CN-121985119-A - Video decoding device, video encoding device, video decoding method, and video encoding method

CN121985119ACN 121985119 ACN121985119 ACN 121985119ACN-121985119-A

Abstract

A moving image decoding device, a moving image encoding device, a moving image decoding method, and a moving image encoding method, wherein the moving image decoding device is provided with a parameter decoding unit that decodes (i) one or more reference picture list structures included in a sequence parameter set and (ii) a first flag indicating whether first reference picture list information is present in a slice header of an nal_unit_type IDR picture and (ii) a second flag indicating whether second reference picture list information is present in a picture header, and a prediction parameter deriving unit that derives (i) the first reference picture list information using the nal_unit_type or the first flag and the second flag in the slice header or derives the second reference picture list information using the second flag in the picture header, and (ii) derives the reference picture list based on the reference picture list structures.

Inventors

CHUJO TAKESHI
IKAI TOMOHIRO
AONO TOMOKO
SASAKI EIICHI
HASHIMOTO TOMONORI
ZHOU TIANYANG
YASUGI YUKINOBU

Assignees

夏普株式会社

Dates

Publication Date: 20260505
Application Date: 20210326
Priority Date: 20200331

Claims (5)

1. A moving image decoding apparatus for decoding encoded data, the moving image decoding apparatus comprising: A parameter decoding section configured to decode an index of a reference picture list structure in a case where a value of a flag indicating whether a reference picture list i is derived based on one of the reference picture list structures is equal to 1, and A prediction parameter derivation section configured to determine whether a syntax element specifying a NAL unit type indicates instantaneous decoding refresh pictures, Wherein, the One of the reference picture list structures is defined by a list index variable and a reference picture list index variable, In case the value of the flag is equal to 1, the reference picture list index variable is set to a value equal to the index of the reference picture list structure, In the case where the value of the flag is equal to 0, setting the reference picture list index variable equal to the number of reference picture list structures in the sequence parameter set, and In case the syntax element indicates that a refresh picture is decoded instantaneously, a value of a second syntax element is derived equal to 0, wherein the second syntax element specifies a number of entries in the reference picture list structure and is defined by a variable i and the reference picture list index variable.
2. A moving image encoding device for encoding data, the moving image encoding device comprising: a parameter encoding section configured to encode an index of a reference picture list structure in a case where a value of a flag indicating whether a reference picture list i is derived based on one of the reference picture list structures is equal to 1, and A prediction parameter derivation section configured to determine whether a syntax element specifying a NAL unit type indicates instantaneous decoding refresh pictures, Wherein, the One of the reference picture list structures is defined by a list index variable and a reference picture list index variable, In case the value of the flag is equal to 1, the reference picture list index variable is set to a value equal to the index of the reference picture list structure, In the case where the value of the flag is equal to 0, setting the reference picture list index variable equal to the number of reference picture list structures in the sequence parameter set, and In case the syntax element indicates that a refresh picture is decoded instantaneously, a value of a second syntax element is derived equal to 0, wherein the second syntax element specifies a number of entries in the reference picture list structure and is defined by a variable i and the reference picture list index variable.
3. A moving image decoding method for decoding encoded data, the moving image decoding method comprising: Decoding an index of a reference picture list structure in case the value of a flag is equal to 1, the flag indicating whether a reference picture list i is derived based on one of the reference picture list structures, and Determining whether a syntax element specifying a NAL unit type indicates an instantaneous decoding refresh picture, Wherein, the One of the reference picture list structures is defined by a list index variable and a reference picture list index variable, In case the value of the flag is equal to 1, the reference picture list index variable is set to a value equal to the index of the reference picture list structure, In the case where the value of the flag is equal to 0, setting the reference picture list index variable equal to the number of reference picture list structures in the sequence parameter set, and In case the syntax element indicates that a refresh picture is decoded instantaneously, a value of a second syntax element is derived equal to 0, wherein the second syntax element specifies a number of entries in the reference picture list structure and is defined by a variable i and the reference picture list index variable.
4. A moving image encoding method for encoding data, the moving image encoding method comprising: Encoding an index of a reference picture list structure in case the value of a flag is equal to 1, the flag indicating whether a reference picture list i is derived based on one of the reference picture list structures, and Determining whether a syntax element specifying a NAL unit type indicates an instantaneous decoding refresh picture, Wherein, the One of the reference picture list structures is defined by a list index variable and a reference picture list index variable, In case the value of the flag is equal to 1, the reference picture list index variable is set to a value equal to the index of the reference picture list structure, In the case where the value of the flag is equal to 0, setting the reference picture list index variable equal to the number of reference picture list structures in the sequence parameter set, and In case the syntax element indicates that a refresh picture is decoded instantaneously, a value of a second syntax element is derived equal to 0, wherein the second syntax element specifies a number of entries in the reference picture list structure and is defined by a variable i and the reference picture list index variable.
5. A non-transitory computer readable medium storing a bitstream generated by encoding a moving image, the non-transitory computer readable medium comprising: storing the bitstream, wherein the bitstream comprises an index of a reference picture list structure in case that a value of a flag is equal to 1, the flag indicating whether a reference picture list i is derived based on one of the reference picture list structures; Wherein, the One of the reference picture list structures is defined by a list index variable and a reference picture list index variable, In case the value of the flag is equal to 1, the reference picture list index variable is set to a value equal to the index of the reference picture list structure, In the case where the value of the flag is equal to 0, setting the reference picture list index variable equal to the number of reference picture list structures in the sequence parameter set, and In case the syntax element indicates that a refresh picture is decoded instantaneously, a value of a second syntax element is derived equal to 0, wherein the second syntax element specifies a number of entries in the reference picture list structure and is defined by a variable i and the reference picture list index variable.

Description

Video decoding device, video encoding device, video decoding method, and video encoding method The present application is a divisional application of chinese patent application "moving image decoding apparatus, moving image encoding apparatus, moving image decoding method, and moving image encoding method" (application number: 202180025620.9) having application date of 2021, 3, and 26. Technical Field Embodiments of the present invention relate to a predicted image generating apparatus, a moving image decoding apparatus, and a moving image encoding apparatus. Background In order to efficiently transmit or record a moving image, a moving image encoding device that generates encoded data by encoding the moving image, and a moving image decoding device that generates a decoded image by decoding the encoded data are used. Specific examples of the video encoding scheme include H.264/AVC and H.265/HEVC (High-EFFICIENCY VIDEO CODING: high-efficiency video encoding) schemes. In such a moving image encoding system, an image (picture) constituting a moving image is managed by a hierarchical structure including a slice obtained by dividing the image, a Coding Tree Unit (CTU: coding Tree Unit) obtained by dividing the slice, a Coding Unit (sometimes referred to as Coding Unit (CU)) obtained by dividing the Coding Tree Unit, and a Transform Unit (TU: transform Unit) obtained by dividing the Coding Unit, and encoding/decoding is performed for each CU. In such a moving image encoding system, a prediction image is generally generated based on a locally decoded image obtained by encoding/decoding an input image, and a prediction error (sometimes referred to as a "differential image" or a "residual image") obtained by subtracting the prediction image from the input image (original image) is encoded. As a method for generating a predicted image, inter-picture prediction (inter-frame prediction) and intra-picture prediction (intra-frame prediction) are exemplified. Further, as a technique of encoding and decoding a moving image in recent years, non-patent document 1 is cited. In non-patent document 1, in the management of reference picture lists, a mechanism is adopted in which a plurality of reference picture lists are defined, and the plurality of reference picture lists are referred to and used. In addition, in the weighted prediction, a technique of explicitly defining the number of weights is adopted. Prior art literature Non-patent literature Non-patent literature 1："Versatile Video Coding（Draft 8）",JVET-Q2001-vE,Joint Video Exploration Team（JVET）of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11,2020-3-12 Disclosure of Invention Problems to be solved by the invention However, in non-patent document 1, there is a problem that, in the management of the reference picture list, the reference picture list with the number of reference pictures being 0 can be defined, and thus, the reference picture is not specified. Technical proposal A moving image decoding device according to an aspect of the present invention is a moving image decoding device for deriving a predicted image using a reference picture included in a reference picture list, comprising: A parameter decoding unit for decoding (i) one or more reference picture list structures included in the sequence parameter set and (ii) a first flag indicating whether or not first reference picture list information is present in a slice header of an nal_unit_type IDR picture and a second flag indicating whether or not second reference picture list information is present in a picture header, and a picture parameter set including the first flag and the second flag A prediction parameter derivation section for deriving the prediction parameter, (I) The prediction parameter derivation section derives the first reference picture list information using nal_unit_type or the first flag and the second flag in a slice header, or derives the second reference picture list information using the second flag in a picture header, (Ii) The prediction parameter derivation section derives the reference picture list based on the reference picture list structure, In the case where the first reference picture list is not derived, the number of entries of the reference picture list structure is presumed to be 0. A moving image encoding device according to an aspect of the present invention is a moving image encoding device for deriving a predicted image using a reference picture included in a reference picture list, comprising: A parameter encoding unit for encoding (i) one or more reference picture list structures included in the sequence parameter set and (ii) a first flag indicating whether or not first reference picture list information is present in a slice header of an nal_unit_type IDR picture and a second flag indicating whether or not second reference picture list information is present in a picture header, and a picture parameter set including the first flag and the second flag A prediction