# US 11,451,817 B2 · Method of performing motion vector prediction, and apparatus thereof

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- Number: US 11,451,817 B2
- Document ID: US11451817B2
- Status: Granted
- Kind: B2
- Application number: 17/215,492
- Filed: 2021-03-29
- Published: 2021-07-15
- Granted: 2022-09-20
- Earliest claimed: 2012-05-09
- Assignees: Sun Patent Trust
- Applicants: Sun Patent Trust
- Inventors: Chong Soon Lim; Sue Mon Thet Naing; Takahiro Nishi; Hisao Sasai; Youji Shibahara; Toshiyasu Sugio; Kyoko Tanikawa; Toru Matsunobu; Kengo Terada
- Web page: https://patentgrep.com/patent/US11451817B2

## CPC

- H04N 19/513: Processing of motion vectors
- H04N 19/103: Selection of coding mode or of prediction mode
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
- H04N 19/52: by predictive encoding
- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N 19/61: in combination with predictive coding
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A method of performing motion vector prediction for a current block in a picture is provided which includes: deriving a candidate for a motion vector predictor to code a current motion vector of the current block, from a first motion vector of a first block that is spatially adjacent or temporally adjacent to the current block; adding the derived candidate to a list of candidates; and deriving at least one motion vector predictor based on a selected candidate from the list of candidates, wherein the deriving of the candidate includes determining whether to derive the candidate from the first motion vector, based on a type of a current reference picture and a type of a first reference picture, the current reference picture being referred to from the current block using the current motion vector, the first reference picture being referred to from the first block using the first motion vector.

## Claims

### Claim 1

An encoding method for encoding a current block of a picture to generate a bitstream, the encoding method comprising:
deriving a candidate for a motion vector predictor to encode a current motion vector of the current block, from a first motion vector of a first block which is (i) a neighboring block that is included in a current picture including the current block and is adjacent to the current block or (ii) a co-located block included in a picture identified by a flag in a slice header;
adding the derived candidate to a candidate list;
deriving at least one motion vector predictor based on a candidate selected from the candidate list;
encoding the current motion vector using the derived at least one motion vector predictor; and
encoding the current block using the current motion vector,
wherein the deriving of the candidate includes determining whether to derive the candidate from the first motion vector, based on a type of a current reference picture and a type of a first reference picture, the current reference picture being referred to from the current block using the current motion vector, and the first reference picture being referred to from the first block using the first motion vector,
each of the type of the current reference picture and the type of the first reference picture is one of a long term reference picture and a short term reference picture, and
in the determining, (i) the candidate is determined to be derived from the first motion vector when the type of the current reference picture and the type of the first reference picture are the same, and (ii) the candidate is derived, from the candidate list which includes one or more candidates, by using a motion vector other than the first motion vector when the type of the current reference picture and the type of the first reference picture are different.

### Claim 2

An encoding apparatus for encoding a current block of a picture to generate a bitstream, the encoding apparatus comprising:
processing circuitry; and
storage accessible from the processing circuitry,
wherein the processing circuitry executes the steps of:
deriving a candidate for a motion vector predictor to encode a current motion vector of the current block, from a first motion vector of a first block which is (i) a neighboring block that is included in a current picture including the current block and is adjacent to the current block or (ii) a co-located block included in a picture identified by a flag in a slice header;
adding the derived candidate to a candidate list;
deriving at least one motion vector predictor based on a candidate selected from the candidate list;
encoding the current motion vector using the derived at least one motion vector predictor; and
encoding the current block using the current motion vector,
wherein the deriving of the candidate includes determining whether to derive the candidate from the first motion vector, based on a type of a current reference picture and a type of a first reference picture, the current reference picture being referred to from the current block using the current motion vector, and the first reference picture being referred to from the first block using the first motion vector,
each of the type of the current reference picture and the type of the first reference picture is one of a long term reference picture and a short term reference picture, and
in the determining, (i) the candidate is determined to be derived from the first motion vector when the type of the current reference picture and the type of the first reference picture are the same, and (ii) the candidate is derived, from the candidate list which includes one or more candidates, by using a motion vector other than the first motion vector when the type of the current reference picture and the type of the first reference picture are different.

### Claim 3

An encoding apparatus for encoding a current block of a picture to generate a bitstream, the encoding apparatus comprising:
a candidate deriving unit configured to derive a candidate for a motion vector predictor to encode a current motion vector of the current block, from a first motion vector of a first block which is (i) a neighboring block that is included in a current picture including the current block and is adjacent to the current block or (ii) a co-located block included in a picture identified by a flag in a slice header;
an adding unit configured to add the derived candidate to a candidate list;
a motion vector predictor deriving unit configured to derive at least one motion vector predictor based on a candidate selected from the candidate list;
an encoding unit configured to encode the current motion vector using the derived at least one motion vector predictor, and encode the current block using the current motion vector,
wherein the candidate deriving unit is configured to determine whether to derive the candidate from the first motion vector, based on a type of a current reference picture and a type of a first reference picture, the current reference picture being referred to from the current block using the current motion vector, and the first reference picture being referred to from the first block using the first motion vector,
each of the type of the current reference picture and the type of the first reference picture is one of a long term reference picture and a short term reference picture, and
the candidate deriving unit is configured to (i) determine that the candidate is to be derived from the first motion vector when the type of the current reference picture and the type of the first reference picture are the same, and (ii) derive the candidate, from the candidate list which includes one or more candidates, by using a motion vector other than the first motion vector when the type of the current reference picture and the type of the first reference picture are different.