# US 12,120,301 B2 · Constraining operational bit depth of adaptive loop filtering for coding of video data at different bit depth > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,301 B2 - Document ID: US12120301B2 - Status: Granted - Kind: B2 - Application number: 17/465,149 - Filed: 2021-09-02 - Published: 2022-03-31 - Granted: 2024-10-15 - Earliest claimed: 2020-09-30 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Dmytro Rusanovskyy; Luong Pham Van; Marta Karczewicz - Web page: https://patentgrep.com/patent/US12120301B2 ## CPC - H04N 19/132: Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking - H04N 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) - H04N 19/157: Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter - H04N 19/182: the unit being a pixel - H04N 19/186: the unit being a colour or a chrominance component - H04N 19/42: characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation (H04N19/635 takes precedence) - H04N 19/635: characterised by filter definition or implementation details - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N 19/82: involving filtering within a prediction loop - H04N 19/85: using pre-processing or post-processing specially adapted for video compression - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Example devices and techniques for coding video data are described. An example device includes memory configured to store the video data and one or more processors implemented in circuitry and communicatively coupled to the memory. The one or more processors being configured to adjust an input bit depth of reconstructed samples of video data to a fixed bit depth, wherein the fixed bit depth is different than the input bit depth. The one or more processors are configured to classify the reconstructed samples at the fixed bit depth and determine a filter based on the classification. The one or more processors are configured to adaptive loop filter the reconstructed samples at the input bit depth based on the determined filter and process the adaptively loop filtered samples. ## Claims ### Claim 1 A method of coding video data, the method comprising: adjusting an input bit depth of reconstructed samples of video data to a fixed bit depth, wherein the fixed bit depth is different than the input bit depth and wherein adjusting the input bit depth comprises right bit shifting of a reconstructed sample value by a number of bits to generate a right-bit-shifted reconstructed sample value, wherein the number of bits is based on the input bit depth and an operational bit depth of a classifier; classifying the reconstructed samples at the fixed bit depth; determining a filter based on the classification; adaptive loop filtering the reconstructed samples at the input bit depth based on the determined filter; and processing the adaptive loop filtered samples. ### Claim 2 (depends on 1) The method of claim 1, wherein processing the adaptive loop filtered samples comprises storing the adaptive loop filtered samples in a decoded picture buffer. ### Claim 3 (depends on 1) The method of claim 1, wherein the fixed bit depth is less than the input bit depth. ### Claim 4 (depends on 1) The method of claim 1, wherein adjusting the input bit depth comprises fetching a number of most significant bits of a reconstructed luma sample, the number being equal to the fixed bit depth. ### Claim 5 (depends on 1) The method of claim 1, further comprising applying a rounding offset to the right-bit-shifted reconstructed sample value. ### Claim 6 (depends on 1) The method of claim 1, further comprising refraining from applying a rounding offset to the right-bit-shifted reconstructed sample value. ### Claim 7 (depends on 1) The method of claim 1, wherein the adjusting the input bit depth is based on an offset value and the offset value is predetermined to be 0 or set to be 0 if the number of bits is less than 1. ### Claim 8 (depends on 1) The method of claim 1, wherein the adjusting the input bit depth comprises deriving an adjusted bit depth sample based on sample values of other color components associated with a currently processed color component. ### Claim 9 (depends on 8) The method of claim 8, wherein the other color components comprise chroma components and the currently processed color component comprises a luma component. ### Claim 10 (depends on 9) The method of claim 9, wherein deriving an adjusted bit depth sample comprises applying a color transform. ### Claim 11 A device for coding video data, the device comprising: memory configured to store the video data; and one or more processors implemented in circuitry and communicatively coupled to the memory, the one or more processors being configured to: adjust an input bit depth of reconstructed samples of video data to a fixed bit depth, wherein the fixed bit depth is different than the input bit depth and wherein as part of adjusting the input bit depth the one or more processors are configured to right bit shift a reconstructed sample value by a number of bits to generate a right-bit-shifted reconstructed sample value, wherein the number of bits is based on the input bit depth and an operational bit depth of a classifier; classify the reconstructed samples at the fixed bit depth; determine a filter based on the classification; adaptive loop filter the reconstructed samples at the input bit depth based on the determined filter; and process the adaptive loop filtered samples. ### Claim 12 (depends on 11) The device of claim 11, wherein the fixed bit depth is less than the input bit depth. ### Claim 13 (depends on 11) The device of claim 11, wherein as part of adjusting the input bit depth the one or more processors are configured to fetch a number of most significant bits of a reconstructed luma sample, the number being equal to the fixed bit depth. ### Claim 14 (depends on 11) The device of claim 11, wherein the one or more processors are further configured to apply a rounding offset to the right-bit-shifted reconstructed sample value. ### Claim 15 (depends on 11) The device of claim 11, wherein the one or more processors are further configured refrain from applying a rounding offset to the right-bit-shifted reconstructed sample value. ### Claim 16 (depends on 11) The device of claim 11, wherein the one or more processors adjust the input bit depth based on an offset value and the offset value is predetermined to be 0 or set to be 0 if the number of bits is less than 1. ### Claim 17 (depends on 11) The device of claim 11, wherein as part of adjusting the input bit depth, the one or more processors are configured to derive an adjusted bit depth sample based on sample values of other color components associated with a currently processed color component. ### Claim 18 (depends on 17) The device of claim 17, wherein the other color components comprise chroma components and the currently processed color component comprises a luma component. ### Claim 19 (depends on 18) The device of claim 18, wherein as part of deriving the adjusted bit depth sample, the one or more processors are configured to apply a color transform. ### Claim 20 (depends on 11) The device of claim 11, further comprising at least one of: a camera configured to capture the video data; or a display device configured to display the video data. ### Claim 21 A non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors to: adjust an input bit depth of reconstructed samples of video data to a fixed bit depth, wherein the fixed bit depth is different than the input bit depth and wherein as part of adjusting the input bit depth the one or more processors are configured to right bit shift a reconstructed sample value by a number of bits to generate a right-bit-shifted reconstructed sample value, wherein the number of bits is based on the input bit depth and an operational bit depth of a classifier; classify the reconstructed samples at the fixed bit depth; determine a filter based on the classification; adaptive loop filter the reconstructed samples at the input bit depth based on the determined filter; and process the adaptive loop filtered samples. ### Claim 22 A device for coding video data, the device comprising: means for adjusting an input bit depth of reconstructed samples of video data to a fixed bit depth, wherein the fixed bit depth is different than the input bit depth and wherein adjusting the input bit depth comprises right bit shifting of a reconstructed sample value by a number of bits to generate a right-bit-shifted reconstructed sample value, wherein the number of bits is based on the input bit depth and an operational bit depth of a classifier; means for classifying the reconstructed samples at the fixed bit depth; means for determining a filter based on the classification; means for adaptive loop filtering the reconstructed samples at the input bit depth based on the determined filter; and means for processing the adaptive loop filtered samples.