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 length indicator associated with an encoded representation of a slice is parsed. The length indicator is indicative of a length of an extension field present in a slice header of the encoded representation. A decoder can then determine to ignore, during decoding of the encoded representation, any value of the extension field in the slice header where these values are identified based on the length indicator. As a consequence, an extension field can be added to slice headers and still enable legacy decoders to correctly decode the encoded representations.

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 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: Data that is predicted across pictures in a video sequence is managed by separating the data into multiple data types. Instead of keeping all data associated with a decoded picture, such as picture sample values and motion vector data, data associated with a decoded picture is split by data type to enable storing only a subset of all data associated with a decoded picture.

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 decodes one or more code words in a loop that is run N times by decoding an indication of whether a picture is a long-term picture or not and deriving a positive integer K[i]>0 for each long-term picture. An indicator value V[i] is derived for each long-term picture by subtracting the value of the positive integer K[i] from a picture indicator value P of the current picture. For each of the indicator values V[i], the indicator value V[i] is compared with values associated with pictures stored in the DPB. The method keeps the pictures stored in the DPB marked as short-term or long-term for which there is a match with one of the indicator values V[i] in the DPB as long-term pictures, and marks long-term pictures for which there is no match with any indicator value V[i] as unused for reference in the DPB.

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: According to an embodiment, an encoder is configured to ensure that for each long-term picture of a RPS of a picture i the value of a flag referred to as delta_poc_msb_present_flag[i] is equal to 1 when there are at least two reference pictures in a decoded picture buffer with lsb's of the POC referred to as pic_order_cnt_lsb equal to the lsb's of the respective long-term picture i denoted POC lsbLt[i]. When the delta_poc_msb_present_flag is equal to 1, the long-term picture is indicated by the full POC.

Abstract: A decoder can receive a bitstream. The bitstream can include at least one output process syntax element for configuring an output process. The decoder can determine that the output process is disabled. The decoder can decode a current picture from the bitstream. The decoder can, responsive to determining that the output process is disabled, output the current picture as an output picture.

Abstract: In encoding a picture, comprising a plurality of tiles, into a bitstream, a method and apparatus is provided for signaling the tile attribute values per-tile, using a compact syntax. These embodiments signal per-tile attribute values. The tile attributes may, for example, be in the form of a set of tile syntax elements (one syntax element per tile attribute), or for example in the form of a set of flags to enable or disable the usage of the tile attributes. These embodiments provide freedom for an encoder to assign the tile attribute values per tile, or per any subset of tiles in a picture, and the attribute values are signaled in a compact syntax at least once. A corresponding method and apparatus for decoding a picture is also described.

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: 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 and decoder for determining that a decoder conforming to a first profile is capable of decoding a first picture of a video bitstream conforming to a second profile is provided. The method includes obtaining an indicator value, the indicator value indicating conformance to a profile. The method includes determining whether the first picture in the video bitstream is a still picture. The method includes responsive to the indicator value indicating conformance to the second profile and the first picture is determined to be a still picture, determining that the decoder conforming to the first profile is capable of decoding the first picture of the video bitstream.

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: A method decodes one or more code words in a loop that is run N times by decoding an indication of whether a picture is a long-term picture or not and deriving a positive integer K[i]>0 for each long-term picture. An indicator value V[i] is derived for each long-term picture by subtracting the value of the positive integer K[i] from a picture indicator value P of the current picture. For each of the indicator values V[i], the indicator value V[i] is compared with values associated with pictures stored in the DPB. The method keeps the pictures stored in the DPB marked as short-term or long-term for which there is a match with one of the indicator values V[i] in the DPB as long-term pictures, and marks long-term pictures for which there is no match with any indicator value V[i] as unused for reference in the DPB.

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: There are provided mechanisms for signaling region information in a bitstream for region-wise unpacking of regions from a packed picture to a projected picture. The method comprises defining a scale factor that is common for all regions of a picture. The method comprises signaling the scale factor in the bitstream. The method further comprises, for each of at least one region of a picture, applying the scale factor to each item of the region information for the region to produce a set of scaled values. The method comprises signaling the scaled values in the bitstream. Mechanisms for parsing region information from a bitstream for region-wise unpacking of regions from a packed picture to a projected picture are also provided.

Abstract: According to an embodiment, an encoder is configured to ensure that for each long-term picture of a RPS of a picture i the value of a flag referred to as delta_poc_msb_present_flag[i] is equal to 1 when there are at least two reference pictures in a decoded picture buffer with lsb's of the POC referred to as pic_order_cnt_lsb equal to the lsb's of the respective long-term picture i denoted POC lsbLt[i]. When the delta_poc_msb_present_flag is equal to 1, the long-term picture is indicated by the full POC.