CN114302138A - Determination of Combined Predictor in Video Codec - Google Patents

Abstract

A method for video decoding, comprising: for each CU: obtaining an optimal intra prediction mode, wherein the optimal intra prediction mode comprises one of the following 6 intra prediction modes: a planar mode, a DC mode, an upper block angle mode, a left block angle mode, a vertical mode, and a horizontal mode; determining an intra prediction value corresponding to the optimal intra prediction mode; obtaining partition information for the CU, wherein the partition information comprises angle parameters and prediction modes (intra-frame prediction and inter-frame prediction), the partition information partitions the CU to obtain two partition areas, one of the two partition areas adopts intra-frame prediction, and the other partition area adopts inter-frame prediction; determining a first combined prediction value based on the prediction mode for the two divided areas; determining a second combined prediction value based on the intra prediction value and the first combined prediction value; and taking the second combined predicted value as the predicted value of the CU.

Description

Determination of Combined Predictor in Video Codec

technical field

The present invention relates to the field of image and video processing, and more particularly, to a method, apparatus and medium for determination based on combined prediction values.

Background technique

Digital video capabilities can be incorporated into a variety of devices, including digital televisions, digital direct broadcasting systems, wireless broadcasting systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, e-book readers, digital cameras, Digital recording devices, digital media players, video game devices, video game consoles, cellular or satellite radio telephones, so-called "smart phones", video teleconferencing devices, video streaming devices, etc.

Digital video equipment implements video coding techniques such as those provided by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264/MPEG-4, Part 10, Advanced Video Coding (AVC), Those described in the High Efficiency Video Coding (HEVC) standard, ITU-TH.265/High Efficiency Video Coding (HEVC), Versatile Video Coding (VVC) (H.266), and standards defined by extensions of such standards technology. By implementing such video encoding techniques, video devices can transmit, receive, encode, decode and/or store digital video information more efficiently.

In April 2010, two major international video coding standards organizations, VCEG and MPEG, established a joint video compression group, JCT-VC (Joint collaborative Team on Video Coding), to jointly develop high-efficiency video coding standards.

In 2013, JCT-VC completed the development of the HEVC (High efficiency video coding) standard (also known as H.265), and subsequently released several versions.

HEVC proposes a new syntax unit: coding unit (CU) is the basic unit for prediction, transform, quantization and entropy coding, prediction unit (PU) is the basic unit for intra-frame and inter-frame prediction, and transform unit (TU) is for performing The basic unit of transform and quantization. Additionally, each CU defines regions that share the same prediction mode (intra or inter).

As shown in FIG. 1 , in HEVC, switching between intra prediction mode and inter prediction mode can be performed. In the intra-frame prediction mode and the inter-frame prediction mode, HEVC adopts the coding structure of the coding tree unit (CTU), and the CTU is the basic processing unit of HEVC coding and decoding. A CTU consists of 1 luma CTB, 2 chroma CTBs and corresponding syntax elements. Figure 2 shows the CTU structure after one LCU (largest coding unit) encoding. In HEVC, the LCU may contain only one coding unit (CU), or may be divided into CUs of different sizes using the CTU quad-tree structure.

There are four size CUs in HEVC, the sizes are: 64x64, 32x32, 16x16 and 8x8. The smaller the CU block, the deeper it is in the CTU tree. When the CU is 64x64, 32x32 and 16x16, it is called 2Nx2N mode (indicating that it can be divided into smaller CUs), and when the CU is 8x8, it is called NxN mode (indicating that no further division is possible). For intra prediction, a CU is split into two PartModes (2Nx2N and NxN), depending on whether it can be split into smaller CUs. CUs of size 64x64, 32x32 and 16x16 belong to 2Nx2N, and CUs of size 8x8 belong to NxN.

In HEVC, PU is the basic unit for intra-frame and inter-frame prediction. The division of PU is based on CU and has five regular sizes of 64x64, 32x32, 16x16, 8x8 and 4x4. More specifically, the PU size is based on PartMode: the PU size is the same as the CU for a 2Nx2N PartMode, and for an NxN PartMode a CU can be divided into four 4x4 sub-PUs. For the 2N*2N CU mode, the optional modes for intra-frame prediction PU include 2N*2N and N*N, and there are 8 optional modes for inter-frame prediction PU, including 4 symmetric modes (2N*2N, N*2N , 2N*N, N*N) and 4 asymmetric modes (2N*nU, 2N*nD, nL*2N, nR*2N), where 2N*nU and 2N*nD are 1:3 and 3 above and below respectively :1 ratio, nL*2N and nR*2N are divided in the ratio of 1:3 and 3:1 respectively.

In HEVC, the Lagrangian rate-distortion optimization (RDO) of H.264/AVC is still used for mode selection, and its RDO is calculated for each intra mode:

J=D+λR (1)

Among them, J is the Lagrangian cost (ie RD-cost), D is the distortion of the current intra mode, R is the number of bits required to encode all the information in the current prediction mode, and λ is the Lagrangian factor. where D is usually implemented using the sum of absolute Hadamard transform differences (SATD).

Processing a frame of video image requires first dividing it into multiple LCUs (64x64), and then encoding each LCU in turn. Each LCU is recursively divided in turn, and it determines whether to continue dividing by calculating the RD-cost of the current depth. An LCU can be divided into 8x8 units at least, as shown in Figure 2. The encoder determines whether to continue the division by comparing the RD-cost value of the depth. If the sum of the coding costs of the four sub-CUs in the current depth is greater than the current CU, the division is not continued; otherwise, the division continues until the division ends.

Those skilled in the art can easily understand that since CTU is a tree-like coding structure that divides LCUs into CUs, the CU division method in CTUs starts with LCUs, so these two terms are often used interchangeably in the art.

In intra prediction, each PU uses a total of 35 prediction modes. Using Rough Mode Decision (RMD), we can obtain three candidate modes for 64x64, 32x32 and 16x16 blocks and eight candidate modes for 8x8 and 4x4 blocks. The best candidate list for each PU size is obtained by merging the most probable modes (MPMs) from neighboring blocks. Then, the best intra prediction mode for the current PU is selected by RDO. When the intra prediction of all PUs included in the current CU is completed, the intra prediction of the current CU is completed. Selecting the sub-optimal CU intra-prediction with the smaller RD-cost is done by comparing the RD-cost of the current CU and the total RD-cost of the current CU and its four sub-CUs of its four sub-CUs. When all CU partitions are completed, the current CTU intra prediction is completed. For HEVC, when encoding the LCU, intra prediction of 85 CUs (one 64x64 CU, four 32x32 CUs, sixteen 16x16 CUs and sixty-four 8x8 CUs) should be performed. When a CU is encoded, intra prediction of one PU or four sub-PUs should be performed. A large number of CUs and PUs lead to high complexity of intra prediction.

In order to develop new technologies beyond HEVC, a new organization, the Joint Video Exploration Term (Joint Video Exploration Term), was established in 2015 and renamed the Joint Video Experts Term (JVET) in 2018. On the basis of HEVC, the research on Versatile Video Coding VVC (H.266) was proposed by JVET at the San Diego Conference in the United States on April 10, 2018. A new generation of improved H.265/HEVC Video coding technology whose main goal is to improve existing HEVC to provide higher compression performance while optimizing for emerging applications (360° panoramic video and High Dynamic Range (HDR) video). The first version of VVC was completed in August 2020 and officially released as the H.266 standard on the ITU-T website.

Relevant documents and testbeds for HEVC and VVC are available at https://jvet.hhi.fraunhofer.de/ and relevant proposals for VVC are available at http://phenix.it-sudparis.eu/jvet/.

VVC still uses the hybrid coding framework adopted by H.264, and the general block diagram of its VTM8 encoder is shown in Figure 1. Inter and Intra Predictive Coding: De-correlation between temporal and spatial domains. Transform coding: Transform coding the residuals to remove spatial correlations. Entropy coding: Eliminate statistical redundancy. Within the framework of hybrid coding, VVC will focus on researching new coding tools or techniques to improve video compression efficiency.

Although both VVC and HEVC use a tree structure for CTU division, VVC uses a different tree structure CTU division method from HEVC. And, compared with HEVC, the maximum size of CTU in VVC reaches 128x128.

As described above, in HEVC, a quad-tree structure is used to divide a CTU into CUs (ie, coding trees). Decisions about intra-coding and inter-coding are made at the leaf node CU. In other words, one leaf node CU defines a region that shares the same prediction mode (eg, intra prediction or inter prediction). Then, each leaf-CU can be further divided into 1, 2 or 4 prediction unit PUs according to the PU partition type. Within each PU, the same prediction process is used and relevant information is sent to the decoder section on a PU basis. After the PU-based prediction process has obtained the residual block, the leaf CU may be divided into TUs according to another quadtree-like structure similar to the coding tree of the CU.

In VVC, a quadtree partition structure with nested multi-type trees is adopted, wherein the nested multi-type trees use binary trees and ternary trees. An example of such a nested multi-type tree for VVC is the quadtree-binary tree (QTBT) structure. The QTBT structure includes two levels: a first level divided according to quadtree division, and a second level divided according to binary tree division. The root node of the QTBT structure corresponds to the CTU. The leaf nodes of the binary tree correspond to coding units (CUs). The different forms of CU, PU and TU are removed in VVC. A CTU is first divided by a quadtree, and then further divided by a multi-type tree. As shown in FIG. 3 , VVC specifies four multi-type tree division modes: horizontal binary tree division, vertical binary tree division, horizontal ternary tree division, and vertical ternary tree division. The leaf nodes of the multi-type tree are called coding units (CUs), and unless the CU is too large for the maximum transform length, the CU partition is used for prediction and transform processing without further partitioning. This means that in most cases, CUs, PUs and TUs have the same block size in this quadtree partition structure with nested multi-type trees. The exception to this is when the maximum supported transform length is less than the width or height of the color components of the CU. FIG. 4 shows a specific embodiment of a CTU-to-CU partition with a quad-tree partition structure of nested multi-type trees in VVC, wherein the bold box represents the quad-tree partition, and the remaining edges represent the multi-type tree segmentation.

After CU partitioning, the video data of the CU representing prediction and/or residual information and other information is encoded. The prediction information indicates how the CU is to be predicted in order to form the prediction block of the CU. Residual information typically represents the sample-by-sample differences between the samples of the CU before encoding and the samples of the prediction block.

To predict a CU, a prediction block of the CU may typically be formed through inter prediction or intra prediction. Inter prediction generally refers to predicting a CU from data of a previously coded picture, while intra prediction generally refers to predicting a CU from previously coded data of the same picture. To perform inter prediction, a prediction block may be generated using one or more motion vectors. A motion search may typically be performed, eg, as a difference between a CU and a reference block, to identify reference blocks that closely match the CU. The difference metric may be calculated using sum of absolute differences (SAD), sum of squared differences (SSD), mean absolute difference (MAD), mean square error (MSD), or other such difference calculations to determine whether a reference block is different from the current CUs are closely matched. In some examples, the current CU may be predicted using uni-directional prediction or bi-directional prediction.

VVC also provides an affine motion compensation mode, which can be thought of as an inter prediction mode. In the affine motion compensation mode, two or more motion vectors can be determined that represent non-translational motion, such as zoom-in or zoom-out, rotation, perspective motion, or other types of irregular motion.

In order to perform intra prediction, an intra prediction mode for generating a prediction block may be selected. VVC provides 67 intra prediction modes, including various directional modes, as well as plane mode and DC mode. Typically, an intra-prediction mode is selected that describes neighboring samples to the current block (eg, a block of a CU) from which the samples of the current block are predicted. Assuming the CTUs and CUs are decoded in raster scan order (left-to-right, top-to-bottom decoding order or right-to-left, top-to-bottom decoding order), these samples can typically be Above, above and to the left or to the left of the current block in the same picture.

Data representing the prediction mode of the current block is encoded. For example, for an inter prediction mode, the video encoder 200 may encode data indicating which of various available inter prediction modes to use and motion information for the corresponding mode. For uni-directional or bi-directional inter prediction, for example, advanced motion vector prediction (AMVP) or merge mode may be used to encode motion vectors. Similar modes can be used to encode motion vectors for affine motion compensation modes.

After prediction such as intra prediction or inter prediction of the block, residual data for the block may be calculated. Residual data, such as a residual block, represents the sample-by-sample difference between the block and the predicted block for the block formed using the corresponding prediction mode. One or more transforms may be applied to the residual block to produce transformed data in the transform domain rather than the sample domain. For example, a discrete cosine transform (DCT), integer transform, wavelet transform, or conceptually similar transforms may be applied to the residual video data. Additionally, video encoder 200 may apply a secondary transform after a primary transform, eg, Mode Dependent Non-Separable Secondary Transform (MDNSST), Signal Dependent Transform, Karhunen-Loeve Transform (KLT), and the like. Transform coefficients are generated after applying one or more transforms.

As described above, after any transform used to generate transform coefficients, quantization of the transform coefficients may be performed according to the quantized coefficients (QP). Quantization generally refers to the process of quantizing transform coefficients to possibly reduce the amount of data used to represent the coefficients, thereby providing further compression. By performing a quantization process, the bit depth associated with some or all coefficients may be reduced. For example, an n-bit value may be rounded to an m-bit value during quantization, where n is greater than m. In some examples, to perform quantization, a bitwise right shift of the value to be quantized may be performed. Quantization coefficients (QPs) are usually included in the header information using a run of syntax elements.

After quantization, the transform coefficients may be scanned, resulting in a one-dimensional vector from a two-dimensional matrix including the quantized transform coefficients. The scan can be designed to place higher energy (and therefore lower frequency) coefficients at the front of the vector and lower energy (and therefore higher frequency) transform coefficients at the back of the vector. In some examples, the quantized transform coefficients may be scanned using a predefined scan order to produce a serialized vector, and then the quantized transform coefficients of the vector are entropy encoded. In other examples, adaptive scanning can be performed. After scanning the quantized transform coefficients to form a one-dimensional vector, the one-dimensional vector may be entropy encoded, eg, according to context adaptive binary arithmetic coding (CABAC), and the values for the syntax elements, which describe the Metadata associated with encoded video data for use by video decoder 300 in decoding the video data.

During encoding, syntax data, such as block-based syntax data, picture-based syntax data, and sequence-based syntax data, or other syntax data, such as sequence parameter sets, may be generated, eg, in picture headers, block headers, slice headers (SPS), Picture Parameter Set (PPS) or Video Parameter Set (VPS). A video decoder may similarly decode such syntax data to determine how to decode corresponding video data. These information can be called "header information".

In this manner, a bitstream may be generated that includes encoded video data (eg, syntax elements describing partitioning from pictures into blocks (eg, CUs) and prediction and/or residual information for the blocks).

In the prior art including HEVC and VVC, although the case of obtaining a combined prediction value based on multiple reference frames is considered, the intra prediction value and inter prediction for a coding unit (CU) are not considered The values are combined in some way so that both intra- and inter-predictors cannot be fully utilized.

In addition, in the prior art, the video data block is usually divided in the form of CU or PU. This kind of division is limited to the division in the vertical and horizontal directions, so the limitation is large, and the video within the block cannot be optimally dealt with. Internal changes in content.

In addition, in the prior art, some segmentations in non-vertical and horizontal directions are proposed, but these segmentations are all performed within the intra-frame prediction stage or the inter-frame prediction stage, that is, the segmented blocks or all perform intra-frame prediction Or both perform inter-frame prediction, thereby limiting the application range of segmentation in non-vertical and horizontal directions. Moreover, the segmentation in the non-vertical and horizontal directions in the prior art usually only proposes a novel segmentation method, and does not consider the prediction situation of the adjacent blocks of the current video block (CU or PU) during segmentation. (eg whether the neighboring blocks are intra-predicted or inter-predicted).

Therefore, for the video block segmentation in the prior art, there is still a great need for improvement.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention proposes that for each CU, by combining the intra-frame prediction value and the inter-frame prediction value of the CU, the gains of both the intra-frame prediction and the inter-frame prediction of the CU are fully utilized. When considering intra-prediction values, the present invention considers a reduced number of intra-prediction modes among all intra-prediction modes of the entire CU, for example, adopts 6 representative intra-prediction modes, and determines the best frame therefrom Intra prediction mode. In this way, the gain of intra prediction can be fully utilized while reducing the amount of computation.

When considering inter-frame prediction values, the present invention does not perform inter-frame prediction based on CUs as in the prior art, but further divides CUs in non-vertical and horizontal directions and uses prediction methods based on adjacent CUs ( That is, whether adjacent CUs are intra-frame prediction or inter-frame prediction) to further determine the prediction modes (intra-frame prediction, inter-frame prediction) of the two partitioned regions. In order to avoid conceptual ambiguity, the present invention refers to such inter-frame prediction as "first combined prediction", and the "first combined prediction" may be intra-frame prediction, inter-frame prediction, or intra-frame and inter-frame mixing of two divided regions Combined forecast for forecast. In this way, the present invention fully considers the prediction situation of adjacent blocks to perform the segmentation of the current CU and the determination of the prediction method, so that the video content in the current CU can be fully considered, which is in a specific video content (for example, the same object, such as a soccer ball). , windows, etc.) are divided into two CTUs or CUs.

Thus, in one aspect, the present invention provides a method for video decoding, comprising:

obtain information about the current coding tree unit (CTU) of the current frame from a syntax element of the video stream;

obtain information on coding unit (CU) partitioning of the current CTU from syntax elements of the video stream; and

For each CU:

The optimal intra prediction mode is obtained in the syntax element at the CTU level or the syntax element at the CU level, wherein the optimal intra prediction mode includes one of the following 6 intra prediction modes: plane mode, DC mode, upper block Angle Mode, Left Block Angle Mode, Vertical Mode and Horizontal Mode;

determining an intra prediction value corresponding to the best intra prediction mode;

Partition information for the CU is obtained in a CTU-level syntax element or a CU-level syntax element, the partition information includes an angle parameter and a prediction method (intra prediction, inter prediction), the partition information combines the CU Performing segmentation to obtain two segmentation regions, one of the two segmentation regions adopts intra-frame prediction, and the other region adopts inter-frame prediction;

for the two divided regions, determining a first combined prediction value based on the prediction method;

determining a second combined predictor based on the intra predictor and the first combined predictor;

The second combined predicted value is used as the predicted value of the CU.

In a further aspect, when both the left CU and the upper CU use inter-frame prediction, the angle parameter is the first acute angle parameter, and the left area uses inter-frame prediction, and the right area uses intra-frame prediction; When both the CU and the upper CU use intra-frame prediction, the angle parameter is the second acute angle parameter, and the left area uses intra-frame prediction, and the right-side area uses inter-frame prediction; when the left CU uses intra-frame prediction and the upper CU uses intra-frame prediction When inter prediction is used, the angle parameter is the third obtuse angle parameter, and intra prediction is used for the left area and inter prediction is used for the right area; and when the left CU uses inter prediction and the upper CU uses intra prediction , the angle parameter is the fourth obtuse angle parameter, and the left region adopts inter-frame prediction, and the right region adopts intra-frame prediction.

In a further aspect, determining a second combined predicted value based on the intra predicted value and the first combined predicted value further comprises: performing a weighted average of the intra predicted value and the first combined predicted value , to determine the second combined predicted value.

In a further aspect, the segmentation information further includes a displacement value corresponding to the angle parameter, the displacement value representing a vertical displacement relative to a corresponding angle.

On the other hand, the present invention also proposes a method for video encoding and decoding, comprising:

Get the current coding tree unit (CTU) of the current frame;

performing coding unit (CU) partitioning on the current CTU; and

For each CU:

Determine the best intra prediction mode corresponding to the following 6 intra prediction modes: plane mode, DC mode, upper block angle mode, left block angle mode, vertical mode and horizontal mode;

determining an intra prediction value corresponding to the best intra prediction mode;

According to the prediction methods (intra-frame prediction, inter-frame prediction) of the left CU and the upper CU, the CU is divided by the dividing line corresponding to the angle parameter to obtain two divided regions, and according to the prediction methods of the left CU and the upper CU (intra-frame prediction, inter-frame prediction), one of the two divided regions adopts intra-frame prediction, and the other region adopts inter-frame prediction;

determining a first combined predicted value for the two segmented regions;

determining a second combined predictor based on the intra predictor and the first combined predictor; and

The CU is predicted using the second combined predictor as a predictor for the CU.

In a further aspect, the dividing line further corresponds to a displacement value corresponding to the angle parameter, the displacement value representing a vertical displacement relative to a corresponding angle.

In a further aspect, when both the left CU and the upper CU adopt inter-frame prediction, the CU is segmented using the first acute angle parameter, and the left-side region adopts inter-frame prediction, and the right-side region adopts intra-frame prediction; When both the CU and the upper CU use intra-frame prediction, the second acute angle parameter is used to segment the CU, and the left area uses intra-frame prediction, and the right-side area uses inter-frame prediction; when the left CU uses intra-frame prediction and the upper CU uses intra-frame prediction When inter prediction is used, the CU is segmented using the third obtuse angle parameter, and intra prediction is used for the left area and inter prediction is used for the right area; and when the left CU uses inter prediction and the upper CU uses intra prediction , the CU is segmented using the fourth obtuse angle parameter, and the left region adopts inter prediction, and the right region adopts intra prediction.

In a further aspect, determining a second combined predicted value based on the intra predicted value and the first combined predicted value further comprises: performing a weighted average of the intra predicted value and the first combined predicted value , to determine the second combined predicted value.

In a further aspect, determining the optimal intra prediction mode corresponding to the following 6 intra prediction modes: plane mode, DC mode, upper block angle mode, left block angle mode, vertical mode and horizontal mode further comprises: for all The six intra-frame prediction modes are used to determine an optimal intra-frame prediction cost value; and an intra-frame prediction mode corresponding to the optimal intra-frame prediction cost value is determined as the optimal intra-frame prediction mode.

On the other hand, the present invention also provides a computing device capable of performing video decoding, comprising:

a memory that stores executable code for video encoding and decoding;

One or more processors or video codecs for executing executable code for video codecs stored in memory to perform the method of claim 1 .

On the other hand, the present invention also provides a computer-readable storage medium, which stores codes for performing video encoding and decoding, and when the codes are executed, can realize the above-mentioned video encoding or video decoding method .

Description of drawings

Figure 1 shows an embodiment of a generalized block diagram of a general encoder for HEVC/VVC.

Figure 2 shows a schematic diagram of a coding tree (CTU) in HEVC.

Figure 3 shows a multi-type tree partitioning pattern for VVC.

FIG. 4 shows a specific embodiment of a CTU-to-CU partition of a quadtree partition structure with nested multi-type trees of VVC.

Figures 5(a)-5(d) illustrate a non-limiting way of dividing non-vertical and horizontal dividing according to an embodiment of the present invention.

FIG. 6 illustrates a video encoding method according to an embodiment of the present invention.

FIG. 7 shows a schematic diagram of a device for implementing a coding and decoding method according to an embodiment of the present invention.

Detailed ways

Various schemes are now described with reference to the figures. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. Obviously, however, these schemes can be implemented without these specific details.

As used in this application, the terms "component," "module," "system," and the like are intended to refer to computer-related entities such as, but not limited to, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. For example, both an application running on a computing device and the computing device can be components. One or more components can reside within a process and/or thread of execution, and a component can be localized on one computer and/or distributed across two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. Components may communicate by means of local and/or remote processes, for example, based on signals having one or more data packets, for example, from interacting with another component in a local system, a distributed system by means of signals, and/or with another component in a distributed system. Data for a component on a network such as the Internet that interacts with other systems by means of signals.

In the prior art including HEVC and VVC, although the case of obtaining a combined prediction value based on multiple reference frames is considered, the intra prediction value and inter prediction for a coding unit (CU) are not considered The values are combined in some way so that both intra- and inter-predictors cannot be fully utilized.

In addition, in the prior art, the video data block is usually divided in the form of CU or PU. This kind of division is limited to the division in the vertical and horizontal directions, so the limitation is large, and the video within the block cannot be optimally dealt with. Internal changes in content.

In addition, in the prior art, some segmentations in non-vertical and horizontal directions are proposed, but these segmentations are all performed within the intra-frame prediction stage or the inter-frame prediction stage, that is, the segmented blocks or all perform intra-frame prediction Or both perform inter-frame prediction, thereby limiting the application range of segmentation in non-vertical and horizontal directions. Moreover, the segmentation in the non-vertical and horizontal directions in the prior art usually only proposes a novel segmentation method, and does not consider the prediction situation of the adjacent blocks of the current video block (CU or PU) during segmentation. (eg whether the neighboring blocks are intra-predicted or inter-predicted).

In order to solve the above technical problems, the present invention proposes that for each CU, by combining the intra-frame prediction value and the inter-frame prediction value of the CU, the gains of both the intra-frame prediction and the inter-frame prediction of the CU are fully utilized.

When considering the intra prediction value, the present invention does not traverse all the 35 prediction modes in HEVC and 67 prediction modes in VVC to find the best intra prediction mode, but considers all intra prediction modes of the entire CU a reduced number of intra-prediction modes in and determine the best intra prediction mode from it. In this way, the gain of intra prediction can be fully utilized while reducing the amount of computation.

When considering inter-frame prediction values, the present invention does not perform inter-frame prediction based on CUs as in the prior art, but further divides CUs in non-vertical and horizontal directions and uses prediction methods based on adjacent CUs ( That is, whether adjacent CUs are intra-frame prediction or inter-frame prediction) to further determine the prediction modes (intra-frame prediction, inter-frame prediction) of the two partitioned regions. In order to avoid conceptual ambiguity, the present invention refers to such inter-frame prediction as "first combined prediction", and the "first combined prediction" may be intra-frame prediction, inter-frame prediction, or intra-frame and inter-frame mixing of two divided regions Combined forecast for forecast.

In this way, the present invention fully considers the prediction situation of adjacent blocks to perform the segmentation of the current CU and the determination of the prediction method, so that the video content in the current CU can be fully considered, which is in a specific video content (for example, the same object, such as a soccer ball). , windows, etc.) are divided into two CTUs or CUs.

Figures 5(a)-5(d) illustrate a non-limiting way of dividing non-vertical and horizontal dividing according to an embodiment of the present invention. The angles and division positions in the figures are exemplary. It is easy to understand that the angles in the figures can vary from acute to obtuse. In a preferred embodiment, a set of angles (including several angle values within the open set (0,90) degrees and (90,180) degrees) can be predefined, indicated and signaled with an angle index, thereby saving signaling overhead. In an alternative embodiment, the angle value may be directly determined and signaled. In addition, the division position can also be changed. In a preferred embodiment, for a specific angle, the division position may be defined by a vertical displacement relative to the angle, where the vertical displacement may be relative to four vertices or centers of a video data block (eg CU) point, or relative to other reference locations, the scope of the invention is not limited thereto.

In addition, as shown in the figure, regardless of the angle and displacement used, the left and right blocks are bound to be obtained after division, although the left and right blocks may have various shapes.

In Figures 5(a)-5(d), A1 and B1 correspond to the left (eg CU) block and the upper block (eg CU) of the current video data block (eg CU), respectively. The figure shows the preferred positions of the left CU and the upper CU, that is, the bottom edge of the left CU corresponds to the bottom edge of the current CU, and the right side of the upper CU corresponds to the right side of the current CU. These position definitions are conventional definitions in VVC. In other embodiments, the left CU and the upper CU at other positions may also be used for other video coding and decoding methods or standards, and the scope of the present invention is not limited thereto.

In a specific embodiment, as shown in Figures 5(a)-5(d), when both the left block (A1) and the upper block (B1) use the inter prediction mode, the division method used is shown in Figure 5 As shown in (a); when both A1 and B1 use the intra-frame prediction mode, the division method used is shown in Figure 5(b); when A1 uses the intra-frame prediction mode and B1 uses the inter-frame prediction mode, the use is shown in Figure 5(b). 5(c); when A1 adopts the inter-frame prediction mode and B1 adopts the intra-frame prediction mode, as shown in Fig. 5(d). However, the angles and displacements in Figures 5(a)-5(d) are exemplary, and the scope of the present invention is not limited thereto.

FIG. 6 illustrates a video encoding method according to an embodiment of the present invention. According to the video encoding method of FIG. 6 , the original uncompressed video can be encoded, and the encoded video bitstream can be finally output.

In step 601, the current CTU of the current frame is obtained. In HEVC/VVC, a frame can be directly divided into CTUs, or a frame can be divided into slices and/or tiles at first, but it is ultimately encoded in CTU units. The division relationship of slices, tiles and CTUs can be found in the related protocols of HEVC/VVC. However, the scope of the present invention is not limited to this, but can be applied to any image data block-based video coding method.

In step 603, coding unit (CU) segmentation is performed on the current CTU. In one embodiment, the CU may be obtained by dividing the CTU in a quad-tree manner according to the HEVC and previous video coding standards. In an alternative embodiment, the CU partitioning may be performed in accordance with QTBT or other similar nesting structures in VVC or later video coding standards. However, the scope of the present invention is not limited to this, but can be applied to any image data block-based video coding method.

After the CU segmentation is performed, CU traversal within the CTU is performed, wherein the following operations are performed for each CU.

In step 605, for the current CU, determine the best intra prediction mode corresponding to the following 6 intra prediction modes: plane mode, DC mode, upper block angle mode, left block angle mode, vertical mode and horizontal mode. Details of these intra prediction modes can be found in the relevant HEVC/VVC protocols.

In a preferred embodiment, an optimal intra-frame prediction cost value may be determined for the six intra-frame prediction modes, and an intra-frame prediction mode corresponding to the optimal intra-frame prediction cost value may be determined as the optimal intra-frame prediction cost value. Intra prediction mode.

After the optimal intra prediction mode is determined, the intra prediction value of the current CU corresponding to the optimal intra prediction mode is determined.

In step 607, for the current CU, according to the prediction mode (intra-frame prediction or inter-frame prediction) of the left CU of the current CU and the upper CU, the CU is divided by the dividing line corresponding to the specific angle parameter to obtain two divisions region, and according to the prediction modes (intra-frame prediction, inter-frame prediction) of the left CU and the upper CU, one of the two divided regions adopts intra-frame prediction, and the other region adopts inter-frame prediction. Figures 5(a)-5(d) show an example of such a segmentation.

For the division, in a preferred embodiment, for a specific division angle, the division position may be defined by means of a vertical displacement relative to the angle, where the vertical displacement may be relative to a video data block (eg CU) of the four vertices or center points, or relative to other reference positions, the scope of the present invention is not limited thereto.

In one embodiment, in the segmentation, a fixed angle and a fixed displacement may be used, as shown in Figs. 5(a)-5(d). In this way, the fixed angle and fixed displacement may not have to be signaled in the encoded video stream.

In another embodiment, in the segmentation, a set of angles (including several angle values within the open set (0,90) degrees and (90,180) degrees) can be predefined, indicated by angle indices and encoded in the Signaled in the video stream. Additionally or alternatively, in the partitioning, a set of one or more fixed displacements corresponding to each angle may be predefined and indicated by displacement indices and signaled in the encoded video stream.

In one embodiment, the optimal angle and optimal displacement may be selected among a subset of these angles and these displacements based on a cost function. In one embodiment, the subset of angles may obey an acute or obtuse angle range determined based on the prediction modes (intra prediction, inter prediction) of the left CU and the upper CU as defined below, ie (0,90 ) degree subset and (90, 180) degree subset.

In an alternative embodiment, the angle value may be determined directly and signaled in the encoded video stream. In one embodiment, the vertical displacement value relative to a particular angle can be directly determined and signaled in the encoded video stream.

In one embodiment, these signals may be placed in CU or CTU level syntax elements in the encoded video stream.

For a specific angle parameter, according to the prediction mode (intra-frame prediction or inter-frame prediction) of the left CU of the current CU and the upper CU (intra-frame prediction or inter-frame prediction), the CU is divided by the dividing line corresponding to the angle parameter to obtain two divided regions, and According to the prediction mode (intra-frame prediction or inter-frame prediction) of the left CU and the upper CU, one of the two divided regions adopts intra-frame prediction, and the other region adopts inter-frame prediction. Here, the angle parameter refers to the angle used for division.

As a preferred embodiment, when both the left CU and the upper CU use inter-frame prediction, the first acute angle parameter is used to segment the CU, and the left area uses inter-frame prediction, and the right-side area uses intra-frame prediction.

As a preferred embodiment, when both the left CU and the upper CU use intra-frame prediction, the second acute angle parameter is used to segment the CU, and the left area uses intra-frame prediction, and the right-side area uses inter-frame prediction.

As a preferred embodiment, when the left CU adopts intra prediction and the upper CU adopts inter prediction, the third obtuse angle parameter is used to segment the CU, and the left region adopts intra prediction, and the right region adopts inter prediction .

As a preferred embodiment, when the left CU adopts inter prediction and the upper CU adopts intra prediction, the fourth obtuse angle parameter is used to segment the CU, and the left region adopts inter prediction, and the right region adopts intra prediction .

In addition to the angle parameter, a displacement value corresponding to the angle parameter can also be used, the displacement value representing the vertical displacement with respect to the corresponding angle. As mentioned above, the displacement value may be fixed, selected from a set of predefined values, and the like.

For these two partitioned regions, the first combined predictor for the current CU is determined. It is easy to understand that the first combined predicted value is a combination of the predicted values of the corresponding divided regions obtained by the two divided regions according to their respective prediction modes.

In step 609, a second combined prediction value is determined based on the intra prediction value and the first combined prediction value. In a preferred embodiment, the second combined predicted value is determined by performing a weighted average of the intra-frame predicted value obtained in step 605 and the first combined predicted value obtained in step 607 . However, the scope of the present invention is not limited to this, and any combination method can be adopted, such as simple averaging and the like.

In step 611, the current CU is predicted using the second combined prediction value as the prediction value of the current CU. In one embodiment, the residual value of the current CU is obtained by subtracting the predicted value from the video data value of the current CU. It is easy to understand that in step 611, usually due to the CTU-to-CU segmentation process, the video data value of the current CU should have been retrieved and temporarily stored in the memory. Alternatively, the original uncoded video data value of the current CU may be obtained through retrieval in step 611 .

Finally, the residual value of the current CU is added to the encoded video stream after scanning, quantization, and entropy encoding. It is readily understood that signaling of other relevant parameters may be conveyed using syntax elements in the encoded video stream.

On the decoder side, operations substantially complementary to the method of FIG. 6 can be performed.

For example, at the decoder side, information about the current coding tree unit (CTU) of the current frame can be obtained from syntax elements of the video stream. Information on coding unit (CU) partitioning of the current CTU may be obtained from syntax elements of the video stream.

For each CU, an optimal intra prediction mode can be obtained in a CTU-level syntax element or a CU-level syntax element, where the optimal intra prediction mode includes one of the following 6 intra prediction modes: plane mode, DC mode, upper block angle mode, left block angle mode, vertical mode and horizontal mode.

The intra prediction value corresponding to the optimal intra prediction mode may be determined.

For each CU, partition information for the current CU can be obtained in a CTU-level syntax element or a CU-level syntax element, the partition information including an angle parameter and a prediction method (intra prediction or inter prediction), the partition The information divides the CU to obtain two divided regions, one of the two divided regions adopts intra-frame prediction, and the other region adopts inter-frame prediction.

As a further embodiment, the segmentation information further includes a displacement value corresponding to the angle parameter, where the displacement value represents a vertical displacement relative to the corresponding angle. In one embodiment, the vertical displacement may be relative to the four vertices or center points of the video data block (eg, CU), or relative to other reference locations, the scope of the present invention is not limited thereto.

In one embodiment, the angle parameter is an angle index value for a particular angle in a subset of a predefined set of angles.

In one embodiment, the displacement value is an index value of a set of vertical displacements corresponding to the particular angle. The subset of angles may obey the acute or obtuse angle range determined based on the prediction modes (intra prediction, inter prediction) of the left CU and the upper CU as defined below, that is, the (0,90) degree subset and ( 90,180) degree subset.

In one embodiment, the displacement value may be a predefined fixed displacement value corresponding to a specific angle.

As a further embodiment, the prediction mode included in the segmentation information may indicate which of each segmented region uses intra-frame prediction and which one may use inter-frame prediction. In a preferred embodiment, the prediction mode may only indicate the prediction mode of one of the divided regions, and the prediction mode of the other divided region may be implicitly determined because it is different from the prediction mode of the divided region.

In a preferred embodiment, for example, when the left CU and the upper CU both use inter prediction, the angle parameter is the first acute angle parameter, and the left area uses inter prediction, and the right area uses intra prediction . In a preferred embodiment, for example, when intra-frame prediction is used for both the left CU and the upper CU, the angle parameter is the second acute angle parameter, and the left area uses intra-frame prediction, and the right-side area uses inter-frame prediction . In a preferred embodiment, for example, when the left CU adopts intra prediction and the upper CU adopts inter prediction, the angle parameter is the third obtuse angle parameter, and the left region adopts intra prediction, and the right region adopts Inter prediction. In a preferred embodiment, for example, when the left CU adopts inter prediction and the upper CU adopts intra prediction, the angle parameter is the fourth obtuse angle parameter, and the left region adopts inter prediction, and the right region adopts Intra prediction.

After obtaining the segmentation information of the current CU (which may include angle parameters and prediction modes, and additionally may include displacement values) and prediction modes, a first combination may be determined based on their respective prediction modes for the two segmentation regions Predictive value. It is easy to understand that the first combined predicted value is a combination of the predicted values of the corresponding divided regions obtained by the two divided regions according to their respective prediction modes.

The second combined predicted value of the current CU may be determined as the predicted value of the current CU based on the intra predicted value and the first combined predicted value determined above. In a preferred embodiment, the second combined predicted value is determined by performing a weighted average of the obtained intra-frame predicted value and the first combined predicted value. However, the scope of the present invention is not limited to this, and any combination method can be adopted, such as simple averaging and the like.

The residual value of the current CU may be obtained from the video stream. It is readily understood that this step may be performed before the other steps, or may be performed concurrently with one or more of the other steps.

Video data for the current CU may be reconstructed based on residual values for the current CU and prediction values for the current CU.

Figure 6 shows a device that can be used for video encoding and decoding, the device comprising: a processor and a memory, the memory including processor executable codes for implementing various video encoding and decoding methods of the present invention or instructions, wherein the processor may be a video codec.

According to another aspect, the present disclosure may also relate to an encoder for implementing the above encoding method. The encoder can be dedicated hardware. According to another aspect, the present disclosure may also relate to a corresponding decoder for decoding an encoded video stream. According to another aspect, the present disclosure may also relate to a video codec for the above-mentioned encoding method or decoding method.

According to a specific embodiment of the present invention, the device may be one or more of a system on a chip (SOC), a computer, a server, and a cloud server.

According to another aspect, the present disclosure may also relate to a computer program product for performing the methods described herein. According to a further aspect, the computer program product has a non-transitory storage medium having computer code/instructions stored thereon which, when executed by a processor, can implement the various operations described herein.

Although the above discussion mainly focuses on HEVC/VVC, those skilled in the art can easily understand that the present invention can obviously be applied to other video codec standards, as long as these video codec standards adopt a video data block method similar to HEVC/VVC That's it.

In this disclosure, the terms "picture" and "frame" are often used interchangeably unless it is clearly indicated that a feature or operation is specific to the "frame".

When implemented in hardware, the video encoder may use a general purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic A device, discrete hardware component, or any combination thereof designed to perform the functions described herein is implemented or performed. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, eg, a combination of a DSP and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration. Additionally, at least one processor may include one or more modules operable to perform one or more of the steps and/or operations described above.

When implemented in hardware, the video encoder or device containing the video codec may be a system on a chip (SOC).

When the video encoder is implemented with hardware circuits such as ASIC, FPGA, etc., it may include various circuit blocks configured to perform various functions. Those skilled in the art can design and implement these circuits in various ways according to various constraints imposed on the entire system to achieve various functions disclosed in the present invention.

While the foregoing disclosure discusses exemplary aspects and/or embodiments, it should be noted that many changes and/or changes may be made herein without departing from the scope of the described aspects and/or embodiments as defined by the claims. Revise. Furthermore, although elements of the described aspects and/or embodiments are described or claimed in the singular, the plural is contemplated unless limitation to the singular is expressly stated. Additionally, all or a portion of any aspect and/or embodiment may be used in conjunction with all or a portion of any other aspect and/or embodiment, unless indicated to the contrary.

According to example 1, a method for video decoding, comprising:

obtain information about the current coding tree unit (CTU) of the current frame from a syntax element of the video stream;

obtain information on coding unit (CU) partitioning of the current CTU from syntax elements of the video stream; and for each CU: obtain the best intra prediction mode from the video stream, wherein the best intra prediction mode is The prediction mode includes one of the following 6 intra prediction modes: plane mode, DC mode, upper block angle mode, left block angle mode, vertical mode and horizontal mode; determine the intra prediction corresponding to the best intra prediction mode The segmentation information for the CU is obtained from the video stream, the segmentation information includes angle parameters and prediction methods (intra-frame prediction, inter-frame prediction), and the segmentation information divides the CU to obtain two segmentation regions , one of the two divided regions adopts intra-frame prediction, and the other region adopts inter-frame prediction; for the two divided regions, the first combined prediction value is determined based on the prediction method; based on the intra-frame prediction The predicted value and the first combined predicted value are used to determine a second combined predicted value; the second combined predicted value is used as the predicted value of the CU.

According to example 2, the method of example 1, wherein: when the left CU and the upper CU both use inter prediction, the angle parameter is the first acute angle parameter, and the left area uses inter prediction, the right The area adopts intra-frame prediction; when both the left CU and the upper CU use intra-frame prediction, the angle parameter is the second acute angle parameter, and the left area adopts intra-frame prediction, and the right-side area adopts inter-frame prediction; When the side CU adopts intra prediction and the upper CU adopts inter prediction, the angle parameter is the third obtuse angle parameter, and the left region adopts intra prediction and the right region adopts inter prediction; and when the left CU adopts frame prediction When inter prediction is used and the upper CU uses intra prediction, the angle parameter is the fourth obtuse angle parameter, and the left area uses inter prediction, and the right area uses intra prediction.

According to example 3, the method of example 1 or 2, wherein determining a second combined prediction value based on the intra prediction value and the first combined prediction value further comprises: by comparing the intra prediction value A weighted average is performed with the first combined predicted value to determine the second combined predicted value.

According to example 4, the method of any one of examples 1-3, wherein the segmentation information further includes a displacement value corresponding to the angle parameter, the displacement value representing a vertical displacement relative to a corresponding angle.

According to example 5, a method for video encoding and decoding, comprising:

Get the current coding tree unit (CTU) of the current frame;

performing coding unit (CU) partitioning on the current CTU; and

For each CU: determine the best intra prediction mode corresponding to the following 6 intra prediction modes: plane mode, DC mode, upper block angle mode, left block angle mode, vertical mode and horizontal mode; The intra-frame prediction value corresponding to the best intra-frame prediction mode; according to the prediction modes (intra-frame prediction, inter-frame prediction) of the left CU and the upper CU, use the dividing line corresponding to the angle parameter to divide the CU to obtain two divisions area, and according to the prediction methods (intra-frame prediction, inter-frame prediction) of the left CU and the upper CU, one of the two divided areas adopts intra-frame prediction, and the other area adopts inter-frame prediction; a divided region, determining a first combined prediction value; based on the intra prediction value and the first combined prediction value, determining a second combined prediction value; and using the second combined prediction value as the prediction of the CU value to predict the CU.

According to example 6, the method of example 4, wherein the dividing line further corresponds to a displacement value corresponding to the angle parameter, the displacement value representing a vertical displacement relative to a corresponding angle.

According to example 7, the method of example 4 or 5, wherein: when both the left CU and the upper CU employ inter prediction, the CU is segmented using the first acute angle parameter, and the left region employs inter prediction , the right region adopts intra-frame prediction; when both the left CU and the upper CU adopt intra-frame prediction, the second acute angle parameter is used to segment the CU, and the left region adopts intra-frame prediction, and the right-side region adopts inter-frame prediction When the left CU adopts intra prediction and the upper CU adopts inter prediction, use the third obtuse angle parameter to segment the CU, and the left area adopts intra prediction, and the right area adopts inter prediction; and when the left When the CU adopts inter prediction and the upper CU adopts intra prediction, the fourth obtuse angle parameter is used to segment the CU, and the left region adopts inter prediction, and the right region adopts intra prediction.

According to example 8, the method of any one of examples 4-6, wherein determining a second combined predictor based on the intra predictor and the first combined predictor further comprises: The intra-frame predicted value and the first combined predicted value are weighted averaged to determine the second combined predicted value.

According to example 9, the method of any one of examples 4-7, wherein an optimal intra prediction mode corresponding to the following 6 intra prediction modes is determined: planar mode, DC mode, upper block angle mode, The left block angle mode, the vertical mode and the horizontal mode further include: determining an optimal intra prediction cost value for the 6 intra prediction modes; and determining an intra prediction mode corresponding to the optimal intra prediction cost value as the best intra prediction mode.

According to example 10, a computing device capable of performing video decoding, comprising: a memory storing executable code for video encoding and decoding; one or more processors or video codecs for performing storage in the memory Executable code for video encoding and decoding to perform the method as described in Example 1.

Claims (10)

1. A method for video decoding, comprising:

obtaining information on a current Coding Tree Unit (CTU) of a current frame from a syntax element of a video stream;

obtaining information on Coding Unit (CU) partitioning of the current CTU from a syntax element of a video stream; and

for each CU:

obtaining an optimal intra prediction mode from a video stream, wherein the optimal intra prediction mode comprises one of the following 6 intra prediction modes: a planar mode, a DC mode, an upper block angle mode, a left block angle mode, a vertical mode, and a horizontal mode;

determining an intra prediction value corresponding to the optimal intra prediction mode;

obtaining partition information for the CU from a video stream, wherein the partition information comprises an angle parameter and a prediction mode (intra-frame prediction and inter-frame prediction), the partition information partitions the CU into two partition areas, one of the two partition areas adopts intra-frame prediction, and the other partition area adopts inter-frame prediction;

determining a first combined prediction value based on the prediction mode for the two divided areas;

determining a second combined prediction value based on the intra prediction value and the first combined prediction value;

and taking the second combined predicted value as the predicted value of the CU.

2. The method of claim 1, wherein:

when the left-side CU and the upper CU adopt inter-frame prediction, the angle parameter is a first acute angle parameter, the left-side area adopts inter-frame prediction, and the right-side area adopts intra-frame prediction;

when both the left-side CU and the upper CU adopt intra-frame prediction, the angle parameter is a second acute angle parameter, the left-side area adopts intra-frame prediction, and the right-side area adopts inter-frame prediction;

when the left-side CU adopts intra-frame prediction and the upper CU adopts inter-frame prediction, the angle parameter is a third obtuse angle parameter, the left-side area adopts intra-frame prediction, and the right-side area adopts inter-frame prediction; and

when the left-side CU employs inter-frame prediction and the upper CU employs intra-frame prediction, the angle parameter is a fourth obtuse angle parameter, and the left-side area employs inter-frame prediction and the right-side area employs intra-frame prediction.

3. The method of claim 1 or 2, wherein determining a second combined predictor based on the intra predictor and the first combined predictor further comprises:

determining the second combined predictor by weighted averaging the intra predictor and the first combined predictor.

4. The method of any of claims 1-3, wherein the segmentation information further includes a displacement value corresponding to the angle parameter, the displacement value representing a vertical displacement relative to a corresponding angle.

5. A method for video coding, comprising:

obtaining a current Coding Tree Unit (CTU) of a current frame;

performing Coding Unit (CU) partitioning on the current CTU; and

for each CU:

determining an optimal intra prediction mode corresponding to the following 6 intra prediction modes: a planar mode, a DC mode, an upper block angle mode, a left block angle mode, a vertical mode, and a horizontal mode;

determining an intra prediction value corresponding to the optimal intra prediction mode;

dividing the CU by a dividing line corresponding to the angle parameter according to prediction methods (intra prediction and inter prediction) of the left-side CU and the upper CU to obtain two divided regions, and according to the prediction methods (intra prediction and inter prediction) of the left-side CU and the upper CU, one of the two divided regions adopts intra prediction and the other adopts inter prediction;

determining a first combined predicted value for the two partitioned areas;

determining a second combined prediction value based on the intra prediction value and the first combined prediction value; and

predicting the CU by taking the second combined predicted value as a predicted value of the CU.

6. The method of claim 4, wherein the split line further corresponds to a displacement value corresponding to the angle parameter, the displacement value representing a vertical displacement relative to a corresponding angle.

7. The method of claim 4 or 5, wherein:

when both the left-side CU and the upper CU adopt inter-frame prediction, the first acute angle parameter is used for dividing the CU, the left-side area adopts inter-frame prediction, and the right-side area adopts intra-frame prediction;

when both the left-side CU and the upper CU adopt intra-frame prediction, the second acute angle parameter is used for dividing the CUs, the intra-frame prediction is adopted in the left-side area, and the inter-frame prediction is adopted in the right-side area;

when the left-side CU adopts intra-frame prediction and the upper CU adopts inter-frame prediction, the third obtuse angle parameter is used for dividing the CU, the left-side area adopts intra-frame prediction, and the right-side area adopts inter-frame prediction; and

when the left-side CU employs inter prediction and the upper CU employs intra prediction, the CU is partitioned using the fourth obtuse angle parameter, and the left-side region employs inter prediction and the right-side region employs intra prediction.

8. The method of any of claims 4-6, wherein determining a second combined predictor based on the intra predictor and the first combined predictor further comprises:

determining the second combined predictor by weighted averaging the intra predictor and the first combined predictor.

9. The method according to any of claims 4-7, wherein the best intra prediction mode is determined corresponding to the following 6 intra prediction modes: the planar mode, the DC mode, the upper block angle mode, the left block angle mode, the vertical mode, and the horizontal mode further include:

determining an optimal intra prediction cost value for the 6 intra prediction modes; and

and determining the intra-frame prediction mode corresponding to the optimal intra-frame prediction cost value as the optimal intra-frame prediction mode.

10. A computing device capable of performing video decoding, comprising:

a memory storing executable code for video coding;

one or more processors or video codecs to execute executable code stored in memory for video codec to perform the method of claim 1.

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