Abstract: An object of the embodiments is to achieve an improved reference picture handling. That is achieved by taking into account whether the reference pictures in the decoded picture buffer are long-term reference pictures or short-term reference pictures when determining how they should be marked when the information of the reference picture set is received. The reference pictures are marked as “used for short-term reference” or “used for long-term reference” in the Decoded Picture Buffer (DPB) depending on whether they are included as short-term pictures or long-term pictures in the RPS of a current picture.

Abstract: A method for determining one or more temporal sublayer properties from a bitstream is provided. The method includes determining, from the bitstream, a number N of temporal sublayers for which one or more temporal sublayer properties are specified. The method includes for each temporal sublayer of the N temporal sublayers having one or more temporal sublayer property values, decoding the one or more temporal sublayer property values from the bitstream wherein the one or more temporal sublayer property values includes one or more of: sublayer referencing information; output sublayer set information; picture width and picture height per temporal sublayer information; sublayer multiview information; sublayer auxiliary information; and/or sublayer quality information.

Abstract: A method for decoding a video bitstream comprising a sequence of pictures comprising a picture A and a picture B, wherein picture A starts a recovery point period and picture B ends the recovery point period. The method includes obtaining the video bitstream and decoding from the video bitstream a normative indication of the recovery point period. The normative indication of the recovery point period indicates that picture A starts the recovery point period and/or that picture B ends the recovery point period.

Abstract: Methods to decode a picture from a bitstream are discussed. A partitioning structure of the picture is determined, wherein the partitioning structure defines at least first and second partitions of the picture. At least one dependency syntax element is decoded from the bitstream, and whether the second partition is dependent on or independent of the first partition is determined based on the at least one dependency syntax element. The picture is decoded from the bitstream based on determining whether the second partition of the picture is dependent on or independent of the first partition of the picture. Related methods of encoding and related devices are also discussed.

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 decoding a current block in a current picture of a video bitstream includes decoding, from the video bitstream, a first motion vector for the current block relative to a first reference block of a first reference picture having a first picture order count, and decoding, from the video bitstream, a second motion vector for the current block relative to a second reference block of a second reference picture having a second picture order count. A similarity metric is generated based on a comparison of the first motion vector and the second motion vector. The method further includes determining whether to refine the first motion vector based on the similarity metric, generating a first refined motion vector from the first motion vector, and performing motion compensation to derive a first reference block from the first reference picture using the first refined motion vector.

Abstract: An encoder is configured to encode a representation of a current picture of a video stream of multiple pictures. The encoder is further configured to encode, for each of a plurality of reference pictures included in a buffer description for the current picture, a respective one-bit flag according to one of two available values for the one-bit flag. The two available values for the one-bit flag include a first value explicitly indicating to a decoder to include the reference picture in a reference picture list for decoding the current picture. The two available values for the one-bit flag further include a second value explicitly indicating to the decoder not to include the reference picture in the reference picture list for decoding the current picture. The encoder is further configured to output the representation of the current picture and the one-bit flags.

Abstract: A method for decoding a picture from a bitstream. In one embodiment, The method includes: receiving a slice header for a slice of the picture, wherein the slice header comprises a state syntax element; decoding a state value from the state syntax element in the slice header, wherein a) if the state value is not equal to a first value, then the state value indicates that i) the bitstream includes for the picture a picture header comprising a set of picture syntax elements and ii) the slice header does not comprise the set of picture syntax elements and b) if the state value is equal to the first value, then the state value indicates that i) the slice header contains said set of picture syntax elements and ii) the bitstream does not include a picture header for the picture; and using the set of picture syntax elements to decode the slice of the picture.

Abstract: A method performed by a video encoder for encoding a current picture belonging to a temporal level identified by a temporal_id. The method includes determining a Reference Picture Set (RPS) for the current picture indicating reference pictures that are kept in a decoded picture buffer (DPB) when decoding the current picture, and when the current picture is a temporal switching point. The method further includes operating to ensure that the RPS of the current picture includes no picture having a temporal_id greater than or equal to the temporal_id of the current picture.

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: There is provided a method for decoding a position and a size for a subpicture, SP, in a picture from a bitstream. The method comprises decoding a coding tree unit, CTU, size from a first syntax element, S1, in the bitstream. The method comprises obtaining a scale factor value, F, wherein F is larger than (1). The method further comprises deriving a scaled position value for the subpicture SP, wherein deriving the scaled position value comprises: i) obtaining a position value based on information in the bitstream and ii) setting the scaled position value equal to the product of the position value and F. The method comprises deriving a size of the subpicture based on the scaled position value.

Abstract: Methods to decode a picture from a bitstream are discussed. A partitioning structure of the picture is determined, wherein the partitioning structure defines at least first and second partitions of the picture. At least one dependency syntax element is decoded from the bitstream, and whether the second partition is dependent on or independent of the first partition is determined based on the at least one dependency syntax element. The picture is decoded from the bitstream based on determining whether the second partition of the picture is dependent on or independent of the first partition of the picture. Related methods of encoding and related devices are also discussed.

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 decoder receives a set of N compressed segments of a first picture, and a set of M compressed segments for a second picture that follows the first picture in a decoding order. Based on the set of N compressed segments, the decoder constructs a decodable picture for the first picture and decodes the decodable picture. Based on the set of M compressed segments, the decoder constructs a decodable second picture in the compressed domain, in which each of the segments of the first picture are placed at the same spatial position as that of a corresponding segment in the second picture and decodes the decodable second picture. Additionally, at least one Intra coded segment is placed at one of the M spatial positions in the compressed domain in which there is no segment of the N segments.

Abstract: A process for selecting a transform set for a prediction block. The process can be used in both an encoder and a decoder. For example, the process can be used in both an encoder and a decoder for a prediction block that has been predicted from a reference block. In some embodiments, both the prediction block and the reference block are intra 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: An encoded representation of a picture of a video stream is decoded by retrieving buffer description from the encoded representation. The buffer description information is used to determine at least one picture identifier identifying a respective reference picture as decoding reference for the picture. A decoded picture buffer is updated based on the determined picture identifier. The encoded representation of the picture itself comprises the information needed by a decoder to identify the reference pictures required to decode the encoded representation.

Abstract: An encoder calculates an indication to a previous reference picture having temporal identity of zero. The encoder creates a first set of indicators to the previous reference picture, to all reference pictures in a first reference picture set of the previous reference picture, and to all pictures following the previous reference picture in decoding order and precede the current picture in decoding order. The encoder sets a flag for picture order count cycle, when a long term reference picture (LTRP) has least significant bits (LSBs) of a picture order count, for which more than one picture in the first set share same value of the LSBs of picture order count as the LTRP. The decoder obtains LSB of a picture order count for a LTRP in a reference picture set of the current picture. The decoder concludes non-compliant bitstream based on indications provided by the flag.

Abstract: A method performed by a video encoder for encoding a current picture belonging to a temporal level identified by a temporal_id. The method includes determining a Reference Picture Set (RPS) for the current picture indicating reference pictures that are kept in a decoded picture buffer (DPB) when decoding the current picture, and when the current picture is a temporal switching point. The method further includes operating to ensure that the RPS of the current picture includes no picture having a temporal_id greater than or equal to the temporal_id of the current picture.