Telefonaktiebolaget Lm Ericsson (publ)

Mitra Damghanian

Martin Pettersson

Rickard Sjöberg

Jack Enhorn

Jacob Ström

Zhi Zhang

Ruoyang Yu

Per Wennersten

Kenneth Andersson

Du Liu

Davood Saffar

There is provided a referencing mechanism for messages (e.g., SEI messages) in order to reduce the bit cost when different versions of messages (e.g., SEI messages) are used in an arbitrary manner in the bitstream, e.g. in an alternating way in the bitstream. In embodiments, two SEI messages are used to express a functionality. In the first SEI message, syntax elements specifying the functionality is provided. The first SEI message may also have an identifier value, which uniquely identifies the instance of that particular SEI message. The second SEI message, typically much smaller and sent more frequently than the first SEI message, is used to reference the first SEI message in order to apply the functionality of the first SEI message to a part of the bitstream determined by the persistence scope of the second SEI message, e.g. for the picture or subpicture it was sent with.

Message referencing

A method performed by a decoder for decoding a bitstream comprising a picture parameter set, PPS, and a first set of slices. The method includes obtaining the picture parameter set. The method also includes decoding a syntax element included in the picture parameter set to obtain an indicator value. The decoder is configured such that if the indicator value is set to a first value then the decoder determines that a picture header included in the bitstream comprises a parameter value corresponding to a particular parameter, otherwise the decoder determines that each slice included in the first set of slices comprises a parameter value corresponding to the particular parameter. If the picture header comprises the parameter value corresponding to the particular parameter, then this parameter value is used to decode slice data of each slice included in the first set of slices.

Signaling parameter value information in a parameter set to reduce the amount of data contained in an encoded video bitstream

A method for decoding a picture from a bitstream. The method includes decoding a tile partition structure from one or more syntax elements in the bitstream. The method includes determining a number of tiles N in the picture. The method includes decoding a number of partitions in the picture, wherein each partition comprises an integer number of tiles. The method includes deriving a size and/or location for a current partition, wherein deriving the size and/or location for the current partition comprises: decoding one or more location syntax elements for the current partition from the bitstream, deriving a top-left position of the current partition as a location of a first tile in raster scan order that is not included in one or more previously derived partition, and deriving the size and/or the location of the current partition from a value of the one or more location syntax element together with a size and/or location of the one or more previously derived partition. The method includes using the derived size and/or location to decode the picture.

Rectangular tile group signaling

A method of decoding an encoded image includes obtaining a layer identification, Layer ID, indicator from a first field of a header for a network abstraction layer, NAL, unit of the encoded image, determining whether the Layer ID indicator is less than a start value, in response to determining that the Layer ID indicator is not less than the start value, determining the Layer ID value based on the Layer ID indicator and based on an extension value provided in a second field of the header, and decoding the NAL unit based on the Layer ID value. Related decoders, encoding methods, encoders and computer program products are disclosed.

Extension of header values in video and image coding units

A method for decoding a picture. The method includes determining a picture width value (PW) for the picture and determining tile width value (TW) based on one or more code words from a bitstream. The method also includes obtaining a remaining width value (RW), where RW value is less than or equal to X, where X is equal to PW−TW. The method also includes determining whether RW is not less than TW. And the method also includes, as a result of determining that RW is not less than TW, setting the value of a column width variable equal to TW.

Uniform tile split with remainder

There are provided mechanisms for processing encoded image data. The method comprises receiving an encoded bitstream comprising parameter set information. The parameter set information may comprise a syntax indicator, a first coded portion comprising first coded sample information for a picture and a second coded portion comprising second coded sample information for the picture. The method further comprises, responsive to a first value of the syntax indicator, decoding the first coded sample information using a picture header syntax element from a picture header of the encoded bitstream. The method further comprises, responsive to the first value of the syntax indicator, decoding the second coded sample information using the picture header syntax element from the picture header of the encoded bitstream.

Methods providing encoding and/or decoding of video using a syntax indicator and picture header

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.

Temporal sublayer information for video coding

There is provided a method for processing a bitstream. The method comprises determining a value, N, wherein N identifies a number of ordered layer representations, wherein N is greater than or equal to 3 such that the N ordered layer representations comprises a highest layer representation, a second highest layer representation, and a third highest layer representation. The method further comprises determining a value for the highest layer representation. The method comprises, after determining the value for the highest layer representation and before determining a value for the third highest layer representation, determining a value for the second highest layer representation. The method comprises, after determining the value for the second highest layer representation, determining a value for the third highest layer representation.

Derivation of a value for each layer representation of a bitstream

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.

Methods providing encoding/decoding of dependent/independent partitions and related devices

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.

Normative indication of recovery point

A method for decoding a picture comprising a virtual boundary from a coded video bitstream. The method includes determining one or more of a maximum picture width or a maximum picture height from one or more syntax elements S1 in the coded video bitstream and determining one or more of a current picture width or a current picture height from one or more syntax elements S2 in the coded video bitstream. The method also includes determining that a virtual boundary syntax element in the coded video bitstream is encoded with a bit length derived from (i) one or more of the maximum picture width or the maximum picture height or (ii) one or more of the current picture width or the current picture height. The method also includes deriving the bit length for the virtual boundary syntax element based on (i) the one or more of the maximum picture width or maximum picture height as a result of determining that a virtual boundary syntax element in the coded video bitstream is encoded with a bit length derived from one or more of the maximum picture width or the maximum picture height or (ii) the one or more of the current picture width or the current picture height as a result of determining that a virtual boundary syntax element in the coded video bitstream is derived from one or more of the current picture width or the current picture height. The method also includes decoding the virtual boundary syntax element from the bitstream based on the derived bit length and determining a spatial picture position of the virtual boundary based on the decoded virtual boundary syntax element.

Virtual boundary signaling

A methods and apparatuses for encoding or decoding a segment in a coded picture. The decoding may include obtaining from a bitstream a value of a first codeword that indicates whether the coded picture may contain bi-directional inter coded segments or not. The decoding may include, based on the value of the first codeword, deriving one or more parameter values by either (a) decoding one or more parameters from the bitstream to obtain the one or more parameter values or (b) inferring the one or more parameter values. The decoding may include decoding the segment in the coded picture based on the one or more parameter values. The encoding may include encoding the first codeword to the bitstream and determining whether to encode one or more parameter values in the bitstream based on a determination of whether the coded picture will contain bi-directional inter coded segments or not.

Decoding based on bi-directional picture condition

A method and decoder is provided for decoding at least one current picture from a bitstream. An indicator value is decoded from the bitstream specifying at least one rule of a plurality of rules, the at least one rule applied to ordering of segments coded in the bitstream, wherein the segments are segments in a segment partition layout. A set of syntax elements from the bitstream specifying a segment partition layout is decoded. A segment partition layout based on the set of syntax elements is derived. The at least one current picture in the bitstream is decoded using the segment partition layout, wherein the ordering of the segments complies with the at least one rule specified. An encoder and corresponding method define the segment partition layout, selects the at least one rule from a set of rules, and encodes the segment partition layout and the indicator value into the bitstream.

Picture segment ordering

There are provided mechanisms performed by a decoder. The method comprises receiving a bitstream. The method comprises processing the received bitstream, wherein: the bitstream comprises a first part of the bitstream, and the first part of the bitstream provides segment presence information, and further wherein i) the segment presence information indicates that at least segments of a first segment type shall not be present in at least a portion of the bitstream, or ii) the segment presence information indicates that at least segments of the first segment type may be present in at least the portion of the bitstream.

Providing segment presence information

There are provided mechanisms performed by a video decoder. The method comprises obtaining a network abstraction layer (NAL) unit having a particular NAL unit type. The obtained NAL unit comprises a NAL unit header. The NAL unit header of the obtained NAL unit comprises at least a first part comprising N bits. The method comprises obtaining NAL unit header (NUH) extension information that indicates whether or not the NAL unit header further comprises a second part that comprises M bits. The method comprises determining, based on the NUH extension information, a NAL unit type value specifying the particular NAL unit type of the obtained NAL unit.

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Upplands-Bro, Sweden

Mitra Damghanian