Abstract: A device for decoding encoded point cloud data can be configured to: for a point of a point cloud, determine a first attribute value for a first color component based on a first predicted value and a first residual value; apply a scaling factor to the first residual value to determine a predicted second residual value, wherein the scaling factor has one or both of a non-integer value or an absolute value greater than one; for the point of the point cloud, receive a second residual value in the encoded point cloud data; determine a final second residual value based on the predicted second residual value and the received second residual value; and for the point of the point cloud, determine a second attribute value for a second color component based on a second predicted value and the final second residual value.

Abstract: A device for decoding encoded point cloud data can be configured to, for a point of a point cloud, determine a first color value for a first color component based on a first predicted value and a first residual value; apply a scaling factor to the first residual value to determine a predicted second residual value, wherein the scaling factor has one or both of a non-integer value or an absolute value greater than one; for the point of the point cloud, receive a second residual value in the encoded point cloud data; determine a final second residual value based on the predicted second residual value and the received second residual value; and for the point of the point cloud, determine a second color value for a second color component based on a second predicted value and the final second residual value.

Abstract: A video decoder can be configured to receive a syntax element indicating whether chroma scaling matrices are signaled for the video data; in response to determining that chroma scaling matrices are signaled for the video data, determine a chroma scaling matrix for a block of video data; determine a block of chroma transform coefficients for the block of video data; dequantize a first chroma transform coefficient of the block of chroma transform coefficients using a first scaling value from the chroma scaling matrix; dequantize a second chroma transform coefficient of the block of chroma transform coefficients using a second scaling value from the chroma quantization matrix; and determine a chroma residual block for the block of video data based on the first dequantized chroma transform coefficients and the second dequantized chroma transform coefficient.

Abstract: A video coder determines a plurality of available Matrix Intra Prediction (MIP) parameter sets (MPS's) for a picture of video data. The plurality of available MPS's is a union of (i) a subset of all default MPS's and (ii) a set of additional MPS's that are signaled in the bitstream. Each of the default MPS's is associated with a predefined MIP mode in a codec. Each of the set of additional MPS's is associated with a new MIP mode in a set of new MIP modes. The video decoder uses a MIP mode associated with an MPS in the plurality of available MPS's to generate a prediction block for a current block of the picture.

Abstract: A method of encoding point cloud data includes signaling at least one of: a first syntax element indicating that planar mode is disabled for a current node when angular mode is enabled; or a second syntax element indicating that angular mode is enabled for the current node; bypassing signaling of values for a planar mode for the current node in a condition where the first syntax element indicates that the planar mode is disabled for the current node when the angular mode is enabled, or in a condition where the second syntax element indicates that the angular mode is enabled for the current node; and encoding the current node in a mode other than the planar mode.

Abstract: Example devices and techniques for coding point cloud data are described. An example device includes memory configured to store the point cloud data and one or more processors communicatively coupled to the memory. The one or more processors are configured to determine least two reference points in a reference point cloud frame of the point cloud data. The one or more processors are configured to apply radius interpolation to the at least two reference points to obtain at least one radius inter predictor for at least one current point in a current point cloud frame of the point cloud data. The one or more processors are configured to code the current point cloud frame based on the at least one radius inter predictor for the at least one current point in the current point cloud frame.

Abstract: An example method of encoding a point cloud includes, responsive to determining that a first point of the point cloud is a first point in a first group of points of one or more groups of points of the point cloud, encoding, in a bitstream, one or more syntax elements related to inter prediction for the first group of points. The example method may further include, responsive to determining that a second point of the point cloud is included in the first group of points but is not the first point in the first group of points, skip re-encoding, for the second point, the one or more syntax elements related to inter prediction for the first group of points.

Abstract: An example device for coding point cloud data includes a memory configured to store point cloud data; and one or more processors implemented in circuitry and configured to: determine at least one of 1) that a node of an octree of the point cloud data is not inter predictable or 2) that angular mode is enabled for the node; in response to determining the at least one of 1) that the node is not inter predictable or 2) that angular mode is enabled for the node, determine an inferred direct coding mode (IDCM) mode for the node; and code occupancy data of the node using the determined IDCM mode.

Abstract: Techniques are described of using Position Dependent Intra Prediction Combination (PDPC). A video coder such as a video encoder or a video decoder utilizes PDPC in cases where a current block intra mode predicted using an angular intra prediction mode.

Abstract: A method of decoding point cloud data comprises obtaining a bitstream that includes an arithmetically encoded syntax element indicating a vertical point position offset within a node of a tree that represents 3-dimensional positions of points in a point cloud represented by the point cloud data; and decoding the vertical point position offset, wherein decoding the vertical point position offset comprises: determining a laser index of a laser candidate in a set of laser candidates, wherein the determined laser index indicates a laser beam that intersects the node; determining a context index based on whether the laser beam is above a first distance threshold, between the first distance threshold and a second distance threshold, between the second distance threshold and a third distance threshold, or below the third distance threshold; and arithmetically decoding a bin of the vertical point position offset using a context indicated by the determined context index.

Abstract: In some examples, a method of decoding a point cloud includes decoding an initial QP value from an attribute parameter set. The method also includes determining a first QP value for a first component of an attribute of point cloud data from the initial QP value. The method further includes determining a QP offset value for a second component of the attribute of the point cloud data and determining a second QP value for the second component of the attribute from the first QP value and from the QP offset value. The method includes decoding the point cloud data based on the first QP value and further based on the second QP value.

Abstract: An example device for coding point cloud data includes a memory configured to store point cloud data; and one or more processors implemented in circuitry and configured to: determine whether inter prediction data is coded for a current node of an octree of the point cloud data; determine whether planar mask data is coded for the current node; when at least one of the inter prediction data or the planar mask data is coded for the current node, avoid coding a single occupancy value for the current node, the single occupancy value indicating whether only a single sub-node of the current node includes a point; and code the current node. The processors may also be configured to determine a context for entropy coding the planar mask data according to planar mask data for a collocated node in a reference frame when the planar mask data is coded.

Abstract: In some examples, a method of decoding a point cloud includes determining a first slice QP value for a first component of an attribute in a slice of point cloud data. The method also includes decoding a first delta QP value for the first component of the attribute for a region in the slice and determining a first region QP value for the first component of the attribute in the region from the first slice QP value and from the first delta QP value. The method further includes decoding a second delta QP value for the second component of the attribute for the region and determining a second region QP value for the second component of the attribute in the region from the second delta QP value. The method includes decoding the point cloud data based on the first and second region QP values.

Abstract: An example device for processing a point cloud includes: a memory configured to store at least a portion of the point cloud; and one or more processors implemented in circuitry and configured to: obtain planar information of a reference block of the point cloud; determine, based on the planar information of the reference block, a context; context-adaptive code, based on the context, a syntax element that indicates whether a current node is coded using a planar mode; code, based on the current node being coded using the planar mode, the current node using the planar mode.

Abstract: A method of decoding point cloud data comprises obtaining a bitstream that is encoded to comply with one or more constraints and decoding the bitstream, wherein decoding the bitstream comprises: determining a residual value of a first component of an attribute of a point; generating a predicted value of a second component of the attribute of the point; and reconstructing the second component as a sum of the predicted value of the second component and a multiplication product of a scale factor for the second component and the residual value of the first component, wherein the constraints include a constraint that limits the first component of the attribute of the point, the residual value of the first component of the attribute of the point, the second component of the attribute, and the residual value of the second component of the attribute of the point to one or more predefined bitdepths.

Abstract: A video decoder can be configured to receive, for a first chroma component of a block of the video data, information for first residual samples that correspond to a difference between a first chroma block of the first chroma component and a first prediction block of the first chroma component; determine intermediate reconstructed samples based on the first residual samples; receive, for a second chroma component of the block of video data, information for second residual samples that correspond to a difference between a second chroma block of the second chroma component and the intermediate reconstructed samples; reconstruct the first chroma block based on the first residual samples and the first prediction block; reconstruct the second chroma block based on the second residual samples and the intermediate reconstructed samples; and output decoded video data comprising the reconstructed first chroma block and the reconstructed second chroma block.

Abstract: A video decoder can be configured to determine that a new scaling list for a set of scaling lists is to be predicted from a reference scaling list, wherein the new scaling list corresponds to a new scaling matrix; receive a syntax element that identifies an ID number corresponding to a scaling list of the set of scaling lists that is to be used as the reference scaling list; determine that the set of scaling lists does not include a scaling list with the ID number; and in response to determining that the set of scaling lists does not include the scaling list with the ID number, determine the new scaling matrix based on a set of default values.

Abstract: A video coder is configured to determine a split type of a block of video data from an intra prediction mode associated with a neighboring block. The video coder may determine an intra prediction mode associated with a neighboring block of the current block of video data, determine a split type of the current block of video data based on the intra prediction mode associated with the neighboring block, split the current block of video data into a plurality of sub-partitions based on the determined split type, and code the plurality of sub-partitions.

Abstract: A device for coding video data includes a processor configured to generate an inter-prediction block and an intra-prediction block for a current block of video data; for each sample of a prediction block to be generated: determine a first weight for the sample according to a position of the sample in the prediction block; determine a second weight for the sample according to the position of the sample in the prediction block; apply the first weight to a sample at the position in the inter-prediction block to generate a weighted inter-prediction sample; apply the second weight to a sample at the position in the intra-prediction block to generate a weighted intra-prediction sample; and calculate a value for the sample at the position in the prediction block using the weighted inter-prediction sample and the weighted intra-prediction sample; and code the current block using the prediction block.

Abstract: A video decoder can be configured to determine a predicted luma quantization parameter (QP) for a luma component of a coding unit; receive, in the bitstream of encoded video data, first syntax indicating a luma delta QP value for the luma component; determine a QP value for the luma component based on the predicted luma QP and the luma delta QP value; determine a predicted chroma QP for a chroma component of the coding unit; receive, in the bitstream of encoded video data, second syntax indicating a chroma delta QP value for the chroma component of the coding unit; and determine a QP value for the chroma component of the coding unit based on the predicted chroma QP and the chroma delta QP value.