# US 12,003,786 B2 · Entropy-coding for video encoding and decoding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,786 B2 - Document ID: US12003786B2 - Status: Granted - Kind: B2 - Application number: 17/428,403 - Filed: 2020-08-06 - Published: 2022-04-28 - Granted: 2024-06-04 - Earliest claimed: 2019-08-06 - Assignees: Hyundai Motor Company; Kia Corporation; Kwangwoon University Industry-Academic Collaboration Foundation - Applicants: Hyundai Motor Company; Kia Corporation; Kwangwoon University Industry-Academic Collaboration Foundation - Inventors: Dong Gyu Sim; Sea Nae Park; Jong Seok Lee; Seung Wook Park; Wha Pyeong Lim - Web page: https://patentgrep.com/patent/US12003786B2 ## CPC - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - H04N 19/103: Selection of coding mode or of prediction mode - H04N 19/13: Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] - H04N 19/136: Incoming video signal characteristics or properties - H04N 19/184: the unit being bits, e.g. of the compressed video stream - H04N 19/186: the unit being a colour or a chrominance component - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method is executed to efficiently operate a bin buffer to limit a bin-to-bit ratio in entropy encoding and decoding related to bitstream generation and parsing. In addition, a method of configuring a list includes various entropy encoding/decoding methods and adaptively uses the entropy encoding/decoding methods for each basic unit of entropy encoding/decoding. ## Claims ### Claim 1 A method for entropy decoding executed by a video decoding apparatus, the method comprising: receiving a bitstream that has been generated by encoding a picture; performing an arithmetic decoding process to generate at least one bin string each including at least one bin by decoding the bitstream; and generating a syntax element through inverse binarization of the bin string, wherein the number of bins generated by decoding the bitstream satisfies a constraint that the number does not exceed a threshold; wherein the threshold is a value calculated based on a size of the picture, a sampling ratio between a luma component and a chroma component, and a bit depth; and wherein the threshold is variably set according to a tier or level of a video. ### Claim 2 (depends on 1) The method of claim 1, wherein in order to satisfy a constraint that the number of bins does not exceed the threshold, the performing of the arithmetic decoding process comprises: increasing a counter by N per bit read and decrementing the counter by M according to occurrence of one bin, wherein M and N are natural numbers and are determined based on the threshold; and selectively performing context-based adaptive binary arithmetic decoding or uniform probability-based binary arithmetic decoding depending on whether the counter is greater than N. ### Claim 3 (depends on 1) The method of claim 1, wherein the arithmetic decoding process comprises: generating a detailed section from a current section for decoding; obtaining a current probability value for a most probable symbol (MPS) using a first context model and a second context model for each of the syntax element, and generating an MPS value; calculating a length of a section of a least probable symbol (LPS) using the detailed section and the MPS value, and updating the current section using the length of the section of the LPS; generating one bin using an offset of a preset length acquired from the bitstream and the updated current section, and re-adjusting, when a value of the LPS is determined as the one bin, the offset and the current section, wherein the value of the LPS is generated from a value of the MPS; updating the first context model and the second context model; and when the readjusted current section is less than a preset threshold, renormalizing the current section and the offset. ### Claim 4 (depends on 3) The method of claim 3, wherein the updating of the first context model and the second context model comprises: calculating a first adaptation rate and a second adaptation rate for each of the syntax element; and updating the first context model using the first adaptation rate and updating the second context model using the second adaptation rate, wherein the first context model is clipped to a maximum possible value of a probability of the first context model, and the second context model is clipped to a maximum possible value of a probability of the second context model. ### Claim 5 A method for entropy encoding syntax elements generated according to predictive encoding of each block constituting a picture, the method comprising: binarizing each of the syntax elements and generating at least one bin string each including at least one bin; performing an arithmetic coding process to generate encoded data from the bin string; and generating a bitstream comprised of one or more network abstraction layer (NAL) units from the encoded data, wherein the number of bins relative to a length of the one or more NAL units is constrained not to exceed a threshold; wherein the threshold is a value calculated based on a size of the picture, a sampling ratio between a luma component and a chroma component, and a bit depth; and wherein the threshold is variably set according to a tier or level of an image. ### Claim 6 (depends on 5) The method of claim 5, wherein when the number of bins relative to the length of the one or more NAL units exceeds the threshold, each of the one or more NAL units is configured by inserting one or more zero words of a predefined length. ### Claim 7 (depends on 5) The method of claim 5, wherein in order to satisfy a constraint that the number of bins does not exceed the threshold, the performing of the arithmetic coding process comprises: increasing a counter by N per bit and decrementing the counter by M per bin, wherein M and N are natural numbers and are determined based on the threshold; and selectively performing context-based adaptive binary arithmetic coding or uniform probability-based binary arithmetic coding depending on whether the counter is greater than N. ### Claim 8 A method for transmitting a bitstream containing encoded video data, the method comprising: generating the bitstream by encoding syntax elements generated according to predictive encoding for each block constituting a picture; and transmitting the bitstream to a video decoding apparatus, wherein generating the bitstream comprises: binarizing each of the syntax elements to generate at least one bin string each including at least one bin; performing an arithmetic coding process to generate encoded data from the bin string; and generating a bitstream comprised of one or more network abstraction layer (NAL) units from the encoded data, wherein the number of bins relative to a length of the one or more NAL units is constrained not to exceed a threshold, wherein the threshold is a value calculated based on a size of the picture, a sampling ratio between a luma component and a chroma component, and a bit depth, wherein the threshold is variably set according to a tier or level of an image.