Abstract: A method related to adaptive usage of pixel-based and block-based affine motion compensation and includes performing sub-block-based affine transform prediction on an affine block with a first sub-block size if the first sub-block size is greater than or equal to a first sub-block size threshold. If the first sub-block size is less than the first sub-block size threshold, it is determined whether a pixel-based motion vector field is not applied for performing motion compensation for the affine block. If the motion vector field is not applied, a sub-block-based affine motion prediction is performed with a second sub-block size that is based on the first sub-block size. If the pixel-based motion vector field is applied, motion compensation is performed for a sub-block of the affine block using the pixel-based motion vector field.

Abstract: A method of coding implemented by a decoding device, comprising obtaining a video bitstream; decoding the video bitstream to obtain an initial intra prediction mode value for chroma component of a current coding block; determining whether a ratio between a width for luma component of the current coding block and a width for chroma component of the current coding block is equal to a threshold or not; obtaining a mapped intra prediction mode value for chroma component of the current coding block according to a predefined mapping relationship and the initial intra prediction mode value, when it's determined that the ratio is equal to the threshold; obtaining a prediction sample value for chroma component of the current coding block according to the mapped intra prediction mode value.

Abstract: The present disclosure provides example computer-implemented methods and decoders of video coding for prediction of a block using an inter prediction mode to obtain predicted samples for the block. One example method includes defining a size of a subblock that is smaller than the size of the block. A position of the subblock within the block is specified. One or more allowed split directions of a triangle partitioning mode (TPM) is determined for the subblock depending on which of the sides of the subblock coincide with the sides of the block. One or more predicted samples for the block is obtained by using TPM partitioning performed for the subblock in accordance with the size of the subblock, the position of the subblock within the block, and TPM split direction of the subblock. The block is reconstructed based on the one or more predicted samples.

Abstract: A method comprising: signaling a set of low-level indicators for a predicted block, wherein each of the indicators of the set enables or disables an intra prediction smoothing mechanism for the predicted block; signaling a first set of high-level indicators on a slice-level or a higher level, wherein each of the high-level indicators of the first set determines signaling for an intra prediction smoothing mechanism which is enabled or disabled by an indicator of the set of low-level indicators; and signaling a second set of high-level indicators, wherein each of the high-level indicators of the second set determines the presence of at least one of the corresponding high-level indicators of the first set, and wherein the values of corresponding high-level indicators of the first set are inferred to be zero when the value signaled by high-level indicator of the second set is zero.

Abstract: The present disclosure provides a method of decoding an encoded signal. The method includes receiving at least one bitstream comprising an encoded signal, the signal being entropy encoded with one or more Gaussian mixture models (GMMs), and the at least one bitstream comprising information for obtaining parameters of the one or more GMMs. The method further includes obtaining the GMM parameters based on the information from the at least one bitstream; and entropy decoding the signal using the GMMs with the obtained GMM parameters. The present disclosure further refers to a corresponding encoding method, decoder and encoder.

Abstract: A method of coding performed by a decoding device and a decoder are disclosed. The method comprises: obtaining a bitstream for a current picture; obtaining a quantity of tiles in a tile row of the current picture; obtaining a value of an address of a current slice comprised in the current picture; obtaining a value of a horizontal coordinate according to the value of the address of the current slice; and when a difference value between the quantity of tiles in the tile row of the current picture and the value of the horizontal coordinate is not equal to a first threshold, parsing an indication value for a slice width from the bitstream for the current picture.

Abstract: A method performs combined inter-intra prediction of a current block in video coding. The combined intra-inter-prediction is used for providing a prediction block, and the weights for the intra- and inter-prediction blocks used to obtain the prediction block can be finely tuned The method includes: determining prediction information for a neighboring block adjacent to the current block, the prediction information comprising a prediction mode used for prediction of the neighboring block, determining whether matrix-based intra prediction (MIP) is to be used for the prediction of the current block; and predicting the current block as a weighted sum of an intra-predicted block and an inter-predicted block. The weights of the inter-predicted block and the intra-predicted block are determined based on the prediction information for the neighboring block and the determining whether MIP is to be used for the prediction of the current block.

Abstract: A method of coding performed by a decoding device and a decoder are disclosed. The method comprises: obtaining a bitstream for a current picture; obtaining a quantity of tiles in a tile row of the current picture; obtaining a value of an address of a current slice, the current slice is comprised in the current picture; obtaining a value of a horizontal coordinate according to the value of the address of the current slice; parsing an indication value for a slice width from the bitsteam for the current picture, when a difference value between the quantity of tiles in the tile row of the current picture and the value of the horizontal coordinate is not equal to a first threshold.

Abstract: A conditional coding of components of an image is described. A method of encoding at least a portion of an image is provided, which comprises encoding a primary component of the image independently from at least one secondary component and encoding the at least one secondary component of the image using information from the primary component. Further, it is provided a method of encoding at least a portion of an image, comprising providing a residual comprising a primary residual component for a primary component of the image and at least one secondary residual component for at least one secondary component of the image that is different from the primary component, encoding the primary residual component independently from the at least one secondary residual component and encoding the at least one secondary residual component using information from the primary residual component.

Abstract: This application provides methods and apparatuses for encoding image or video related data into a bitstream. The present disclosure may be applied in the field of artificial intelligence (AI)-based video or picture compression technologies, and in particular, to the field of neural network-based video compression technologies. A neural network (generalized difference) is applied to a signal and a predicted signal during the encoding to obtain a generalized residual. During the decoding another neural network (generalized sum) may be applied to a reconstructed generalized residual and the predicted signal to obtain a reconstructed signal.

Abstract: A motion information storing method comprises: determining a distance between a sample set in the current block and the common boundary; and comparing the distance with a threshold to determine whether third motion information is stored for the sample set, wherein the third motion information is derived by the first motion information and the second motion information.

Abstract: A method of coding is described. The method can include obtaining a bitstream for a current picture, obtaining a value of a first indicator for the current picture according to the bitstream indicating a slice type, and obtaining a value of a second indicator for the current picture according to the bitstream indicating whether a weighted prediction parameter is present in a picture header or slice header of the bitstream. The method can also include parsing a value of the weighted prediction parameter for a current block of a current slice of the current picture from the bitstream. Furthermore, the method can include predicting the current block according to the value of the weighted prediction parameter.

Abstract: Signalling of syntax elements in a sequence parameter set of a video bitstream is addressed. Particularly, it is provided a method of decoding a video bitstream wherein a sequence parameter set, SPS, is coded that contains syntax elements that apply to a video sequence, the method comprising obtaining a value of a first syntax element from the SPS used to specify whether a decoded picture buffer, DPB, parameters syntax structure is present in the SPS and obtaining a value of a second syntax element from the SPS, at least when determining that the value of the first syntax element specifies that the DPB parameters syntax structure is present in the SPS, used to specify the presence of a DPB syntax element in the DPB parameters syntax structure, wherein the DPB syntax element is applied to a temporal sublayer except for the highest temporal sublayer in the video sequence.

Abstract: Reference picture management scheme is provided in the context of video coding. A method of decoding an encoded video sequence, comprising obtaining a value of a reference picture list (RPL) syntax element from a bitstream of the encoded video sequence, the RPL syntax element specifying whether syntax elements related to reference picture lists are present in the bitstream, when the RPL syntax element specifies that the syntax elements related to the reference picture lists are present in the bitstream, obtaining, from the bitstream, values of the syntax elements related to the reference picture lists; and constructing at least one reference picture list for inter prediction using the obtained values of the syntax elements related to the reference picture lists.

Abstract: A method of coding implemented by a decoding device, comprising obtaining a bitstream; obtaining a value of an indicator for a current block according to the bitstream; obtaining a value of a first parameter for the current block and a value of a second parameter for the current block, according to the value of the indicator and a predefined lookup table; obtaining a value of a sample distance for a sample which is located in the current block, according to the value of the first parameter and the value of the second parameter; obtaining a prediction value for the sample, according to the value of the sample distance for the sample.

Abstract: A method of coding implemented is provided. The method includes the following operations: obtained the height and width of a prediction block without applying clipping operation; calculating a value of a vertical component of an intra prediction sample based on the height and width of the prediction block; calculating a value of a horizontal component of the intra prediction sample based on the height and width of the prediction block; and generating the intra prediction sample based on the value of the vertical component and the value of the horizon component.

Abstract: Methods and apparatuses are described for entropy encoding and decoding of a latent tensor, which includes separating the latent tensor into segments in the spatial dimensions, each segment including at least one latent tensor element. An arrangement of the segments is processed by a neural network; the neural network includes at least one attention layer. Based on the processed segment a probability model is obtained for entropy encoding or decoding of a latent tensor element.

Abstract: A method of coding implemented by a decoding/encoding device for coding video data includes for a block coded in affine mode, determining control point motion vectors (CPMVs); determining a reference area in a reference picture corresponding to a sub-block of the affine coded block based on the CPMVs; setting a variable clipMVX equal to TRUE if a size of the reference area is greater than a predefined threshold, otherwise setting a variable clipMVX equal to FALSE; deriving a pixel-based motion vector field for the affine coded block; wherein, if the variable clipMVX is equal to TRUE, the deriving the pixel-based motion vector field further comprises motion vector clipping based on a first clipping range, wherein the first clipping range is determined based on the determined CPMVs and a size of the affine coded block.

Abstract: A method of coding implemented by a decoding device, comprising obtaining a video bitstream; decoding the video bitstream to obtain an initial intra prediction mode value for chroma component of a current coding block; determining whether a ratio between a width for luma component of the current coding block and a width for chroma component of the current coding block is equal to a threshold or not; obtaining a mapped intra prediction mode value for chroma component of the current coding block according to a predefined mapping relationship and the initial intra prediction mode value, when it's determined that the ratio is equal to the threshold; obtaining a prediction sample value for chroma component of the current coding block according to the mapped intra prediction mode value.

Abstract: A method of obtaining a chrominance quantization parameter (QP) for chrominance components based on a luminance QP for a luminance component, wherein the method is performed by a decoder, and comprises parsing a received bitstream to obtain the luminance QP and information of a mapping function (ƒ) which associates a QP index (QPi) to a chrominance QP (QPc); obtaining the QPi based at least in part on the luminance QP; obtaining the mapping function based on the obtained information of the mapping function; and obtaining a QPc based on the obtained mapping function and the obtained QPi.