Abstract: A prediction unit (60) for an encoder (24) or decoder (44) implements matrix based intra prediction Input boundary samples for a current block are downsampled to obtain reduced boundary samples for matrix multiplication and/or linear interpolation, or both. In one embodiment, downsampling is performed in a manner that aligns the reduced boundary samples with an output of a matrix multiplication unit of the prediction unit. In other embodiments, downsampling is performed without averaging. The embodiments reduce the complexity of the prediction unit and the latency of the encoder (24) or decoder (44).

Abstract: A method, decoder, and apparatus are provided. Responsive to a current block being a MIP predicted block, it is determined whether it has one or multiple transform blocks. A MIP weight matrix to be used to decode the current block is determined based on a MIP prediction mode. Responsive to the MIP predicted block having one transform block, the MIP predicted block is derived based on the MIP weight matrix and previously decoded elements in the bitstream. Responsive to the MIP predicted block having multiple transform blocks: deriving a first MIP predicted block is derived based on the MIP weight matrix and previously decoded elements in the bitstream and remaining MIP predicted blocks are derived based further on decoded elements in at least one decoded transform block of the current block. The MIP predicted block(s) are output for subsequent processing.

Abstract: An encoded video sequence including a plurality of images may be decoded. First and second adjacent blocks of an image of an encoded video sequence may be provided. A line of pixels including pixels of the first and second blocks may be defined extending across a boundary between the first and second blocks. A first reference value may be calculated based on a first pixel of the pixels from the first block. A second reference value may be calculated based on a second pixel of the pixels from the second block. Filtered pixel values for each pixel of the line of pixels between the first pixel and the second pixel may be calculated using interpolation based on the first and/or second reference values. Filtered blocks may be generated using the filtered pixel values, and a decoded video sequence may be generated based on the filtered blocks.

Abstract: A method for deblocking at least one boundary of a coding unit. The method includes determining that the coding unit uses a sub-block transform, wherein the sub-block transform generates a transform sub-block boundary within the coding unit, thereby forming at least a transform sub-block within the coding unit; as a result of determining that the coding unit uses the sub-block transform, determining a maximum filter length based on a dimension of the transform sub-block within the coding unit, wherein the maximum filter length indicates a maximum number of samples to modify when deblocking a boundary of the coding unit; and deblocking the boundary of the coding unit based on the determined maximum filter length.

Abstract: A method for deblocking at least one boundary of a coding unit, wherein the boundary forms a first side and a second side of the coding unit, wherein a video picture comprises the coding unit, and wherein the first and second sides use a same reference picture. The method includes obtaining a first motion vector component in the first side; obtaining a second motion vector component in the second side; determining whether an absolute difference between the first motion vector component and the second motion vector component is equal to or larger than a predetermined threshold that is less than 1 sample; and as a result of determining that the absolute difference between the first motion vector component and the second motion vector component is equal to or larger than the predetermined threshold, applying deblocking to the vertical or horizontal boundary between the first side and the second side.

Abstract: A decoder can be configured to obtain a current inter block and a plurality of previously decoded inter blocks. Each inter block of the plurality of inter blocks can include a motion vector having a resolution. The decoder generates a list of motion vector predictor candidates that is used to predict the motion vector that is associated with the current inter block. Generating the list of motion vector predictor candidates can include defining a set of inter blocks that includes a number of previously decoded inter blocks; scanning the inter blocks in the set of inter blocks in a scanning order; and for each of the inter blocks in the set of inter blocks: deriving a motion vector prediction candidate using the motion vector of the inter block; and determining whether a criterion is satisfied.

Abstract: An encoded video sequence including a plurality of images may be decoded. First and second adjacent blocks of an image of an encoded video sequence may be provided. A line of pixels including pixels of the first and second blocks may be defined extending across a boundary between the first and second blocks. A first reference value may be calculated based on a first pixel of the pixels from the first block. A second reference value may be calculated based on a second pixel of the pixels from the second block. Filtered pixel values for each pixel of the line of pixels between the first pixel and the second pixel may be calculated using interpolation based on the first and/or second reference values. Filtered blocks may be generated using the filtered pixel values, and a decoded video sequence may be generated based on the filtered blocks.

Abstract: Methods and apparatuses for applying a deblocking to a coding unit in video pictures a provided. In one aspect, the deblocking is applied to sub-block boundaries in the coding unit and to implicit transform unit boundaries in the coding unit.

Abstract: A method for deriving a value for a first syntax element, Syntax_A. The method comprises determining whether Syntax_A is present in a bitstream. The method comprises, as a result of determining that Syntax_A is not present in the bitstream, deriving the value for Syntax_A to be equal to a first value, B, if a first condition is satisfied, or deriving the value for Syntax_A to be equal to a second value, C, if a second condition is satisfied.

Abstract: A method for deblocking at least one boundary of a coding unit. The method includes determining that the coding unit uses a sub-block transform, wherein the sub-block transform generates a transform sub-block boundary within the coding unit, thereby forming at least a transform sub-block within the coding unit; as a result of determining that the coding unit uses the sub-block transform, determining a maximum filter length based on a dimension of the transform sub-block within the coding unit, wherein the maximum filter length indicates a maximum number of samples to modify when deblocking a boundary of the coding unit; and deblocking the boundary of the coding unit based on the determined maximum filter length.

Abstract: There are provided mechanisms for encoding an image. The method comprises determining adaptive loop filter, ALF, coefficient values. The method comprises determining a scaling factor. The method further comprises generating scaled ALF coefficient values by applying the scaling factor to one or more of the ALF coefficient values. The method comprises providing the scaled ALF coefficient values to a decoder, wherein providing the scaled ALF coefficient values to the decoder comprises encoding the scaled ALF coefficient values in a bitstream and conveying the bitstream over a network. The determined ALF coefficient values reduce an error between reconstructed image components and original image components and the determined scaling factor improves subjective performance for image to be encoded.

Abstract: A method for encoding or decoding an image. The method includes obtaining a coding tree block (CTB) having a vertical size (CtbSizeY) and a horizontal size (CtbSizex), the CTB comprising set of sample values associated with the image, the set of sample values comprising a current sample value having a location (x,y) within the CTB, where x is a horizontal value and y is a vertical value. The method also includes selecting a filter strength value for the current sample based on y and filtering the current sample using the selected filter strength value. Selecting a filter strength value for the current sample based on y comprises: i) determining whether the following first condition is true: (y==(CtbSizeY?5) OR y==(CtbSizeY?4)) AND var==1, where var is a variable that is set equal to 1 as a result of a determination that a second condition is satisfied; and ii) choosing a filter strength value of 10 as a result of determining that the first condition is true.

Abstract: An asymmetric deblocking method for deblocking a boundary between a P block and a Q block such that 5 samples within the P block and 7 or 3 samples within the Q block are modified. The method includes determining a value refP based on at least p5, determining a value refQ based on at least qx, wherein qx is q3 or q7; determining a value refMiddle based on at least p0 and q0, wherein p0 is directly adjacent to the boundary and q0 is directly adjacent to the boundary; performing a linear interpolation between refP and refMiddle; and performing a linear interpolation between refQ and refMiddle.

Abstract: Methods and apparatuses for applying a deblocking to a coding unit in video pictures. In one aspect, the deblocking is applied to sub-block boundaries in the coding unit and to implicit transform unit boundaries in the coding unit.

Abstract: A method for encoding or decoding an image of a video sequence is provided. The method comprises obtaining a set of sample values associated with the image. The method comprises determining a relative location of the current sample value with respect to a virtual boundary. The virtual boundary is defined with respect to a block boundary between the first block of sample values and a second block of sample values. The virtual boundary is parallel with the block boundary and separated from the block boundary by at least one row or column of sample values included in the first block of sample values. The method comprises a filter strength value based on the determined relative location of the current sample value with respect to the virtual boundary. The method comprises filtering the current sample value based on the selected filter strength value.

Abstract: The long filter decision in VVC is modified by adding at least one gradient check that at least includes sample p6 or q6. This makes it possible to avoid using the long filters when there is some natural structure at sample p6 or q6. In one specific embodiment at least two gradient checks including both q6 and p6 are added. In another embodiment, the dpq threshold is modified from beta>>2 to beta>>4. This threshold change embodiment may be used in conjunction with or instead of the embodiment in which a gradient check that includes p6 and/or q6 is added to the long filter decision.

Abstract: A method (400) for filtering luma block edges. The method includes assigning a value to a first decision variable by performing a block edge decision process using a first set of input samples; assigning a value to a second decision variable by performing the block edge decision process using a second set of input samples; assigning a value to a third decision variable by performing the block edge decision process using a third set of input samples; and assigning a value to a fourth decision variable by performing the block edge decision process using a fourth set of input samples. The method also includes determining that a long filter condition is satisfied.

Abstract: A method for deriving a value for a first syntax element, Syntax_A. The method comprises determining whether Syntax_A is present in a bitstream. The method comprises, as a result of determining that Syntax_A is not present in the bitstream, deriving the value for Syntax_A to be equal to a first value, B, if a first condition is satisfied, or deriving the value for Syntax_A to be equal to a second value, C, if a second condition is satisfied.

Abstract: A first filter decision value is calculated for a block of pixels in a video frame based on pixel values of pixels in a first line of pixels in the block. A second filter decision value is also calculated for the block based on pixel values of pixels in a corresponding first line of pixels in a neighboring block in the video frame. The first filter decision value is used to determine how many pixels in a line of pixels in the block to filter relative to a block boundary between the block and the neighboring block. The second filter decision value is used to determine how many pixels in a corresponding line of pixels in the neighboring block to filter relative to the block boundary.

Abstract: An asymmetric deblocking method for deblocking a boundary between a P block and a Q block such that 5 samples within the P block and 7 or 3 samples within the Q block are modified. The method includes determining a value refP based on at least p5, determining a value refQ based on at least qx, wherein qx is q3 or q7; determining a value refMiddle based on at least p0 and q0, wherein p0 is directly adjacent to the boundary and q0 is directly adjacent to the boundary; performing a linear interpolation between refP and refMiddle; and performing a linear interpolation between refQ and refMiddle.