KR-20260068138-A - DPB OPERATION-BASED IMAGE OR VIDEO CODING

KR20260068138AKR 20260068138 AKR20260068138 AKR 20260068138AKR-20260068138-A

Abstract

According to the disclosure of this document, a DPB (Decoded Picture Buffer) can be updated based on information related to the DPB. The information related to the DPB may include a syntax element related to the maximum required size of the DPB. In updating the DPB, a bumping process may be invoked based on a first condition in which the number of pictures in the DPB is not greater than or equal to the value obtained by adding 1 to the value of the syntax element related to the maximum required size of the DPB.

Inventors

파루리시탈
헨드리헨드리
김승환

Assignees

엘지전자 주식회사

Dates

Publication Date: 20260513
Application Date: 20210607
Priority Date: 20200609

Claims (13)

In an image decoding method performed by a decoding device, A step of obtaining image information including DPB (Decoded Picture Buffer) related information from a bitstream; A step of updating the DPB based on the above DPB-related information; and It includes a step of decoding the current picture based on the above DPB, The above DPB-related information includes syntax elements related to the maximum required size of the above DPB, and If the above current picture is not the first picture of the current AU (access unit) which is a CVSS (coded video sequence start) AU (access unit) that is not AU 0, the bumping process is repeatedly invoked until the number of pictures in the above DPB is less than the value of the syntax element related to the maximum required size of the above DPB plus 1, based only on the case where the first condition is satisfied that the number of pictures in the above DPB is greater than or equal to the value of the syntax element related to the maximum required size of the above DPB plus 1. An image decoding method in which the above AU 0 is the first AU of the bitstream.
In paragraph 1, The above DPB-related information includes syntax elements related to the maximum picture reorder count of the DPB or syntax elements related to the maximum latency of the DPB, and The call to the above bumping process is, A video decoding method characterized by not being determined based on a second condition based on a syntax element related to the maximum picture reorder number of the above DPB or a third condition based on a syntax element related to the maximum latency of the above DPB.
In paragraph 2, A video decoding method characterized by the fact that the bumping process is not called based on the case where the second condition or the third condition is satisfied but the first condition is not satisfied.
In paragraph 2, The second condition above is a condition regarding whether the number of pictures in the DPB marked as "needed for output" is greater than the value of a syntax element related to the maximum picture reorder number of the DPB, and The third condition above is a condition regarding whether there is at least one picture in the DPB marked as "needed for output" where the value of the syntax element related to the maximum latency of the DPB is not equal to 0, and the related variable PicLatencyCount is greater than or equal to MaxLatencyPictures. A video decoding method characterized in that the above MaxLatencyPictures is derived by (value of a syntax element related to the maximum picture reorder number of the above DPB + value of a syntax element related to the maximum latency of the above DPB - 1).
In paragraph 1, An image decoding method characterized by the DPB fullness decreasing by 1 for the empty picture storage buffer within the DPB during the bumping process called based on the case satisfying the first condition above.
In paragraph 1, A video decoding method characterized by not performing an operation to additionally decrease the DPB fullness by 1 for the empty picture storage buffer within the DPB after the bumping process called based on the case satisfying the first condition is performed.
In a video encoding method performed by an encoding device, Step of generating DPB (Decoded Picture Buffer) related information; A step of updating the DPB based on the above DPB-related information; and It includes a step of encoding image information containing the above DPB-related information, and The above DPB-related information includes syntax elements related to the maximum required size of the above DPB, and If the above current picture is not the first picture of the current AU (access unit) which is a CVSS (coded video sequence start) AU (access unit) that is not AU 0, the bumping process is repeatedly invoked until the number of pictures in the above DPB is less than the value of the syntax element related to the maximum required size of the above DPB plus 1, based only on the case where the first condition is satisfied that the number of pictures in the above DPB is greater than or equal to the value of the syntax element related to the maximum required size of the above DPB plus 1. A video encoding method in which the above AU 0 is the first AU of the bitstream.
In Paragraph 7, The above DPB-related information includes syntax elements related to the maximum picture reorder count of the DPB or syntax elements related to the maximum latency of the DPB, and The call to the above bumping process is, A video encoding method characterized by not being determined based on a second condition based on a syntax element related to the maximum picture reorder number of the above DPB or a third condition based on a syntax element related to the maximum latency of the above DPB.
In paragraph 8, A video encoding method characterized in that the bumping process is not called based on the case where the second condition or the third condition is satisfied but the first condition is not satisfied.
In paragraph 8, The second condition above is a condition regarding whether the number of pictures in the DPB marked as "needed for output" is greater than the value of a syntax element related to the maximum picture reorder number of the DPB, and The third condition above is a condition regarding whether there is at least one picture in the DPB marked as "needed for output" where the value of the syntax element related to the maximum latency of the DPB is not equal to 0, and the related variable PicLatencyCount is greater than or equal to MaxLatencyPictures. A video encoding method characterized in that the above MaxLatencyPictures is derived by (value of a syntax element related to the maximum picture reorder number of the above DPB + value of a syntax element related to the maximum latency of the above DPB - 1).
In Paragraph 7, A video encoding method characterized by decreasing the DPB fullness by 1 for the empty picture storage buffer within the DPB during the bumping process called based on the case satisfying the first condition above.
In Paragraph 7, A video encoding method characterized by not performing an operation to additionally decrease the DPB fullness by 1 for the empty picture storage buffer within the DPB after the bumping process called based on the case satisfying the first condition is performed.
In a method for transmitting data regarding image information, Step of generating DPB (Decoded Picture Buffer) related information; A step of updating the DPB based on the above DPB-related information; and It includes a step of encoding image information containing the above DPB-related information, and The above DPB-related information includes syntax elements related to the maximum required size of the above DPB, and If the above current picture is not the first picture of the current AU (access unit) which is a CVSS (coded video sequence start) AU (access unit) that is not AU 0, the bumping process is repeatedly invoked until the number of pictures in the above DPB is less than the value of the syntax element related to the maximum required size of the above DPB plus 1, based only on the case where the first condition is satisfied that the number of pictures in the above DPB is greater than or equal to the value of the syntax element related to the maximum required size of the above DPB plus 1. A data transmission method in which the above AU 0 is the first AU of the above bitstream.

Description

DPB Operation-Based Image or Video Coding This technology relates to video or image coding, and, for example, to coding technology related to DPB operations in an image or video coding system. Recently, the demand for high-resolution, high-quality video, such as 4K or 8K or higher UHD (Ultra High Definition) video, is increasing across various fields. As video data becomes higher resolution and higher quality, the amount of information or bits transmitted increases relative to existing video data; therefore, when transmitting video data using media such as existing wired or wireless broadband lines or storing video data using existing storage media, transmission and storage costs increase. In addition, interest in and demand for immersive media such as VR (Virtual Reality), AR (Artificial Reality) content, and holograms have recently been increasing, and the broadcasting of video content with characteristics different from reality, such as game footage, is on the rise. Accordingly, high-efficiency image/video compression technology is required to effectively compress, transmit, store, and play back high-resolution, high-quality image/video information having various characteristics as described above. Furthermore, measures are needed to improve the efficiency of video coding, and to this end, effective coding techniques related to DPB operations are required. Figure 1 schematically illustrates an example of a video/image coding system that can be applied to embodiments of the present document. FIG. 2 is a diagram schematically illustrating the configuration of a video/image encoding device to which embodiments of the present document can be applied. FIG. 3 is a diagram schematically illustrating the configuration of a video/image decoding device to which embodiments of the present document can be applied. Figure 4 illustrates an exemplary encoding procedure according to an embodiment of the present document. Figure 5 illustrates an exemplary decoding procedure according to an embodiment of the present document. FIGS. 6 and 7 schematically illustrate an example of a video/image encoding method and related components according to the embodiment(s) of the present document. FIGS. 8 and 9 schematically illustrate an example of a video/image decoding method and related components according to the embodiment(s) of the present document. FIG. 10 shows an example of a content streaming system to which the embodiments disclosed in this document can be applied. As this document is subject to various modifications and may have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit this document to specific embodiments. Terms used in this document are used merely to describe specific embodiments and are not intended to limit the technical scope of this document. Singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprising" or "having" in this document are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the document, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Meanwhile, each component in the drawings described in this document is depicted independently for the convenience of explaining different characteristic functions and does not imply that each component is implemented in separate hardware or separate software. For example, two or more components may be combined to form a single component, or a single component may be divided into multiple components. Embodiments in which each component is integrated and/or separated are also included within the scope of this document, provided that they do not deviate from the essence of this document. In this document, "A or B" may mean "only A," "only B," or "both A and B." Alternatively, in this document, "A or B" may be interpreted as "A and/or B." For example, in this document, "A, B or C" may mean "only A," "only B," "only C," or "any combination of A, B and C." The slash (/) or comma used in this document may mean "and/or." For example, "A/B" may mean "A and/or B." Accordingly, "A/B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B or C." In this document, "at least one of A and B" may mean "only A," "only B," or "both A and B." Additionally, in this document, the expressions "at least one of A or B" or "at least one of A and/or B" may be interpreted as synonymous with "at least one of A and B." Additionally, in this document, "at least one of A, B and C" may mean "only A," "only B," "only C," or "any combination of A, B and C." Also, "at least one of A, B or C" or "at least one of A, B and/or C" may mean "at least one of A, B and C." Additionally, parentheses used in this document may mean "f