks corresponding to the respective gate flag is signaled in the constraint information in the same syntax structure; determining, based on the gate flag of the constraint information group of the at least one constraint information group, whether the constraint information group of the gate flag is present in the constraint information; determining prediction information for the subset of coding blocks based on whether the constraint information group of the gate flag is present in the constraint information; and reconstructing the subset of coding blocks based on the prediction information. ### Claim 2 (depends on 1) The method of claim 1, wherein the constraint information group of the gate flag is determined to be present in the constraint information; and the determining the prediction information includes determining the prediction information for the subset of coding blocks based on the plurality of constraint flags in the constraint information group of the gate flag. ### Claim 3 (depends on 1) The method of claim 1, wherein the constraint information group of the gate flag is determined not to be present in the constraint information. ### Claim 4 (depends on 1) The method of claim 1, wherein each gate flag indicates that the constraint information group corresponding to the respective gate flag is not present in the constraint information, and no constraint flags are present in the constraint information. ### Claim 5 (depends on 1) The method of claim 1, wherein the syntax structure is a high level syntax structure for at least one picture, and the subset of coding blocks includes coding blocks in the at least one picture. ### Claim 6 (depends on 1) The method of claim 1, wherein one or more of the at least one constraint information group are present in the coded video bitstream, a plurality of constraint flags in the one or more of the at least one constraint information group is signaled according to a predetermined order, and the determining the prediction information further includes run-decoding the plurality of constraint flags; and determining the prediction information for the subset of coding blocks based on the plurality of constraint flags. ### Claim 7 (depends on 2) The method of claim 2, wherein the plurality of constraint flags in the constraint information group of the gate flag is signaled according to a predetermined order, and the determining the prediction information further includes run-decoding the plurality of constraint flags. ### Claim 8 (depends on 2) The method of claim 2, wherein an offset and a length are present in the constraint information indicating that the plurality of constraint flags in the constraint information group of the gate flag is present in the constraint information. ### Claim 9 (depends on 1) The method of claim 1, wherein one or more of the at least one constraint information group are present in the coded video bitstream; for each of the one or more of the at least one constraint information group, an offset and a length are present in the constraint information indicating that at least one constraint flag in the respective one of the one or more of the at least one constraint information group is present in the constraint information; and a number of the offsets is signaled in the coded video bitstream. ### Claim 10 (depends on 1) The method of claim 1, wherein one or more of the at least one constraint information group are present in the coded video bitstream, and one or more syntax elements in the constraint information are byte aligned, the one or more syntax elements including the gate flag for each of the at least constraint information group and a plurality of constraint flags in the one or more of the at least one constraint information group. ### Claim 11 An apparatus for video decoding, comprising processing circuitry configured to: obtain a gate flag for each of at least one constraint information group in constraint information in a syntax structure signaled in a coded video bitstream, each gate flag indicating whether a constraint information group of the at least one constraint information group corresponding to the respective gate flag is present in the constraint information, the constraint information being for a subset of coding blocks in the coded video bitstream, and the constraint information group of the gate flag including a plurality of constraint flags for the subset of coding blocks, wherein the gate flag for each of the at least one constraint information group is signaled in the constraint information in the syntax structure and each gate flag indicates whether the plurality of constraint flags for the subset of coding blocks corresponding to the respective gate flag is signaled in the constraint information in the same syntax structure; determine, based on the gate flag of the constraint information group of the at least one constraint information group, whether the constraint information group of the gate flag is present in the constraint information; determine prediction information for the subset of coding blocks based on whether the constraint information group of the gate flag is present in the constraint information; and reconstruct the subset of coding blocks based on the prediction information. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the constraint information group of the gate flag is determined to be present in the constraint information; and the processing circuitry is configured to determine the prediction information for the subset of coding blocks based on the plurality of constraint flags in the constraint information group of the gate flag. ### Claim 13 (depends on 11) The apparatus of claim 11, wherein the constraint information group of the gate flag is determined not to be present in the constraint information. ### Claim 14 (depends on 11) The apparatus of claim 11, wherein each gate flag indicates that the constraint information group corresponding to the respective gate flag is not present in the constraint information, and no constraint flags are present in the constraint information. ### Claim 15 (depends on 11) The apparatus of claim 11, wherein the syntax structure is a high level syntax structure for at least one picture, and the subset of coding blocks includes coding blocks in the at least one picture. ### Claim 16 (depends on 11) The apparatus of claim 11, wherein one or more of the at least one constraint information group are present in the coded video bitstream, a plurality of constraint flags in the one or more of the at least one constraint information group is signaled according to a predetermined order, and the processing circuitry is configured to: run-decode the plurality of constraint flags; and determine the prediction information for the subset of coding blocks based on the plurality of constraint flags. ### Claim 17 (depends on 12) The apparatus of claim 12, wherein the plurality of constraint flags in the constraint information group of the gate flag is signaled according to a predetermined order, and the processing circuitry is configured to run-decode the plurality of constraint flags. ### Claim 18 (depends on 12) The apparatus of claim 12, wherein an offset and a length are present in the constraint information indicating that the plurality of constraint flags in the constraint information group of the gate flag is present in the constraint information. ### Claim 19 (depends on 11) The apparatus of claim 11, wherein one or more of the at least one constraint information group are present in the coded video bitstream, and one or more syntax elements in the constraint information are byte aligned, the one or more syntax elements including the gate flag for each of the at least constraint information group and a plurality of constraint flags in the one or more of the at least one constraint information group. ### Claim 20 A non-transitory computer-readable storage medium storing instructions executable by at least one processor to perform: obtaining a gate flag for each of at least one constraint information group in constraint information in a syntax structure signaled in a coded video bitstream, each gate flag indicating whether a constraint information group of the at least one constraint information group corresponding to the respective gate flag is present in the constraint information, the constraint information being for a subset of coding blocks in the coded video bitstream, and the constraint information group of the gate flag including a plurality of constraint flags for the subset of coding blocks, wherein the gate flag for each of the at least one constraint information group is signaled in the constraint information in the syntax structure and each gate flag indicates whether the plurality of constraint flags for the subset of coding blocks corresponding to the respective gate flag is signaled in the constraint information in the same syntax structure; determining, based on the gate flag of the constraint information group of the at least one constraint information group, whether the constraint information group of the gate flag is present in the constraint information; determining prediction information for the subset of coding blocks based on whether the constraint information group of the gate flag is present in the constraint information; and reconstructing the subset of coding blocks based on the prediction information.