Telefonaktiebolaget Lm Ericsson (publ)

Velos Media, LLC

Ericsson Ab

Velos Media International Limited

Rickard Sjöberg

Jonatan Samuelsson

Martin Pettersson

Mitra Damghanian

Kenneth Andersson

Jacob Ström

Ruoyang Yu

Zhi Zhang

Per Wennersten

Andrey Norkin

Clinton Priddle

Thomas Rusert

Jack Enhorn

Du Liu

Per Fröjdh

Magnus Westerlund

Zhuangfei Wu

Davood Saffar

Chris Phillips

Robert Hammond Forsman

Bo Burman

Sarel Cohen

Alois Martin Bock

Kristofer Dovstam

Thorsten Lohmar

Torbjörn Einarsson

Jörg Huschke

Richard Mitic

Markus Kampmann

Christopher Hollmann

Joel Askelöf

Torbjörm Einarsson

Ian Tapp

Zhuangfel Wu

Jonathan Samuelsson

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 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.

Extension data handling

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 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.

Transform selection in a video encoder and/or video decoder

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

A prediction unit for an encoder or decoder 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 or decoder.

Simplified downsampling for matrix based intra prediction

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.

Arrangements and methods of encoding picture belonging to a temporal level

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 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.

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Stockholm, Sweden

Rickard Sjöberg