Abstract: A method for decoding point cloud data comprises, based on a comparison of a maximum difference value and a threshold, applying an inverse function to a set of one or more jointly coded values to recover (i) residual values for attribute values of a current point of point cloud data and (ii) a predictor index that indicates a predictor in a predictor list, wherein predictors in the predictor list are based on attribute values of one or more neighbor points; determining predicted attribute values based on the predictor index; and reconstructing the attribute values of the current point based on the residual values and the predicted attribute values.

Abstract: Techniques are described using Position Dependent Intra Prediction Combination (PDPC) with wide angle intra prediction. For example, a size of the current block of video data can be determined. Based on the size, a wide angle intra-prediction mode can be determined for the current block. A prediction block for the current block can be determined using the wide angle intra-prediction mode. A prediction sample from the prediction block can be modified to generate a modified prediction sample using PDPC, which can include determining one or more reference samples that are external to the current block based on the wide angle intra-prediction mode, and modifying the prediction sample to generate the modified prediction sample based on the determined one or more reference samples.

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 method of decoding video data includes predicting luma samples for a block of the video data using matrix intra prediction (MIP), where using MIP comprises down-sampling a set of luma neighboring samples to generate down-sampled luma neighboring samples. The method further includes predicting chroma samples for the block using cross-component linear model (CCLM) prediction, where using CCLM prediction comprises predicting the chroma samples for the block based on the down-sampled luma neighboring samples generated from the MIP. The method further includes determining a prediction block for the block based on the luma samples and the chroma samples, decoding a residual block for the block, and combining the prediction block and the residual block to decode the block.

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 method of decoding a point cloud comprises: reconstructing a position of a point of the point cloud; determining a quantized attribute value for the point; deriving a quantization parameter (QP) bit depth offset for the point; deriving a QP range for the point based on the QP bit depth offset for the point; determining a quantization step size for the point based on the QP range for the point; and inverse quantizing the quantized attribute value for the point based on the quantization step size for the point.

Abstract: An example device for coding a point cloud includes a memory configured to store the point cloud and one or more processors communicatively coupled to the memory. The one or more processors are configured to determine a value of a numerator syntax element, the value of the numerator syntax element being indicative of a numerator of a scale factor of the point cloud. The one or more processors are configured to determine a value of a denominator syntax element, the value of the denominator syntax element being indicative of a denominator of the scale factor of the point cloud. The one or more processors are configured to process the point cloud at least in part based on the scale factor of the point cloud.

Abstract: A video decoder configured to determine a block of video data is intra predicted using an angular intra prediction mode, wherein the angular intra prediction mode is one of a bottom-left intra prediction mode or a top-right intra prediction mode; determine an aspect ratio of the block; locate one or more reference samples corresponding to the angular intra prediction mode; apply position dependent intra prediction combination to the reference samples to determine modified reference samples based on the aspect ratio of the block; and generate a predictive block for the block based on the modified reference samples.

Abstract: A method of encoding video data includes determining a first rate-distortion value associated with encoding a first chroma block of a coding unit of the video data with a first transform type, determining a second rate-distortion value associated with encoding the first chroma block of the coding unit of the video data with a second transform type, determining that the first transform type provides better rate-distortion than second transform type based on the first rate-distortion value and the second rate-distortion value, based on the determination that the first transform type provides better rate-distortion, determining a third rate-distortion value associated with encoding the coding unit with joint coding of chroma residuals (JCCR) with the first transform type, and avoiding determining a fourth rate-distortion value associated with encoding the coding unit with JCCR with the second transform type, and encoding the coding unit with JCCR with the first transform type.

Abstract: A video encoder and video decoder may code video data using intra prediction and a block-based delta pulse code modulation (BDPCM) mode. The BDPCM mode may include a vertical mode and a horizontal mode. The video encoder and video decoder may be configured to align the direction of an intra prediction mode to the direction of a BDPCM mode for both luma and chroma blocks.

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: An example device for decoding video data includes a memory configured to store video data; and one or more processors implemented in circuitry and configured to: generate an intra-prediction block for a current block of video data using an angular intra-prediction mode, the angular intra-prediction mode being an upper-right angular intra-prediction mode or a lower-left angular intra-prediction mode; determine a prediction direction of the angular intra-prediction mode; for at least one sample of the intra-prediction block for the current block: calculate a gradient term for the at least one sample along the prediction direction; and combine a value of an intra-predicted sample of the intra-prediction block at a position of the at least one sample of the intra-prediction block with the gradient term to produce a value of the at least one sample of the intra-prediction block; and decode the current block using the intra-prediction block.

Abstract: Provided are systems and methods for processing 360-degree video data by obtaining at least one 360-degree rectangular formatted projected picture; detecting a projection boundary in the at least one 360-degree rectangular formatted projected picture; disabling at least one of an in-loop filtering, an intra-prediction, or an inter-prediction, based on detecting the at least one 360-degree rectangular formatted projected picture comprises the projection boundary; and generating an encoded video bitstream.

Abstract: Provided are systems and methods for processing 360-degree video data. In various implementations, a spherical representation of a 360-degree video frame can be segmented into a top region, a bottom region, and a middle region. The middle region can be mapped into one or more rectangular areas of an output video frame. The top region can be mapped into a first rectangular area of the output video frame using a mapping that converts a square to a circle, such that pixels in the circular top region are expanded to fill the first rectangular region. The bottom region can be mapped into a second rectangular area of the output video frame such that pixels in the circular bottom region are expanded to fill the second rectangular region.

Abstract: A video decoder can be configured to determine that a block of the video data is encoded using an adaptive color transform (ACT); determine that the block is encoded in a joint chroma mode, wherein for the joint chroma mode a single chroma residual block is encoded for a first chroma component of the block and a second chroma component of the block; determine a quantization parameter (QP) for the block; determine an ACT quantization parameter (QP) offset for the block based on the block being encoded using the ACT and encoded in the joint chroma mode; and determine an ACT QP for the block based on the QP and the ACT QP offset.

Abstract: A video coder selects a set of wide-angle intra prediction directions based on a size of a luma block of a picture having a YUV 4:2:2 chroma sampling format. Additionally, the video coder determines an intra prediction direction for the luma block. The intra prediction direction for the luma block is in the set of wide-angle intra prediction directions. The video coder also determines an intra prediction direction for a chroma block. The luma block is collocated in the picture with the chroma block. The chroma block has a different width/height ratio than the luma block. The intra prediction direction for the chroma block is guaranteed to have the intra prediction direction for the luma block. The video coder uses the intra prediction directions for the luma and chroma blocks to generate prediction blocks for the luma and chroma blocks, respectively.

Abstract: In some examples, a device includes a memory configured to store a current block of the video data and one or more processors coupled to the memory. The one or more processors may be configured to derive a reference sample position (RSP) for a current sample of a current block according to one or more RSP derivation models. The one or more RSP derivation models may include a circular model, an elliptical model, a piece-wise linear model, a table-based model, or a parametric model. The one or more processors may be further configured to determine a reference sample value for a reference sample at the RSP, determine a predicted value for the current sample using the reference sample value, and code the current sample using the predicted value.

Abstract: An example method includes decoding, from an encoded video bitstream, a sequence parameter set (SPS) referred to by one or more pictures of video data, wherein decoding the SPS comprises: parsing, at a first position in the SPS, a syntax element that indicates whether joint coding of chroma residuals is enabled or disabled for the one or more pictures of video data referring to the SPS; and parsing, at a second position in the SPS that is after the first position, one or more syntax elements representing a quantization parameter (QP) mapping table.

Abstract: A video decoder obtains a transpose flag from the bitstream. The video decoder determines an input vector based on neighboring samples for a current block of the video data. The transpose flag indicates whether the input vector is transposed. Additionally, the video decoder determines a prediction signal. Determining the prediction signal includes multiplying a MIP matrix by the input vector. The prediction signal includes values corresponding to a first set of locations in a prediction block for the current block and the MIP matrix corresponds to the MIP mode index. The video decoder applies an interpolation process to the prediction signal to determine values corresponding to a second set of locations in the prediction block for the current block.

Abstract: An example device for coding video data includes a 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 are configured to determine whether scaling matrices may be applied to a low-frequency non-separable transform (LFNST) coded block. The one or more processors are also configured to, based on a determination that scaling matrices may not be applied to the LFNST coded block, not applying the scaling matrices to the LFNST coded block. The one or more processors are also configured to code the video data without applying the scaling matrices to the LFNST coded block.