Abstract: In one example, a method for coding video data includes identifying a scan path for scanning significance information associated with a quantized transform coefficient. The method also includes determining a context support neighborhood for entropy coding the significance information associated with the quantized transform coefficient, wherein the context support neighborhood excludes one or more context support elements that are located in the scan path. The method also includes coding the significance information using the modified context support neighborhood.

Abstract: A method of decoding data indicative of a subset of transform coefficients is described. The coefficients are indicative of a block of video data. The method may include determining that no transform coefficient in the subset of transform coefficients has an absolute value greater than one, and, based on the determining, skipping one or more decoding passes on the subset of transform coefficients, the decoding passes relating to decoding level information associated with the subset of transform coefficients.

Abstract: In one example, an apparatus for coding video data comprises a video coder configured to obtain a motion vector for predicting a video block with a non-4:2:0 chroma format, determine a video block size for the video block, modify the motion vector to generate a modified motion vector for obtaining samples of at least one reference picture with which to predict the video block if the video block size meets a size criterion, and generate a prediction block for the video block using the samples of the at least one reference picture and the modified motion vector.

Abstract: A video encoder determines that the last significant coefficient (LSC) of a transform coefficient block occurs at a given ordinal position according to a coding scanning order. The video encoder generates a coordinate indicator that specifies the coordinates of a given transform coefficient in the transform coefficient block. The given transform coefficient occurs at the same ordinal position according to an assumed scanning order. A video decoder receives the coordinate indicator and converts the coordinate indicator into a scan-based LSC indicator. The scan-based LSC indicator indicates the ordinal position of the LSC.

Abstract: In one example, an apparatus for context adaptive entropy coding may include a coder configured to determine one or more initialization parameters for a context adaptive entropy coding process based on one or more initialization parameter index values. The coder may be further configured to determine one or more initial context states for initializing one or more contexts of the context adaptive entropy coding process based on the initialization parameters. The coder may be still further configured to initialize the contexts based on the initial context states. In some examples, the initialization parameters may be included in one or more tables, wherein, to determine the initialization parameters, the coder may be configured to map the initialization parameter index values to the initialization parameters in the tables. Alternatively, the coder may be configured to calculate the initialization parameters using the initialization parameter index values and one or more formulas.

Abstract: This disclosure relates to processing video data, including processing video data to conform to a high dynamic range/wide color gamut (HDR/WCG) color container. As will be explained in more detail below, the techniques of the disclosure including dynamic range adjustment (DRA) parameters and apply the DRA parameters to video data in order to make better use of an HDR/WCG color container. The techniques of this disclosure may also include signaling syntax elements that allow a video decoder or video post processing device to reverse the DRA techniques of this disclosure to reconstruct the original or native color container of the video data.

Abstract: Disclosed are techniques for coding coefficients of a video block having a non-square shape defined by a width and a height, comprising coding one or more of x- and y-coordinates that indicate a position of a last non-zero coefficient within the block according to an associated scanning order, including coding each coordinate by determining one or more contexts used to code the coordinate based on one of the width and the height that corresponds to the coordinate, and coding the coordinate by performing a context adaptive entropy coding process based on the contexts. Also disclosed are techniques for coding information that identifies positions of non-zero coefficients within the block, including determining one or more contexts used to code the information based on one or more of the width and the height, and coding the information by performing a context adaptive entropy coding process based on the contexts.

Abstract: A reduction in the number of binarizations and/or contexts used in context adaptive binary arithmetic coding (CABAC) for video coding is proposed. In particular, this disclosure proposes techniques that may lower the number contexts used in CABAC by up to 56.

Abstract: A video decoder may adaptively disable, based on a syntax element, one or more filters used for intra-prediction. In addition, the video decoder may perform intra-prediction to generate prediction data for a current block of a current video slice. Furthermore, a video encoder may adaptively disable one or more filters used for intra-prediction. Furthermore, the video encoder may signal a syntax element that controls the one or more filters. In addition, the video encoder may perform intra prediction to generate prediction data for a current video block the video data.

Abstract: In some examples, a video coder employs a two-level technique to code information that identifies a position within the block of transform coefficients of one of the coefficients that is a last significant coefficient (LSC) for the block according to a scanning order associated with the block of transform coefficients. For example, a video coder may code a sub-block position that identifies a position of one of the sub-blocks that includes the LSC within the block, and code a coefficient position that identifies a position of the LSC within the sub-block that includes the LSC.

Abstract: In an example, a method of decoding video data using palette mode may include receiving, from an encoded video bitstream, a first syntax element defining a value indicative of a scan order. The method may include receiving, from the encoded video bitstream, a second syntax element defining a value indicative of a swap operation. The method may include reconstructing a palette block from a plurality of palette index values based on the value of the second syntax element indicative of the swap operation.

Abstract: A video coding device generates a motion vector (MV) candidate list for a prediction unit (PU) of a coding unit (CU) that is partitioned into four equally-sized PUs. The video coding device converts a bi-directional MV candidate in the MV candidate list into a uni-directional MV candidate. In addition, the video coding device determines a selected MV candidate in the merge candidate list and generates a predictive video block for the PU based at least in part on one or more reference blocks indicated by motion information specified by the selected MV candidate.

Abstract: Disclosed are techniques for coding coefficients of a video block having a non-square shape defined by a width and a height, comprising coding one or more of x- and y-coordinates that indicate a position of a last non-zero coefficient within the block according to an associated scanning order, including coding each coordinate by determining one or more contexts used to code the coordinate based on one of the width and the height that corresponds to the coordinate, and coding the coordinate by performing a context adaptive entropy coding process based on the contexts. Also disclosed are techniques for coding information that identifies positions of non-zero coefficients within the block, including determining one or more contexts used to code the information based on one or more of the width and the height, and coding the information by performing a context adaptive entropy coding process based on the contexts.

Abstract: A video encoder generates a sequence of sample adaptive offset (SAO) syntax elements for a coding tree block. The SAO syntax elements include regular context-adaptive binary arithmetic coding (CABAC) coded bins for a color component and bypass-coded bins for the color component. None of the bypass-coded bins is between two of the regular CABAC-coded bins in the sequence. The video encoder uses regular CABAC to encode the regular CABAC-coded bins and uses bypass coding to encode the bypass-coded bins. The video encoder outputs the SAO syntax elements in a bitstream. A video decoder receives the bitstream, uses regular CABAC to decode the regular CABAC-coded bins, uses bypass coding to decode the bypass-coded bins, and modifies a reconstructed picture based on the SAO syntax elements.

Abstract: In an example, aspects of this disclosure relate to a method of coding data that includes coding a sequence of bins according to a context adaptive entropy coding process. A current coding cycle used to code at least one bin of the sequence of bins includes determining a context for the bin; selecting a probability model based on the context, wherein the probability model is updated based on a value of a previous bin coded with the context and coded at least two coding cycles prior to the current coding cycle; applying the probability model to code the bin; and updating the probability model based on a value of the bin.

Abstract: Techniques are described to extend palette-mode coding techniques to cases where chroma components are at a different resolution than luma components. The entries of the palette table includes three color values and the three color values or a single one of the three color values are selected based on whether a pixel includes both a luma component and chroma components or only a luma component.

Abstract: A video coding process that includes defining a context derivation neighborhood for one of a plurality of transform coefficients based on a transform coefficient scan order. The process also includes determining a context for the one of the plurality of transform coefficients based on the context derivation neighborhood. The process also includes coding the one of the plurality of transform coefficients based on the determined context.

Abstract: A device for decoding video data may be configured to determine a block of the video data is coded using a palette-based coding mode; determine a sample of the block of video data is coded using a copy from top mode or an index mode; and decode a greater than zero flag to indicate whether a run value is greater than zero, wherein the run value specifies a number of samples subsequent to the sample that have a same mode as the sample.

Abstract: A video coder determines, based at least in part on a distance between a current sub-block of a transform coefficient block and a sub-block that contains a last significant coefficient (LSC) of the transform coefficient block, coding contexts for significance flags for transform coefficients of the current sub-block. Furthermore, the video coder entropy codes, based on the coding contexts for the significance flags for the transform coefficients of the current sub-block, the significance flags for the transform coefficients of the current sub-block.

Abstract: This disclosure describes techniques for coding transform coefficients associated with a block of residual video data in a video coding process. Aspects of this disclosure include the selection of a scan order for both significance map coding and level coding, as well as the selection of contexts for entropy coding consistent with the selected scan order. This disclosure proposes a harmonization of the scan order to code both the significance map of the transform coefficients as well as to code the levels of the transform coefficient. It is proposed that the scan order for the significance map should be in the inverse direction (i.e., from the higher frequencies to the lower frequencies). This disclosure also proposes that transform coefficients be scanned in sub-sets as opposed to fixed sub-blocks. In particular, transform coefficients are scanned in a sub-set consisting of a number of consecutive coefficients according to the scan order.