WO2020125595A1

WO2020125595A1 - Video coder-decoder and corresponding method

Info

Publication number: WO2020125595A1
Application number: PCT/CN2019/125740
Authority: WO
Inventors: 杨海涛; 赵寅; 赵日洋; 李忠良; 肖晶
Original assignee: 华为技术有限公司
Priority date: 2018-12-16
Filing date: 2019-12-16
Publication date: 2020-06-25

Abstract

Disclosed in the present application are a video coder-decoder and a corresponding method, relating to the technical field of video encoding and decoding, and helping to improve video encoding and decoding performance. In the present application, encoding and decoding are referred to together as coding-decoding. The video coding-decoding method comprises: on the basis of a size relationship between the width and the height of a current image block, a block division strategy is determined for the current image block; said block division strategy is applied to the current image block to obtain an encoded block; and by means of performing reconstruction on the obtained encoded block, reconstruction of the current image block is achieved.

Description

Video decoder and corresponding method

This application requires a Chinese patent application filed with the State Intellectual Property Office on December 16, 2018, with the application number 201811546224.7, and the application name is "video encoder, video decoder, and corresponding method", and the country filed on May 6, 2019 Intellectual Property Office, the application number is 201910372891.6, the priority of the Chinese patent application with the application name "video decoder and corresponding method", the entire content of which is incorporated by reference in this application.

Technical field

This application relates to the technical field of video encoding and decoding, in particular to a video decoder and corresponding method.

Background technique

Digital video capabilities can be incorporated into a variety of devices, including digital TVs, digital live broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, electronics Book readers, digital cameras, digital recording devices, digital media players, video game devices, video game consoles, cellular or satellite radiotelephones (so-called "smart phones"), video teleconferencing devices, video streaming devices And the like. Digital video equipment implements video compression technology, for example, in MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264/MPEG-4 Part 10 Advanced Video Coding (advanced video coding, AVC) The video compression techniques described in the defined standards, the video coding standard H.265/high efficiency video coding (HEVC) standard, and extensions to such standards. Video devices can more efficiently transmit, receive, encode, decode, and/or store digital video information by implementing such video compression techniques. Among them, MPEG is the abbreviation of moving picture expert group (moving picture experts) group. ITU-T is the abbreviation of ITU-T for ITU Telecommunication Standardization Sector.

For block-based video coding, a video slice (ie, a video frame or a portion of a video frame) may be divided into several image blocks, which may also be called tree blocks, coding units (CU), and/or Or coding node. How to divide video frames or video strips to improve video encoding and decoding performance has become an urgent technical problem to be solved.

Summary of the invention

The embodiments of the present application provide a video decoder and corresponding methods, which help to improve the performance of video encoding and decoding. In the embodiments of the present application, encoding and decoding are collectively referred to as decoding.

In a first aspect, a video decoding method is provided, which includes: first, determining a block division strategy for the current image block according to the size relationship between the width and height of the current image block. Then, the block division strategy is applied to the current image block to obtain a coding block. Next, the reconstruction of the current image block is achieved by reconstructing the obtained coding block. In this technical solution, the block division strategy of the current image block is determined conditionally to obtain the coding block. In this way, it helps to reduce the complexity of the division and thereby improve the performance of video encoding and decoding.

Among them, the coding block may also be called a coding unit. In one example, this technical solution can be applied to the second-level coding tree in the extended quad-tree (EQT) scheme, that is, the current image block can be any of the second-level coding trees An image block. The coding block may be a leaf node in a coding tree such as a second-level coding tree.

In a possible design, determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes: determining whether the current image block meets the first condition. The first condition includes that the width of the current image block is less than the product of the first threshold and the height of the current image block. Then, when the current image block does not satisfy the first condition, the block division strategy is determined to be the division in the vertical direction. The vertical direction is perpendicular to the direction of the side where the width of the current image block is located. In this way, when the width of the current image block is greater than or equal to the product of the first threshold and the height, it is not necessary to program information indicating the division direction of the current image block into the code stream, so transmission bit overhead can be saved. In addition, the technical solution helps to limit the width-to-height ratio of leaf nodes in the coding tree to a certain range, thereby facilitating coding.

In a possible design, according to the relationship between the width and height of the current image block, determining the block division strategy of the current image block includes: determining whether the current image block satisfies the second condition. The second condition includes that the height of the current image block is less than the product of the first threshold and the width of the current image block. Then, when the current image block does not satisfy the second condition, the block division strategy is determined to be the division in the horizontal direction. The horizontal direction is perpendicular to the direction of the side where the height of the current image block is located. In this way, when the height of the current image block is greater than or equal to the product of the first threshold and the width, it is not necessary to program information indicating the division direction of the current image block into the code stream, so transmission bit overhead can be saved. In addition, the technical solution helps to limit the height to width ratio of leaf nodes in the coding tree within a certain range, thereby facilitating coding.

In a possible design, determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes: determining whether the current image block meets the first condition. The first condition includes that the width of the current image block is less than the product of the first threshold and the height of the current image block. Then, when the current image block does not satisfy the first condition, it is determined that the block division strategy of the current image block does not include the division in the horizontal direction. The horizontal direction is perpendicular to the direction of the side where the height of the current image block is located. Based on this, the current image block may or may not be divided subsequently. For example, whether to divide the current image block can be determined according to the block strategy of the current image block combined with other information, such as the principle of minimum CU size and the principle of minimum rate distortion optimization (RDO). If it is determined to divide the current image block, there is no need to incorporate information indicating the division direction of the current image block into the code stream, so this technical solution helps to save transmission bit overhead. In addition, the technical solution helps to limit the width-to-height ratio of leaf nodes in the coding tree to a certain range, thereby facilitating coding.

In a possible design, according to the relationship between the width and height of the current image block, determining the block division strategy of the current image block includes: determining whether the current image block satisfies the second condition. The second condition includes that the height of the current image block is less than the product of the first threshold and the width of the current image block. Then, when the current image block does not satisfy the second condition, it is determined that the block division strategy of the current image block does not include the division in the vertical direction. The vertical direction is perpendicular to the direction of the side where the width of the current image block is located. Based on this, the current image block may or may not be divided subsequently. If it is determined to divide the current image block, there is no need to incorporate information indicating the division direction of the current image block into the code stream, so this technical solution helps to save transmission bit overhead. In addition, the technical solution helps to limit the height to width ratio of leaf nodes in the coding tree within a certain range, thereby facilitating coding.

In a possible design, the first threshold is the maximum value of the ratio of the length of the long side to the length of the short side of the node in the allowed coding tree (such as the second-level coding tree in the EQT scheme).

In one possible design, the first threshold is a value greater than 1. Optionally, the first threshold may be an integer power of 2.

In a possible design, the method may further include: parsing the code stream to obtain identification information, where the identification information is used to indicate the division type of the current image block. Correspondingly, applying the block division strategy to the current image block to obtain an encoded block includes: based on the block division strategy (specifically, the block division strategy determined when the first condition is not met), using the division type indicated by the identification information , Dividing the current image block into the vertical direction to obtain the coding block. In this possible design, the video decoding method is specifically a video decoding method.

In a possible design, the method may further include: parsing the code stream to obtain identification information, where the identification information is used to indicate the division type of the current image block. Correspondingly, applying the block division strategy to the current image block to obtain an encoded block includes: based on the block division strategy (specifically, the block division strategy determined when the second condition is not met), using the division type indicated by the identification information To divide the current image block into the horizontal direction. In this possible design, the video decoding method is specifically a video decoding method.

In a possible design, determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes: determining whether the current image block meets the third condition. The third condition includes that the width of the current image block is smaller than the product of the second threshold and the height of the current image block. Then, when the current image block does not satisfy the third condition, the block division strategy is determined as an extended quadtree division with the division direction in the vertical direction. The vertical direction is perpendicular to the direction of the side where the width of the current image block is located. In this way, when the width of the current image block is greater than or equal to the product of the second threshold and the height, and the current image block is expanded by quadtree division, there is no need to program the code stream to indicate the division direction of the current image block Information, so it can save the transmission bit overhead. In addition, the technical solution helps to limit the width-to-height ratio of leaf nodes in the coding tree to a certain range, thereby facilitating coding.

In a possible design, according to the relationship between the width and height of the current image block, determining the block division strategy of the current image block includes: determining whether the current image block satisfies the fourth condition. The fourth condition includes that the height of the current image block is less than the product of the second threshold and the width of the current image block. Then, when the current image block does not satisfy the fourth condition, the block division strategy is determined to be an extended quadtree division with the division direction in the horizontal direction. The horizontal direction is perpendicular to the direction of the side where the height of the current image block is located. In this way, when the height of the current image block is greater than or equal to the product of the second threshold and the width, and the current image block is expanded by quadtree division, there is no need to program the code stream to indicate the division direction of the current image block Information, so it can save the transmission bit overhead. In addition, the technical solution helps to limit the height to width ratio of leaf nodes in the coding tree within a certain range, thereby facilitating coding.

In a possible design, determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes: determining whether the current image block meets the third condition. The third condition includes that the width of the current image block is smaller than the product of the second threshold and the height of the current image block. Then, when the current image block does not satisfy the third condition, it is determined that the block division strategy of the current image block does not include the extended quadtree division in the horizontal direction, and the horizontal direction is perpendicular to the direction of the side where the height of the current image block is located. Based on this, the current image block may or may not be divided subsequently.

In a possible design, according to the relationship between the width and height of the current image block, determining the block division strategy of the current image block includes: determining whether the current image block satisfies the fourth condition. The fourth condition includes that the height of the current image block is less than the product of the second threshold and the width of the current image block. Then, when the current image block does not satisfy the fourth condition, it is determined that the block division strategy of the current image block does not include the extended quadtree division in the vertical direction, and the vertical direction is perpendicular to the direction of the side where the width of the current image block lies . Based on this, the current image block may or may not be divided subsequently.

In a possible design, the second threshold is one-half the maximum value of the ratio of the length of the long side to the length of the short side of the allowed coding tree (such as the second-level coding tree in the EQT scheme).

In one possible design, the second threshold is a value greater than 1. Optionally, the second threshold may be an integer power of 2.

In a possible design, the method may further include: parsing the code stream to obtain identification information, where the identification information is used to indicate the division type of the current image block. Correspondingly, applying the block division strategy to the current image block to obtain the encoded block includes: based on the block division strategy (specifically the block division strategy determined when the third condition is not met), when the identification information indicates that the current image block When the extended quadtree is divided, the current image block is divided into the extended quadtree in the vertical direction. In this possible design, the video decoding method is specifically a video decoding method.

In a possible design, the method may further include: parsing the code stream to obtain identification information, where the identification information is used to indicate the division type of the current image block. Correspondingly, applying the block division strategy to the current image block to obtain the coding block includes: based on the block division strategy (specifically the block division strategy determined when the fourth condition is not satisfied), when the identification information indicates that the current image block When the extended quadtree is divided, the current image block is divided into horizontal quadtrees. In this possible design, the video decoding method is specifically a video decoding method.

In a second aspect, a video decoding method is provided, including: if the length of the long side of the image block to be divided in the image to be decoded is twice the length of the short side of the image block to be divided, dividing the image block to be divided Binary tree division whose direction is perpendicular to the long side of the image block to be divided to obtain the divided image block. For example, if the width of the image block to be divided in the image to be decoded is twice the height, then the image block to be divided is divided into vertical binary trees to obtain the divided image block. For another example, if the height of the image block to be divided in the image to be decoded is twice as wide, then the image block to be divided is horizontally binary tree divided to obtain the divided image block. Then, according to the divided image blocks, the image to be decoded is reconstructed. In this way, the conditional division of the image blocks to be divided is helpful to reduce the division complexity, thereby improving the video codec performance. In addition, if the length of the long side of the image block to be divided is twice the length of the short side of the image block to be divided, there is no need to program the division method (including the division type and division direction) of the current image block into the code stream. ) Information, so transmission bit overhead can be saved. In addition, by dividing the current image block into a binary tree perpendicular to the long side of the current image block, the current image block can be divided into two square image blocks. Compared with the non-square rectangular image block, the subsequent block of the square image block The possibility of being divided is higher, therefore, the technical solution helps to improve the encoding accuracy of video pictures.

In a possible design, the long side of the image block to be divided is 128 pixels long, and the short side is 64 pixels long. For example, when the size of the image block to be divided is 128*64 (that is, the width is 128 pixels in length and the height is 64 pixels in length), the image block to be divided is divided into vertical binary trees. As another example, when the size of the image block to be divided is 64*128 (that is, the width is 64 pixel lengths and the height is 128 pixel lengths), the image block to be divided is divided into horizontal binary trees.

In a possible design, the length of the short side of the image block to be divided is equal to the side size of the maximum transform unit (TU), or the length of the short side of the image block to be divided is equal to the virtual pipeline data unit (virtual pipeline data unit) , VPDU) side dimensions.

In a possible design, the image blocks to be divided are boundary image blocks. Wherein, if one or more pixels in the current node exceed the current image boundary, the current node is said to exceed the image boundary. In this case, the current node is a boundary image block.

In a third aspect, a video decoding method is provided, which includes: if the width of the image block to be divided in the image to be decoded is greater than the height, vertical binary tree division is performed on the image block to be divided to obtain the divided image block; and /Or, if the height of the image block to be divided in the image to be decoded is greater than the width, then the image block to be divided is divided into horizontal binary trees to obtain the divided image block. Then, according to the divided image blocks, the image to be decoded is reconstructed. In this way, the conditional division of the image blocks to be divided is helpful to reduce the division complexity, thereby improving the video codec performance. In addition, the technical solution does not need to include information indicating the division manner (including division type and division direction) of dividing the current image block in the code stream, so transmission bit overhead can be saved. In addition, in this technical solution, the current image block is divided into two square image blocks. Compared with a non-square rectangular image block, the subsequent blocks of the square image block are more likely to be divided. Therefore, this technical solution helps Improve the encoding accuracy of video pictures.

In a possible design, when the size of the image block to be divided is 128*64 (that is, the width is 128 pixels in length and the height is 64 pixels in length), the image block to be divided is divided into vertical binary trees.

In a possible design, when the size of the image block to be divided is 64*128 (that is, the width is 64 pixels in length and the height is 128 pixels in length), the image block to be divided is divided into horizontal binary trees.

In a possible design, the image blocks to be divided are boundary image blocks.

According to a fourth aspect, a video decoding method is provided, which includes: according to whether the current image block satisfies the first condition, determining whether to allow the current image block to be divided in a horizontal direction by a binary tree, where the horizontal direction is perpendicular to the height of the current image block For the direction of the edge, the first condition includes: the width of the current image block is less than the product of the first threshold and the height of the current image block, where, in the case where the current image block satisfies the first condition, it is determined to allow the current image block Binary tree division in the horizontal direction; if it is determined that the current image block is allowed to be divided in the horizontal direction, the coding block of the current image block is obtained; the reconstruction of the current image block is achieved by reconstructing the obtained coding block. In this way, the current image block is conditionally divided to obtain an encoding block, which helps to reduce the complexity of the division and thereby improve the performance of video encoding and decoding.

According to a fifth aspect, a video decoding method is provided, which includes: according to whether a current image block satisfies a second condition, determining whether to allow a binary tree division of the current image block in a vertical direction, the vertical direction being perpendicular to the width of the current image block In the direction of the edge, the second condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block, where, in the case where the current image block meets the second condition, it is determined that the current image is allowed The block is divided into two binary trees in the vertical direction; if it is determined that the current image block is allowed to be divided in the vertical direction, the coding block of the current image block is obtained; the current image block is realized by reconstructing the obtained coding block Refactoring. In this way, the current image block is conditionally divided to obtain an encoding block, which helps to reduce the complexity of the division and thereby improve the performance of video encoding and decoding.

According to a sixth aspect, a video decoding method is provided, which includes: according to whether the current image block satisfies the first condition, determining whether to allow the current image block to be divided in a horizontal direction, the horizontal direction being perpendicular to the high side of the current image block Direction, the first condition includes: the width of the current image block is less than the product of the first threshold and the height of the current image block, where, in the case where the current image block does not meet the first condition, it is determined that the current image block is not allowed Divide the horizontal direction; if it is determined that the current image block is not allowed to be divided horizontally, obtain the coding block of the current image block; by reconstructing the obtained coding block, the current image block is re-implemented Structure. In this way, the current image block is conditionally divided to obtain an encoding block, which helps to reduce the complexity of the division and thereby improve the performance of video encoding and decoding.

According to a seventh aspect, a video decoding method is provided, which includes: according to whether the current image block satisfies the second condition, determine whether to allow the current image block to be divided in the vertical direction, where the vertical direction is perpendicular to the width of the current image block The direction of the edge, the second condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block, where, in the case where the current image block does not meet the second condition, it is determined that the current image block is not allowed Perform the vertical division; when it is determined that the current image block is not allowed to be divided vertically, obtain the coding block of the current image block; by reconstructing the obtained coding block to achieve the re-weight of the current image block Structure. In this way, the current image block is conditionally divided to obtain an encoding block, which helps to reduce the complexity of the division and thereby improve the performance of video encoding and decoding.

According to an eighth aspect, a video decoding apparatus is provided, the apparatus including the first aspect or the second aspect or the third aspect, or any one of the first aspect or the second aspect or the third aspect The module (or unit) of the method in the design.

In a ninth aspect, a video decoder is provided. The video decoder includes: a nonvolatile memory and a processor coupled to each other. The processor calls the program code stored in the memory to perform any one of the first aspect to the seventh aspect, or a part of the method in any possible design of the first aspect or the seventh aspect or All steps.

According to a tenth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores a program code, wherein the program code includes any of the first to seventh aspects, or the first Instructions for any or all steps of the method in any one of the implementation manners of the aspect to the seventh aspect.

According to an eleventh aspect, there is provided a computer program product which, when run on a computer, causes the computer to perform any one of the first aspect to the seventh aspect, or any one of the first aspect to the seventh aspect Instructions for some or all steps of a method in an implementation.

It should be understood that the beneficial effects of any of the video decoding apparatus, video decoder, computer readable storage medium, and computer program product provided above can correspond to the beneficial effects of the method embodiments provided in the corresponding aspects above, I won't repeat them here.

BRIEF DESCRIPTION

1A is a schematic block diagram of a video encoding and decoding system applied in an embodiment of this application;

1B is a schematic block diagram of another video encoding and decoding system applied in an embodiment of this application;

2 is a schematic/conceptual block diagram of an example of an encoder implementing an embodiment of the present application;

3 is a schematic/conceptual block diagram of an example of a decoder implementing an embodiment of the present application;

4 is a schematic structural diagram of a video decoding device according to an embodiment of the present application;

5 is a schematic block diagram of an implementation manner of a decoding device according to an embodiment of the present application;

FIG. 6 is a schematic diagram of several division methods applicable to embodiments of the present application;

7 is a schematic diagram of a coding tree and its corresponding division method applicable to embodiments of the present application;

8 is a schematic flowchart of a video decoding method provided by an embodiment of the present application;

9 is a schematic flowchart of an image block division method provided by an embodiment of the present application;

10 is a schematic flowchart of another image block division method provided by an embodiment of the present application;

11 is a schematic flowchart of another image block division method provided by an embodiment of the present application;

12 is a schematic flowchart of another image block division method provided by an embodiment of the present application;

13 is a schematic flowchart of a video encoding method according to an embodiment of the present application;

14 is a schematic flowchart of a video decoding method provided by an embodiment of the present application;

15 is a schematic structural diagram of a video decoder provided by an embodiment of the present application;

16 is a schematic structural diagram of another video decoder provided by an embodiment of the present application;

17 is a schematic diagram of a video communication system applicable to embodiments of the present application;

18 is a schematic flowchart of another video decoding method provided by an embodiment of the present application;

FIG. 19 is a schematic flowchart of another video decoding method according to an embodiment of the present application.

detailed description

The following describes the embodiments of the present application with reference to the drawings in the embodiments of the present application. In the following description, reference is made to the accompanying drawings that form a part of the present disclosure and illustrate specific aspects of the embodiments of the present application by way of illustration or may use specific aspects of the embodiments of the present application. It should be understood that the embodiments of the present application may be used in other aspects, and may include structural or logical changes not depicted in the drawings. Therefore, the following detailed description should not be interpreted in a restrictive sense, and the scope of the present application is defined by the appended claims. For example, it should be understood that the disclosure in conjunction with the described method may be equally applicable to the corresponding device or system for performing the method, and vice versa. For example, if one or more specific method steps are described, the corresponding device may contain one or more units such as functional units to perform the one or more method steps described (eg, one unit performs one or more steps , Or multiple units, each of which performs one or more of multiple steps), even if such one or more units are not explicitly described or illustrated in the drawings. On the other hand, for example, if a specific device is described based on one or more units such as a functional unit, the corresponding method may include a step to perform the functionality of one or more units (eg, one step executes one or more units Functionality, or multiple steps, each of which performs the functionality of one or more of the multiple units), even if such one or more steps are not explicitly described or illustrated in the drawings. Further, it should be understood that, unless expressly stated otherwise, the features of the exemplary embodiments and/or aspects described herein may be combined with each other.

Video coding generally refers to processing a sequence of pictures that form a video or video sequence. In the field of video coding, the terms "picture", "frame" or "image" may be used as synonyms. Video coding as used herein refers to video encoding or video decoding. Video encoding is performed on the source side, and usually includes processing (eg, by compressing) the original video picture to reduce the amount of data required to represent the video picture, thereby storing and/or transmitting more efficiently. Video decoding is performed on the destination side and usually involves inverse processing relative to the encoder to reconstruct the video picture. The “encoding” of video pictures involved in the embodiments should be understood as referring to the “encoding” or “decoding” of video sequences. The combination of the encoding part and the decoding part is also called codec (encoding and decoding).

The video sequence includes a series of pictures, which are further divided into slices, and the slices are further divided into blocks. Video coding is performed in units of blocks. In some new video coding standards, the concept of blocks is further expanded. For example, a macroblock can be further divided into multiple prediction blocks that can be used for predictive coding. Or, basic concepts such as coding unit (ie CU), prediction unit (prediction unit (PU) and transform unit (ie TU) are used, functionally divided into various block units, and a new tree-based structure is used for description. There is a similar tree structure for PU and TU. PU can correspond to the prediction block and is the basic unit of predictive coding. The CU is further divided into multiple PUs according to the division mode. The TU can correspond to the transform block and is the basic unit for transforming the prediction residual. However, regardless of CU, PU or TU, they all belong to the concept of block (or image block) in essence.

The coding tree unit (in the coding tree (CTU)) is split into multiple CUs by using a quadtree structure represented as a coding tree. A decision is made at the CU level whether to use inter-picture (temporal) or intra-picture (spatial) prediction to encode picture regions. Each CU can be further split into one, two, or four PUs according to the PU split type. The same prediction process is applied within a PU, and related information is transmitted to the decoder on the basis of the PU. After obtaining the residual block by applying a prediction process based on the PU split type, the CU may be divided into TUs according to other quadtree structures similar to the coding tree used for the CU. In the latest development of video compression technology, quad-tree and binary-tree (QTBT) are used to divide frames to divide coding blocks. In the QTBT block structure, the CU may have a square or rectangular shape.

In this article, for ease of description and understanding, the image block to be encoded in the current encoded image may be referred to as the current block (or current image block). For example, in encoding, it refers to the block currently being encoded; in decoding, it refers to the current Decoded block. The decoded image block used to predict the current block in the reference image is referred to as a reference block, that is, the reference block is a block that provides a reference signal for the current block, where the reference signal represents a pixel value within the image block. The block in the reference image that provides the prediction signal for the current block may be a prediction block, where the prediction signal represents a pixel value or a sample value or a sample signal within the prediction block. For example, after traversing multiple reference blocks, the best reference block is found. This best reference block will provide a prediction for the current block. This block is called a prediction block.

In the case of lossless video coding, the original video picture can be reconstructed, that is, the reconstructed video picture has the same quality as the original video picture (assuming no transmission loss or other data loss during storage or transmission). In the case of lossy video encoding, further compression is performed by, for example, quantization to reduce the amount of data required to represent the video picture, but the decoder side cannot fully reconstruct the video picture, that is, the quality of the reconstructed video picture is better than the original video picture. The quality is lower or worse.

Several video coding standards of H.261 belong to "lossy hybrid video codec" (ie, combining spatial and temporal prediction in the sample domain with 2D transform coding for applying quantization in the transform domain). Each picture of a video sequence is usually divided into non-overlapping block sets, which are usually encoded at the block level. In other words, the encoder side usually processes the encoded video at the block (video block) level. For example, the prediction block is generated by spatial (intra-picture) prediction and temporal (inter-picture) prediction. From the current block (current processing or pending) Processed block) subtract the prediction block to obtain the residual block, transform the residual block in the transform domain and quantize the residual block to reduce the amount of data to be transmitted (compressed), and the decoder side will perform inverse processing relative to the encoder Partially applied to coded or compressed blocks to reconstruct the current block for representation. In addition, the encoder duplicates the decoder processing loop so that the encoder and decoder generate the same prediction (eg, intra prediction and inter prediction) and/or reconstruction for processing, ie encoding subsequent blocks.

The system architecture applied in the embodiments of the present application is described below. Referring to FIG. 1A, FIG. 1A exemplarily shows a schematic block diagram of a video encoding and decoding system 10 applied in an embodiment of the present application. As shown in FIG. 1A, the video encoding and decoding system 10 may include a source device 12 and a destination device 14, the source device 12 generates encoded video data, and therefore, the source device 12 may be referred to as a video encoding device. The destination device 14 may decode the encoded video data generated by the source device 12, and therefore, the destination device 14 may be referred to as a video decoding device. Various implementations of source device 12, destination device 14, or both may include one or more processors and memory coupled to the one or more processors. The memory may include, but is not limited to, RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store the desired program code in the form of instructions or data structures accessible by the computer, as described herein.

The communication connection between the source device 12 and the destination device 14 may be via a link 13, and the destination device 14 may receive the encoded video data from the source device 12 via the link 13. Link 13 may include one or more media or devices capable of moving encoded video data from source device 12 to destination device 14. In one example, link 13 may include one or more communication media that enable source device 12 to transmit encoded video data directly to destination device 14 in real time. In this example, the source device 12 may modulate the encoded video data according to a communication standard (eg, a wireless communication protocol), and may transmit the modulated video data to the destination device 14. The one or more communication media may include wireless and/or wired communication media, such as a radio frequency (RF) spectrum or one or more physical transmission lines. The one or more communication media may form part of a packet-based network, such as a local area network, a wide area network, or a global network (eg, the Internet). The one or more communication media may include routers, switches, base stations, or other devices that facilitate communication from source device 12 to destination device 14.

The source device 12 includes an encoder 20. Alternatively, the source device 12 may further include a picture source 16, a picture pre-processor 18, and a communication interface 22. In a specific implementation form, the encoder 20, the picture source 16, the picture pre-processor 18, and the communication interface 22 may be hardware components in the source device 12, or may be software programs in the source device 12. They are described as follows:

Picture source 16, which can include or can be any type of picture capture device, for example to capture real-world pictures, and/or any type of picture or comment (for screen content encoding, some text on the screen is also considered to be encoded Part of the picture or image) generation device, for example, a computer graphics processor for generating computer animation pictures, or for acquiring and/or providing real-world pictures, computer animation pictures (for example, screen content, virtual reality, VR) pictures) in any category of equipment, and/or any combination thereof (eg, augmented reality (AR) pictures). The picture source 16 may be a camera for capturing pictures or a memory for storing pictures. The picture source 16 may also include any type of (internal or external) interface that stores previously captured or generated pictures and/or acquires or receives pictures. When the picture source 16 is a camera, the picture source 16 may be, for example, a local or integrated camera integrated in the source device; when the picture source 16 is a memory, the picture source 16 may be a local or integrated, for example, integrated in the source device Memory. When the picture source 16 includes an interface, the interface may be, for example, an external interface that receives pictures from an external video source. The external video source is, for example, an external picture capture device, such as a camera, an external memory, or an external picture generation device. The external picture generation device, for example It is an external computer graphics processor, computer or server. The interface may be any type of interface according to any proprietary or standardized interface protocol, such as a wired or wireless interface, an optical interface.

The picture can be regarded as a two-dimensional array or matrix of picture elements. The pixels in the array can also be called sampling points. The number of sampling points in the horizontal and vertical directions (or axes) of the array or picture defines the size and/or resolution of the picture. In order to represent colors, three color components are usually used, that is, a picture can be represented or contain three sampling arrays. For example, in the RBG format or color space, the picture includes corresponding red, green, and blue sampling arrays. However, in video coding, each pixel is usually expressed in a luminance/chrominance format or color space. For example, for a picture in YUV format, it includes the luminance component indicated by Y (sometimes also indicated by L) and the two indicated by U and V. Chroma components. The luma component Y represents luminance or gray-scale horizontal intensity (for example, both are the same in gray-scale pictures), and the two chroma components U and V represent chroma or color information components. Accordingly, the picture in the YUV format includes a luminance sampling array of luminance sampling values (Y), and two chrominance sampling arrays of chrominance values (U and V). RGB format pictures can be converted or transformed into YUV format and vice versa, this process is also called color transformation or conversion. If the picture is black and white, the picture may include only the brightness sampling array. In the embodiment of the present application, the picture transmitted from the picture source 16 to the picture processor may also be referred to as original picture data 17.

The picture pre-processor 18 is configured to receive the original picture data 17 and perform pre-processing on the original picture data 17 to obtain the pre-processed picture 19 or the pre-processed picture data 19. For example, the pre-processing performed by the picture pre-processor 18 may include trimming, color format conversion (eg, conversion from RGB format to YUV format), color grading, or denoising.

The encoder 20 (or video encoder 20) is used to receive the pre-processed picture data 19, and process the pre-processed picture data 19 in a related prediction mode (such as the prediction mode in various embodiments herein), thereby The encoded picture data 21 is provided (the structural details of the encoder 20 will be further described below based on FIG. 2 or FIG. 4 or FIG. 5). In some embodiments, the encoder 20 may be used to execute various embodiments described below to implement the application of the division method described in this application on the encoding side.

The communication interface 22 can be used to receive the encoded picture data 21, and can transmit the encoded picture data 21 to the destination device 14 or any other device (such as a memory) via the link 13 for storage or direct reconstruction. The other device may be any device used for decoding or storage. The communication interface 22 may be used, for example, to encapsulate the encoded picture data 21 into a suitable format, such as a data packet, for transmission on the link 13.

The destination device 14 includes a decoder 30, and optionally, the destination device 14 may further include a communication interface 28, a post-picture processor 32, and a display device 34. They are described as follows:

The communication interface 28 may be used to receive the encoded picture data 21 from the source device 12 or any other source, such as a storage device, such as an encoded picture data storage device. The communication interface 28 can be used to transmit or receive the encoded picture data 21 through the link 13 between the source device 12 and the destination device 14 or through any type of network. The link 13 is, for example, a direct wired or wireless connection. A network of a category is, for example, a wired or wireless network or any combination thereof, or a private network and a public network of any category, or any combination thereof. The communication interface 28 may be used, for example, to decapsulate the data packet transmitted by the communication interface 22 to obtain the encoded picture data 21.

Both the communication interface 28 and the communication interface 22 may be configured as a one-way communication interface or a two-way communication interface, and may be used, for example, to send and receive messages to establish a connection, confirm and exchange any other communication link and/or for example encoded picture data Information about data transmission.

The decoder 30 (or referred to as the decoder 30) is used to receive the encoded picture data 21 and provide the decoded picture data 31 or the decoded picture 31 (hereinafter, the decoder 30 will be further described based on FIG. 3 or FIG. 4 or FIG. 5 Structural details). In some embodiments, the decoder 30 may be used to execute various embodiments described below to implement the application of the division method described in this application on the decoding side.

The post-picture processor 32 is configured to perform post-processing on the decoded picture data 31 (also referred to as reconstructed picture data) to obtain post-processed picture data 33. The post-processing performed by the image post-processor 32 may include: color format conversion (for example, conversion from YUV format to RGB format), color adjustment, retouching or resampling, or any other processing, and may also be used to convert the post-processed image data 33transmitted to the display device 34.

The display device 34 is used to receive post-processed picture data 33 to display pictures to, for example, a user or a viewer. The display device 34 may be or may include any type of display for presenting reconstructed pictures, for example, an integrated or external display or monitor. For example, the display may include a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a plasma display, a projector, a micro LED display, a liquid crystal on silicon (LCoS), Digital light processor (digital light processor, DLP) or any other type of display.

Although FIG. 1A illustrates the source device 12 and the destination device 14 as separate devices, device embodiments may also include the functionality of the source device 12 and the destination device 14 or both, ie, the source device 12 or The corresponding functionality and the destination device 14 or corresponding functionality. In such embodiments, the same hardware and/or software may be used, or separate hardware and/or software, or any combination thereof may be used to implement the source device 12 or corresponding functionality and the destination device 14 or corresponding functionality .

It is obvious to those skilled in the art based on the description that the existence and (accurate) division of the functionality of different units or the functionality of the source device 12 and/or the destination device 14 shown in FIG. 1A may vary according to actual devices and applications. Source device 12 and destination device 14 may include any of a variety of devices, including any type of handheld or stationary devices, such as notebook or laptop computers, mobile phones, smartphones, tablets or tablet computers, cameras, desktops Computers, set-top boxes, televisions, cameras, in-vehicle devices, display devices, digital media players, video game consoles, video streaming devices (such as content service servers or content distribution servers), broadcast receiver devices, broadcast transmitter devices And so on, and can not use or use any kind of operating system.

Both the encoder 20 and the decoder 30 can be implemented as any of various suitable circuits, for example, one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (application-specific integrated circuits) circuit, ASIC), field-programmable gate array (FPGA), discrete logic, hardware, or any combination thereof. If the techniques are partially implemented in software, the device may store the instructions of the software in a suitable non-transitory computer-readable storage medium, and may use one or more processors to execute the instructions in hardware to perform the techniques of the present disclosure . Any one of the foregoing (including hardware, software, a combination of hardware and software, etc.) may be regarded as one or more processors.

In some cases, the video encoding and decoding system 10 shown in FIG. 1A is only an example, and the technology of the present application may be applied to video encoding settings that do not necessarily include any data communication between encoding and decoding devices (eg, video encoding or video decoding). In other examples, data can be retrieved from local storage, streamed on the network, and so on. The video encoding device may encode the data and store the data to the memory, and/or the video decoding device may retrieve the data from the memory and decode the data. In some examples, encoding and decoding are performed by devices that do not communicate with each other but only encode data to and/or retrieve data from memory and decode the data.

Referring to FIG. 1B, FIG. 1B is an explanatory diagram of an example of a video coding system 40 including the encoder 20 of FIG. 2 and/or the decoder 30 of FIG. 3, according to an exemplary embodiment. The video decoding system 40 can implement a combination of various technologies in the embodiments of the present application. In the illustrated embodiment, the video decoding system 40 may include an imaging device 41, an encoder 20, a decoder 30 (and/or a video encoder/decoder implemented by the logic circuit of the processing unit 46), an antenna 42, One or more processors 43, one or more memories 44, and/or display devices 45.

As shown in FIG. 1B, the imaging device 41, the antenna 42, the processing unit 46, the encoder 20, the decoder 30, the processor 43, the memory 44, and/or the display device 45 can communicate with each other. As discussed, although the video coding system 40 is shown with the encoder 20 and the decoder 30, in different examples, the video coding system 40 may include only the encoder 20 or only the decoder 30.

In some examples, antenna 42 may be used to transmit or receive an encoded bitstream of video data. Additionally, in some examples, the display device 45 may be used to present video data. In some examples, the logic circuit may be implemented by the processing unit 46. The processing unit 46 may include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, and the like. The video decoding system 40 may also include an optional processor 43, which may similarly include ASIC logic, a graphics processor, a general-purpose processor, and the like. In some examples, the logic circuit may be implemented by hardware, such as dedicated hardware for video encoding, etc., and the processor 43 may be implemented by general-purpose software, an operating system, or the like. In addition, the memory 44 may be any type of memory, such as volatile memory (for example, static random access memory (SRAM), dynamic random access memory (DRAM), etc.) or nonvolatile memory Memory (for example, flash memory, etc.), etc. In a non-limiting example, the memory 44 may be implemented by cache memory. In some examples, the logic circuit can access the memory 44 (eg, for implementing the image buffer). In other examples, the logic circuit and/or processing unit 46 may include memory (eg, cache, etc.) for implementing image buffers and the like.

In some examples, the encoder 20 implemented by logic circuits may include an image buffer (eg, implemented by the processing unit 46 or the memory 44) and a graphics processing unit (eg, implemented by the processing unit 46). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include an encoder 20 implemented by logic circuits to implement the various modules discussed with reference to FIG. 2 and/or any other encoder system or subsystem described herein. Logic circuits can be used to perform the various operations discussed herein.

In some examples, decoder 30 may be implemented by logic circuits in a similar manner to implement the various modules discussed with reference to decoder 30 of FIG. 3 and/or any other decoder systems or subsystems described herein. In some examples, the decoder 30 implemented by the logic circuit may include an image buffer (implemented by the processing unit or the memory 44) and a graphics processing unit (for example, implemented by the processing unit 46). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include a decoder 30 implemented by logic circuits to implement the various modules discussed with reference to FIG. 3 and/or any other decoder systems or subsystems described herein.

In some examples, antenna 42 may be used to receive an encoded bitstream of video data. As discussed, the encoded bitstream may include data related to encoded video frames, indicators, index values, mode selection data, etc. discussed herein, such as data related to encoding partitions (eg, transform coefficients or quantized transform coefficients , (As discussed) an optional indicator, and/or data defining the encoding division). The video coding system 40 may also include a decoder 30 coupled to the antenna 42 and used to decode the encoded bitstream. The display device 45 is used to present video frames.

It should be understood that in the example described with reference to the encoder 20 in the embodiment of the present application, the decoder 30 may be used to perform the reverse process. Regarding signaling syntax elements, the decoder 30 may be used to receive and parse such syntax elements and decode the relevant video data accordingly. In some examples, encoder 20 may entropy encode syntax elements into an encoded video bitstream. In such instances, decoder 30 may parse such syntax elements and decode the relevant video data accordingly.

It should be noted that the decoding method described in the embodiment of the present application is mainly used in a decoding process, and this process exists in both the encoder 20 and the decoder 30.

Referring to FIG. 2, FIG. 2 shows a schematic/conceptual block diagram of an example of an encoder 20 for implementing an embodiment of the present application. In the example of FIG. 2, the encoder 20 includes a residual calculation unit 204, a transform processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transform processing unit 212, a reconstruction unit 214, a buffer 216, a loop filter Unit 220, decoded picture buffer (DPB) 230, prediction processing unit 260, and entropy encoding unit 270. The prediction processing unit 260 may include an inter prediction unit 244, an intra prediction unit 254, and a mode selection unit 262. The inter prediction unit 244 may include a motion estimation unit and a motion compensation unit (not shown). The encoder 20 shown in FIG. 2 may also be referred to as a hybrid video encoder or a video encoder based on a hybrid video codec.

For example, the residual calculation unit 204, the transform processing unit 206, the quantization unit 208, the prediction processing unit 260, and the entropy encoding unit 270 form the forward signal path of the encoder 20, while the inverse quantization unit 210, the inverse transform processing unit 212, and the The construction unit 214, the buffer 216, the loop filter 220, the DPB 230, and the prediction processing unit 260 form the backward signal path of the encoder, where the backward signal path of the encoder corresponds to the signal path of the decoder (see FIG. 3). Decoder 30).

The encoder 20 receives a picture 201 or an image block 203 of the picture 201 through, for example, an input 202, for example, forming a picture in a picture sequence of a video or a video sequence. The image block 203 may also be called a current picture block or a picture block to be encoded, and the picture 201 may be called a current picture or a picture to be encoded (especially when the current picture is distinguished from other pictures in video encoding, the other pictures are the same video sequence That is, the previously encoded and/or decoded pictures in the video sequence of the current picture are also included).

An embodiment of the encoder 20 may include a division unit (not shown in FIG. 2) for dividing the picture 201 into a plurality of blocks such as image blocks 203, usually into a plurality of non-overlapping blocks. The division unit can be used to use the same block size for all pictures in the video sequence and a corresponding grid that defines the block size, or to change the block size between pictures or subsets or picture groups, and divide each picture into The corresponding block.

In one example, the prediction processing unit 260 of the encoder 20 may be used to perform any combination of the above division techniques.

Like picture 201, image block 203 is also or can be regarded as a two-dimensional array or matrix of sampling points with sample values, although its size is smaller than picture 201. In other words, the image block 203 may include, for example, one sampling array (for example, the brightness array in the case of black and white picture 201) or three sampling arrays (for example, one brightness array and two chroma arrays in the case of color picture) or An array of any other number and/or category depending on the color format applied. The number of sampling points in the horizontal and vertical directions (or axes) of the image block 203 defines the size of the image block 203.

The encoder 20 shown in FIG. 2 is used to encode the picture 201 block by block, for example, to perform encoding and prediction on each image block 203.

The residual calculation unit 204 is used to calculate the residual block 205 based on the picture image block 203 and the prediction block 265 (other details of the prediction block 265 are provided below), for example, by subtracting the sample value of the picture image block 203 sample by sample (pixel by pixel) The sample values of the block 265 are depredicted to obtain the residual block 205 in the sample domain.

The transform processing unit 206 is used to apply a transform such as discrete cosine transform (DCT) or discrete sine transform (DST) on the sample values of the residual block 205 to obtain transform coefficients 207 in the transform domain . The transform coefficient 207 may also be called a transform residual coefficient, and represents a residual block 205 in the transform domain.

The transform processing unit 206 may be used to apply integer approximations of DCT/DST, such as the transform specified by AVS, AVS2, and AVS3. Compared with the orthogonal DCT transform, this integer approximation is usually scaled by a factor. In order to maintain the norm of the residual block processed by the forward and inverse transform, an additional scaling factor is applied as part of the transform process. The scaling factor is usually selected based on certain constraints. For example, the scaling factor is a power of two used for the shift operation, the bit depth of the transform coefficient, the accuracy, and the trade-off between implementation cost, and so on. For example, a specific scaling factor can be specified for the inverse transform by the inverse transform processing unit 212 on the decoder 30 side (and corresponding inverse transform by the inverse transform processing unit 212 on the encoder 20 side), and accordingly, the encoder can be The 20 side specifies a corresponding scaling factor for the positive transform through the transform processing unit 206.

The quantization unit 208 is used to quantize the transform coefficient 207 by, for example, applying scalar quantization or vector quantization to obtain the quantized transform coefficient 209. The quantized transform coefficient 209 may also be referred to as a quantized residual coefficient 209. The quantization process can reduce the bit depth associated with some or all of the transform coefficients 207. For example, n-bit transform coefficients can be rounded down to m-bit transform coefficients during quantization, where n is greater than m. The degree of quantization can be modified by adjusting quantization parameters (QP). For example, for scalar quantization, different scales can be applied to achieve thinner or coarser quantization. A smaller quantization step size corresponds to a finer quantization, and a larger quantization step size corresponds to a coarser quantization. The appropriate quantization step size can be indicated by QP. For example, the quantization parameter may be an index of a predefined set of suitable quantization steps. For example, smaller quantization parameters may correspond to fine quantization (smaller quantization step size), larger quantization parameters may correspond to coarse quantization (larger quantization step size), and vice versa. The quantization may include dividing by the quantization step size and the corresponding quantization or inverse quantization performed by, for example, inverse quantization 210, or may include multiplying the quantization step size. According to some standard embodiments such as AVS, AVS2, AVS3, quantization parameters may be used to determine the quantization step size. Generally speaking, the quantization step size can be calculated based on the quantization parameter using a fixed-point approximation including an equation of division. Additional scaling factors can be introduced for quantization and inverse quantization to restore the norm of the residual block that may be modified due to the scale used in the fixed-point approximation of the equations for quantization step size and quantization parameter. In an example embodiment, the scale of inverse transform and inverse quantization may be combined. Alternatively, a custom quantization table can be used and signaled from the encoder to the decoder in the bitstream, for example. Quantization is a lossy operation, where the larger the quantization step, the greater the loss.

The inverse quantization unit 210 is used to apply the inverse quantization of the quantization unit 208 on the quantized coefficients to obtain the inverse quantization coefficients 211, for example, based on or using the same quantization step size as the quantization unit 208, apply the quantization scheme applied by the quantization unit 208 Inverse quantization scheme. The inverse quantized coefficient 211 may also be referred to as an inverse quantized residual coefficient 211, which corresponds to the transform coefficient 207, although the loss due to quantization is usually not the same as the transform coefficient.

The inverse transform processing unit 212 is used to apply the inverse transform of the transform applied by the transform processing unit 206, for example, inverse DCT or inverse DST, to obtain the inverse transform block 213 in the sample domain. The inverse transform block 213 may also be referred to as an inverse transform dequantized block 213 or an inverse transform residual block 213.

The reconstruction unit 214 (eg, summer 214) is used to add the inverse transform block 213 (ie, the reconstructed residual block 213) to the prediction block 265 to obtain the reconstructed block 215 in the sample domain, for example, The sample values of the reconstructed residual block 213 and the sample values of the prediction block 265 are added.

Optionally, a buffer unit 216 (or simply "buffer" 216), such as a line buffer 216, is used to buffer or store the reconstructed block 215 and corresponding sample values for, for example, intra prediction. In other embodiments, the encoder may be used to use the unfiltered reconstructed blocks and/or corresponding sample values stored in the buffer unit 216 for any type of estimation and/or prediction, such as intra prediction.

For example, an embodiment of the encoder 20 may be configured such that the buffer unit 216 is used not only to store the reconstructed block 215 for intra prediction 254, but also for the loop filter unit 220 (not shown in FIG. 2) Out), and/or, for example, causing the buffer unit 216 and the decoded picture buffer unit 230 to form a buffer. Other embodiments may be used to use the filtered block 221 and/or blocks or samples from the decoded picture buffer 230 (neither shown in FIG. 2) as an input or basis for intra prediction 254.

The loop filter unit 220 (or simply "loop filter" 220) is used to filter the reconstructed block 215 to obtain the filtered block 221, so as to smoothly perform pixel conversion or improve video quality. The loop filter unit 220 is intended to represent one or more loop filters, such as deblocking filters, sample-adaptive offset (SAO) filters, or other filters, such as bilateral filters, Adaptive loop filter (adaptive loop filter, ALF), or sharpening or smoothing filter, or collaborative filter. Although the loop filter unit 220 is shown as an in-loop filter in FIG. 2, in other configurations, the loop filter unit 220 may be implemented as a post-loop filter. The filtered block 221 may also be referred to as the filtered reconstructed block 221. The decoded picture buffer 230 may store the reconstructed encoding block after the loop filter unit 220 performs a filtering operation on the reconstructed encoding block.

Embodiments of the encoder 20 (correspondingly, the loop filter unit 220) may be used to output loop filter parameters (eg, sample adaptive offset information), for example, directly output or by the entropy encoding unit 270 or any other The entropy encoding unit outputs after entropy encoding, for example, so that the decoder 30 can receive and apply the same loop filter parameters for decoding.

The decoded picture buffer (decoded picture buffer, DPB) 230 may be a reference picture memory for storing reference picture data for the encoder 20 to encode video data. DPB 230 can be formed by any of a variety of memory devices, such as dynamic random access memory (dynamic random access memory (DRAM) (including synchronous DRAM (synchronous DRAM, SDRAM), magnetoresistive RAM (magnetoresistive RAM, MRAM), resistive RAM (resistive RAM, RRAM)) or other types of memory devices. The DPB 230 and the buffer 216 may be provided by the same memory device or separate memory devices. In a certain example, a decoded picture buffer (DPB) 230 is used to store the filtered block 221. The decoded picture buffer 230 may be further used to store other previous filtered blocks of the same current picture or different pictures such as previous reconstructed pictures, such as the previously reconstructed and filtered block 221, and may provide the complete previous The reconstructed ie decoded pictures (and corresponding reference blocks and samples) and/or partially reconstructed current pictures (and corresponding reference blocks and samples), for example for inter prediction. In a certain example, if the reconstructed block 215 is reconstructed without in-loop filtering, a decoded picture buffer (DPB) 230 is used to store the reconstructed block 215.

The prediction processing unit 260, also known as the block prediction processing unit 260, is used to receive or acquire the image block 203 (current image block 203 of the current picture 201) and reconstructed picture data, such as the same (current) picture from the buffer 216 Reference samples and/or reference picture data 231 of one or more previously decoded pictures from the decoded picture buffer 230, and used to process such data for prediction, that is, to provide an inter prediction block 245 or The prediction block 265 of the intra prediction block 255.

The mode selection unit 262 may be used to select a prediction mode (eg, intra or inter prediction mode) and/or the

corresponding prediction block

245 or 255 used as the prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215.

An embodiment of the mode selection unit 262 may be used to select a prediction mode (for example, from those prediction modes supported by the prediction processing unit 260), which provides the best match or the minimum residual (the minimum residual means Better compression in transmission or storage), or provide minimum signaling overhead (minimum signaling overhead means better compression in transmission or storage), or consider or balance both at the same time. The mode selection unit 262 may be used to determine a prediction mode based on rate distortion optimization (RDO), that is, to select a prediction mode that provides minimum bit rate distortion optimization, or to select a prediction mode in which the related bit rate distortion at least meets the prediction mode selection criteria .

The prediction process performed by the example of the encoder 20 (for example, by the prediction processing unit 260) and the mode selection (for example, by the mode selection unit 262) will be explained in detail below.

As described above, the encoder 20 is used to determine or select the best or optimal prediction mode from the (predetermined) prediction mode set. The set of prediction modes may include, for example, intra prediction modes and/or inter prediction modes.

The intra prediction mode set may include 35 different intra prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in H.265, or may include 67 Different intra prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in the developing H.266.

In a possible implementation, the set of inter prediction modes depends on the available reference pictures (ie, for example, the aforementioned at least partially decoded pictures stored in DBP 230) and other inter prediction parameters, for example, depending on whether the entire reference picture is used or only Use a part of the reference picture, for example the search window area surrounding the area of the current block, to search for the best matching reference block, and/or for example depending on whether pixel interpolation such as half-pixel and/or quarter-pixel interpolation is applied For example, the set of inter prediction modes may include advanced motion vector (advanced motion vector prediction, AMVP) mode and merge mode. In a specific implementation, the set of inter prediction modes may include an improved control point-based AMVP mode according to an embodiment of the present application, and an improved control point-based merge mode. In one example, the intra prediction unit 254 may be used to perform any combination of inter prediction techniques described below.

In addition to the above prediction modes, the embodiments of the present application may also apply skip mode and/or direct mode.

The prediction processing unit 260 may be further used to divide the image block 203 into smaller block partitions or sub-blocks, for example, by iteratively using quad-tree (QT) division, binary-tree (BT) division Or triple-tree (TT) or extended quad-tree (ie EQT) partitioning, or any combination thereof, and for performing predictions for each of block partitions or sub-blocks, for example, where mode selection includes selection of partitioned The tree structure of the image block 203 and the selection of the prediction mode applied to each of the block partitions or sub-blocks.

The inter prediction unit 244 may include a motion estimation (ME) unit (not shown in FIG. 2) and a motion compensation (MC) unit (not shown in FIG. 2). The motion estimation unit is used to receive or acquire a picture image block 203 (current picture image block 203 of the current picture 201) and a decoded picture 231, or at least one or more previously reconstructed blocks, for example, one or more other/different The reconstructed block of the previously decoded picture 231 is used for motion estimation. For example, the video sequence may include the current picture and the previously decoded picture 31, or in other words, the current picture and the previously decoded picture 31 may be part of the picture sequence forming the video sequence, or form the picture sequence.

For example, the encoder 20 may be used to select a reference block from multiple reference blocks of the same or different pictures in multiple other pictures, and provide a reference picture and/or provide a reference to a motion estimation unit (not shown in FIG. 2) The offset (spatial offset) between the position of the block (X, Y coordinates) and the position of the current block is used as an inter prediction parameter. This offset is also called a motion vector (MV).

The motion compensation unit is used to acquire inter prediction parameters, and perform inter prediction based on or using inter prediction parameters to obtain inter prediction blocks 245. The motion compensation performed by the motion compensation unit (not shown in FIG. 2) may include extracting or generating a prediction block based on a motion/block vector determined by motion estimation (possibly performing interpolation of sub-pixel accuracy). Interpolation filtering can generate additional pixel samples from known pixel samples, potentially increasing the number of candidate prediction blocks that can be used to encode picture blocks. Once the motion vector for the PU of the current picture block is received, the motion compensation unit 246 may locate the prediction block pointed to by the motion vector in a reference picture list. Motion compensation unit 246 may also generate syntax elements associated with blocks and video slices for use by decoder 30 when decoding picture blocks of video slices.

Specifically, the above inter prediction unit 244 may transmit a syntax element to the entropy encoding unit 270, where the syntax element includes inter prediction parameters (such as an inter prediction mode selected for the current block prediction after traversing multiple inter prediction modes Instructions). In a possible application scenario, if there is only one inter prediction mode, the inter prediction parameters may not be carried in the syntax element. In this case, the decoding terminal 30 may directly use the default prediction mode for decoding. It can be understood that the inter prediction unit 244 may be used to perform any combination of inter prediction techniques.

The intra prediction unit 254 is used to acquire, for example, a picture block 203 (current picture block) that receives the same picture and one or more previously reconstructed blocks, such as reconstructed neighboring blocks, for intra estimation. For example, the encoder 20 may be used to select an intra prediction mode from a plurality of (predetermined) intra prediction modes.

Embodiments of the encoder 20 may be used to select an intra prediction mode based on optimization criteria, for example, based on a minimum residual (eg, an intra prediction mode that provides the prediction block 255 most similar to the current picture block 203) or minimum rate distortion.

The intra prediction unit 254 is further used to determine the intra prediction block 255 based on the intra prediction parameters of the intra prediction mode as selected. In any case, after selecting the intra-prediction mode for the block, the intra-prediction unit 254 is also used to provide the intra-prediction parameters to the entropy encoding unit 270, that is, to provide an indication of the selected intra-prediction mode for the block Information. In one example, the intra prediction unit 254 may be used to perform any combination of intra prediction techniques.

Specifically, the above-mentioned intra-prediction unit 254 may transmit a syntax element to the entropy encoding unit 270, where the syntax element includes intra-prediction parameters (such as an intra-prediction mode selected for the current block prediction after traversing multiple intra-prediction modes) Instructions). In a possible application scenario, if there is only one intra prediction mode, the intra prediction parameters may not be carried in the syntax element. In this case, the decoding terminal 30 may directly use the default prediction mode for decoding.

The entropy coding unit 270 is used to entropy coding algorithms or schemes (for example, variable length coding (VLC) scheme, context adaptive VLC (context adaptive VLC, CAVLC) scheme, arithmetic coding scheme, context adaptive binary arithmetic Coding (context adaptive) binary arithmetic coding (CABAC), syntax-based context-adaptive binary arithmetic coding (SBAC), probability interval entropy (probability interval interpartitioning entropy, PIPE) coding or other entropy Coding method or technique) applied to a single or all of the quantized residual coefficients 209, inter prediction parameters, intra prediction parameters, and/or loop filter parameters (or not applied) to obtain the output 272 to For example, the encoded picture data 21 output in the form of an encoded bit stream 21. The encoded bitstream may be transmitted to the video decoder 30 or archived for later transmission or retrieval by the video decoder 30. The entropy encoding unit 270 may also be used to entropy encode other syntax elements of the current video slice being encoded.

Other structural variations of video encoder 20 may be used to encode video streams. For example, the non-transform based encoder 20 may directly quantize the residual signal without the transform processing unit 206 for certain blocks or frames. In another embodiment, the encoder 20 may have a quantization unit 208 and an inverse quantization unit 210 combined into a single unit.

Specifically, in the embodiment of the present application, the encoder 20 may be used to implement the encoding method described in the following embodiments.

It should be understood that other structural changes of the video encoder 20 may be used to encode the video stream. For example, for some image blocks or image frames, the video encoder 20 can directly quantize the residual signal without processing by the transform processing unit 206, and accordingly, without processing by the inverse transform processing unit 212; or, for some For image blocks or image frames, the video encoder 20 does not generate residual data, and accordingly does not need to be processed by the transform processing unit 206, quantization unit 208, inverse quantization unit 210, and inverse transform processing unit 212; or, the video encoder 20 may convert The reconstructed image block is directly stored as a reference block without being processed by the filter 220; alternatively, the quantization unit 208 and the inverse quantization unit 210 in the video encoder 20 may be merged together. The loop filter 220 is optional, and in the case of lossless compression coding, the transform processing unit 206, quantization unit 208, inverse quantization unit 210, and inverse transform processing unit 212 are optional. It should be understood that the inter prediction unit 244 and the intra prediction unit 254 may be selectively enabled according to different application scenarios.

Referring to FIG. 3, FIG. 3 shows a schematic/conceptual block diagram of an example of a decoder 30 for implementing an embodiment of the present application. The video decoder 30 is used to receive encoded picture data (eg, encoded bitstream) 21, for example, encoded by the encoder 20, to obtain the decoded picture 231. During the decoding process, video decoder 30 receives video data from video encoder 20, such as an encoded video bitstream and associated syntax elements representing picture blocks of the encoded video slice.

In the example of FIG. 3, the decoder 30 includes an entropy decoding unit 304, an inverse quantization unit 310, an inverse transform processing unit 312, a reconstruction unit 314 (such as a summer 314), a buffer 316, a loop filter 320, a The decoded picture buffer 330 and the prediction processing unit 360. The prediction processing unit 360 may include an inter prediction unit 344, an intra prediction unit 354, and a mode selection unit 362. In some examples, video decoder 30 may perform a decoding pass that is generally inverse to the encoding pass described with reference to video encoder 20 of FIG. 2.

The entropy decoding unit 304 is used to perform entropy decoding on the encoded picture data 21 to obtain, for example, quantized coefficients 309 and/or decoded encoding parameters (not shown in FIG. 3), for example, inter prediction, intra prediction parameters , Any or all of the loop filter parameters and/or other syntax elements (decoded). The entropy decoding unit 304 is further used to forward inter prediction parameters, intra prediction parameters, and/or other syntax elements to the prediction processing unit 360. Video decoder 30 may receive syntax elements at the video slice level and/or the video block level.

The inverse quantization unit 310 may be functionally the same as the inverse quantization unit 110, the inverse transform processing unit 312 may be functionally the same as the inverse transform processing unit 212, the reconstruction unit 314 may be functionally the same as the reconstruction unit 214, and the buffer 316 may be functionally Like the buffer 216, the loop filter 320 may be functionally the same as the loop filter 220, and the decoded picture buffer 330 may be functionally the same as the decoded picture buffer 230.

The prediction processing unit 360 may include an inter prediction unit 344 and an intra prediction unit 354, wherein the inter prediction unit 344 may be similar in function to the inter prediction unit 244, and the intra prediction unit 354 may be similar in function to the intra prediction unit 254 . The prediction processing unit 360 is generally used to perform block prediction and/or obtain the prediction block 365 from the encoded data 21, and receive or obtain prediction-related parameters and/or information about the entropy decoding unit 304 (explicitly or implicitly). Information about the selected prediction mode.

When the video slice is encoded as an intra-coded (I) slice, the intra prediction unit 354 of the prediction processing unit 360 is used to signal-based the intra prediction mode and the previous decoded block from the current frame or picture. Data to generate a prediction block 365 for the picture block of the current video slice. When the video frame is encoded as an inter-coded (ie, B or P) slice, the inter prediction unit 344 (eg, motion compensation unit) of the prediction processing unit 360 is used for the motion vector-based and received from the entropy decoding unit 304 Other syntax elements generate a prediction block 365 for the video block of the current video slice. For inter prediction, a prediction block may be generated from a reference picture in a reference picture list. The video decoder 30 may construct the reference frame lists: list 0 and list 1 based on the reference pictures stored in the DPB 330 using default construction techniques.

The prediction processing unit 360 is used to determine the prediction information for the video block of the current video slice by parsing the motion vector and other syntax elements, and use the prediction information to generate the prediction block for the current video block being decoded. In an example of the present application, the prediction processing unit 360 uses some received syntax elements to determine the prediction mode (eg, intra or inter prediction) of the video block used to encode the video slice, and the inter prediction slice type ( For example, B slice, P slice, or GPB slice), construction information for one or more of the reference picture lists for slices, motion vectors for each inter-coded video block for slices, The inter prediction status and other information of each inter-coded video block of the slice to decode the video block of the current video slice. In another example of the present disclosure, the syntax elements received by the video decoder 30 from the bitstream include an adaptive parameter set (adaptive parameter set, APS), a sequence parameter set (SPS), and a picture parameter set (picture parameter (set, PPS) or the syntax element in one or more of the stripe headers.

The inverse quantization unit 310 may be used to inverse quantize (ie, inverse quantize) the quantized transform coefficients provided in the bitstream and decoded by the entropy decoding unit 304. The inverse quantization process may include using the quantization parameters calculated by the video encoder 20 for each video block in the video slice to determine the degree of quantization that should be applied and also determine the degree of inverse quantization that should be applied.

The inverse transform processing unit 312 is used to apply an inverse transform (eg, inverse DCT, inverse integer transform, or conceptually similar inverse transform process) to the transform coefficients, so as to generate a residual block in the pixel domain.

The reconstruction unit 314 (eg, summer 314) is used to add the inverse transform block 313 (ie, the reconstructed residual block 313) to the prediction block 365 to obtain the reconstructed block 315 in the sample domain, for example by The sample values of the reconstructed residual block 313 are added to the sample values of the prediction block 365.

The loop filter unit 320 (during the encoding loop or after the encoding loop) is used to filter the reconstructed block 315 to obtain the filtered block 321 to smoothly perform pixel conversion or improve video quality. In one example, the loop filter unit 320 may be used to perform any combination of filtering techniques described below. The loop filter unit 320 is intended to represent one or more loop filters, such as deblocking filters, SAO filters, or other filters, such as bilateral filters, ALF, or sharpening or smoothing filters, or collaborative filtering Device. Although the loop filter unit 320 is shown as an in-loop filter in FIG. 3, in other configurations, the loop filter unit 320 may be implemented as a post-loop filter.

The decoded video block 321 in a given frame or picture is then stored in a decoded picture buffer 330 that stores reference pictures for subsequent motion compensation.

The decoder 30 is used, for example, to output the decoded picture 31 through the output 332 for presentation to the user or for the user to view.

Other variations of video decoder 30 may be used to decode the compressed bitstream. For example, the decoder 30 may generate the output video stream without the loop filter unit 320. For example, the non-transform based decoder 30 may directly inversely quantize the residual signal without the inverse transform processing unit 312 for certain blocks or frames. In another embodiment, the video decoder 30 may have an inverse quantization unit 310 and an inverse transform processing unit 312 combined into a single unit.

Specifically, in the embodiment of the present application, the decoder 30 is used to implement the decoding method described in the embodiment below.

It should be understood that other structural variations of video decoder 30 may be used to decode the encoded video bitstream. For example, the video decoder 30 may generate an output video stream without processing by the filter 320; or, for certain image blocks or image frames, the entropy decoding unit 304 of the video decoder 30 does not decode the quantized coefficients, and accordingly does not It needs to be processed by the inverse quantization unit 310 and the inverse transform processing unit 312. The loop filter 320 is optional; and in the case of lossless compression, the inverse quantization unit 310 and the inverse transform processing unit 312 are optional. It should be understood that, according to different application scenarios, the inter prediction unit and the intra prediction unit may be selectively enabled.

It should be understood that in the encoder 20 and the decoder 30 of the present application, the processing results for a certain link can be further processed and output to the next link, for example, in interpolation filtering, motion vector derivation or loop filtering, etc. After the link, the results of the corresponding link are further clipped or shift shifted.

Referring to FIG. 4, FIG. 4 is a schematic structural diagram of a video decoding device 400 (for example, a video encoding device 400 or a video decoding device 400) provided by an embodiment of the present application. The video coding apparatus 400 is suitable for implementing the embodiments described herein. In one embodiment, the video coding device 400 may be a video decoder (eg, decoder 30 of FIG. 1A) or a video encoder (eg, encoder 20 of FIG. 1A). In another embodiment, the video decoding device 400 may be one or more components in the decoder 30 of FIG. 1A or the encoder 20 of FIG. 1A described above.

The video decoding device 400 includes: an inlet port 410 for receiving data and a receiver unit (Rx) 420, a processor for processing data, a logic unit or a central processing unit (CPU) 430, and a transmitter for transmitting data A unit (Tx) 440 and an exit port 450, and a memory 460 for storing data. The video decoding device 400 may further include a photoelectric conversion component and an electro-optical (EO) component coupled to the inlet port 410, the receiver unit 420, the transmitter unit 440, and the outlet port 450 for the outlet or inlet of the optical signal or the electrical signal.

The processor 430 is implemented by hardware and software. The processor 430 may be implemented as one or more CPU chips, cores (eg, multi-core processors), FPGA, ASIC, and DSP. The processor 430 communicates with the inlet port 410, the receiver unit 420, the transmitter unit 440, the outlet port 450, and the memory 460. The processor 430 includes a decoding module 470 (for example, an encoding module 470 or a decoding module 470). The encoding/decoding module 470 implements the embodiments disclosed herein to implement the division method provided by the embodiments of the present application. For example, the encoding/decoding module 470 implements, processes, or provides various encoding operations. Therefore, the encoding/decoding module 470 provides a substantial improvement to the function of the video decoding device 400 and affects the conversion of the video decoding device 400 to different states. Alternatively, the encoding/decoding module 470 is implemented with instructions stored in the memory 460 and executed by the processor 430.

The memory 460 includes one or more magnetic disks, tape drives, and solid-state hard disks, and can be used as an overflow data storage device for storing programs when these programs are selectively executed, as well as instructions and data read during program execution. The memory 460 may be volatile and/or non-volatile, and may be read only memory (ROM), random access memory (RAM), random access memory (ternary content-addressable memory (TCAM), and/or static Random Access Memory (SRAM).

Referring to FIG. 5, FIG. 5 is a simplified block diagram of an apparatus 500 that can be used as either or both of the source device 12 and the destination device 14 in FIG. 1A according to an exemplary embodiment. The device 500 can implement the technology of the present application. In other words, FIG. 5 is a schematic block diagram of an implementation manner of an encoding device or a decoding device (referred to simply as a decoding device 500) according to an embodiment of the present application. The decoding device 500 may include a processor 510, a memory 530, and a bus system 550. The processor and the memory are connected through a bus system, the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory. The memory of the decoding device stores the program code, and the processor can call the program code stored in the memory to perform various video encoding or decoding methods described in this application, especially various new decoding methods. In order to avoid repetition, they are not described in detail here.

In the embodiment of the present application, the processor 510 may be a central processing unit (CPU), and the processor 510 may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), or off-the-shelf. Programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 530 may include a ROM device or a RAM device. Any other suitable type of storage device may also be used as the memory 530. The memory 530 may include code and data 531 accessed by the processor 510 using the bus 550. The memory 530 may further include an operating system 533 and an application program 535 including at least one program that allows the processor 510 to perform the video encoding or decoding method described in the present application (in particular, the decoding method described in the present application). For example, the application program 535 may include applications 1 to N, which further include a video encoding or decoding application (referred to as a video coding application for short) that performs the video encoding or decoding method described in this application.

In addition to the data bus, the bus system 550 may also include a power bus, a control bus, and a status signal bus. However, for clarity, various buses are marked as the bus system 550 in the figure.

Optionally, the decoding device 500 may also include one or more output devices, such as a display 570. In one example, the display 570 may be a tactile display that merges the display with a tactile unit that operably senses touch input. The display 570 may be connected to the processor 510 via the bus 550.

The key terms and technologies involved in the embodiments of the present application are described below to facilitate readers' understanding:

CTU: An image consists of multiple CTUs. A CTU usually corresponds to a square image area. A CTU contains the luminance pixels and chrominance pixels in this image area, or only the luminance pixels or only the chrominance pixels. The size of the CTU can be set to 64×64, of course, it can also be set to other values, such as 128×128 or 256×256. The 64×64 CTU is a rectangular pixel lattice containing 64 columns, and each column contains 64 pixels. The explanation of CTUs of other sizes is similar to this and will not be repeated here. The CTU may correspond to some syntax elements, which are used to indicate how to divide the CTU into at least one CU, and information used to decode each CU to obtain a reconstructed image.

CU: usually corresponds to an A×B rectangular area, containing A×B luma pixels and its corresponding chroma pixels. Among them, A is the width of the rectangle, B is the height of the rectangle, A and B may be the same or different. The value of A and B is usually an integer power of 2, for example, 128, 64, 32, 16, 8, 4, etc. A CU can obtain a reconstructed image of an A×B rectangular area through the decoding process. The decoding process usually includes prediction, inverse quantization, and inverse transform.

The division method can be characterized by the division type and division direction. The division type may be a binary tree division type or an extended quadtree division type. The dividing direction may be a vertical direction or a horizontal direction. The horizontal direction is the direction perpendicular to the side where the height of the current image block is located. The vertical direction is the direction perpendicular to the side where the width of the current image block is located. Based on this, the division mode may be a horizontal binary tree division mode, a vertical binary tree division mode, a horizontally expanded quadtree division mode, or a vertically extended quadtree division mode. In addition, the division mode may also be characterized by only the division type, for example, the quadtree division mode has the same meaning as the quadtree division type.

BT (Binary Tree): It is a tree structure, a node can be divided into two child nodes. In the coding method using a binary tree, the nodes on a binary tree structure may not be divided, or may be divided into two nodes at the next level. The method of dividing a node into two nodes includes a horizontal binary tree division method and a vertical binary tree division method. Among them, the horizontal binary tree division method is specifically: the area corresponding to the node is divided into upper and lower areas of the same size, and each area corresponds to a node, as shown in (a) in FIG. 6. The vertical binary tree division method is specifically as follows: the area corresponding to the node is divided into left and right areas of the same size, and each area corresponds to a node, as shown in (b) in FIG. 6.

QT (Quad Tree): It is a tree structure, a node can be divided into four child nodes. The AVS video standard uses the CTU division method based on the quadtree. Specifically, the CTU is used as the root node, and each node corresponds to a square area; a node can no longer be divided (in this case, the corresponding area is a CU), Or it can be divided into four nodes at the next level, that is, the square area is divided into four square areas of the same size, and the height and width of each square area after division are half of the height and width of the area before division , Each zone corresponds to a node. As shown in (c) in Figure 6.

EQT (Extended Quadtree): It is a tree structure, a node can be divided into four child nodes. In the coding method using EQT, a node on an extended quadtree structure may not be divided, or may be divided into four nodes at the next level. The method of dividing one node into four nodes includes: horizontally expanding quadtree division method and vertically expanding quadtree division method. Among them, the horizontal quadtree division method is as follows: first horizontal three points, the area corresponding to the node is divided into upper, middle, and lower areas, each area corresponds to a node, of which the upper, middle, and lower areas The heights are 1/4, 1/2, and 1/4 of the node height, respectively, and then the nodes in the middle area are divided into left and right areas of the same size, as shown in (d) in FIG. 6. The vertical expansion quadtree is divided into three parts: first, vertically divide the area corresponding to the node into three areas of left, center, and right, each area corresponds to a node, and the three areas of left, center, and right The widths are 1/4, 1/2, and 1/4 of the node height, respectively, and the nodes in the middle area are divided into upper and lower areas of the same size, as shown in (e) in FIG. 6.

The QTBT scheme is a cascade of QT division and BT division. Specifically, the CTU is first divided according to QT, and the leaf nodes of QT are allowed to continue to be divided using BT, as shown in FIG. 7, that is, the first-level coding tree is QT and the second-level coding tree is BT. Among them, each endpoint in the right figure of FIG. 7 represents a node, a node connected with 4 solid lines represents a quadtree division, a node connected with 2 dotted lines represents a binary tree division, a to m are 13 leaf nodes, each leaf The node corresponds to 1 CU; "1" on the binary tree node indicates vertical division, and "0" indicates horizontal division; a CTU is divided according to the right figure of FIG. 7, and 13 CUs from a to m can be obtained, as shown in FIG. 7 Shown on the left.

The advantage of the QTBT scheme is that the shape of the CU is more diverse, so as to better adapt to the content of the local image. The QT division in the AVS2 video coding standard makes all CUs only be square, that is, the width of the CU is equal to the height of the CU. The width of the CU is the number of columns of pixels included in the CU, and the height of the CU is the number of rows of pixels included in the CU. After BT division is introduced, the width and height of the CU may be different, for example, the ratio of width to height is 2, 4, 8, 16, 1/2, 1/4, 1/8, or 1/16. Under QTBT, the width and height of all CUs cannot be smaller than the side length of the smallest CU. The smallest CU size can be included in the SPS, for example, the smallest CU can be set to 4×4.

Based on the QTBT scheme, the AVS3 video coding standard proposes the EQT scheme, that is, the first-level coding tree can be divided by QT, and the second-level coding tree can be divided by BT and EQT. More specifically, the CTU is used as the root node of the first-level coding tree. The first-level coding tree uses QT division to divide the CTU into the first-level coding tree leaf nodes; the first-level coding tree leaf nodes are used as The root node of the second-level coding tree. The second-level coding tree can adopt the above-mentioned horizontal BT division, vertical BT division, horizontal EQT division, and vertical EQT division. The leaf nodes of the tree continue to be divided into the leaf nodes of the second-level coding tree.

In the second-level coding tree, for the encoder, it is usually determined whether to divide the current image block (that is, the current node) based on the minimum CU size principle and the minimum rate distortion optimization (RDO) principle, and if The division method used for division. Specifically: first, based on the principle of minimum CU size, determine the possible division method of the current image block, that is, according to the size of each image block obtained after division must be greater than or equal to the minimum CU size, determine the division method applicable to the current image block. If all candidate division methods (ie, horizontal BT division method, vertical BT division method, horizontal EQT division method, and vertical EQT division method) are not applicable, it is determined that the current image block cannot be divided. Otherwise, calculate and compare the RDO when the current image block is not divided with the RDO when using every possible division method. If the RDO is the smallest when it is not divided, it is determined that the current image block is not divided; if a certain division method is used If the RDO is the smallest, it is determined that the current image block will be divided in the following manner. This method needs to traverse all possible division methods that are determined for the current image block based on the principle of minimum CU size, so as to determine the division method for dividing the current image block, and therefore, the coding complexity is high. In addition, if it is determined that a certain division method is used to divide the current image block, the code stream carries information indicating the division type and division direction of the division method, and therefore, the transmission overhead of the code stream is large.

Based on this, the embodiments of the present application provide a video encoding method and a corresponding decoding method. The technical solutions provided by the embodiments of the present application are explained in detail below with reference to the drawings.

As shown in FIG. 8, it is a schematic flowchart of a video decoding method provided by an embodiment of the present application. The method shown in Figure 8 includes the following steps:

S001: The decoder determines the block division strategy of the current image block according to the relationship between the width and height of the current image block.

Among them, when the video decoding method is specifically a video encoding method, the decoder is specifically an encoder. When the video decoding method is specifically a video decoding method, the decoder is specifically a decoder.

The current image block may be any image block in the process of dividing the image to be decoded. For example, any image block in the second-level coding tree.

The block division strategy refers to a strategy for obtaining coded blocks based on the current image block. For example, the block division strategy of the current image block may include: for the current image block, which division method is illegal. As another example, the block division strategy of the current image block may include: a target division manner adopted when dividing the current image block, and the like.

It can be understood that the decoder may determine the division method applicable to the current image block based on the minimum CU size principle. Therefore, in a possible implementation, the "minimum CU size principle" can be used as part of the block division strategy. In another possible implementation, the "minimum CU size principle" and the block division strategy can be considered as two independent strategies. For convenience of description, the latter is used as an example in the following description.

S002: The decoder applies the block division strategy to the current image block to obtain an encoded block.

The coding block can be regarded as a leaf node in the coding tree (such as the second-level coding tree in the EQT scheme). The relevant explanation about the coding block can refer to the above, or can refer to the prior art.

Specifically: If the decoder is based on a block division strategy (optionally, it can also be based on other strategies such as the minimum CU size principle and the minimum RDO principle, etc.) and determines not to divide the current image block, the current image block can be used as the coding tree In the leaf node. In this case, the current image block can be used as a coding block.

If the decoder is based on the block division strategy (optional, it can also be based on other strategies such as the minimum CU size principle and the minimum RDO principle, etc.) and determines that the current image block needs to be divided, the divided image blocks can be used as The current image block, and then execute S001 to S002, and so on, until the current image block is no longer divided, the current image block is used as a leaf node in the coding tree. In this case, the current image block can be used as a coding block.

S003: The decoder reconstructs the obtained coding block to reconstruct the current image block. The specific implementation of this step can refer to the description above, or can refer to the prior art.

In this technical solution, the block division strategy of the current image block is determined conditionally to obtain the coding block. In this way, it helps to reduce the complexity of the division and thereby improve the performance of video encoding and decoding.

The above S001 to S002 can be considered as the image block division method provided by the embodiment of the present application. The image block division method provided by the embodiment of the present application will be described below with reference to FIGS. 9-12.

As shown in FIG. 9, it is a schematic flowchart of an image block division method provided by an embodiment of the present application. The method shown in Figure 9 includes the following steps:

S101: The encoder determines whether the width of the current image block is less than the product of the first threshold and the height of the current image block.

If not, S102 is executed. If yes, execute S103.

Optionally, the first threshold is the maximum value of the ratio of the long side length to the short side length of the nodes in the allowed coding tree (such as the second-level coding tree described above). Optionally, the first threshold is a value greater than 1, such as an integer greater than 1. Optionally, the first threshold is an integer power of 2, for example, the first threshold is 4, 8, or 16, etc. It should be noted that, if no description is given, the specific examples in the embodiments of the present application are described by taking the value of the first threshold greater than 1 as an example.

S102: The encoder determines the first candidate set. The first candidate set is a set composed of legal division methods for the current image block. Among them, the first candidate set does not include a division manner in which the division direction is the horizontal direction. In other words, the horizontal division method is illegal. Then, it is determined whether to divide the current image block according to the first candidate set, and the target division manner adopted when dividing.

If it is determined to divide the current image block, S105 is executed.

If it is determined that the current image block is not divided, S108 is performed.

Specifically, the encoder may first determine the block division strategy of the current image block. The block division strategy includes the division that does not include the division direction in the horizontal direction. That is, when the current image block does not satisfy the first condition, it is determined that the block division strategy of the current image block does not include the division in the horizontal direction. The first condition includes that the width of the current image block is smaller than the product of the first threshold and the height of the current image block. Then, based on at least the block division strategy, the first candidate set is determined. For example, the encoder may determine the first candidate set based on the "minimum CU size principle" and the block division strategy. Assuming that based on the "minimum CU principle", the determined division methods applicable to the current image block include a vertical binary tree division method, a vertically extended quadtree division method, a horizontal binary tree division method, and a horizontally extended quadtree division method, then: The first candidate set may include a vertical binary tree division mode and a vertically extended quadtree division mode, but does not include a horizontal binary tree division mode and a horizontally expanded quadtree division mode. In other words, the legal division method for the current image block is the vertical division method.

In one example, determining whether to divide the current image block according to the candidate set, and the target division method used when dividing may include: calculating and comparing the RDO when the current image block is not divided and using each of the candidate sets RDO when dividing by a possible division method; if RDO is minimum when not dividing, it is determined that the current image block is not divided; if RDO is minimum when using a certain division method in the candidate set, the division method is determined as the target division the way. In another example, if the candidate set is empty, it is determined not to divide the current image block. The candidate set in these two examples may be the first candidate set, or the second candidate set or the third candidate set below.

It can be understood that when the first threshold is a value greater than 1, the determination result of S101 is "No", that is, the width of the current image block is greater than or equal to the product of the first threshold and the height of the current image block. Explanation: the current image The width of the block is the long side and the height is the short side. According to the description of S102, it is known that, by default, the encoder is not perpendicular to the short side (specifically, high) of the current image block. During specific implementation, the encoder and decoder may predefine that when the judgment result of S101 is “No”, the division method perpendicular to the short side (specifically high) of the current image block is illegal.

S103: The encoder determines whether the height of the current image block in the image to be encoded is less than the product of the first threshold and the width of the current image block.

If not, S104 is executed. If yes, S106 is executed.

S104: The encoder determines the second candidate set. The second candidate set is a set composed of legal division methods for the current image block. Among them, the second candidate set does not include a division manner in which the division direction is the vertical direction. In other words, the vertical division method is illegal. Then, it is determined whether to divide the current image block according to the second candidate set, and the target division manner adopted when dividing.

If it is determined to divide the current image block, S105 is executed.

Specifically, the encoder first determines the block division strategy of the current image block. The block division strategy includes the division that does not include the division direction in the vertical direction. That is, when the current image block does not satisfy the second condition, it is determined that the block division strategy of the current image block does not include the division in the vertical direction. The second condition includes that the height of the current image block is less than the product of the first threshold and the width of the current image block. Then, at least based on the block division strategy, a second candidate set is determined. For example, the encoder may determine the second candidate set based on the "minimum CU size principle" and the block division strategy. Assuming that based on the "minimum CU principle", the determined division methods applicable to the current image block include a vertical binary tree division method, a vertically extended quadtree division method, a horizontal binary tree division method, and a horizontally extended quadtree division method, then: The second candidate set may include a horizontal binary tree division mode and a horizontally expanded quadtree division mode, but does not include a vertical binary tree division mode and a vertically extended quadtree division mode. In other words, the legal division method for the current image block is the horizontal direction.

It can be understood that when the first threshold is a value greater than 1, the judgment result of S103 is "No", that is, the height of the current image block is greater than or equal to the product of the first threshold and the width of the current image block. Explanation: the current image The height of the block is the long side and the width is the short side. According to the description of S104, it is known that the encoder's default division method perpendicular to the short side (specifically the width) of the current image block is illegal. In a specific implementation, the encoder and decoder may predefine that when the judgment result of S103 is “No”, the division method perpendicular to the short side (specifically the width) of the current image block is illegal.

S105: The encoder divides the current image block according to the target division mode. And, the first identification information and the second identification information are encoded into the code stream. The first identification information is used to indicate whether to divide the current image block (specifically, division). The second identification information is used to indicate the division type of the target division manner (for example, binary tree division type or extended quadtree division type).

After executing S105, execute S109.

S106: The encoder determines a third candidate set. The third candidate set is a set composed of legal division methods for the current image block. Then, it is determined whether to divide the current image block according to the third candidate set, and the target division manner adopted when dividing.

If it is determined to divide the current image block, S107 is performed.

In specific implementation, the encoder may determine the third candidate set based on the "minimum CU size principle". For example, the third candidate set may include a horizontal binary tree division manner, a horizontally expanded quadtree division manner, a vertical binary tree division manner, and a vertically expanded quadtree division manner.

It should be noted that, the execution order of the foregoing S101 to S102 and S103 to S104 may be in no particular order. For example, the encoder may first execute S103, and execute the above S101 when the judgment result of S103 is "Yes", and execute the above S104 when the judgment result of S103 is "No". When the judgment result of S101 is "Yes", the above S106 is executed, and when the judgment result of S101 is "No", the above S102 is executed.

In addition, the encoder may not perform the above-mentioned S101 to S102, or may not perform the above-mentioned S103 to S104. For example, when the above S103 to S104 are not executed, the encoder may directly execute the above S106 when the judgment result of S101 is "YES".

S107: The encoder divides the current image block according to the target division mode. And, the first identification information, the second identification information, and the third identification information are all encoded into the code stream. The first identification information is used to indicate whether to divide the current image block (specifically, division). The second identification information is used to indicate the division type of the target division mode (such as the binary tree division type or the extended quadtree division type), and the third identification information is used to indicate the division direction of the target division mode (such as the horizontal direction or the vertical direction).

After executing S107, execute S109.

S108: The encoder encodes the first identification information into the code stream. The first identification information is used to indicate whether to divide the current image block (specifically, not to divide).

S109: The encoder sends a code stream to the decoder.

It should be noted that, for the "divided image block" obtained after performing the division operation, the encoder may use it as the current image block, and thus return to execution of S101 to S109.

The video coding method provided in this embodiment conditionally determines the block division strategy of the current image block. Compared with the existing EQT scheme for the nodes in the second-level coding tree, the division complexity can be reduced, thereby Improve coding efficiency. Moreover, when the width of the current image block is greater than or equal to the product of the first threshold and the height, and/or the height of the current image block is greater than or equal to the product of the first threshold and the width, the default division direction is the short perpendicular to the current image block The division of edges is illegal. Therefore, there is no need to compile information indicating the division direction of the current image block into the code stream, which can save transmission bit overhead. In addition, this technical solution helps to limit the width-to-height ratio (or height-to-width ratio) of leaf nodes in the coding tree to a certain range, and helps to avoid "slenderness" in the coding process as much as possible Node, which facilitates coding.

As shown in FIG. 10, it is a schematic flowchart of an image block division method provided by an embodiment of the present application. The video decoding method shown in FIG. 10 corresponds to the video encoding method shown in FIG. 9, therefore, for the explanation of related content in this embodiment, reference may be made to the embodiment shown in FIG. 9 described above. The method shown in Figure 10 includes the following steps:

S201: The decoder receives the code stream from the encoder.

S202: The decoder parses the code stream to obtain first identification information, where the first identification information is used to indicate whether to divide the current image block.

If the first identification information indicates that the current image block is not divided, the division process for the current image block ends. In this case, the current image block can be used as a coding block.

If the first identification information indicates that the current image block is divided, the following S203 is performed.

S203: The decoder judges whether the width of the current image block is smaller than the product of the first threshold and the height.

If not, S204 is executed. If yes, execute S205.

S204: The decoder continues to parse the code stream to obtain second identification information, and the second identification information is used to indicate the type of division for dividing the current image block; and the type of division indicated by the second identification information is used for the current image block. The division direction is vertical division.

After executing S204, the division process for the current image block ends.

Specifically, when the judgment result of S203 is "No", the decoder may determine that the block division strategy of the current image block does not include the division in the horizontal direction based on the judgment result. Then, based on the block division strategy, the division type indicated by the second identification information is used to divide the current image block into the vertical direction.

Exemplarily, the division type indicated by the second identification information may include a binary tree division type or an extended quadtree division type, and so on. If the division type indicated by the second identification information is a binary tree division type, the current image block is divided into vertical binary trees; if the division type indicated by the second identification information is an extended quadtree division type, the current image block is divided into Vertically expand the quadtree division.

When the first threshold is a value greater than 1, the judgment result of S203 is "No", that is, the width of the current image block is greater than or equal to the product of the first threshold and the height, indicating that the width of the current image block is the long side and the height is short side.

S205: The decoder determines whether the height of the current image block is less than the product of the first threshold and the width.

If not, S206 is executed. If yes, execute S207.

S206: The decoder continues to parse the code stream to obtain second identification information, and the second identification information is used to indicate the type of division for dividing the current image block; and the type of division indicated by the second identification information is used for the current image block. The division direction is the division in the horizontal direction.

After executing S206, the division process for the current image block ends.

Specifically, when the judgment result of S205 is "No", the decoder may determine that the block division strategy of the current image block does not include the division in the vertical direction based on the judgment result. Then, based on the block division strategy, the division type indicated by the second identification information is used to divide the current image block into the horizontal direction.

Exemplarily, the division type indicated by the second identification information may include a binary tree division type or an extended quadtree division type, and so on. If the division type indicated by the second identification information is a binary tree division type, horizontal binary tree division is performed on the current image block; if the division type indicated by the second identification information is an extended quadtree division type, horizontal level is performed on the current image block Extended quadtree division.

When the first threshold is a value greater than 1, the judgment result of S205 is "No", that is, the height of the current image block is greater than or equal to the product of the first threshold and the width, indicating that the height of the current image block is the long side and the width is short side.

S207: The decoder continues to parse the code stream to obtain second identification information and third identification information. The second identification information is used to indicate the division type of the current image block, and the third identification information is used to indicate the current image block. The division direction of the division; and, using the division type indicated by the second identification information, divide the current image block into the division direction indicated by the third identification information.

After performing S207, the division process for the current image block ends.

For example, when the division type indicated by the second identification information is a binary tree division type, and the division direction indicated by the third identification information is a horizontal division, horizontal binary tree division is performed on the current image block. Other examples are not listed one by one.

Specifically, the decoder may perform the operation of parsing the code stream once to obtain the second identification information and the third identification information. Alternatively, the decoder may perform the operation of parsing the code stream once to obtain second identification information, and perform another operation of parsing the code stream to obtain third identification information, and the two parsing steps may be in no particular order.

It should be noted that the execution order of the foregoing S203 to S204 and S205 to S206 may be in no particular order. For example, the decoder may first execute S205, and execute the above S203 when the judgment result of S205 is "Yes", and execute the above S206 when the judgment result of S205 is "No". In addition, when the judgment result of S203 is "Yes", the above S207 is executed, and when the judgment result of S203 is "No", the above S204 is executed.

In addition, the decoder may not perform the above S203 to S204, or may not perform the above S205 to S206. For example, when the above S205 to S206 are not executed, the decoder can directly execute the above S207 when the judgment result of S203 is "YES". It can be understood that, in a specific implementation, if the encoder executes the above S101 to S102, the decoder executes the above S203 to S204; if the encoder performs the above S103 to S104, the decoder executes the above S205 to S206.

It should be noted that, for the "divided image block" obtained after performing the division operation, the decoder may use it as the current image block, so as to execute S202-S207.

In the video decoding method provided in this embodiment, when the width of the current image block is greater than or equal to the product of the first threshold and the height, and/or the height of the current image block is greater than or equal to the product of the first threshold and the width, the decoder defaults to dividing The direction is perpendicular to the short side of the current image block, which is illegal. In this way, the encoder does not need to incorporate information indicating the division direction of the current image block into the code stream, so transmission bit overhead can be saved. In addition, this technical solution helps to limit the width-to-height ratio (or height-to-width ratio) of leaf nodes in the coding tree to a certain range, and helps to avoid "slenderness" in the coding process as much as possible Node, which facilitates coding.

As shown in FIG. 11, it is a schematic flowchart of a method for dividing an image block according to an embodiment of the present application. The relevant descriptions of the current image block, the first identification information, the second identification information and the third identification information in this embodiment can all refer to the above. The method shown in Figure 11 includes the following steps:

S301: The encoder determines whether the width of the current image block is less than the product of the second threshold and the height of the current image block.

If not, S302 is executed. If yes, execute S303.

Optionally, the second threshold is one-half the maximum value of the ratio of the length of the long side to the length of the short side of the node in the allowed coding tree. Optionally, the second threshold is a value greater than 1, such as an integer greater than 1. Optionally, the second threshold is an integer power of 2, for example, the second threshold is 2, 4, or 8, and so on. It should be noted that, if no description is given, the specific examples in the embodiments of the present application are described by taking the value of the second threshold greater than 1 as an example.

S302: The encoder determines the first candidate set. The first candidate set is a set composed of legal division methods for the current image block. Among them, the first candidate set does not include an expanded quadtree division manner in which the division direction is the horizontal direction. In other words, it is illegal to divide the quadtree in the horizontal direction. Then, it is determined whether to divide the current image block according to the first candidate set, and the target division manner adopted when dividing.

If it is determined to divide the current image block, S305 is executed.

If it is determined that the current image block is not divided, S308 is executed.

Specifically, the encoder may first determine the block division strategy of the current image block. The block division strategy includes the division of the extended quadtree that does not include the horizontal division direction. That is, when the current image block does not satisfy the third condition, it is determined that the block division strategy of the current image block does not include the extended quadtree division in which the division direction is the horizontal direction. The third condition includes that the width of the current image block is smaller than the product of the second threshold and the height of the current image block. Then, based on at least the block division strategy, the first candidate set is determined. For example, the encoder may determine the first candidate set based on the "minimum CU size principle" and the block division strategy. Assuming that based on the "minimum CU principle", the determined division methods applicable to the current image block include a vertical binary tree division method, a vertically extended quadtree division method, a horizontal binary tree division method, and a horizontally extended quadtree division method, then: The first candidate set may include a horizontal binary tree division manner, a vertical binary tree division manner, and a vertical expansion quadtree division manner, but does not include a horizontal expansion quadtree division manner.

S303: The encoder determines whether the height of the current image block in the image to be encoded is less than the product of the second threshold and the width of the current image block.

If not, execute S304; if yes, execute S306.

S304: The encoder determines the second candidate set. The second candidate set is a set composed of legal division methods for the current image block. Wherein, the second candidate set does not include the extended quadtree division manner in which the division direction is the vertical direction. In other words, it is illegal to divide the quadtree in the vertical direction. Then, it is determined whether to divide the current image block according to the second candidate set, and the target division manner adopted when dividing.

If it is determined to divide the current image block, S305 is executed.

Specifically, the encoder may first determine the block division strategy of the current image block. The block division strategy includes the division of the extended quadtree that does not include the vertical division direction. That is, when the current image block does not satisfy the fourth condition, it is determined that the block division strategy of the current image block does not include the extended quadtree division with the vertical division direction. The fourth condition includes that the height of the current image block is less than the product of the second threshold and the width of the current image block. Then, at least based on the block division strategy, a second candidate set is determined. For example, the encoder may determine the second candidate set based on the "minimum CU size principle" and the block division strategy. Assuming that based on the "minimum CU principle", the determined division methods applicable to the current image block include a vertical binary tree division method, a vertically extended quadtree division method, a horizontal binary tree division method, and a horizontally extended quadtree division method, then: The second candidate set may include a horizontal binary tree division manner, a vertical binary tree division manner, and a horizontally expanded quadtree division manner, but does not include a vertically extended quadtree division manner.

S305: The encoder divides the current image block according to the target division mode. and:

If the division type of the target division mode is a binary tree division type, the first identification information, the second identification information, and the third identification information are all encoded into the code stream, where the first identification information is used to indicate whether to divide the current image block (Specifically, division), the second identification information is used to indicate the division type of the target division mode (specifically, binary tree division type), and the third identification information is used to indicate the division direction of the target division mode (specifically, horizontal direction or vertical direction) .

If the division type of the target division mode is the extended quadtree division type, the first identification information and the second identification information are encoded into the code stream, where the first identification information is used to indicate whether to divide the current image block (specifically Division), the second identification information is used to indicate the division type of the target division mode (specifically, the division type of the extended quadtree).

After executing S305, execute S309.

For S306 to S309, refer to S106 to S109 above.

It should be noted that, for the "divided image block" obtained after performing the division operation, the encoder may use it as the current image block, and thus return to execute S301 to S309.

In this embodiment, the encoder determines whether to divide the current image block, and the specific implementation manner of the target division mode adopted when dividing, can refer to the above, and will not be described here.

It should be noted that the execution order of the above S301 to S302 and S303 to S304 may be in no particular order. For example, the encoder may execute S303 first, and execute the above S301 when the judgment result of S303 is “Yes”, and execute the above S304 when the judgment result of S303 is “No”. In addition, when the judgment result of S301 is “Yes”, the above S306 is executed, and when the judgment result of S301 is “No”, the above S302 is executed.

In addition, the encoder may not perform the above S301 to S302, or may not perform the above S303 to S304. For example, when the above S303 to S304 are not executed, the encoder may directly execute the above S306 when the judgment result of S301 is "Yes".

In the video coding method provided in this embodiment, the block division strategy of the current image block is determined conditionally, which can reduce the division complexity compared with the existing EQT scheme for the nodes in the second-level coding tree. Thereby improving coding efficiency. Moreover, when the width of the current image block is greater than or equal to the product of the second threshold and the height, and/or the height of the current image block is greater than or equal to the product of the second threshold and the width, the default division direction is the short perpendicular to the current image block The method of dividing the extended quadtree is illegal. Therefore, when the division type is extended quadtree division, it is not necessary to compile information indicating the division direction of the current image block into the code stream, which can save transmission bit overhead. In addition, this technical solution helps to limit the width-to-height ratio (or height-to-width ratio) of leaf nodes in the coding tree to a certain range, and helps to avoid "slenderness" in the coding process as much as possible Node, which facilitates coding.

As shown in FIG. 12, it is a schematic flowchart of an image block division method provided by an embodiment of the present application. The video decoding method shown in FIG. 12 corresponds to the video encoding method shown in FIG. 11. The method shown in Figure 12 includes the following steps:

S401: The decoder receives the code stream from the encoder.

S402: The decoder parses the code stream to obtain first identification information, where the first identification information is used to indicate whether to divide the current image block.

If the first identification information indicates that the current image block is divided, S403 is executed.

If the first identification information indicates that the current image block is not divided, the division process for the current image block ends.

S403: The decoder determines whether the width of the current image block is less than the product of the second threshold and the height of the current image block.

If not, S404 is executed. If yes, execute S405.

S404: The decoder continues to parse the code stream to obtain second identification information, where the second identification information is used to indicate the division type of the current image block. and:

If the second identification information is used to indicate the binary tree division of the current image block, the decoder continues to parse the code stream to obtain third identification information, and the third identification information is used to indicate the division direction of the current image block. When the third identification information is used to indicate that the current image block is divided horizontally, the current image block is divided into horizontal binary trees. When the third identification information is used to indicate that the current image block is vertically divided, the current image block is vertically divided into binary trees.

If the second identification information is used to indicate that the current image block is divided into extended quadtrees, then the current image block is vertically divided into quadtrees.

After executing S404, the division process for the current image block ends.

S405: The decoder determines whether the height of the current image block is less than the product of the second threshold and the width of the current image block.

If not, S406 is executed. If yes, execute S407.

S406: The decoder continues to parse the code stream to obtain second identification information, where the second identification information is used to indicate the division type of the current image block. and:

If the second identification information is used to indicate that the current image block is extended quadtree division, then the current image block is horizontally extended quadtree division.

After performing S406, the division process for the current image block ends.

S407: Refer to the above S207.

After performing S407, the division process for the current image block ends.

It should be noted that, for the "divided image block" obtained after performing the division operation, the decoder may use it as the current image block, so as to execute S402 to S407.

It should be noted that the execution order of the above S403 to S404 and S405 to S406 may be in no particular order. For example, the decoder may execute S405 first, and execute the above S403 when the judgment result of S405 is "Yes", and execute the above S406 when the judgment result of S405 is "No". In addition, when the judgment result of S403 is "Yes", the above S407 is executed, and when the judgment result of S403 is "No", the above S404 is executed.

In addition, the decoder may not perform the above-mentioned S403 to S404, or may not perform the above-mentioned S405 to S406. For example, when the above S405 to S406 are not executed, the decoder may directly execute the above S407 when the judgment result of S403 is "Yes". It can be understood that, in a specific implementation, if the encoder performs the above S301 to S302, the decoder performs the above S403 to S404; if the encoder performs the above S303 to S304, the decoder performs the above S405 to S406.

In the video decoding method provided in this embodiment, when the width of the current image block is greater than or equal to the product of the second threshold and the height, and/or the height of the current image block is greater than or equal to the product of the second threshold and the width, the decoder defaults The division direction is perpendicular to the short side of the current image block, which is illegal. In this way, when the division type is extended quad-tree division, the encoder does not need to encode information indicating the division direction of the current image block into the code stream, so transmission bit overhead can be saved. In addition, this technical solution helps to limit the width-to-height ratio (or height-to-width ratio) of leaf nodes in the coding tree to a certain range, and helps to avoid "slenderness" in the coding process as much as possible Node, which facilitates coding.

As shown in FIG. 13, it is a schematic flowchart of a video encoding method provided by an embodiment of the present application. The method shown in Figure 13 includes the following steps:

S501: The encoder determines whether the length of the long side of the current image block in the image to be encoded is twice the length of the short side of the current image block.

If yes, execute S502. If not, S503 is executed.

S502: The encoder determines the first candidate set. The first candidate set includes performing a binary tree division on the current image block in a direction perpendicular to the long side of the current image block. And determine whether to divide the current image block according to the first candidate set. Wherein, if it is determined to divide the current image block, the current image block may be referred to as an image block to be divided.

If it is determined to divide the current image block, S503 is performed.

If it is determined that the current image block is not divided, S506 is performed.

Specifically: when the width of the current image block is the long side and the height is the short side, the first candidate set includes a vertical binary tree division manner. When the width of the current image block is the short side and the height is the long side, the first candidate set includes a horizontal binary tree division manner.

S503: The encoder divides the current image block into a binary tree perpendicular to the long side of the current image block. And, the first identification information is encoded into the code stream. The first identification information is used to indicate whether to divide the current image block (specifically, division).

After executing S503, execute S507.

S504-S507: refer to the above-mentioned S104-S107.

It should be noted that, for the "divided image block" obtained after performing the division operation, the encoder may use it as the current image block, and thus return to execute S501 to S507.

In the video encoding method provided in this embodiment, when the length of the long side of the current image block is twice the length of the short side of the current image block, if the current image block is divided, the encoder defaults to dividing the direction perpendicular to the current image Binary tree division on the long side of the block. In this way, on the one hand, compared with the method for dividing nodes in the second-level coding tree in the existing EQT scheme, the technical solution provided by the embodiments of the present application can reduce the division complexity, thereby improving coding efficiency. On the other hand, if the current image block is divided, there is no need to incorporate information indicating the division method (including the division type and division direction) of the current image block into the code stream, so transmission bit overhead can be saved. In addition, by dividing the current image block into a binary tree perpendicular to the long side of the current image block, the current image block can be divided into two square image blocks. Compared with the non-square rectangular image block, the subsequent blocks of the square image block are The possibility of division is higher, so it helps to improve the encoding accuracy of video pictures.

As shown in FIG. 14, it is a schematic flowchart of a video decoding method according to an embodiment of the present application. The video decoding method shown in FIG. 14 corresponds to the video encoding method shown in FIG. 13. The method shown in Figure 14 includes the following steps:

S601: The decoder receives the code stream from the encoder.

S602: The decoder parses the code stream to obtain first identification information, where the first identification information is used to indicate whether to divide the current image block in the image to be decoded.

If the first identification information indicates that the current image block is divided, S603 is performed.

S603: The decoder determines whether the length of the long side of the current image block is equal to twice the length of the short side of the current image block.

If yes, execute S604. If not, S605 is executed.

S604: The decoder divides the current image block into a binary tree perpendicular to the long side of the current image block.

After executing S604, the division process for the current image block ends.

S605: Refer to the above S205.

It should be noted that, for the "divided image block" obtained after performing the division operation, the decoder may use it as the current image block, so as to execute S602 to S605.

In the video decoding method provided in this embodiment, when the length of the long side of the current image block is twice the length of the short side of the current image block, if the current image block is divided, the decoder defaults to dividing the direction perpendicular to the current image Binary tree division on the long side of the block. In this way, the encoder does not need to incorporate information indicating the division method (including the division type and division direction) of the current image block into the code stream, so transmission bit overhead can be saved.

For the embodiment shown in FIG. 13 or FIG. 14, the following provides several optional implementation methods:

Optionally, the length of the long side of the current image block is 2a pixels long, and the length of the short side is a pixel length. Among them, a is an integer, a is usually an integer power of 2. For example, the long side of the current image block is 128 pixels long, and the short side is 64 pixels long.

Optionally, the short side length of the current image block is equal to the side size of the largest transformation unit (ie, TU), or the short side length of the current image block is equal to the side size of the virtual pipeline data unit (ie, VPDU).

Among them, VPDU, which can also be called a hardware pipeline unit, is defined as a non-overlapping unit in the image, the size can be a*a, and the side size is a pixel length. In the hardware decoder, consecutive VPDUs are processed in parallel by multiple pipelines simultaneously. The size of the VPDU is roughly proportional to the buffer size in most pipeline stages, so it is important to keep the VPDU size small. In most hardware decoders, the size of the VPDU can be set to the size of the largest transformation unit. However, in the AVS3 video coding standard, expanding the quadtree (EQT) and binary tree (BT) partitions may result in an increase in the size of the VPDU. In order to maintain the VPDU size as a*a (such as 64x64) brightness samples, the same brightness sample cannot span different VPDUs.

Optionally, the current image block is a boundary image block. Wherein, if one or more pixels in the current node exceed the current image boundary, the current node is said to exceed the image boundary. In this case, the current node is a boundary image block.

It should be noted that, for any of the video decoding (including encoding and decoding) methods provided above, if the current image block is divided, the decoder may recode the image block to be decoded based on the divided image block If the current image block is not divided, the decoder can perform operations such as reconstruction of the image block to be decoded based on the current image block, and the specific implementation process can refer to the prior art.

In addition, it should be noted that, in the case of no conflict, some features of at least two video encoding methods described above (such as the video encoding methods described in FIG. 9, FIG. 11, or FIG. 13) can be combined to form New video encoding method. Correspondingly, the corresponding features in the video decoding methods corresponding to the at least two video encoding methods can be combined to form a new video decoding method.

For example, when the second threshold is one-half of the first threshold, in one example, the video encoding method after combining FIG. 9 and FIG. 11 may include:

If the ratio of the length of the long side to the length of the short side of the current image block is greater than or equal to the first threshold, the legal division method for the current image block does not include the division of the current image block perpendicular to the short side of the image block to be divided the way;

If the ratio of the long side length to the short side length of the current image block is less than the first threshold and greater than or equal to the second threshold, the legal division method for the current image block does not include dividing the current image block perpendicular to the image to be divided The extended quadtree partition of the short side of the block. It can be understood that since the width and height of the current image block are usually integer powers of 2, when both the second threshold and the first threshold are integer powers of 2, "the length and length of the long side of the current image block The ratio of side lengths is less than the first threshold and greater than or equal to the second threshold" is equivalent to "the ratio of the length of the long side to the length of the short side of the current image block is equal to the second threshold". For example, assuming that the first threshold is 8, and the second threshold is 4, the ratio of the length of the long side to the length of the short side is less than 8 and greater than or equal to 4. There is only one possibility, namely, the length of the long side and the length of the short side The ratio is equal to 4.

If the ratio of the long edge length to the short edge length of the current image block is less than the second threshold, the legal division method for the current image block may include a horizontal binary tree division method, a vertical binary tree division method, a horizontally extended quadtree division method, and a vertical Direct expansion of quadtree division.

Other examples are not listed one by one.

Based on any one of the embodiments provided above, the following describes specific implementation manners of the first identification information, the second identification information, and the third identification information.

For example, if the current image block is not divided, the first identification information may be a binary number "0". If the current image block is divided, the first identification information may be a binary number "1".

For example, if the division type of the target division mode is a binary tree division type, the second identification information may be a binary number "0". If the determined division type is an extended quadtree division type, the second identification information may be a binary number "1".

For example, if the division direction of the target division mode is the horizontal direction, the third identification information may be a binary number "0". If the determined division direction is the vertical direction, the third identification information may be a binary number "1".

For example, the first identification information may be information contained in the "split_flag" field in the code stream.

For example, the second identification information may be information contained in the "SplitMode" field in the code stream. When SplitMode is 1, it indicates the binary tree division type; when SplitMode is 0, it indicates the extended quadtree division type. Of course not limited to this.

For example, the third identification information may be information contained in the "SplitDir" field in the code stream. When SplitMode is 1, it means vertical division, and SplitDir is 0, which means horizontal division. Of course not limited to this.

The above mainly introduces the solutions provided by the embodiments of the present application from the perspective of a method. In order to realize the above-mentioned functions, it includes hardware structures and/or software modules corresponding to performing each function. Those skilled in the art should be easily aware that, in conjunction with the exemplary units and algorithm steps described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed by hardware or computer software driven hardware depends on the specific application of the technical solution and design constraints. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

The embodiments of the present application may divide the encoder/decoder function modules according to the above method examples, for example, each function module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or software function modules. It should be noted that the division of the modules in the embodiments of the present application is schematic, and is only a division of logical functions. In actual implementation, there may be another division manner.

As shown in FIG. 15, it is a schematic block diagram of a video decoder 140 provided by an embodiment of the present application. The video decoder 140 may specifically be an encoder or a decoder. When the video decoder 140 is an encoder, the video decoder 140 may be used to execute any video encoding method provided by the embodiments of the present application, as shown in FIG. 9, FIG. 11, or FIG. 13. When the video decoder 140 is a decoder, the video decoder 140 may be used to execute any one of the video decoding methods provided in the embodiments of the present application, as shown in FIG. 10, FIG. 12, or FIG. 14.

The video decoder 140 may include a division unit 1401 and a reconstruction unit 1402. Optionally, as shown in FIG. 16, when the video decoder 140 is specifically a video decoder, the video decoder may further include an entropy decoding unit 1403.

For example, the video decoder 140 may be the encoder 20 in FIG. 2. In this case, the dividing unit 1401 may be a sub-unit in the prediction processing unit 260, or may be in conjunction with the prediction processing unit 260, the reconstruction unit 214, and The entropy encoding units 270 are all connected to one unit; the reconstruction unit 1402 may be the reconstruction unit 214.

For another example, the video decoder 140 may be the decoder 30 in FIG. 3. In this case, the division unit 1401 may be a subunit in the prediction processing unit 360, or may be the prediction processing unit 360 and the reconstruction unit 314. One unit connected to the entropy decoding unit 304; the reconstruction unit 1402 may be the reconstruction unit 314.

In some embodiments, the dividing unit 1401 is configured to determine the block division strategy of the current image block according to the relationship between the width and height of the current image block; and apply the block division strategy to the current image block To get the coded block. The reconstruction unit 1402 is configured to reconstruct the current image block by reconstructing the obtained coding block.

Optionally, the dividing unit 1401 is specifically configured to: determine whether the current image block satisfies the first condition. The first condition includes: the width of the current image block is less than the product of the first threshold and the height of the current image block; the current image block does not satisfy In the first condition, it is determined that the block division strategy is division in the vertical direction, and the vertical direction is perpendicular to the direction of the side where the width of the current image block is located.

Optionally, the dividing unit 1401 is specifically configured to determine whether the current image block satisfies the second condition. The second condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block; In the second condition, it is determined that the block division strategy is a division in a horizontal direction, and the horizontal direction is perpendicular to the direction of the side where the height of the current image block is located.

Optionally, the dividing unit 1401 is specifically configured to: determine whether the current image block satisfies the first condition. The first condition includes: the width of the current image block is less than the product of the first threshold and the height of the current image block; the current image block does not satisfy In the first condition, it is determined that the block division strategy of the current image block does not include the division in the horizontal direction, and the horizontal direction is perpendicular to the direction of the side where the height of the current image block is located. For example, in conjunction with FIG. 9, the dividing unit 1401 may be used to perform S102 and S105. For another example, with reference to FIG. 10, the dividing unit 1401 may be used to perform S203 and S204.

Optionally, the dividing unit 1401 is specifically configured to determine whether the current image block satisfies the second condition. The second condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block; In the second condition, it is determined that the block division strategy of the current image block does not include the division in the vertical direction, and the vertical direction is perpendicular to the direction of the side where the width of the current image block is located. For example, with reference to FIG. 9, the dividing unit 1401 may be used to perform S103 and S104. For another example, with reference to FIG. 10, the dividing unit 1401 may be used to perform S205 and S207.

Optionally, the entropy decoding unit 1403 may be used to parse the code stream to obtain identification information, and the identification information is used to indicate the division type of the current image block. Correspondingly, the dividing unit 1401 is specifically used to divide the current image block based on the block division strategy (specifically, the block division strategy determined when the first condition is not met), using the division type indicated by the identification information, Vertical division to obtain coded blocks. For example, referring to FIG. 10, the entropy decoding unit 1403 may be used to perform the parsing step in S204. The dividing unit 1401 may be used to perform the dividing step in S204.

Optionally, the entropy decoding unit 1403 may be used to parse the code stream to obtain identification information, and the identification information is used to indicate the division type of the current image block. Correspondingly, the dividing unit 1401 is specifically used to divide the current image block based on the block division strategy (specifically, the block division strategy determined when the second condition is not met), using the division type indicated by the identification information, Horizontal division. For example, referring to FIG. 10, the entropy decoding unit 1403 may be used to perform the parsing step in S207. The dividing unit 1401 may be used to perform the dividing step in S207.

Optionally, the first threshold is the maximum value of the ratio of the length of the long side to the length of the short side of the allowed nodes in the coding tree.

Optionally, the first threshold is a value greater than 1. Optionally, the first threshold is an integer power of 2.

Optionally, the dividing unit 1401 is specifically configured to: determine whether the current image block satisfies the third condition, the third condition includes: the width of the current image block is less than the product of the second threshold and the height of the current image block; In the third condition, it is determined that the block division strategy is an extended quadtree division with a vertical division direction, and the vertical direction is perpendicular to the direction of the side where the width of the current image block is located.

Optionally, the dividing unit 1401 is specifically configured to determine whether the current image block satisfies the fourth condition. The fourth condition includes: the height of the current image block is less than the product of the second threshold and the width of the current image block; In the fourth condition, it is determined that the block division strategy is an extended quadtree division with a horizontal division direction, and the horizontal direction is perpendicular to the direction of the side where the height of the current image block is located.

Optionally, the dividing unit 1401 is specifically configured to: determine whether the current image block satisfies the third condition, the third condition includes: the width of the current image block is less than the product of the second threshold and the height of the current image block; In the third condition, it is determined that the block division strategy of the current image block does not include the expanded quadtree division in the horizontal direction, and the horizontal direction is perpendicular to the direction of the side where the height of the current image block is located. For example, referring to FIG. 11, the dividing unit 1401 may be used to perform the steps of determining the first candidate set in S301 and S302. For another example, with reference to FIG. 12, the dividing unit 1401 may be used to perform the dividing step in S404 when the second identification information is used to instruct to perform an extended quadtree division on the current image block.

Optionally, the dividing unit 1401 is specifically configured to: determine whether the current image block satisfies the fourth condition. The fourth condition includes: the height of the current image block is less than the product of the second threshold and the width of the current image block; In the fourth condition, it is determined that the block division strategy of the current image block does not include the extended quadtree division in the vertical direction, and the vertical direction is perpendicular to the direction of the side where the width of the current image block is located. For example, referring to FIG. 11, the dividing unit 1401 may be used to perform the steps of determining the second candidate set in S303 and S304. For another example, with reference to FIG. 12, the dividing unit 1401 may be used to perform the dividing step in S406 when the second identification information is used to instruct to perform an extended quadtree division on the current image block.

Optionally, the entropy decoding unit 1403 may be used to parse the code stream to obtain identification information, and the identification information is used to indicate the division type of the current image block. Correspondingly, the dividing unit 1401 is specifically used to: based on the block division strategy (specifically, the block division strategy determined when the third condition is not satisfied), when the identification information indicates that the current image block is expanded by quadtree division, the current The image block is divided into extended quadtrees with the vertical division direction. For example, with reference to FIG. 12, the entropy decoding unit 1403 may be used to perform the parsing step in S404 when the second identification information is used to indicate the extended quadtree division of the current image block, and the division unit 1401 may be used to perform the When the second identification information is used to indicate the step of dividing the current image block into an extended quadtree.

Optionally, the entropy decoding unit 1403 may be used to parse the code stream to obtain identification information, and the identification information is used to indicate the division type of the current image block. Correspondingly, the dividing unit 1401 is specifically used for: based on the block division strategy (specifically, the block division strategy determined when the fourth condition is not satisfied), when the identification information indicates that the current image block is expanded by quadtree division, the current The image block is divided into horizontal quadtrees in the horizontal direction. For example, with reference to FIG. 12, the entropy decoding unit 1403 may be used to perform the parsing step in S406 when the second identification information is used to indicate the extended quadtree division of the current image block. The dividing unit 1401 may be used to perform the dividing step in S406 when the second identification information is used to instruct to perform an extended quadtree division on the current image block.

Optionally, the second threshold is one-half the maximum value of the ratio of the length of the long side to the length of the short side of the node in the allowed coding tree.

Optionally, the second threshold is a value greater than 1. Optionally, the second threshold is an integer power of 2.

In other embodiments, the dividing unit 1401 is configured to divide the image block to be divided vertically if the length of the long side of the image block to be divided in the image to be decoded is twice the length of the short side of the image block to be divided Based on the binary tree division on the long side of the image block to be divided, the divided image block is obtained. The reconstruction unit 1402 is configured to reconstruct the image to be decoded according to the divided image blocks. For example, with reference to FIG. 13, the dividing unit 1401 may be used to perform the dividing operation in S503. For another example, in conjunction with FIG. 14, the dividing unit 1401 may be used to perform S604.

Optionally, the long side of the image block to be divided is 128 pixels long, and the short side is 64 pixels long.

Optionally, the short side length of the image block to be divided is equal to the side size of the maximum transformation unit TU, or the short side length of the image block to be divided is equal to the side size of the virtual pipeline data unit VPDU.

Optionally, the image block to be divided is a boundary image block.

In some embodiments, the dividing unit 1401 is configured to determine whether to allow a binary tree division of the current image block in the horizontal direction according to whether the current image block satisfies the first condition, the horizontal direction is perpendicular to the direction of the side of the current image block where the height is located , The first condition includes: the width of the current image block is less than the product of the first threshold and the height of the current image block, where, in the case where the current image block satisfies the first condition, it is determined that the current image block is allowed to be divided in a horizontal direction by a binary tree And, in the case where it is determined that the current image block is allowed to be divided in a binary tree in the horizontal direction, the coding block of the current image block is acquired. The reconstruction unit 1402 is configured to reconstruct the current image block by reconstructing the obtained coding block.

In some embodiments, the dividing unit 1401 is configured to determine whether to allow the current image block to be divided into a binary tree in the vertical direction according to whether the current image block satisfies the second condition, and the vertical direction is perpendicular to the side of the width of the current image block Direction, the second condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block, where, in the case where the current image block satisfies the second condition, it is determined that vertical direction of the current image block is allowed The binary tree partition of; and, in the case where it is determined that the current image block is allowed to be vertically binary tree partitioned, the coding block of the current image block is obtained. The reconstruction unit 1402 is configured to reconstruct the current image block by reconstructing the obtained coding block.

In some embodiments, the dividing unit 1401 is configured to determine whether to allow the current image block to be divided in a horizontal direction according to whether the current image block satisfies the first condition, the horizontal direction is perpendicular to the direction of the side where the current image block is high, The first condition includes: the width of the current image block is less than the product of the first threshold and the height of the current image block, where, in the case where the current image block does not satisfy the first condition, it is determined that horizontal division of the current image block is not allowed ; In the case where it is determined that the current image block is not allowed to be divided in the horizontal direction, the coding block of the current image block is obtained. The reconstruction unit 1402 is configured to reconstruct the current image block by reconstructing the obtained coding block.

In some embodiments, the dividing unit 1401 is configured to determine whether to allow the current image block to be divided in the vertical direction according to whether the current image block satisfies the second condition, the vertical direction is perpendicular to the side of the width of the current image block Direction, the second condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block, where, in the case where the current image block does not meet the second condition, it is determined that the current image block is not allowed to be vertical The division of the direction; if it is determined that the current image block is not allowed to be divided in the vertical direction, the coding block of the current image block is obtained. The reconstruction unit 1402 is configured to reconstruct the current image block by reconstructing the obtained coding block.

It is understandable that each module in the video decoder 140 provided by the embodiment of the present application is a functional body that implements various execution steps included in the corresponding method provided above, that is, it has the capability to implement the complete implementation of the embodiment of the present application. The various steps of these steps and the functional body of the expansion and deformation of these steps, please refer to the introduction of the corresponding methods above for details. For the sake of brevity, this article will not repeat them.

It should be noted that for the EQT scheme, since the nodes of the second-level coding tree can be divided using BT and EQT, encoding a node needs to try up to four divisions, and its child nodes can also try up to four divisions, encoding complexity Higher. Based on this, the present invention provides a new CU division method and device to reduce the complexity of system division of CUs.

The invention is applied to a video codec. The video communication system is shown in Figure 17. The communication system includes a source device 12 and a sink device 14, and a connection line 15 therebetween. Among them, the source device includes a video memory 16, a video encoder 18, a transmitter 20, and a video capture device 23. The receiving device 14 includes a receiver 22, a video decoder 24 and a display device 26. The present invention is applicable to the video encoder 18 and the video decoder 24.

Embodiment 1 relates to a video decoding method.

Perform decoding operation on the CTU according to the coding information of at least one CTU in the compressed code stream to obtain the reconstructed image block of the CTU. When decoding a CTU, CU parsing processing (steps 1 and 2) and CU decoding processing (step 3) will be performed on each of the CUs, and finally all the reconstructed pixels of the CTU will be obtained. Among them, step 2 is the key of the present invention, and steps 1 and 3 are prior art. The flowchart is shown in Figure 18.

The size of the CTU can be 64×64, 128×128, 256×256, etc. A CTU is divided into a group of non-overlapping CUs. This group of CUs covers the entire CTU; a group of CUs includes one or more CUs. A CU contains luma pixels in N rows and M columns, or chroma pixels in N rows and M columns, or luma pixels in N rows and M columns, and chroma pixels in N/2 rows and M/2 columns (such as the YUV420 format), Either include luminance pixels in N rows and M columns and chrominance pixels in N rows and M columns (such as YUV444 format), or RGB pixels including N rows and M columns (such as RGB format). Where N and M are integer powers of 2.

Step 1: Using the CTU as the root node of the first-level coding tree, analyze the division information of the first-level coding tree to obtain the first-level coding leaf node. Among them, the division method of the first-level coding tree is QT division or no division.

This step is the prior art, for example, the process of dividing the CTU into QT leaf nodes in the AVS scheme. More specifically, including: using the CTU as the root node, parsing the code stream to obtain the syntax element SplitFlag, if SplitFlag is 0, the node is a first-level coding leaf node, otherwise the node is divided into four first-level nodes according to the quadtree division method For child nodes in the coding tree, the width and height of each child node is half of that node. For each child node, parse the code stream to obtain the syntax element SplitFlag to determine whether this node is a first-level coding leaf node; if not, continue to divide according to the quadtree; and so on, until the width of the node is equal to the threshold MinQTSize (for example, 4 ), this node defaults to the first-level coding leaf node, and SplitFlag defaults to 0.

Step 2: Taking the leaf node of the first-level coding tree as the root node of the second-level coding tree, parse the second-level coding tree information, obtain the second-level coding leaf node, and parse the coding unit corresponding to the second-level coding leaf node CU. Among them, the division method of the second-level coding tree includes 2 binary tree divisions (horizontal bisection, vertical bisection) and 2 extended quadtree divisions (horizontal, vertical); in the resolution of the resolution node, if the size of a node If it is 64×128 or 128×64, the node is divided into two 64×64 sub-blocks or not divided by default.

The second-level coding tree is divided differently from the first-level coding tree. For example, in this embodiment, the second-level coding tree includes 4 divisions, and the first-level coding tree includes 1 division.

The above “analyzing the coding unit CU corresponding to the second-level coding leaf node” is the prior art, and reference may be made to the coding unit analysis in the AVS standard, which is not limited in the present invention.

"Analyze the second-level coding tree information to obtain the second-level coding leaf node", including:

Parse the split information STSplitMode of each node in the second-level coding tree;

If the division information indicates that the node is not divided (for example, STSplitMode=0), the node is a second-level coding leaf node;

If the partition information instructs the node to perform a binary tree partition (such as STSplitMode=1 or 2), select a partition mode indicated by the partition information to divide the node into 2 child nodes, and for each child node, analyze its partition information to determine it For example, when STSplitMode=1, the partition information instructs the node to perform a horizontal binary tree division and divide the node into 2 horizontal child nodes; when STSplitMode=2, the partition information indicates that the node performs a vertical binary tree division and divides the node It is 2 vertical child nodes.

If the partition information instructs the node to perform an extended quadtree partition (such as STSplitMode=3 or 4), select a partition mode indicated by the partition information to divide the node into 4 child nodes, and parse its partition information for each child node in turn Then determine its division mode; when STSplitMode=3, the division information instructs the node to perform the horizontal expansion quadtree division; when STSplitMode=4, the division information instructs the node to perform the vertical expansion quadtree division.

It should be understood that STSplitMode and its value are only used to indicate different division modes, and other distinguishable expressions (such as different codewords) are also within the protection scope of the present invention.

In the present invention, the division method of the node is determined, that is, whether the node is not divided or continues to be divided, and which division method is used if the division is continued.

In the present invention, a division limitation for nodes of an extended quadtree is added, that is, "if any of the nodes has a side length greater than 32, the node does not divide the extended quadtree by default."

The leaf node of the second-level coding tree corresponds to a coding unit CU, and the coding unit syntax structure in the code stream (for example, coding_unit() syntax structure in H.265) is parsed to obtain the coding information of the CU, including the prediction mode of the CU , Transform coefficients and other information.

Preferably, in the above step 2, the determination of the second-level coded leaf node and the analysis of the coding unit may be performed alternately, more specifically: after obtaining a second-level coded leaf node, the information of the coding unit corresponding to this node is analyzed; After coding unit information, continue to obtain the next second-level coding leaf node and parse the coding unit information of this leaf node; and so on, until the last second-level coding leaf node among the first-level coding leaf nodes.

Step 3: Decode and reconstruct each CU according to the coding information of each CU determined in step 2, to obtain the reconstructed pixels of each CU, thereby obtaining the reconstructed image of the CTU.

CU decoding includes entropy decoding, inverse quantization, inverse transform, prediction, loop filtering and other processing. The process mainly includes:

Entropy decoding to obtain CU prediction information, quantization parameters, transform coefficients, transform mode and other coding information;

According to the prediction mode, select intra prediction or inter prediction to obtain the predicted pixels of the CU;

If there is a transform coefficient in the CU, the transform coefficient is subjected to inverse quantization and inverse transform processing according to the quantization parameter and the transform mode to obtain the reconstruction residual of the CU. If there is no transform coefficient in the CU, the reconstruction residual of the CU is 0, that is, the reconstruction residual value of each pixel in the CU is 0.

The predicted pixels and the reconstruction residuals are added together to perform loop filter processing to obtain CU reconstruction pixels.

The decoding device corresponding to the present invention may include 2 modules:

The coding tree node analysis module, which completes the processing of steps 1 and 2, that is, parses the code stream, determines the division method of each node on the coding tree, and obtains the manner in which the CTU is divided into CUs and the coding information of each CU. Wherein, if the size of the node is 64×32 or 32×64, the node is divided into two 32×32 sub-blocks or not divided by default.

The CU decoding module, which completes the processing of step 3, that is, decodes each CU to obtain the reconstructed image of the CTU.

Technical effect of the first embodiment of the invention

In the first embodiment of the present invention, by defining a specific division method for a specific block (64×32 or 32×64), CTU division can be made more detailed, and the complexity of CTU division can be reduced (multiple division methods become one division method) ), also increasing the possibility of improving the processing accuracy (32×32 blocks are more likely to be further divided).

Embodiment 2 of the present invention

The second embodiment is an extension of the first embodiment.

In the second embodiment, if the width, height, long side to short side ratio of a node satisfies certain conditions (that is, illegal conditions), the division method of the node is considered illegal (that is, the division method of this node is actually not allowed in use).

For example, when at least one of the following illegal conditions is met, the node defaults to illegal.

1) If the ratio of the long side to the short side of the node is greater than the threshold minRatio, the node is considered invalid. Here, the threshold may be an integer greater than or equal to 1, such as 4.

2) If the side length of the node is less than the threshold minCUSize, it is considered that the node is not divided. Among them, minCUSize is called the minimum CU side length, for example equal to 4.

The thresholds in each of the above conditions can be specified in high-level syntax, or preset as default values.

Specifically, if a child node obtained after applying a certain division method to the current node satisfies any one of the illegal conditions, then the current node cannot be divided in this manner. Therefore, based on the restriction of illegal conditions, the syntax elements that need to be parsed can be further reduced.

Specifically, if the ratio of the long side to the short side of the parent node is equal to the threshold minRatio, the short side cannot be further divided into child nodes. In one example, the threshold minRatio may correspond to the first threshold above. For example, if the width-to-height ratio of the parent node is equal to the threshold 4, horizontal division cannot be continued, because if horizontal division is performed: then in the case of horizontal BT division, the width-to-height ratio of the child node will be equal to 8, exceeding the threshold 4. It is illegal; in the case of horizontal EQT division, the width-to-height ratio of the child nodes will be equal to 16, which exceeds the threshold of 4, which is illegal. However, as long as the child nodes do not meet other illegal conditions, vertical division can still be performed. Therefore, in this case, in the first embodiment, there is no need to analyze the division of STSplitMode=1 and STSplitMode=3, and it is only possible that STSplitMode=2 or STSplitMode=4; In the third embodiment, the values of BtSplitDir and EqtSplitDir can be inferred only by parsing the values of BTSplitMode or EQTSplitMode, and the values of BtSplitDir and EqtSplitDir need not be parsed. Specifically, if BTSplitMode=1 is parsed, BtSplitDir=1 can be inferred; if BTSplitMode=1 is parsed, EqtSplitDir=1 can be inferred.

Similarly, it can be inferred that, in the case of sub-nodes to be divided:

If the length of the short side of a parent node is equal to the threshold minCUSize, then it can only divide BT on the long side; that is, when it is determined that the length of the short side of the current node is equal to the threshold minCUSize, only the value of BTSplitMode can be analyzed to obtain the current The division of nodes.

If the ratio of the long side to the short side of a parent node is equal to twice the threshold minRatio, then it cannot divide EQT on the short side; that is, when it is judged that the ratio of the long side to the short side of the current node is equal to twice the threshold minRatio As long as the value of EQTSplitMode is 1, it can be obtained that the current node is divided into EQT along the long side (that is, it is not EqtSplitDir).

If the length of the short side of a parent node is twice the threshold minCUSize, then it cannot divide EQT on the short side; that is, when it is determined that the length of the short side of the current node is equal to twice the threshold minCUSize, as long as the value of EQTSplitMode is resolved Is 1, you can get the current node division method is the EQT along the long side (that is, it is EqtSplitDir if not used).

If the width and height of a parent node are twice the threshold minCUSize, then it cannot be divided by EQT; that is, when it is determined that the width and height of the current node are twice the threshold minCUSize, only BTSplitMode and BtSpliDir are used to resolve, not Analyze EQTSplitMode.

Technical effect of the second embodiment of the present invention

In the second embodiment of the present invention, by comparing the relationship between the size of the current node and the threshold minCUSize and/or the threshold minRatio, the impossible division mode of the current node (the invention point of the second embodiment) is eliminated, thereby reducing the complexity of the entire analysis process, Improve the efficiency of the system.

Embodiment 3 of the present invention

The third embodiment is an extension of the first embodiment. This embodiment modifies the following steps in step two of the first embodiment:

In step two, "parse the second-level coding tree information to obtain the second-level coding leaf node" may also include:

Parsing the split information BTSplitMode and EQTSplitMode of each node in the second-level coding tree;

If the split information indicates that the node is not split (eg, BTSplitMode=0 and EQTSplitMode=0), the node is a second-level coded leaf node;

If the partition information instructs the node to perform a binary tree partition (such as BtSplitMode=1), then select a partition mode indicated by the partition information to divide the node into two child nodes, and for each child node, analyze its partition information to determine its partition Way; for example, when BtSplitDir=0, the partition information instructs the node to divide the horizontal binary tree, dividing the node into 2 horizontal child nodes; when BtSplitDir=1, the partition information instructs the node to divide the vertical binary tree, dividing the node into 2 Vertical child nodes.

If the partition information instructs the node to perform an extended quadtree partition (such as EQTSplitMode=1), then select a partition mode indicated by the partition information to divide the node into 4 child nodes, and for each child node in turn, analyze its partition information to determine Its division method; when EqtSplitDir=0, the division information instructs the node to perform the horizontal expansion quadtree division; when EqtSplitDir=1, the division information instructs the node to perform the vertical quadtree division.

An example flowchart is shown in Figure 19. It should be understood that the judgments of BTSplitMode and EQTSplitMode in the figure are schematic, and they may be in any order or may be performed at the same time, which is not a limitation of this embodiment.

Technical effect of Embodiment 3 of the present invention

In the third embodiment of the present invention, by introducing independent parameter judgment to classify the nodes by binary tree or extended quadtree, the method and method of positioning division can be positioned more quickly, the parallel processing capacity is improved, and the efficiency of the system is improved.

The embodiment of the present invention defines a specific division mode (divided into 32×32) for a specific block (64×32 or 32×64 block);

The embodiment of the present invention limits the division of the nodes of the extended quadtree, that is, "if any of the nodes has a side length greater than 32, the node does not divide the extended quadtree by default";

The embodiment of the present invention compares the relationship between the size of the current node and the threshold minCUSize and/or the threshold minRatio to exclude the impossible division mode of the current node (Embodiment 2), thereby reducing the complexity of the entire parsing process.

The beneficial effect is to reduce the complexity of CTU division (multiple divisions become one division or no division), thereby improving the efficiency of the entire system.

Those skilled in the art will appreciate that the functions described in conjunction with the various illustrative logical blocks, modules, and algorithm steps described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions described by the various illustrative logical blocks, modules, and steps may be stored or transmitted as one or more instructions or codes on the computer-readable medium and executed by the hardware-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to tangible media, such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another (eg, according to a communication protocol). . In this manner, computer-readable media may generally correspond to (1) non-transitory tangible computer-readable storage media, or (2) communication media, such as signals or carrier waves. Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementation of the techniques described in this application. The computer program product may include a computer-readable medium.

By way of example, and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM, or other optical disk storage devices, magnetic disk storage devices, or other magnetic storage devices, flash memory, or may be used to store instructions or data structures The desired program code in the form of and any other medium that can be accessed by the computer. And, any connection is properly called a computer-readable medium. For example, if a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology such as infrared, radio, and microwave is used to transmit instructions from a website, server, or other remote source, then the coaxial cable Wire, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. However, it should be understood that the computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other temporary media, but are actually directed to non-transitory tangible storage media. As used herein, magnetic disks and optical discs include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), and Blu-ray discs, where magnetic discs typically reproduce data magnetically, while optical discs reproduce optically using lasers data. Combinations of the above should also be included in the scope of computer-readable media.

One or more processes such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuits To execute instructions. Accordingly, the term "processor" as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. In addition, in some aspects, the functions described in the various illustrative logical blocks, modules, and steps described herein may be provided within dedicated hardware and/or software modules configured for encoding and decoding, or in combination Into the combined codec. Moreover, the techniques can be fully implemented in one or more circuits or logic elements.

The technology of the present application may be implemented in a variety of devices or equipment, including wireless handsets, integrated circuits (ICs), or a set of ICs (eg, chipsets). Various components, modules or units are described in this application to emphasize the functional aspects of the device for performing the disclosed technology, but do not necessarily need to be implemented by different hardware units. In fact, as described above, various units may be combined in a codec hardware unit in combination with suitable software and/or firmware, or by interoperating hardware units (including one or more processors as described above) provide.

In the above embodiments, the description of each embodiment has its own emphasis. For a part that is not detailed in an embodiment, you can refer to the related descriptions of other embodiments.

The above are only exemplary specific implementations of the present application, but the scope of protection of the present application is not limited to this, and any person skilled in the art may easily think of changes or changes within the technical scope disclosed in the present application. Replacement should be covered within the scope of protection of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A video decoding method, characterized in that it includes:

Determine the block division strategy of the current image block according to the relationship between the width and height of the current image block;

Applying the block division strategy to the current image block to obtain an encoding block;

Reconstructing the obtained coding block to achieve reconstruction of the current image block.
The method according to claim 1, wherein the determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes:

Determining whether the current image block satisfies a first condition, where the first condition includes: the width of the current image block is less than a product of a first threshold and a height of the current image block;

When the current image block does not satisfy the first condition, it is determined that the block division strategy is division in a vertical direction, and the vertical direction is perpendicular to the direction of the side where the width of the current image block is located .
The method according to claim 1, wherein the determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes:

Determining whether the current image block satisfies a second condition, where the second condition includes: a height of the current image block is less than a product of a first threshold and a width of the current image block;

When the current image block does not satisfy the second condition, it is determined that the block division strategy is division in a horizontal direction, and the horizontal direction is perpendicular to the direction of the side where the height of the current image block is located.
The method according to claim 1, wherein the determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes:

Determining whether the current image block satisfies a first condition, where the first condition includes: the width of the current image block is less than a product of a first threshold and a height of the current image block;

When the current image block does not satisfy the first condition, it is determined that the block division strategy of the current image block does not include the division in the horizontal direction, the horizontal direction being perpendicular to the height of the current image block The direction of the side.
The method according to claim 1, wherein the determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes:

Determining whether the current image block satisfies a second condition, where the second condition includes: a height of the current image block is less than a product of a first threshold and a width of the current image block;

When the current image block does not satisfy the second condition, it is determined that the block division strategy of the current image block does not include the division in the vertical direction, and the vertical direction is perpendicular to the width of the current image block The direction of the edge.
The method according to any one of claims 2 to 5, wherein the first threshold is the maximum value of the ratio of the length of the long side to the length of the short side of the allowed nodes in the coding tree.
The method according to claim 2 or 4, wherein the method further comprises:

Parsing the code stream to obtain identification information, where the identification information is used to indicate a division type for dividing the current image block;

Correspondingly, the applying of the block division strategy to the current image block to obtain a coding block includes:

Based on the block division strategy, the division type indicated by the identification information is used to divide the current image block into a vertical direction to obtain a coding block.
The method according to claim 3 or 5, wherein the method further comprises:

Parsing the code stream to obtain identification information, where the identification information is used to indicate a division type for dividing the current image block;

Correspondingly, the applying of the block division strategy to the current image block to obtain a coding block includes:

Based on the block division strategy, the division type indicated by the identification information is used to divide the current image block into a horizontal direction.
The method according to claim 1, wherein the determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes:

Determining whether the current image block satisfies a third condition, where the third condition includes: the width of the current image block is less than the product of the second threshold and the height of the current image block;

When the current image block does not satisfy the third condition, it is determined that the block division strategy is an extended quadtree division with the division direction in the vertical direction, where the vertical direction is perpendicular to the width of the current image block The direction of the side.
The method according to claim 1, wherein the determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes:

Determining whether the current image block satisfies a fourth condition, where the fourth condition includes: a height of the current image block is less than a product of a second threshold and a width of the current image block;

When the current image block does not satisfy the fourth condition, it is determined that the block division strategy is an extended quadtree division with the division direction being a horizontal direction, the horizontal direction being perpendicular to the side where the height of the current image block is located Direction.
The method according to claim 1, wherein the determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes:

Determining whether the current image block satisfies a third condition, where the third condition includes: the width of the current image block is less than the product of the second threshold and the height of the current image block;

When the current image block does not satisfy the third condition, it is determined that the block division strategy of the current image block does not include an extended quadtree division with the division direction being a horizontal direction, the horizontal direction being perpendicular to the current image block The direction of the side where the height is.
The method according to claim 1, wherein the determining the block division strategy of the current image block according to the relationship between the width and height of the current image block includes:

Determining whether the current image block satisfies a fourth condition, where the fourth condition includes: a height of the current image block is less than a product of a second threshold and a width of the current image block;

When the current image block does not satisfy the fourth condition, it is determined that the block division strategy of the current image block does not include an extended quadtree division with a vertical division direction, the vertical direction being perpendicular to the current The direction of the side where the width of the image block lies.
The method according to any one of claims 9 to 12, wherein the second threshold is one-half the maximum value of the ratio of the length of the long side to the length of the short side of the node in the allowed coding tree.
The method according to claim 9 or 11, wherein the method further comprises:

Parsing the code stream to obtain identification information, where the identification information is used to indicate a division type for dividing the current image block;

Correspondingly, the applying of the block division strategy to the current image block to obtain a coding block includes:

Based on the block division strategy, when the identification information indicates that the current image block is to be divided into an extended quadtree, the current image block is divided into an extended quadtree in a vertical direction.
The method according to claim 10 or 12, wherein the method further comprises:

Parsing the code stream to obtain identification information, where the identification information is used to indicate a division type for dividing the current image block;

Correspondingly, the applying of the block division strategy to the current image block to obtain a coding block includes:

Based on the block division strategy, when the identification information indicates that the current image block is to be divided into extended quadtrees, the current image block is divided into horizontally extended quadtrees.
A video decoder is characterized by comprising:

A dividing unit, configured to determine a block division strategy of the current image block according to the relationship between the width and height of the current image block; and, apply the block division strategy to the current image block to obtain an encoding block;

The reconstruction unit is configured to reconstruct the current image block by reconstructing the obtained coding block.
The video decoder according to claim 16, wherein the dividing unit is specifically configured to:

Determining whether the current image block satisfies a first condition, where the first condition includes: the width of the current image block is less than a product of a first threshold and a height of the current image block;

When the current image block does not satisfy the first condition, it is determined that the block division strategy is division in a vertical direction, and the vertical direction is perpendicular to the direction of the side where the width of the current image block is located .
The video decoder according to claim 16, wherein the dividing unit is specifically configured to:

Determining whether the current image block satisfies a second condition, where the second condition includes: a height of the current image block is less than a product of a first threshold and a width of the current image block;

When the current image block does not satisfy the second condition, it is determined that the block division strategy is division in a horizontal direction, and the horizontal direction is perpendicular to the direction of the side where the height of the current image block is located.
The video decoder according to claim 16, wherein the dividing unit is specifically configured to:

Determining whether the current image block satisfies a first condition, where the first condition includes: the width of the current image block is less than a product of a first threshold and a height of the current image block;

When the current image block does not satisfy the first condition, it is determined that the block division strategy of the current image block does not include the division in the horizontal direction, the horizontal direction being perpendicular to the height of the current image block The direction of the side.
The video decoder according to claim 16, wherein the dividing unit is specifically configured to:

Determining whether the current image block satisfies a second condition, where the second condition includes: a height of the current image block is less than a product of a first threshold and a width of the current image block;

When the current image block does not satisfy the second condition, it is determined that the block division strategy of the current image block does not include the division in the vertical direction, and the vertical direction is perpendicular to the width of the current image block The direction of the edge.
The video decoder according to any one of claims 17 to 20, wherein the first threshold is the maximum value of the ratio of the long side length to the short side length of the allowed nodes in the coding tree.
The video decoder according to claim 17 or 19, wherein the video decoder further comprises:

The entropy decoding unit is used to parse the code stream to obtain identification information, and the identification information is used to indicate the division type of the current image block;

Correspondingly, the dividing unit is specifically used to divide the current image block into a vertical direction based on the block division strategy and using the division type indicated by the identification information, to obtain an encoding block.
The video decoder according to claim 18 or 20, wherein the video decoder further comprises:

An entropy decoding unit is used to parse the code stream to obtain identification information, and the identification information is used to indicate the division type of the current image block;

Correspondingly, the dividing unit is specifically configured to divide the current image block into a horizontal direction based on the block division strategy and using the type of division indicated by the identification information.
The video decoder according to claim 16, wherein the dividing unit is specifically used for:

Determining whether the current image block satisfies a third condition, where the third condition includes: the width of the current image block is less than the product of the second threshold and the height of the current image block;

When the current image block does not satisfy the third condition, it is determined that the block division strategy is an extended quadtree division with the division direction in the vertical direction, where the vertical direction is perpendicular to the width of the current image block The direction of the side.
The video decoder according to claim 16, wherein the dividing unit is specifically configured to:

Determining whether the current image block satisfies a fourth condition, where the fourth condition includes: a height of the current image block is less than a product of a second threshold and a width of the current image block;

When the current image block does not satisfy the fourth condition, it is determined that the block division strategy is an extended quadtree division with the division direction being a horizontal direction, the horizontal direction being perpendicular to the side where the height of the current image block lies Direction.
The video decoder according to claim 16, wherein the dividing unit is specifically used for:

Determining whether the current image block satisfies a third condition, where the third condition includes: the width of the current image block is less than the product of the second threshold and the height of the current image block;

When the current image block does not satisfy the third condition, it is determined that the block division strategy of the current image block does not include an extended quadtree division with the division direction being a horizontal direction, the horizontal direction being perpendicular to the current image block The direction of the side where the height is.
The video decoder according to claim 16, wherein the dividing unit is specifically configured to:

Determining whether the current image block satisfies a fourth condition, where the fourth condition includes: a height of the current image block is less than a product of a second threshold and a width of the current image block;

When the current image block does not satisfy the fourth condition, it is determined that the block division strategy of the current image block does not include an extended quadtree division with a vertical division direction, the vertical direction being perpendicular to the current The direction of the side where the width of the image block lies.
The video decoder according to any one of claims 24 to 27, wherein the second threshold is half of the maximum value of the ratio of the long side length to the short side length of the allowed nodes in the coding tree One.
The video decoder according to claim 24 or 26, wherein the video decoder further comprises:

An entropy decoding unit is used to parse the code stream to obtain identification information, and the identification information is used to indicate the division type of the current image block;

Correspondingly, the dividing unit is specifically configured to: based on the block dividing strategy, when the identification information indicates that the current image block is divided into an extended quadtree, the direction of dividing the current image block is vertical Directional quadtree division.
The video decoder according to claim 25 or 27, wherein the video decoder further comprises:

An entropy decoding unit is used to parse the code stream to obtain identification information, and the identification information is used to indicate the division type of the current image block;

Correspondingly, the dividing unit is specifically configured to: based on the block dividing strategy, when the identification information indicates that the current image block is divided into an extended quadtree, the direction of dividing the current image block is a horizontal direction The division of the extended quadtree.
A video decoding method, characterized in that it includes:

If the length of the long side of the image block to be divided in the image to be decoded is twice the length of the short side of the image block to be divided, the dividing direction of the image block to be divided is perpendicular to that of the image block to be divided Binary tree division on the long side to obtain the divided image blocks;

Reconstruct the image to be decoded according to the divided image blocks.
The method according to claim 31, wherein the length of the long side of the image block to be divided is 128 pixels, and the length of the short side is 64 pixels.
The method according to claim 31 or 32, wherein the short side length of the image block to be divided is equal to the side size of the maximum transform unit TU, or the short side length of the image block to be divided is equal to virtual pipeline data The side dimensions of the unit VPDU.
The method according to any one of claims 31 to 33, wherein the image block to be divided is a boundary image block.
A video decoder is characterized by comprising:

A dividing unit, configured to divide the image block to be divided if the length of the long side of the image block to be divided in the image to be decoded is twice the length of the short side of the image block to be divided Binary tree division on the long side of the image block to be divided to obtain the divided image block;

The reconstruction unit is configured to reconstruct the image to be decoded according to the divided image blocks.
The video decoder according to claim 35, wherein the long side of the image block to be divided is 128 pixels long, and the short side is 64 pixels long.
The video decoder according to claim 35 or 36, wherein the length of the short side of the image block to be divided is equal to the side size of the maximum transform unit TU, or the length of the short side of the image block to be divided is equal to The side size of the virtual pipeline data unit VPDU.
The video decoder according to any one of claims 35 to 37, wherein the image block to be divided is a boundary image block.
A video decoding device, comprising a memory and a processor; the memory is used to store program code; the processor is used to call the program code to execute any one of claims 1 to 15. Methods.
A video decoding device, comprising a memory and a processor; the memory is used to store program code; the processor is used to call the program code to execute any one of claims 31 to 34 Methods.
A computer-readable storage medium, characterized by comprising program code, which when run on a computer causes the computer to execute the method according to any one of claims 1 to 15.
A computer-readable storage medium, comprising program code, which when run on a computer, causes the computer to execute the method according to any one of claims 31 to 34.
A video decoding method, characterized in that it includes:

According to whether the current image block satisfies the first condition, determine whether to allow a binary tree division of the current image block in a horizontal direction, the horizontal direction being perpendicular to the direction of the side of the current image block where the height is located, the first condition The method includes: the width of the current image block is smaller than the product of the first threshold and the height of the current image block, wherein, in the case where the current image block satisfies the first condition, it is determined that the current image block is allowed Divide the binary tree in the horizontal direction;

Acquiring a coding block of the current image block when it is determined that horizontal tree binary division is allowed for the current image block;

Reconstructing the obtained coding block to achieve reconstruction of the current image block.
A video decoding method, characterized in that it includes:

According to whether the current image block satisfies the second condition, it is determined whether the current image block is allowed to be divided into a binary tree in the vertical direction, the vertical direction is perpendicular to the direction of the side where the width of the current image block is located, the first The second condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block, wherein, in the case where the current image block satisfies the second condition, it is determined that the current The image block is divided into two binary trees in the vertical direction;

Acquiring a coding block of the current image block if it is determined that vertical binary tree division is allowed for the current image block;

Reconstructing the obtained coding block to achieve reconstruction of the current image block.
A video decoding method, characterized in that it includes:

According to whether the current image block satisfies the first condition, determine whether to allow the current image block to be divided in a horizontal direction, the horizontal direction being perpendicular to the direction of the side where the current image block is high, the first condition includes : The width of the current image block is smaller than the product of the first threshold and the height of the current image block, wherein, in the case where the current image block does not satisfy the first condition, it is determined that the current image is not allowed The blocks are divided horizontally;

Acquiring a coding block of the current image block if it is determined that horizontal division of the current image block is not allowed;

Reconstructing the obtained coding block to achieve reconstruction of the current image block.
A video decoding method, characterized in that it includes:

According to whether the current image block satisfies the second condition, it is determined whether the current image block is allowed to be divided in a vertical direction, the vertical direction is perpendicular to the direction of the side where the width of the current image block is located, the second The condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block, wherein, in the case where the current image block does not satisfy the second condition, it is determined that the The current image block is divided in the vertical direction;

Acquiring a coding block of the current image block if it is determined that vertical division of the current image block is not allowed;

Reconstructing the obtained coding block to achieve reconstruction of the current image block.
A video decoding device is characterized by comprising:

A dividing unit, configured to determine whether to allow the current image block to be divided into a binary tree in a horizontal direction according to whether the current image block satisfies the first condition, the horizontal direction being perpendicular to the direction of the side where the current image block is high, The first condition includes: the width of the current image block is less than a product of a first threshold and a height of the current image block, where, in the case where the current image block satisfies the first condition, it is determined that Dividing the current image block into a binary tree in the horizontal direction; and, in a case where it is determined that the current image block is allowed to be divided into a binary tree in the horizontal direction, acquiring the coding block of the current image block;

The reconstruction unit is configured to reconstruct the current image block by reconstructing the obtained coding block.
A video decoding device is characterized by comprising:

A dividing unit, configured to determine whether to allow a binary tree division of the current image block in a vertical direction according to whether the current image block satisfies the second condition, the vertical direction being perpendicular to the side of the width of the current image block Direction, the second condition includes: a height of the current image block is less than a product of a first threshold and a width of the current image block, wherein, if the current image block satisfies the second condition, it is determined Allowing a vertical binary tree division of the current image block; and, if it is determined that a vertical binary tree division is allowed for the current image block, acquiring a coding block of the current image block;

The reconstruction unit is configured to reconstruct the current image block by reconstructing the obtained coding block.
A video decoding device is characterized by comprising:

The dividing unit is configured to determine whether to allow the current image block to be divided in a horizontal direction according to whether the current image block satisfies the first condition, the horizontal direction being perpendicular to the direction of the side where the current image block is high, so The first condition includes: the width of the current image block is smaller than the product of the first threshold and the height of the current image block, where, in the case where the current image block does not satisfy the first condition, it is determined that it is not allowed Dividing the current image block in the horizontal direction; when it is determined that the current image block is not allowed to be divided in the horizontal direction, acquiring the coding block of the current image block;

The reconstruction unit is configured to reconstruct the current image block by reconstructing the obtained coding block.
A video decoding device is characterized by comprising:

A dividing unit, configured to determine whether to allow the current image block to be divided in a vertical direction according to whether the current image block satisfies the second condition, the vertical direction being perpendicular to the direction of the side where the width of the current image block is located , The second condition includes: the height of the current image block is less than the product of the first threshold and the width of the current image block, where, in the case where the current image block does not satisfy the second condition, it is determined It is not allowed to divide the current image block in the vertical direction; if it is determined that the current image block is not allowed to be divided in the vertical direction, obtain the coding block of the current image block;

The reconstruction unit is configured to reconstruct the current image block by reconstructing the obtained coding block.
A video decoding device, comprising a memory and a processor; the memory is used to store program code; the processor is used to call the program code to execute any one of claims 43 to 46 Methods.
A computer-readable storage medium, comprising program code, which when run on a computer, causes the computer to execute the method according to any one of claims 43 to 46.