# US 11,445,182 B2 · Implementation aspects in intra block copy in video coding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,182 B2 - Document ID: US11445182B2 - Status: Granted - Kind: B2 - Application number: 17/384,246 - Filed: 2021-07-23 - Published: 2021-11-25 - Granted: 2022-09-13 - Earliest claimed: 2019-03-04 - Assignees: Beijing Bytedance Network Technology Co., Ltd.; Bytedance Inc. - Applicants: Beijing Bytedance Network Technology Co., Ltd.; Bytedance Inc. - Inventors: Jizheng Xu; Li Zhang; Kai Zhang; Hongbin Liu; Yue Wang - Web page: https://patentgrep.com/patent/US11445182B2 ## CPC - 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 19/176: the region being a block, e.g. a macroblock - H04N 19/423: characterised by memory arrangements (H04N19/433 takes precedence) - H04N 19/593: involving spatial prediction techniques - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method of visual media processing includes determining, for a conversion between a current video block of visual media data and a bitstream representation of the current video block, a buffer that stores reference samples for prediction in an intra block copy mode; for a sample spatially located at location of the current video block relative to an upper-left position of a coding tree unit including the current video block and having a block vector, computing a corresponding reference in the buffer at a reference location, wherein the reference location is determined using the block vector and the location; and upon determining that the reference location lies outside the buffer, re-computing the reference location based at least in part on a location of the current video block relative to the coding tree unit including the current video block. ## Claims ### Claim 1 A method of visual media processing, comprising: determining, for a conversion of a current video block of a video and a bitstream of the video, that a first coding mode is applied on the current video block; deriving a first block vector (BVx, BVy) for the current video block; generating prediction samples for the current video block based on the first block vector and a luma buffer, wherein reconstructed samples of previous video blocks without being applied a filtering operation are stored in the luma buffer, and wherein in the first coding mode, the prediction samples are derived from a same picture including the current video block; and performing the conversion based on the prediction samples; wherein a size of the luma buffer is indicated by M=mW and N=H, wherein M is a width of the luma buffer, N is a height of the luma buffer, W is a width of a coding tree block including the current video block, and H is a height of a coding tree block including the current video block, wherein m is a positive integer and derived based on W or H, wherein W, H, M and N are all positive integers, and wherein, for any pixel (x0, y0) in the current video block, y0+BVy and x0+BVx are restricted to a certain range. ### Claim 2 (depends on 1) The method of claim 1, wherein y0+BVy should be in a range of [0, . . . , N−1], and x0+BVx should be in a range of [0, . . . , M−1]. ### Claim 3 (depends on 1) The method of claim 1, wherein the luma buffer is reset before coding a picture or a slice. ### Claim 4 (depends on 3) The method of claim 3, wherein elements of the luma buffer are reset with a fixed value. ### Claim 5 (depends on 1) The method of claim 1, wherein the reference area includes nearest available m−1 coding tree blocks in a coding tree block row. ### Claim 6 (depends on 1) The method of claim 1, wherein after reconstructing a position (x, y) relative to an upper-left corner of a picture, a value at position (x mod M, y mod N) in the luma buffer is updated with a reconstructed value of the position (x, y). ### Claim 7 (depends on 1) The method of claim 1, wherein the conversion includes encoding the current video block into the bitstream. ### Claim 8 (depends on 1) The method of claim 1, wherein the conversion includes decoding the current video block from the bitstream. ### Claim 9 An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to: determine, for a conversion of a current video block of a video and a bitstream of the video, that a first coding mode is applied on the current video block; derive a first block vector (BVx, BVy) for the current video block; generate prediction samples for the current video block based on the first block vector and a luma buffer, wherein reconstructed samples of previous video blocks without being applied a filtering operation are stored in the luma buffer, and wherein in the first coding mode, the prediction samples are derived from a same picture including the current video block; and perform the conversion based on the prediction samples, wherein a size of the luma buffer is indicated by M=mW and N=H, wherein M is a width of the luma buffer, N is a height of the luma buffer, W is a width of a coding tree block including the current video block, and H is a height of a coding tree block including the current video block, wherein m is a positive integer and derived based on W or H, wherein W, H, M and N are all positive integers, and wherein for any pixel (x0, y0) in the current video block, y0+BVy and x0+BVx are restricted to a certain range. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein y0+BVy should be in a range of [0, . . . , N−1], and x0+BVx should be in a range of [0, . . . , M−1]. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein the luma buffer is reset before coding a picture or a slice. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein elements of the luma buffer are reset with a fixed value. ### Claim 13 (depends on 9) The apparatus of claim 9, wherein the reference area includes nearest available m−1 coding tree blocks in a coding tree block row. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein after reconstructing a position (x, y) relative to an upper-left corner of a picture, a value at position (x mod M, y mod N) in the luma buffer is updated with a reconstructed value of the position (x, y). ### Claim 15 (depends on 9) The apparatus of claim 9, wherein the conversion includes encoding the current video block into the bitstream. ### Claim 16 (depends on 9) The apparatus of claim 9, wherein the conversion includes decoding the current video block from the bitstream. ### Claim 17 A non-transitory computer-readable storage medium storing instructions that cause a processor to: determine, for a conversion of a current video block of a video and a bitstream of the video, that a first coding mode is applied on the current video block; derive a first block vector (BVx, BVy) for the current video block; generate prediction samples for the current video block based on the first block vector and a luma buffer, wherein reconstructed samples of previous video blocks without being applied a filtering operation are stored in the luma buffer, and wherein in the first coding mode, the prediction samples are derived from a same picture including the current video block; and perform the conversion based on the prediction samples, wherein a size of the luma buffer is indicated by M=mW and N=H, wherein M is a width of the luma buffer, N is a height of the luma buffer, W is a width of a coding tree block including the current video block, and H is a height of a coding tree block including the current video block, wherein m is a positive integer and derived based on W or H, wherein W, H, M and N are all positive integers, and wherein for any pixel (x0, y0) in the current video block, y0+BVy and x0+BVx are restricted to a certain range. ### Claim 18 A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determining, that a first coding mode is applied on a current video block of the video; deriving a first block vector (BVx, BVy) for the current video block; generating prediction samples for the current video block based on the first block vector and a luma buffer, wherein reconstructed samples of previous video blocks without being applied a filtering operation are stored in the luma buffer, and wherein in the first coding mode, the prediction samples are derived from a same picture including the current video block; and generating the bitstream based on the prediction samples, wherein a size of the luma buffer is indicated by M=mW and N=H, wherein M is a width of the luma buffer, N is a height of the luma buffer, W is a width of a coding tree block including the current video block, and H is a height of a coding tree block including the current video block, wherein m is a positive integer and derived based on W or H, wherein W, H, M and N are all positive integers, and wherein for any pixel (x0, y0) in the current video block, y0+BVy and x0+BVx are restricted to a certain range. ### Claim 19 (depends on 17) The non-transitory computer-readable storage medium of claim 17, wherein the luma buffer is reset before coding a picture or a slice. ### Claim 20 (depends on 18) The non-transitory computer-readable recording medium of claim 18, wherein the luma buffer is reset before coding a picture or a slice.