# US 12,192,511 B2 · Methods and apparatuses for signaling of syntax elements in video coding

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- Number: US 12,192,511 B2
- Document ID: US12192511B2
- Status: Granted
- Kind: B2
- Application number: 17/956,711
- Filed: 2022-09-29
- Published: 2023-02-02
- Granted: 2025-01-07
- Earliest claimed: 2020-03-31
- Assignees: Beijing Dajia Internet Information Technology Co., Ltd.
- Applicants: Beijing Dajia Internet Information Technology Co., Ltd.
- Inventors: Yi-Wen Chen; Xiaoyu Xiu; Tsung-Chuan Ma; Hong-Jheng Jhu; Wei Chen; Xianglin Wang; Bing Yu
- Web page: https://patentgrep.com/patent/US12192511B2

## CPC

- H04N 19/52: by predictive encoding
- H04N 19/521: {for estimating the reliability of the determined motion vectors or motion vector field, e.g. for smoothing the motion vector field or for correcting motion vectors}
- H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
- H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
- H04N 19/174: the region being a slice, e.g. a line of blocks or a group of blocks
- H04N 19/573: Motion compensation with multiple frame prediction using two or more reference frames in a given prediction direction
- H04N 19/577: Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Methods and apparatuses for video coding are provided. The method includes that a decoder determines whether one or more reference picture lists are signaled in a picture header (PH) associated with a picture and whether the one or more reference picture lists indicate that one or more slices associated with the picture are bi-predictive. The method further includes that the decoder adds one or more constraints to one or more syntax elements in the PH in response to determining that the one or more reference picture lists are signaled in the PH and the one or more reference picture lists indicate that the one or more slices are not bi-predictive.

## Claims

### Claim 1

A method for video decoding, comprising:
determining, by a decoder, whether information of one or more reference picture lists is signaled in a picture header (PH) associated with a picture, and determining from the information of the one or more reference picture lists whether one or more slices associated with the picture are bi-predictive in response to determining that the information of the one or more reference picture lists is signaled in the PH; and
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are not bi-predictive, not parsing, by the decoder, one or more syntax elements in the PH.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the one or more syntax elements comprise one or more flags applicable for the one or more slices.

### Claim 3 (depends on 1)

The method according to claim 1, further comprising:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtaining the one or more syntax elements to specify whether a corresponding motion vector difference (MVD) coding syntax structure is not parsed and whether two variables are set to be zero for the one or more slices associated with the PH, wherein the two variables respectively specify a difference between a list vector component and a prediction corresponding to the list vector component;
in response to determining that the one or more syntax elements equal to 0, parsing the MVD coding syntax structure for the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, not parsing the MVD coding syntax structure to decode the one or more slices.

### Claim 4 (depends on 1)

The method according to claim 1, further comprising:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtaining the one or more syntax elements to specify whether bi-directional optical flow (BDOF) inter prediction based inter bi-prediction is disabled for the one or more slices associated with the PH;
in response to determining that the one or more syntax elements equal to 0, enabling the BDOF inter prediction based inter bi-prediction to decode the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, disabling the BDOF inter prediction based inter bi-prediction to decode the one or more slices.

### Claim 5 (depends on 1)

The method according to claim 1, further comprising:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtaining the one or more syntax elements to specify whether decoder motion vector refinement (DMVR) based inter bi-prediction is disabled for the one or more slices associated with the PH;
in response to determining that the one or more syntax elements equal to 0, enabling the DMVR based inter bi-prediction to decode the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, disabling the DMVR based inter bi-prediction to decode the one or more slices.

### Claim 6

An apparatus for video decoding, comprising:
one or more processors; and
a memory configured to store instructions executable by the one or more processors; wherein the one or more processors, upon execution of the instructions, are configured to:
determine whether information of one or more reference picture lists is signaled in a picture header (PH) associated with a picture, and determine from the information of the one or more reference picture lists whether one or more slices associated with the picture are bi-predictive in response to determining that the information of the one or more reference picture lists is signaled in the PH; and
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are not bi-predictive, not parse one or more syntax elements in the PH.

### Claim 7 (depends on 6)

The apparatus according to claim 6, wherein the one or more syntax elements comprise one or more flags applicable for the one or more slices.

### Claim 8 (depends on 6)

The apparatus according to claim 6, wherein the one or more processors are further configured to:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtain the one or more syntax elements to specify whether a corresponding motion vector difference (MVD) coding syntax structure is not parsed and whether two variables are set to be zero for the one or more slices associated with the PH, wherein the two variables respectively specify a difference between a list vector component and a prediction corresponding to the list vector component;
in response to determining that the one or more syntax elements equal to 0, parse the MVD coding syntax structure for the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, not parse the MVD coding syntax structure to decode the one or more slices.

### Claim 9 (depends on 6)

The apparatus according to claim 6, wherein the one or more processors are further configured to:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtain the one or more syntax elements to specify whether bi-directional optical flow (BDOF) inter prediction based inter bi-prediction is disabled for the one or more slices associated with the PH;
in response to determining that the one or more syntax elements equal to 0, enable the BDOF inter prediction based inter bi-prediction to decode the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, disable the BDOF inter prediction based inter bi-prediction to decode the one or more slices.

### Claim 10 (depends on 6)

The apparatus according to claim 6, wherein the one or more processors are further configured to:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtain the one or more syntax elements to specify whether decoder motion vector refinement (DMVR) based inter bi-prediction is disabled for the one or more slices associated with the PH;
in response to determining that the one or more syntax elements equal to 0, enable the DMVR based inter bi-prediction to decode the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, disable the DMVR based inter bi-prediction to decode the one or more slices.

### Claim 11

A non-transitory computer-readable storage medium for video decoding storing a bitstream to be decoded by a method for video decoding comprising:
determining whether information of one or more reference picture lists is signaled in a picture header (PH) associated with a picture, and determining from the information of the one or more reference picture lists whether one or more slices associated with the picture are bi-predictive in response to determining that the information of the one or more reference picture lists is signaled in the PH; and
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are not bi-predictive, not parsing one or more syntax elements in the PH.

### Claim 12 (depends on 11)

The non-transitory computer-readable storage medium according to claim 11, wherein the one or more syntax elements comprise one or more flags applicable for the one or more slices.

### Claim 13 (depends on 11)

The non-transitory computer-readable storage medium according to claim 11, wherein the method further comprises:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtaining the one or more syntax elements to specify whether a corresponding motion vector difference (MVD) coding syntax structure is not parsed and whether two variables are set to be zero for the one or more slices associated with the PH, wherein the two variables respectively specify a difference between a list vector component and a prediction corresponding to the list vector component;
in response to determining that the one or more syntax elements equal to 0, parsing the MVD coding syntax structure for the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, not parsing the MVD coding syntax structure to decode the one or more slices.

### Claim 14 (depends on 11)

The non-transitory computer-readable storage medium according to claim 11, wherein the method further comprises:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtaining the one or more syntax elements to specify whether bi-directional optical flow (BDOF) inter prediction based inter bi-prediction is disabled for the one or more slices associated with the PH;
in response to determining that the one or more syntax elements equal to 0, enabling the BDOF inter prediction based inter bi-prediction to decode the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, disabling the BDOF inter prediction based inter bi-prediction to decode the one or more slices.

### Claim 15 (depends on 11)

The non-transitory computer-readable storage medium according to claim 11, wherein the method further comprises:
in response to determining that the information of the one or more reference picture lists is signaled in the PH and determining from the information of the one or more reference picture lists that the one or more slices are bi-predictive, obtaining the one or more syntax elements to specify whether decoder motion vector refinement (DMVR) based inter bi-prediction is disabled for the one or more slices associated with the PH;
in response to determining that the one or more syntax elements equal to 0, enabling the DMVR based inter bi-prediction to decode the one or more slices; and
in response to determining that the one or more syntax elements equal to 1, disabling the DMVR based inter bi-prediction to decode the one or more slices.