# US 2020/0404281 A1 · Dc intra mode prediction 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 2020/0404281 A1 - Document ID: US20200404281A1 - Status: Published application - Kind: A1 - Application number: 16/905,352 - Filed: 2020-06-18 - Published: 2020-12-24 - Earliest claimed: 2019-06-20 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Adarsh Krishnan Ramasubramonian; Geert Van der Auwera; Luong Pham Van; Marta Karczewicz - Web page: https://patentgrep.com/patent/US20200404281A1 ## 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 19/105: 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 19/159: 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 19/593: involving spatial prediction techniques - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract The disclosure describes examples for determining samples to use for DC intra mode prediction, such as where the samples are in a row or column that is not immediately above or immediately left of the current block. The samples may be aligned with the current block such that a last sample in the samples in a row above the current block is in same column as last column of the current block and such that a last sample in the samples in a column left of the current block is in the same row as the last row of the current block. ## Claims ### Claim 1 A method of decoding video data, the method comprising: determining samples to use for DC intra mode prediction for a current block, wherein determining the samples comprises determining a plurality of samples in at least one of: a non-adjacent row of samples having a last sample that is in the same column as a last column of the current block, wherein the non-adjacent row of samples is more than one row above the current block, or a non-adjacent column of samples having a last sample that is in the same row as a last row of the current block, wherein the non-adjacent column of samples is more than one column left of the current block; and decoding the current block using DC intra mode prediction using the determined samples. ### Claim 2 (depends on 1) The method of claim 1, wherein at least one of: the non-adjacent row of samples having the last sample that is in the same column as the last column of the current block includes a first sample that is in the same column as a first column of the current block, or the non-adjacent column of samples having the last sample that is in the same row as the last row of the current block includes a first sample that is in the same row as a first row of the current block. ### Claim 3 (depends on 1) The method of claim 1, wherein the current block comprises a first block, the non-adjacent row of samples comprises a first non-adjacent row of samples, and the non-adjacent column of samples comprises a first non-adjacent column of samples, the method further comprising: determining samples to use for DC intra mode prediction for a second block, wherein determining the samples to use for DC intra mode prediction for the second block comprises determining a plurality of samples in at least one of: a second non-adjacent row of samples having a first sample that is in first column of the second block and having a last sample that is in the same column as a last column of the current block, wherein the second non-adjacent row of samples is more than three rows above the second block, or a second non-adjacent column of samples having a first sample that is in first row of the second block and having a last sample that is in the same row as a last row of the second block, wherein the second non-adjacent column of samples is more than three columns left of the second block; and decoding the second block using DC intra mode prediction using the determined samples to use for DC intra mode prediction for the second block. ### Claim 4 (depends on 1) The method of claim 1, further comprising: receiving a syntax element indicative of a number of rows or columns the non-adjacent row of samples is above the current block or the non-adjacent column of samples is left of the current block. ### Claim 5 (depends on 1) The method of claim 1, wherein a coordinate for a top-left sample of the current block is (x0, y0), nW is width of the current block, and nH is height of the current block, and MRLIdx is indicative of a number of rows or columns the non-adjacent row of samples is above the current block or the non-adjacent column of samples is left of the current block, the method further comprising determining at least one of: the non-adjacent row of samples having coordinates (x, y0−MRLIdx−1), where x=x0 . . . x0+nW−1, or the non-adjacent column of samples having coordinates (x0−MRLIdx−1, y), where y=y0 . . . y0+nH−1. ### Claim 6 (depends on 1) The method of claim 1, further comprising: performing a weighted average of the determined samples, wherein decoding the current block comprises decoding the current block using DC intra mode prediction using the weighted average of the determined samples. ### Claim 7 (depends on 1) The method of claim 1, wherein decoding comprises: generating a prediction block based on the plurality of samples; determining a residual block, the residual block indicating a difference between the current block and the prediction block; and reconstructing the current block based on the residual block and the prediction block. ### Claim 8 A method of encoding video data, the method comprising: determining samples to use for DC intra mode prediction for a current block, wherein determining the samples comprises determining a plurality of samples in at least one of: a non-adjacent row of samples having a last sample that is in the same column as a last column of the current block, wherein the non-adjacent row of samples is more than one row above the current block, or a non-adjacent column of samples having a last sample that is in the same row as a last row of the current block, wherein the non-adjacent column of samples is more than one column left of the current block; and encoding the current block using DC intra mode prediction using the determined samples. ### Claim 9 (depends on 8) The method of claim 8, wherein at least one of: the non-adjacent row of samples having the last sample that is in the same column as the last column of the current block includes a first sample that is in the same column as a first column of the current block, or the non-adjacent column of samples having the last sample that is in the same row as the last row of the current block includes a first sample that is in the same row as a first row of the current block. ### Claim 10 (depends on 8) The method of claim 8, wherein the current block comprises a first block, the non-adjacent row of samples comprises a first non-adjacent row of samples, and the non-adjacent column of samples comprises a first non-adjacent column of samples, the method further comprising: determining samples to use for DC intra mode prediction for a second block, wherein determining the samples to use for DC intra mode prediction for the second block comprises determining a plurality of samples in at least one of: a second non-adjacent row of samples having a first sample that is in first column of the second block and having a last sample that is in the same column as a last column of the current block, wherein the second non-adjacent row of samples is more than three rows above the second block, or a second non-adjacent column of samples having a first sample that is in first row of the second block and having a last sample that is in the same row as a last row of the second block, wherein the second non-adjacent column of samples is more than three columns left of the second block; and encoding the second block using DC intra mode prediction using the determined samples to use for DC intra mode prediction for the second block. ### Claim 11 (depends on 8) The method of claim 8, further comprising: signaling a syntax element indicative of a number of rows or columns the non-adjacent row of samples is above the current block or the non-adjacent column of samples is left of the current block. ### Claim 12 (depends on 8) The method of claim 8, wherein a coordinate for a top-left sample of the current block is (x0, y0), nW is width of the current block, and nH is height of the current block, and MRLIdx is indicative of a number of rows or columns the non-adjacent row of samples is above the current block or the non-adjacent column of samples is left of the current block, the method further comprising determining at least one of: the non-adjacent row of samples having coordinates (x, y0−MRLIdx−1), where x=x0 . . . x0+nW−1, or the non-adjacent column of samples having coordinates (x0−MRLIdx−1, y), where y=y0 . . . y0+nH−1. ### Claim 13 (depends on 8) The method of claim 8, further comprising: performing a weighted average of the determined samples, wherein encoding the current block comprises encoding the current block using DC intra mode prediction using the weighted average of the determined samples. ### Claim 14 (depends on 8) The method of claim 8, wherein encoding comprises: generating a prediction block based on the plurality of samples; determining a residual block, the residual block indicating a difference between the current block and the prediction block; and signaling information indicative of the residual block. ### Claim 15 A device for decoding video data, the device comprising: memory configured to store one or more samples of rows and columns that are non-adjacent to a current block; and processing circuitry configured to: determine samples to use for DC intra mode prediction for a current block, wherein to determine the samples, the processing circuitry is configured to determine a plurality of samples in at least one of: a non-adjacent row of samples having a last sample that is in the same column as a last column of the current block, wherein the non-adjacent row of samples is more than one row above the current block, or a non-adjacent column of samples having a last sample that is in the same row as a last row of the current block, wherein the non-adjacent column of samples is more than one column left of the current block; and decode the current block using DC intra mode prediction using the determined samples. ### Claim 16 (depends on 15) The device of claim 15, wherein at least one of: the non-adjacent row of samples having the last sample that is in the same column as the last column of the current block includes a first sample that is in the same column as a first column of the current block, or the non-adjacent column of samples having the last sample that is in the same row as the last row of the current block includes a first sample that is in the same row as a first row of the current block. ### Claim 17 (depends on 15) The device of claim 15, wherein the current block comprises a first block, the non-adjacent row of samples comprises a first non-adjacent row of samples, and the non-adjacent column of samples comprises a first non-adjacent column of samples, the processing circuitry is configured to: determine samples to use for DC intra mode prediction for a second block, wherein to determine the samples to use for DC intra mode prediction for the second block, the processing circuitry is configured to determine a plurality of samples in at least one of: a second non-adjacent row of samples having a first sample that is in first column of the second block and having a last sample that is in the same column as a last column of the current block, wherein the second non-adjacent row of samples is more than three rows above the second block, or a second non-adjacent column of samples having a first sample that is in first row of the second block and having a last sample that is in the same row as a last row of the second block, wherein the second non-adjacent column of samples is more than three columns left of the second block; and decode the second block using DC intra mode prediction using the determined samples to use for DC intra mode prediction for the second block. ### Claim 18 (depends on 15) The device of claim 15, wherein the processing circuitry is configured to: receive a syntax element indicative of a number of rows or columns the non-adjacent row of samples is above the current block or the non-adjacent column of samples is left of the current block. ### Claim 19 (depends on 15) The device of claim 15, wherein a coordinate for a top-left sample of the current block is (x0, y0), nW is width of the current block, and nH is height of the current block, and MRLIdx is indicative of a number of rows or columns the non-adjacent row of samples is above the current block or the non-adjacent column of samples is left of the current block, the processing circuitry is configured to determine at least one of: the non-adjacent row of samples having coordinates (x, y0−MRLIdx−1), where x=x0 . . . x0+nW−1, or the non-adjacent column of samples having coordinates (x0−MRLIdx−1, y), where y=y0 . . . y0+nH−1. ### Claim 20 (depends on 15) The device of claim 15, wherein the processing circuitry is configured to: perform a weighted average of the determined samples, wherein to decode the current block, the processing circuitry is configured to decode the current block using DC intra mode prediction using the weighted average of the determined samples. ### Claim 21 (depends on 15) The device of claim 15, wherein to decode, the processing circuitry is configured to: generate a prediction block based on the plurality of samples; determine a residual block, the residual block indicating a difference between the current block and the prediction block; and reconstruct the current block based on the residual block and the prediction block. ### Claim 22 (depends on 15) The device of claim 15, further comprising a display configured to display decoded video data. ### Claim 23 (depends on 15) The device of claim 15, wherein the device comprises one or more of a camera, a computer, a mobile device, a broadcast receiver device, or a set-top box. ### Claim 24 A device for encoding video data, the device comprising: memory configured to store one or more samples of rows and columns that are non-adjacent to a current block; and processing circuitry configured to: determine samples to use for DC intra mode prediction for a current block, wherein to determine the samples, the processing circuitry is configured to determine a plurality of samples in at least one of: a non-adjacent row of samples having a last sample that is in the same column as a last column of the current block, wherein the non-adjacent row of samples is more than one row above the current block, or a non-adjacent column of samples having a last sample that is in the same row as a last row of the current block, wherein the non-adjacent column of samples is more than one column left of the current block; and encode the current block using DC intra mode prediction using the determined samples. ### Claim 25 (depends on 24) The device of claim 24, wherein at least one of: the non-adjacent row of samples having the last sample that is in the same column as the last column of the current block includes a first sample that is in the same column as a first column of the current block, or the non-adjacent column of samples having the last sample that is in the same row as the last row of the current block includes a first sample that is in the same row as a first row of the current block. ### Claim 26 (depends on 24) The device of claim 24, wherein to encode, the processing circuitry is configured to: generate a prediction block based on the plurality of samples; determine a residual block, the residual block indicating a difference between the current block and the prediction block; and signal information indicative of the residual block. ### Claim 27 A computer-readable storage medium storing instructions thereon that when executed cause one or more processors to: determine samples to use for DC intra mode prediction for a current block, wherein the instructions that cause the one or more processors to determine the samples comprise instructions that cause the one or more processors to determine a plurality of samples in at least one of: a non-adjacent row of samples having a last sample that is in the same column as a last column of the current block, wherein the non-adjacent row of samples is more than one row above the current block, or a non-adjacent column of samples having a last sample that is in the same row as a last row of the current block, wherein the non-adjacent column of samples is more than one column left of the current block; and decode the current block using DC intra mode prediction using the determined samples. ### Claim 28 A device for decoding video data, the device comprising: means for determining samples to use for DC intra mode prediction for a current block, wherein the means for determining the samples comprises means for determining a plurality of samples in at least one of: a non-adjacent row of samples having a last sample that is in the same column as a last column of the current block, wherein the non-adjacent row of samples is more than one row above the current block, or a non-adjacent column of samples having a last sample that is in the same row as a last row of the current block, wherein the non-adjacent column of samples is more than one column left of the current block; and means for decoding the current block using DC intra mode prediction using the determined samples.