Picture order count based motion vector pruning

Patent metadata

Field	Value
Publication number	US-10368083-B2
Application number	US-201715431321-A
Country	US
Kind code	B2
Filing date	Feb 13, 2017
Priority date	Feb 15, 2016
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

In general, this disclosure described techniques for pruning a list of motion vector prediction candidates based on picture order count (POC) values. A video coding device may be configured to generate the list of motion vector prediction candidates for a prediction unit (PU) of video data. The video coding device may prune a first motion vector prediction candidate from the list of motion vector prediction candidates when a POC value for a reference picture identified by the first motion vector prediction candidate is equal to a second POC value of a reference picture identified by a second motion vector prediction candidate in the list of motion vector prediction candidates. The video coding device may code the PU using the pruned list.

First claim

What is claimed is:

1. A method of decoding video data, the method comprising:
generating a list of motion vector prediction candidates for a prediction unit (PU) of video data, wherein a first motion vector prediction candidate and a second motion vector prediction candidate from the list of motion vector prediction candidates are bi-directional motion vector prediction candidates;
determining, for the first motion vector prediction candidate from the list of motion vector prediction candidates, a first picture order count (POC) value for a first reference picture identified by the first motion vector prediction candidate;
determining, for the second motion vector prediction candidate from the list of motion vector prediction candidates, a second POC value for a second reference picture identified by the second motion vector prediction candidate;
determining, for the first motion vector prediction candidate, a third POC value for a third reference picture identified by the first motion vector prediction candidate;
determining, for the second motion vector prediction candidate, a fourth POC value for a fourth reference picture identified by the second motion vector prediction candidate;
at least one of determining that a pair-wise equality condition is satisfied by the first motion vector prediction candidate and the second motion vector prediction candidate or determining that a cross-equality condition is satisfied by the first motion vector prediction candidate and the second motion vector prediction candidate,
wherein determining that the pair-wise equality condition is satisfied comprises:
determining that the first POC value is equal to the second POC value;
determining that a first motion vector of the first motion vector prediction candidate is equal to a first motion vector of the second motion vector prediction candidate;
determining that the third POC value is equal to the fourth POC value;
determining that a second motion vector of the first motion vector prediction candidate is equal to a second motion vector of the second motion vector prediction candidate; and
in response to determining that the first POC value is equal to the second POC value, the first motion vector of the first motion vector prediction candidate is equal to the first motion vector of the second motion vector prediction candidate, the third POC value is equal to the fourth POC value, and the second motion vector of the first motion vector prediction candidate is equal to the second motion vector of the second motion vector prediction candidate, determining that the pair-wise equality condition is satisfied, and

wherein determining that the cross-equality condition is satisfied comprises:
determining that the first POC value is equal to the second POC value;
determining that the first motion vector of the first motion vector prediction candidate is equal to the second motion vector of the second motion vector prediction candidate;
determining that the third POC value is equal to the fourth POC value;
determining that the second motion vector of the first motion vector prediction candidate is equal to the first motion vector of the second motion vector prediction candidate; and
in response to determining that the first POC value is equal to the second POC value, the first motion vector of the first motion vector prediction candidate is equal to the second motion vector of the second motion vector prediction candidate, the third POC value is equal to the fourth POC value, and the second motion vector of the first motion vector prediction candidate is equal to the first motion vector of the second motion vector prediction candidate, determining that the cross-equality condition is satisfied;

in response to determining that one of the pair-wise equality condition or the cross-equality condition is satisfied by the first motion vector prediction candidate and the second motion vector prediction candidate, pruning the first motion vector prediction candidate from the list of motion vector prediction candidates to create a pruned list; and
decoding the PU using the pruned list.

2. The method of claim 1 , further comprising deriving the first motion vector of the first motion vector prediction candidate from a first reference picture list, and deriving the first motion vector of the second motion vector prediction candidate from a second reference picture list, and wherein the first reference picture list is different than the second reference picture list.

3. The method of claim 1 , wherein the first motion vector prediction candidate and the second motion vector prediction candidate are motion vector prediction candidates of a sub-prediction unit (sub-PU) of the PU.

4. A video coding device comprising:
a memory configured to store video data; and
one or more processors implemented in circuitry and configured to:
generate a list of motion vector prediction candidates for a prediction unit (PU) of video data, wherein a first motion vector prediction candidate and a second motion vector prediction candidate from the list of motion vector prediction candidates are bi-directional motion vector prediction candidates;
determine, for the first motion vector prediction candidate from the list of motion vector prediction candidates, a first picture order count (POC) value for a first reference picture identified by the first motion vector prediction candidate;
determine, for the second motion vector prediction candidate from the list of motion vector prediction candidates, a second POC value for a second reference picture identified by the second motion vector prediction candidate;
determine, for the first motion vector prediction candidate, a third POC value for a third reference picture identified by the first motion vector prediction candidate;
determine, for the second motion vector prediction candidate, a fourth POC value for a fourth reference picture identified by the second motion vector prediction candidate;
at least one of determine that a pair-wise equality condition is satisfied by the first motion vector prediction candidate and the second motion vector prediction candidate or determine that a cross-equality condition is satisfied by the first motion vector prediction candidate and the second motion vector prediction candidate,
wherein the one or more processors being configured to determine that the pair-wise equality condition is satisfied comprises the one or more processors being configured to:
determine that the first POC value is equal to the second POC value;
determine that a first motion vector of the first motion vector prediction candidate is equal to a first motion vector of the second motion vector prediction candidate;
determine that the third POC value is equal to the fourth POC value;
determine that a second motion vector of the first motion vector prediction candidate is equal to a second motion vector of the second motion vector prediction candidate; and
in response to determining that the first POC value is equal to the second POC value, the first motion vector of the first motion vector prediction candidate is equal to the first motion vector of the second motion vector prediction candidate, the third POC value is equal to the fourth POC value, and the second motion vector of the first motion vector prediction candidate is equal to the second motion vector of the second motion vector prediction candidate, determine that the pair-wise equality condition is satisfied, and

wherein the one or more processors being configured to determine that the cross-equality condition is satisfied comprises the one or more processors being configured to:
determine that the first POC value is equal to the second POC value;
determine that the first motion vector of the first motion vector prediction candidate is equal to

Assignees

• Qualcomm Inc

Inventors

• Chien Wei-Jung
• Lee Sungwon
• Zhang Li
• Karczewicz Marta

Classifications

• H04N19/196

  being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters (processing of motion vectors H04N19/513) · CPC title

• H04N19/573

  Motion compensation with multiple frame prediction using two or more reference frames in a given prediction direction · CPC title

• H04N19/172

  the region being a picture, frame or field · CPC title

• H04N19/70

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title

• H04N19/513 Primary

  Processing of motion vectors · CPC title