WO2020108168A9 - Video image prediction method and device - Google Patents

Abstract

A video image prediction method and device, which are used to solve the problem of low prediction accuracy in existing technology. The method comprises: parsing candidate motion information and an index identifier from a code stream, the candidate motion information comprising a reference frame index and a candidate motion vector identifier of a block to be processed; when an index identifier is a first value, determining a derived reference frame index according to said reference frame index; on the basis of the distance between a reference frame and a current frame and the distance between a derived reference frame and the current frame, scaling a motion vector of a decoded block so as to obtain a derived motion vector of the candidate motion information; and determining a pixel prediction value of the block to be processed on the basis of the candidate motion information, the derived reference frame index and the derived motion vector. Due to a motion information update in an HMVP queue, some optimal motion information is lost. Thus, the derived motion information can make up for the loss of prediction accuracy caused by said motion information, thereby being able to improve prediction accuracy.

Description

Video image prediction method and device

Cross references to related applications

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 201811452886.8, and the application name is "a method and device for video image prediction" on November 30, 2018, the entire content of which is incorporated into this application by reference Medium; this application requires the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 201811559686.2, and the application name is "a method and device for video image prediction" on December 19, 2018, the entire content of which is incorporated by reference In this application.

Technical field

This application relates to the field of image coding and decoding technologies, and in particular to a video image prediction method and device.

Background technique

With the development of information technology, high-definition TV, web conferencing, IPTV, 3D TV and other video services have developed rapidly. Video signals have become the most important way for people to obtain information in daily life due to their intuitiveness and efficiency. Since the video signal contains a large amount of data, it needs to occupy a large amount of transmission bandwidth and storage space. In order to effectively transmit and store video signals, it is necessary to compress and encode video signals. Video compression technology has increasingly become an indispensable key technology in the field of video applications.

The basic principle of video coding and compression is to use the correlation between spatial domain, time domain and codewords to remove redundancy as much as possible. The current popular approach is to adopt a hybrid video coding framework based on image blocks to achieve video coding compression through steps such as prediction (including intra-frame prediction and inter-frame prediction), transformation, quantization, and entropy coding.

The current video coding standard proposes a history-based motion vector prediction (HMVP) method. The HMVP method uses the HMVP queue to add candidate motion information. When adding candidate motion information to the HMVP queue, if the number of candidate motion information in the HMVP queue reaches or exceeds the maximum length of the HMVP queue, the first in and first out (FIFO) principle is used to remove the first one in the queue. Candidate motion information, and the candidate motion information to be added is stored at the end of the HMVP queue.

For P frames, it can only refer to the motion information of the coded blocks of the forward reference frame. When the HMVP queue eliminates candidate motion information, it may eliminate the motion information that can be used for P frames, resulting in pending processing for P frames When the block is subjected to inter-frame prediction, there is less motion information that can be referred to, resulting in lower prediction accuracy.

Summary of the invention

The present application provides a video image prediction method and device to solve the problem of low prediction accuracy in the prior art.

In a first aspect, an embodiment of the present application provides a video image prediction method, including: parsing candidate motion information and index identification from a code stream, where the candidate motion information includes the reference frame index and candidate motion vector identification of the block to be processed, The motion vector identifier is used to indicate the motion vector of the decoded block referenced by the block to be processed; when the index identifier is a first value, a derived reference frame index is determined according to the reference frame index; based on the reference frame The distance between the reference frame indicated by the index and the current frame in which the block to be processed is located, and the distance between the derivative reference frame indicated by the derivative reference frame index and the current frame, are related to the motion of the decoded block A vector is scaled to obtain a derived motion vector of the candidate motion information; the pixel prediction value of the block to be processed is determined based on the candidate motion information, the derived reference frame index, and the derived motion vector.

In the above method, in addition to the selection of candidate motion information contained in the HMVP queue, it also includes newly generated derivative motion information, which can further improve the prediction accuracy of the pixel value of the coding unit. According to the characteristics of candidate motion information in the HMVP queue, any optimal motion information around the coding unit can be used to generate new motion information. In the HMVP queue, part of the optimal motion information is lost due to the update of the motion information, and the derived motion information can make up for the loss of prediction accuracy caused by the motion information, thereby improving the prediction accuracy.

In a possible design, the pixel prediction value of the to-be-processed block is equal to the sum of a first weighted value and a second weighted value, and the first weighted value is equal to the to-be-processed value determined based only on the candidate motion information. The pixel prediction value of the block is multiplied by a first weight value, and the second weight value is equal to the pixel prediction value of the block to be processed determined based on the derived motion vector and the derived reference frame index multiplied by the second weight value, The sum of the first weight and the second weight is equal to 1.

The above design adopts a weighted sum method to determine the pixel prediction value of the block to be processed corresponding to the derived motion information, which can further improve the prediction accuracy, and the method is simple and easy to implement.

In a possible design, the first weight is equal to the second weight.

In a possible design, the method further includes, when the index is identified as a second value, determining the pixel prediction value of the image to be processed only based on the candidate motion information.

The above design is simple to implement by determining whether to derive or not through different index marks.

In a possible design, the derivative motion vector is obtained according to the following formula:

MV'=(d0'/d0)MV;

Wherein, MV' represents the derived motion vector, d0' represents the distance between the derived reference frame and the current frame, d0 represents the distance between the reference frame and the current frame, and MV represents the distance between the reference frame and the current frame. The motion vector of the decoded block.

In a possible design, determining the derived reference frame index according to the reference frame index includes:

When the reference frame index is zero, determine that the derived reference frame index is 1;

When the reference frame index is non-zero, it is determined that the derived reference frame index is 0.

The above design provides a simple and easy way to determine the derived reference frame index.

In the second aspect, this application provides a motion vector decoding method, including:

The code stream is parsed to obtain first identification information, where the first identification information is used to identify the first motion vector in the motion vector set corresponding to the image block to be processed; the code stream is parsed to obtain the second identification information; When the second identification information is the second value, the predicted value of the image block to be processed is obtained according to the first motion vector; when the second identification information is the first value, the prediction value is obtained according to the first motion vector and the first motion vector. The predicted value of the image block to be processed is obtained by two motion vectors, wherein the second motion vector is obtained according to the first motion vector and a preset mapping relationship, and the first value is different from the second value.

With reference to the second aspect, in the first possible implementation manner of the second aspect, before the parsing the code stream to obtain the second identification information, the method further includes:

Determine the strip type of the image where the image block to be processed is located; and/or,

Determining the coding structure of the sequence where the image block to be processed is located; and/or,

Determining the prediction mode of the image block to be processed;

Correspondingly, the parsing the code stream to obtain the second identification information includes:

When the slice type of the image where the image block to be processed is located, and/or the coding structure of the sequence where the image block to be processed is located, and/or the prediction mode of the image block to be processed meets a preset condition, analyze The code stream obtains the second identification information.

With reference to the first possible implementation manner of the second aspect, in the second possible implementation manner of the second aspect, the preset condition includes: the prediction mode is skip mode or direct Mode, and/or, the slice type is a P slice, and/or the coding structure is a low delay P frame (Low Delay P) structure.

With reference to the second aspect or the first possible implementation manner or the second possible implementation manner of the second aspect, in the third possible implementation manner of the second aspect, the second motion vector is obtained by the following formula:

Wherein, MV1 is the first motion vector, MV2 is the second motion vector, d1 is the time domain distance between the first reference frame corresponding to the first motion vector and the image frame where the image block to be processed is located, d2 Is the time domain distance between the second reference frame corresponding to the second motion vector and the image frame where the image block to be processed is located.

With reference to the third possible implementation manner of the second aspect, in the fourth possible implementation manner of the second aspect, the first identification information is further used to identify the first reference frame.

With reference to the third or fourth possible implementation manner of the second aspect, in the fifth possible implementation manner of the second aspect, the method further includes: obtaining the second reference according to the index value of the first reference frame The index value of the frame.

With reference to the fifth possible implementation manner of the second aspect, in a sixth possible implementation manner of the second aspect, the obtaining the index value of the second reference frame according to the index value of the first reference frame, include:

When the index value of the first reference frame is 0, the index value of the second reference frame is 1;

When the index value of the first reference frame is not 0, the index value of the second reference frame is 0.

With reference to the second aspect and any one of the first to sixth possible implementations of the second aspect, in the seventh possible implementation of the second aspect, the first motion vector And the second motion vector to obtain the predicted value of the image block to be processed includes:

Obtaining a first prediction value of the image block to be processed according to the first motion vector and the first reference frame;

Obtaining a second predicted value of the image block to be processed according to the second motion vector and the second reference frame;

The first predicted value and the second predicted value are averaged to serve as the predicted value of the image block to be processed.

With reference to any one of the first to seventh possible implementations of the second aspect, in the eighth possible implementation of the second aspect, when the stripe type of the image where the image block to be processed is located , And/or, the coding structure of the sequence where the image block to be processed is located, and/or, when the prediction mode of the image block to be processed does not meet the preset condition, obtain the to-be-processed image block according to the first motion vector Process the predicted value of the image block.

In a third aspect, an embodiment of the present application provides a video image prediction method, which is applied to the encoding side and includes:

The first candidate motion information is obtained from the historical motion vector prediction queue corresponding to the block to be processed. The first candidate motion information includes the prediction direction of the candidate coded block, the reference frame index of the block to be processed, and the information of the candidate coded block. Motion vector; when the prediction direction is forward and the number of reference frames included in the reference frame list corresponding to the block to be processed is greater than 1, a derived reference frame index is determined according to the reference frame index; based on the reference frame index The distance between the indicated reference frame and the current frame in which the block to be processed is located, and the distance between the derived reference frame indicated by the derived reference frame index and the current frame, are compared to the first candidate motion information The included motion vector is scaled to obtain a derived motion vector of the first candidate motion information; the first candidate motion information is determined based on the first candidate motion information, the derived reference frame index, and the derived motion vector The corresponding pixel prediction value of the block to be processed.

In a possible design, the pixel prediction value of the block to be processed corresponding to the first candidate motion information is equal to the sum of absolute transformed difference (SATD) between the first prediction value and the second prediction value The smallest predicted value;

Wherein, the first prediction value is equal to the pixel prediction value of the block to be processed determined based only on the first candidate motion information, and the second prediction value is equal to the sum of the first weighted value and the second weighted value , The first weighting value is equal to the first prediction value multiplied by the first weighting value, and the second weighting value is equal to the pixel prediction value of the block to be processed determined based on the derived motion vector and the derived reference frame index Multiplied by the second weight value, the sum of the first weight value and the second weight value is equal to 1.

In a possible design, the first weight is equal to the second weight.

In one possible design, it also includes:

When the prediction direction is backward or bidirectional, the pixel prediction value of the image to be processed determined based only on the first candidate motion information is used as the pixel prediction value of the block to be processed corresponding to the first candidate motion information .

In a possible design, N candidate motion information including the first candidate motion information in the historical motion vector prediction queue, where N is an integer greater than or equal to 1, the method further includes:

Selecting the pixel prediction value with the smallest rate-distortion cost among the pixel prediction values respectively corresponding to the N candidate motion information;

Encode the second candidate motion information and index identifier corresponding to the pixel prediction value with the smallest rate-distortion cost into the code stream;

Wherein, when the pixel prediction value corresponding to the second candidate motion information is determined based on the second candidate motion information and the derived motion vector of the second candidate motion information, the index is identified as the first value;

When the pixel prediction value corresponding to the second candidate motion information is determined based only on the second candidate motion information, the index is identified as a second value.

In a possible design, the derived motion vector of the first candidate motion information satisfies the following conditions:

MV'=(d0'/d0)MV;

Wherein, MV' represents the derived motion vector of the first candidate motion information, d0' represents the distance between the derived reference frame and the current frame, d0 represents the distance between the reference frame and the current frame, and MV represents the candidate The motion vector of the coded block.

In a possible design, determining the derived reference frame index according to the reference frame index includes:

When the reference frame index is zero, the derived reference frame index is 1;

When the reference frame index is non-zero, the derived reference frame index is 0.

In a fourth aspect, an embodiment of the present application also provides a video image prediction device, including:

The entropy decoding unit is used to parse candidate motion information and index identification from the code stream. The candidate motion information includes the reference frame index of the block to be processed and the candidate motion vector identification, and the motion vector identification is used to indicate the to-be-processed block. The motion vector of the decoded block referenced by the block;

An inter prediction unit, configured to determine a derived reference frame index according to the reference frame index when the index is identified as a first value; based on the reference frame indicated by the reference frame index and the current frame where the block to be processed is located And the distance between the derived reference frame indicated by the derived reference frame index and the current frame, and the motion vector of the decoded block is scaled to obtain the derived motion vector of the candidate motion information ; Determine the pixel prediction value of the block to be processed based on the candidate motion information, the derived reference frame index and the derived motion vector.

In a possible design, the pixel prediction value of the to-be-processed block is equal to the sum of a first weighted value and a second weighted value, and the first weighted value is equal to the to-be-processed value determined based only on the candidate motion information. The pixel prediction value of the block is multiplied by a first weight value, and the second weight value is equal to the pixel prediction value of the block to be processed determined based on the derived motion vector and the derived reference frame index multiplied by the second weight value, The sum of the first weight and the second weight is equal to 1.

In a possible design, the first weight is equal to the second weight.

In a possible design, the inter-frame prediction unit is also used for:

When the index is identified as a second value, the pixel prediction value of the image to be processed is determined based only on the candidate motion information.

In a possible design, the derivative motion vector is obtained according to the following formula:

MV'=(d0'/d0)MV;

Wherein, MV' represents the derived motion vector, d0' represents the distance between the derived reference frame and the current frame, d0 represents the distance between the reference frame and the current frame, and MV represents the distance between the reference frame and the current frame. The motion vector of the decoded block.

In a possible design, the inter prediction unit is specifically configured to: when determining the derived reference frame index according to the reference frame index:

When the reference frame index is zero, it is determined that the derived reference frame index is 1; or,

When the reference frame index is non-zero, it is determined that the derived reference frame index is 0.

In a fifth aspect, an embodiment of the present application provides an image prediction device. The device includes: a processor and a memory coupled to the processor; the processor is configured to execute various aspects of the first aspect or the second aspect. Method in design.

In a sixth aspect, an embodiment of the present application provides an image prediction device, the device including a processor and a memory coupled to the processor; the processor is configured to execute the methods in various designs of the third aspect.

In a seventh aspect, an embodiment of the present application provides a video decoding device, including a non-volatile storage medium, and a processor, the non-volatile storage medium stores an executable program, and the processor is connected to the non-volatile storage medium. The lossy storage media are coupled with each other and execute the executable program to implement the methods in the first aspect or the second aspect or various implementation manners thereof.

In an eighth aspect, an embodiment of the present application provides a video encoding device, including a non-volatile storage medium and a processor, the non-volatile storage medium stores an executable program, and the processor is connected to the non-volatile storage medium. The lossy storage media are coupled with each other and execute the executable program to implement the method in the third aspect or various implementation manners thereof.

In a ninth aspect, an embodiment of the present application provides a computer-readable storage medium that stores instructions in the computer-readable storage medium, which when run on a computer, causes the computer to execute the first aspect or various implementations thereof The method in either executes the method in the second aspect or its various implementations, or executes the method in the third aspect or its implementations.

In a tenth aspect, an embodiment of the present application provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the method in the first aspect or its various implementations, or execute the second aspect or The methods in various implementation manners thereof, or the methods in the foregoing third aspect or various implementation manners thereof are executed.

It should be understood that the second to tenth aspects of the present application are the same as or similar to the first technical solution of the present application, and the beneficial effects achieved by all aspects and corresponding implementable design methods are similar, and will not be repeated.

Description of the drawings

FIG. 1A is a block diagram of an example of a video encoding and decoding system 10 used to implement an embodiment of the present application;

1B is a block diagram of an example of a video decoding system 40 used to implement an embodiment of the present application;

2 is a block diagram of an example structure of an encoder 20 used to implement an embodiment of the present application;

FIG. 3 is a block diagram of an example structure of a decoder 30 used to implement an embodiment of the present application;

4 is a block diagram of an example of a video decoding device 400 used to implement an embodiment of the present application;

Fig. 5 is a block diagram of another example of an encoding device or a decoding device for implementing an embodiment of the present application;

Fig. 6 is an exemplary schematic diagram of a motion vector and reference frame index used to implement an embodiment of the present application;

FIG. 7 is a schematic diagram of an HMVP queue update manner used to implement an embodiment of the present application;

FIG. 8 is another schematic diagram of an HMVP queue update manner used to implement an embodiment of the present application;

FIG. 9 is another schematic diagram of an HMVP queue update manner used to implement an embodiment of the present application;

FIG. 10 is a schematic flowchart of a video image prediction method used to implement an embodiment of the present application;

FIG. 11 is an exemplary schematic diagram for implementing a derivative motion vector generation of an embodiment of the present application;

FIG. 12 is a schematic flowchart of another video image prediction method used to implement an embodiment of the present application;

FIG. 13 is a schematic diagram of a device 1300 used to implement an embodiment of the present application;

FIG. 14 is a schematic diagram of a device 1400 used to implement an embodiment of the present application;

FIG. 15 is a schematic diagram of a device 1500 for implementing an embodiment of the present application.

detailed description

The embodiments of the present application will be described below in conjunction with 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 or specific aspects that can be used in 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 understood in a restrictive sense, and the scope of this application is defined by the appended claims. For example, it should be understood that the content disclosed in conjunction with the described method may be equally applicable to the corresponding device or system that executes the method, and vice versa. For example, if one or more specific method steps are described, the corresponding device may include one or more units such as functional units to perform the described one or more method steps (for example, 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 functional units, the corresponding method may include one step to perform the functionality of one or more units (for example, one step performs one or more units). The 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 can be combined with each other.

The technical solutions involved in the embodiments of the present application may not only be applied to existing video coding standards (such as H.264, HEVC, etc.), but may also be applied to future video coding standards (such as H.266). The terms used in the implementation mode part of this application are only used to explain specific embodiments of this application, and are not intended to limit this application. The following briefly introduces some concepts that may be involved in the embodiments of the present application.

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" can be used as synonyms. Video encoding used in this article means video encoding or video decoding. Video encoding is performed on the source side and usually includes processing (for example, by compressing) the original video picture to reduce the amount of data required to represent the video picture, so as to store and/or transmit more efficiently. Video decoding is performed on the destination side and usually includes inverse processing relative to the encoder to reconstruct the video picture. The “encoding” of video pictures involved in the embodiments should be understood as involving “encoding” or “decoding” of a video sequence. The combination of the encoding part and the decoding part is also called codec (encoding and decoding).

A video sequence includes a series of pictures, the pictures 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, there are macroblocks (MB) in the H.264 standard, and the macroblocks can be further divided into multiple prediction blocks (partitions) that can be used for predictive coding. In the high-efficiency video coding (HEVC) standard, basic concepts such as coding unit (CU), prediction unit (PU), and transform unit (TU) are used. Divide a variety of block units, and use a new tree-based description. For example, the CU can be divided into smaller CUs according to the quadtree, and the smaller CUs can be further divided to form a quadtree structure. The CU is a basic unit for dividing and encoding the coded image. The PU and TU also have a similar tree structure. The PU can correspond to a prediction block and is the basic unit of prediction 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, no matter CU, PU or TU, they all belong to the concept of block (or image block) in nature.

For example, in HEVC, a 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 in a PU, and relevant information is transmitted to the decoder on the basis of the PU. After the residual block is obtained by applying the prediction process based on the PU split type, the CU may be divided into transform units (TU) according to other quadtree structures similar to the coding tree used for the CU. In the latest development of video compression technology, quadtrees and binary trees (Quad-tree and Binary Tree, QTBT) are used to segment frames to segment coding blocks. In the QTBT block structure, the CU may have a square or rectangular shape.

Herein, for ease of description and understanding, the image block to be encoded in the currently encoded image may be referred to as the current block. For example, in encoding, it refers to the block currently being encoded; in decoding, it refers to the block currently being decoded. The decoded image block used to predict the current block in the reference image is called a reference block, that is, a reference block is a block that provides a reference signal for the current block, where the reference signal represents the pixel value in the image block. The block that provides the prediction signal for the current block in the reference image may be a prediction block, where the prediction signal represents the pixel value or sample value or sample signal in the prediction block. For example, after traversing multiple reference blocks, the best reference block is found. This best reference block will provide prediction for the current block, and 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 coding, for example, quantization performs further compression to reduce the amount of data required to represent the video picture, and the decoder side cannot completely reconstruct the video picture, that is, the quality of the reconstructed video picture is compared with the original video picture The quality is low or poor.

Several video coding standards of H.261 belong to "lossy hybrid video coding and decoding" (that is, 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 a set of non-overlapping blocks, which are usually coded at the block level. In other words, the encoder side usually processes at the block (video block) level, that is, encodes the video. For example, the prediction block is generated by spatial (intra-picture) prediction and temporal (inter-picture) prediction, from the current block (currently processed or to be processed). The processed block) is subtracted from the prediction block to obtain the residual block, the residual block is transformed in the transform domain and the residual block is quantized to reduce the amount of data to be transmitted (compressed), and the decoder side will be inversely processed relative to the encoder Partly applied to the coded or compressed block to reconstruct the current block for representation. In addition, the encoder duplicates the decoder processing loop, so that the encoder and the decoder generate the same prediction (for example, intra prediction and inter prediction) and/or reconstruction for processing, that is, to encode subsequent blocks.

The following describes the system architecture applied by the embodiments of the present application. 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. Therefore, the source device 12 may be referred to as a video encoding device. The destination device 14 can decode the encoded video data generated by the source device 12, and therefore, the destination device 14 can 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 desired program codes in the form of instructions or data structures accessible by a computer, as described herein. The source device 12 and the destination device 14 may include various devices, including desktop computers, mobile computing devices, notebook (for example, laptop) computers, tablet computers, set-top boxes, telephone handsets such as so-called "smart" phones. Computers, televisions, cameras, display devices, digital media players, video game consoles, on-board computers, wireless communication equipment, or the like.

Although FIG. 1A shows the source device 12 and the destination device 14 as separate devices, the device embodiment may also include the source device 12 and the destination device 14 or the functionality of both, that is, the source device 12 or the corresponding The functionality of the destination device 14 or the 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 the corresponding functionality and the destination device 14 or the corresponding functionality .

The source device 12 and the destination device 14 may communicate with each other via a link 13, and the destination device 14 may receive 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, such as 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 (e.g., 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, and optionally, the source device 12 may also include a picture source 16, a picture preprocessor 18, and a communication interface 22. In a specific implementation form, the encoder 20, the picture source 16, the picture preprocessor 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:

The picture source 16, which can include or can be any type of picture capture device, used for example to capture real-world pictures, and/or any type of pictures or comments (for screen content encoding, some text on the screen is also considered to be encoded Picture or part of an image) generating equipment, 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), and/or any combination thereof (for example, 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 (internal or external) interface for storing previously captured or generated pictures and/or acquiring or receiving pictures. When the picture source 16 is a camera, the picture source 16 may be, for example, a local or an integrated camera integrated in the source device; when the picture source 16 is a memory, the picture source 16 may be local or, for example, an integrated camera 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, such as It is an external computer graphics processor, computer or server. The interface can be any type of interface according to any proprietary or standardized interface protocol, such as a wired or wireless interface, and an optical interface.

Among them, 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 axis) 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, pictures can be represented as or contain three sample arrays. For example, in the RBG format or color space, a picture includes corresponding red, green, and blue sample arrays. However, in video coding, each pixel is usually expressed in luminance/chrominance format or color space. For example, for a picture in the YUV format, it includes the luminance component indicated by Y (sometimes indicated by L) and the two indicated by U and V. Chrominance components. The luma component Y represents brightness or gray level intensity (for example, the two are the same in a grayscale picture), and the two chroma components U and V represent chroma or color information components. Correspondingly, a picture in the YUV format includes a luminance sample array of luminance sample values (Y), and two chrominance sample arrays of chrominance values (U and V). Pictures in RGB format can be converted or converted to YUV format, and vice versa. This process is also called color conversion or conversion. If the picture is black and white, the picture may only include the luminance sample 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 preprocessor 18 is configured to receive the original picture data 17 and perform preprocessing on the original picture data 17 to obtain the preprocessed picture 19 or the preprocessed picture data 19. For example, the pre-processing performed by the picture pre-processor 18 may include trimming, color format conversion (for example, conversion from RGB format to YUV format), toning, or denoising.

The encoder 20 (or video encoder 20) is configured to receive the pre-processed picture data 19, and process the pre-processed picture data 19 using a relevant prediction mode (such as the prediction mode in the various embodiments herein), thereby The encoded picture data 21 is provided (the structure 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 implement the various embodiments described below to realize the application of the chrominance block prediction 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, so The other device can 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 also include a communication interface 28, a picture post 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, for example, a storage device, and the storage device is, for example, an encoded picture data storage device. The communication interface 28 can be used to transmit or receive the encoded picture data 21 via the link 13 between the source device 12 and the destination device 14 or via any type of network. The link 13 is, for example, a direct wired or wireless connection. The type of network is, for example, a wired or wireless network or any combination thereof, or any type of private network and public network, 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 can be configured as a one-way communication interface or a two-way communication interface, and can be used, for example, to send and receive messages to establish connections, confirm and exchange any other communication links and/or, for example, encoded picture data Information about the transmission of the transmitted data.

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 (below will further describe the decoder 30 based on FIG. 3 or FIG. 4 or FIG. 5 Structural details). In some embodiments, the decoder 30 may be used to implement the various embodiments described below to realize the application of the chrominance block prediction method described in this application on the decoding side.

The picture post 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 picture post-processor 32 may include: color format conversion (for example, conversion from YUV format to RGB format), toning, trimming or resampling, or any other processing, and can also be used to convert post-processed picture data 33 Transmission to display device 34.

The display device 34 is configured to receive the post-processed image data 33 to display the image to, for example, users or viewers. 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 shows the source device 12 and the destination device 14 as separate devices, the device embodiment may also include the source device 12 and the destination device 14 or the functionality of both, that is, the source device 12 or Corresponding functionality and 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 the corresponding functionality and the destination device 14 or the corresponding functionality .

It is obvious to those skilled in the art based on the description that the functionality of different units or the existence and (accurate) division of the functionality of the source device 12 and/or the destination device 14 shown in FIG. 1A may be different according to actual devices and applications. The source device 12 and the destination device 14 may include any of a variety of devices, including any types 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, vehicle-mounted 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 type 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 (digital signal processors, DSP), and application-specific integrated circuits (application-specific integrated circuits). circuit, ASIC), field-programmable gate array (FPGA), discrete logic, hardware, or any combination thereof. If the technology is partially implemented in software, the device can store the instructions of the software in a suitable non-transitory computer-readable storage medium, and can use one or more processors to execute the instructions in hardware to execute the technology of the present disclosure . Any of the foregoing (including hardware, software, a combination of hardware and software, etc.) can 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 this application can be applied to video encoding settings that do not necessarily include any data communication between encoding and decoding devices (for example, video encoding or video encoding). decoding). In other instances, the data can be retrieved from local storage, streamed on the network, etc. The video encoding device can encode data and store the data to the memory, and/or the video decoding device can retrieve the data from the memory and decode the data. In some instances, encoding and decoding are performed by devices that do not communicate with each other but only encode data to the memory and/or retrieve data from the 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 coding 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 47 of the processing unit 46), and 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 logic circuit 47, 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 encoder 20 and the decoder 30 are used to illustrate the video coding system 40, 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. In addition, in some examples, the display device 45 may be used to present video data. In some examples, the logic circuit 47 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 so on. The video decoding system 40 may also include an optional processor 43, and the optional processor 43 may similarly include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, and the like. In some examples, the logic circuit 47 can be implemented by hardware, such as dedicated video encoding hardware, and the processor 43 can be implemented by general software, an operating system, and the like. In addition, the memory 44 may be any type of memory, such as volatile memory (for example, static random access memory (Static Random Access Memory, SRAM), dynamic random access memory (Dynamic Random Access Memory, DRAM), etc.) or non-volatile memory. Memory (for example, flash memory, etc.), etc. In a non-limiting example, the memory 44 may be implemented by cache memory. In some instances, the logic circuit 47 may access the memory 44 (e.g., to implement an image buffer). In other examples, the logic circuit 47 and/or the processing unit 46 may include a memory (e.g., cache, etc.) for implementing image buffers and the like.

In some examples, the encoder 20 implemented by logic circuits may include an image buffer (e.g., implemented by the processing unit 46 or the memory 44) and a graphics processing unit (e.g., 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 a logic circuit 47 to implement 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 circuit 47 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 instances, the decoder 30 implemented by logic circuits may include an image buffer (implemented by the processing unit 2820 or the memory 44) and a graphics processing unit (implemented by the processing unit 46, for example). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include a decoder 30 implemented by a logic circuit 47 to implement the various modules discussed with reference to FIG. 3 and/or any other decoder system or subsystem 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, indicators, index values, mode selection data, etc., related to the encoded video frame discussed herein, such as data related to encoded partitions (e.g., transform coefficients or quantized transform coefficients). , (As discussed) optional indicators, and/or data defining code partitions). 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, for the example described with reference to the encoder 20 in the embodiments of the present application, the decoder 30 may be used to perform the reverse process. Regarding signaling syntax elements, the decoder 30 can be used to receive and parse such syntax elements, and decode related video data accordingly. In some examples, the encoder 20 may entropy encode the syntax elements into an encoded video bitstream. In such instances, the decoder 30 may parse such syntax elements and decode related video data accordingly.

It should be noted that the method described in the embodiment of the present application is mainly used for the inter-frame prediction process. This process exists in both the encoder 20 and the decoder 30. The encoder 20 and the decoder 30 in the embodiment of the present application may be, for example, H .263, H.264, HEVV, MPEG-2, MPEG-4, VP8, VP9 and other video standard protocols or next-generation video standard protocols (such as H.266, etc.) corresponding to the codec/decoder.

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 transformation processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transformation processing unit 212, a reconstruction unit 214, a buffer 216, and a loop filter. Unit 220, a decoded picture buffer (DPB) 230, a prediction processing unit 260, and an entropy coding 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, and for example, the inverse quantization unit 210, the inverse transform processing unit 212, and the The structure unit 214, the buffer 216, the loop filter 220, the decoded picture buffer (DPB) 230, and the prediction processing unit 260 form the backward signal path of the encoder, wherein the backward signal path of the encoder corresponds to The signal path of the decoder (see decoder 30 in Figure 3).

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

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

Like the picture 201, the 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 that of the picture 201. In other words, the image block 203 may include, for example, one sample array (for example, a luminance array in the case of a black and white picture 201) or three sample arrays (for example, one luminance array and two chrominance arrays in the case of a color picture) or Any other number and/or type of array 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 configured 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 predicted to obtain the residual block 205 in the sample domain.

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

The transform processing unit 206 may be used to apply an integer approximation of DCT/DST, such as a transform specified for HEVC/H.265. 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 transformation, an additional scaling factor is applied as part of the transformation process. The scaling factor is usually selected based on certain constraints. For example, the scaling factor is a trade-off between the power of 2 used for the shift operation, the bit depth of the transform coefficient, accuracy, and implementation cost. For example, on the decoder 30 side, for example, the inverse transformation processing unit 212 for the inverse transformation (and on the encoder 20 side, for example, the inverse transformation processing unit 212 for the corresponding inverse transformation) designate a specific scaling factor, and accordingly, the encoder The 20 side uses the transformation processing unit 206 to specify a corresponding scaling factor for the positive transformation.

The quantization unit 208 is used to quantize the transform coefficient 207 by applying scalar quantization or vector quantization, for example, 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 the quantization parameter (QP). For example, for scalar quantization, different scales can be applied to achieve finer 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 a quantization parameter (QP). For example, the quantization parameter may be an index of a predefined set of suitable quantization steps. For example, a smaller quantization parameter can correspond to fine quantization (smaller quantization step size), and a larger quantization parameter can correspond to coarse quantization (larger quantization step size), and vice versa. Quantization may include division by a quantization step size and corresponding quantization or inverse quantization performed by, for example, inverse quantization 210, or may include multiplication by a quantization step size. Embodiments according to some standards such as HEVC may use quantization parameters to determine the quantization step size. In general, the quantization step size can be calculated based on the quantization parameter using a fixed-point approximation of an equation including 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 equation for the quantization step size and the quantization parameter. In an example embodiment, the scales 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, for example, a bitstream. Quantization is a lossy operation, where the larger the quantization step, the greater the loss.

The inverse quantization unit 210 is configured to apply the inverse quantization of the quantization unit 208 on the quantized coefficients to obtain the inverse quantized coefficients 211, for example, based on or use the same quantization step size as the quantization unit 208, and apply the quantization scheme applied by the quantization unit 208 The inverse quantification scheme. The inversely quantized coefficient 211 may also be referred to as the inversely quantized residual coefficient 211, which corresponds to the transform coefficient 207, although the loss due to quantization is usually different from the transform coefficient.

The inverse transform processing unit 212 is configured to apply the inverse transform of the transform applied by the transform processing unit 206, for example, an inverse discrete cosine transform (DCT) or an inverse discrete sine transform (DST), so as to be in the sample domain Obtain the inverse transform block 213. The inverse transformation block 213 may also be referred to as an inverse transformation and inverse quantization block 213 or an inverse transformation residual block 213.

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

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

For example, the embodiment of the encoder 20 may be configured such that the buffer unit 216 is used not only for storing 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, make the buffer unit 216 and the decoded picture buffer unit 230 form one buffer. Other embodiments may be used to use the filtered block 221 and/or blocks or samples from the decoded picture buffer 230 (none of which are shown in Figure 2) as the input or basis for the intra prediction 254.

The loop filter unit 220 (or "loop filter" 220 for short) is used to filter the reconstructed block 215 to obtain the filtered block 221, thereby smoothly performing pixel conversion or improving 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, auto 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 a filtered reconstructed block 221. The decoded picture buffer 230 may store the reconstructed coded block after the loop filter unit 220 performs a filtering operation on the reconstructed coded block.

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

The decoded picture buffer (DPB) 230 may be a reference picture memory that stores 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 (DRAM) (including synchronous DRAM (SDRAM), 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 a separate memory device. 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 the previously reconstructed picture, such as the previously reconstructed and filtered block 221, and may provide a complete previous Reconstruction is a decoded picture (and corresponding reference blocks and samples) and/or a partially reconstructed current picture (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 obtain the image block 203 (the current image block 203 of the current picture 201) and reconstructed picture data, such as the same (current) picture from the buffer 216 The reference samples and/or the 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, it can be provided as an inter-predicted block 245 or a The prediction block 265 of the intra prediction block 255.

The mode selection unit 262 may be used to select a prediction mode (for example, 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.

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

The prediction processing performed by an example of the encoder 20 (for example, by the prediction processing unit 260) and the mode selection performed (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 a set of (predetermined) prediction modes. The prediction mode set may include, for example, an intra prediction mode and/or an inter prediction mode.

The set of intra prediction modes 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-frame prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in H.266 under development.

In a possible implementation, the set of inter prediction modes depends on the available reference pictures (ie, for example, the aforementioned at least part of the decoded pictures stored in the DBP230) and other inter prediction parameters, such as whether to use the entire reference picture or only use A part of the reference picture, such as 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, The set of inter prediction modes may include, for example, an advanced motion vector (Advanced Motion Vector Prediction, AMVP) mode and a merge mode. In specific implementation, the set of inter-frame prediction modes may include an improved AMVP mode based on control points in the embodiments of the present application, and an improved merge mode based on control points. 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) segmentation and binary-tree (BT) segmentation. Or triple-tree (TT) segmentation, or any combination thereof, and used to perform prediction, for example, for each of the block partitions or sub-blocks, where the mode selection includes selecting the tree structure of the segmented image block 203 and selecting the application The prediction mode for 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 obtain the picture image block 203 (the current picture image block 203 of the current picture 201) and the 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 the reference picture and/or provide a reference to the 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 obtain inter prediction parameters, and perform inter prediction based on or using the inter prediction parameters to obtain the inter prediction block 245. The motion compensation performed by the motion compensation unit (not shown in FIG. 2) may include fetching or generating a prediction block based on a motion/block vector determined by motion estimation (interpolation of sub-pixel accuracy may be performed). Interpolation filtering can generate additional pixel samples from known pixel samples, thereby 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 can locate the prediction block pointed to by the motion vector in a reference picture list. The motion compensation unit 246 may also generate syntax elements associated with the block and the video slice for use by the decoder 30 when decoding the picture block of the video slice.

Specifically, the aforementioned inter-prediction unit 244 may transmit syntax elements to the entropy encoding unit 270, where the syntax elements include inter-prediction parameters (for example, after traversing multiple inter-prediction modes, the inter-prediction mode selected for prediction of the current block is selected). Instructions). In a possible application scenario, if there is only one inter-frame prediction mode, then the inter-frame prediction parameters may not be carried in the syntax element. In this case, the decoder 30 can 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 obtain, for example, receive the picture block 203 (current picture block) of the same picture and one or more previously reconstructed blocks, for example reconstructed adjacent 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.

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

The intra prediction unit 254 is further configured to determine the intra prediction block 255 based on the intra prediction parameters of the selected intra prediction mode. In any case, after selecting the intra prediction mode for the block, the intra prediction unit 254 is also used to provide the entropy coding unit 270 with intra prediction parameters, 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 aforementioned intra-prediction unit 254 may transmit syntax elements to the entropy encoding unit 270, where the syntax elements include intra-prediction parameters (for example, after traversing multiple intra-prediction modes and selecting the intra-prediction mode used for prediction of the current block) Instructions). In a possible application scenario, if there is only one intra prediction mode, the intra prediction parameter may not be carried in the syntax element. In this case, the decoder 30 can directly use the default prediction mode for decoding.

The entropy coding unit 270 is used to apply 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 partitioning entropy (PIPE) coding or other entropy Coding method or technique) applied to quantized residual coefficients 209, inter-frame prediction parameters, intra-frame prediction parameters, and/or loop filter parameters, or all of them (or not applied), to obtain data that can be output by output 272 For example, encoded picture data 21 output in the form of encoded bitstream 21. The encoded bitstream can 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 variants of the video encoder 20 can be used to encode video streams. For example, the non-transform-based encoder 20 can 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 inter-frame prediction method described in the following embodiments.

It should be understood that other structural changes of the video encoder 20 can 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 does not need to be processed 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 The reconstructed image block is directly stored as a reference block without being processed by the filter 220; or, the quantization unit 208 and the inverse quantization unit 210 in the video encoder 20 may be combined together. The loop filter 220 is optional, and for lossless compression coding, the transform processing unit 206, the quantization unit 208, the inverse quantization unit 210, and the inverse transform processing unit 212 are optional. It should be understood that, according to different application scenarios, the inter prediction unit 244 and the intra prediction unit 254 may be selectively activated.

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, for example, encoded picture data (for example, an encoded bit stream) 21 encoded by the encoder 20 to obtain a 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 that represent picture blocks of an 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, and 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 decoding passes that are substantially reciprocal of the encoding passes described with video encoder 20 of FIG. 2.

The entropy decoding unit 304 is configured 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 , Loop filter parameters and/or any one or all of other syntax elements (decoded). The entropy decoding unit 304 is further configured to forward the inter prediction parameters, intra prediction parameters, and/or other syntax elements to the prediction processing unit 360. The video decoder 30 may receive syntax elements at the video slice level and/or the video block level.

The inverse quantization unit 310 can be functionally the same as the inverse quantization unit 110, the inverse transformation processing unit 312 can be functionally the same as the inverse transformation processing unit 212, the reconstruction unit 314 can be functionally the same as the reconstruction unit 214, and the buffer 316 can be functionally identical. 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. The inter prediction unit 344 may be functionally similar to the inter prediction unit 244, and the intra prediction unit 354 may be functionally similar to the intra prediction unit 254. . The prediction processing unit 360 is generally used to perform block prediction and/or obtain a prediction block 365 from the encoded data 21, and to receive or obtain (explicitly or implicitly) prediction-related parameters and/or related parameters from, for example, the entropy decoding unit 304. Information about the selected prediction mode.

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

The prediction processing unit 360 is configured to determine prediction information for a video block of the current video slice by parsing motion vectors and other syntax elements, and use the prediction information to generate a 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 (for example, intra or inter prediction) and the inter prediction slice type (for example, intra or inter prediction) of the video block used to encode the video slice ( For example, B slice, P slice or GPB slice), construction information for one or more of the reference picture list for the slice, motion vector for each inter-coded video block of the slice, 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 (APS), a sequence parameter set (SPS), and a picture parameter set (picture parameter set). parameter set, PPS) or a syntax element in one or more of the slice 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 parameter 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 (for example, an inverse DCT, an inverse integer transform, or a conceptually similar inverse transform process) to transform coefficients in order to generate a residual block in the pixel domain.

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

The loop filter unit 320 (during or after the encoding cycle) is used to filter the reconstructed block 315 to obtain the filtered block 321, so as 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 the filtering techniques described below. The loop filter unit 320 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, auto Adaptive loop filter (ALF), or sharpening or smoothing filter, or collaborative filter. 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 or viewing by the user.

Other variants of the video decoder 30 can be used to decode the compressed bitstream. For example, the decoder 30 may generate an 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 inter-frame prediction method described in the following embodiments.

It should be understood that other structural changes of the video decoder 30 can 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 some 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 for 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 activated.

It should be understood that in the encoder 20 and decoder 30 of the present application, the processing result 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, perform operations such as Clip or shift on the processing result of the corresponding link.

For example, the motion vector of the control point of the current image block derived from the motion vector of the adjacent affine coding block may undergo further processing, which is not limited in this application. For example, restrict the value range of the motion vector to make it within a certain bit width. Assuming that the bit width of the allowed motion vector is bitDepth, the range of the motion vector is -2^(bitDepth-1)~2^(bitDepth-1)-1, where the "^" symbol represents the power. If bitDepth is 16, the value range is -32768～32767. If bitDepth is 18, the value range is -131072～131071. It can be restricted in the following two ways:

Method 1, remove the high bits of the motion vector overflow:

ux=(vx+2 ^bitDepth )%2 ^bitDepth

vx=(ux>=2 ^bitDepth-1 )? (ux-2 ^bitDepth ):ux

uy=(vy+2 ^bitDepth )%2 ^bitDepth

vy=(uy>=2 ^bitDepth-1 )? (uy-2 ^bitDepth ):uy

For example, the value of vx is -32769, and the value obtained by the above formula is 32767. Because in the computer, the value is stored in the form of two's complement, the two's complement of -32769 is 1,0111,1111,1111,1111 (17 bits), the computer's handling of overflow is to discard the high bits, then the value of vx If it is 0111,1111,1111,1111, it is 32767, which is consistent with the result obtained by formula processing.

Method 2, Clipping the motion vector, as shown in the following formula:

vx=Clip3(-2 ^bitDepth-1 ,2 ^bitDepth-1 -1,vx)

vy=Clip3(-2 ^bitDepth-1 ,2 ^bitDepth-1 -1,vy)

The definition of Clip3 is, which means that the value of z is clamped to the interval [x, y]:

Refer to FIG. 4, which 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 device 400 is suitable for implementing the embodiments described herein. In one embodiment, the video coding device 400 may be a video decoder (for example, the decoder 30 of FIG. 1A) or a video encoder (for example, the encoder 20 of FIG. 1A). In another embodiment, the video coding device 400 may be one or more components of the decoder 30 of FIG. 1A or the encoder 20 of FIG. 1A described above.

The video decoding device 400 includes an entry port 410 and a receiver (Rx) 420 for receiving data, a processor, logic unit or central processing unit (CPU) 430 for processing data, and a transmitter ( Tx) 440 and outlet 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 with the inlet port 410, the receiver 420, the transmitter 440, and the outlet port 450 for the outlet or inlet of optical or electrical signals.

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 ingress port 410, the receiver 420, the transmitter 440, the egress 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 chroma block prediction method provided in 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 by 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, and storing 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 as a decoding device 500 for short) according to an embodiment of the 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 by a bus system, the memory is used to store instructions, and the processor is used to execute instructions stored in the memory. The memory of the decoding device stores program codes, and the processor can call the program codes stored in the memory to execute various video encoding or decoding methods described in this application, especially various new inter-frame methods. In order to avoid repetition, it will not be described in detail here.

In the embodiment of the present application, the processor 510 may be a central processing unit (Central Processing Unit, referred to as "CPU"), and the processor 510 may also be other general-purpose processors, digital signal processors (DSP), and dedicated integration Circuit (ASIC), 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 also be any conventional processor or the like.

The memory 530 may include a read only memory (ROM) device or a random access memory (RAM) device. Any other suitable type of storage device can 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. The application program 535 includes at least one program that allows the processor 510 to execute the video encoding or decoding method described in this application (especially the inter prediction method described in this 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) that executes 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 clear description, various buses are marked as the bus system 550 in the figure.

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

At this stage, the video coding and decoding technology mainly adopts a hybrid coding architecture, which uses the correlation of video sequences in space and time dimensions to remove a large amount of redundant information in the video signal to be transmitted. The hybrid coding framework mainly includes two parts: predictive coding and transform coding. Predictive coding uses the coded pixels to predict the pixel currently being coded, and then calculates the residual between the predicted value and the true value, and then encodes and transmits the residual. The core of predictive coding lies in the calculation of MV (motion vector) and the selection of the index of the reference frame in the reference list. MV and reference frame index are shown in Figure 6. At this stage, different types of MVs (motion vectors) and reference lists are obtained based on the types of coded frames and different reference modes. Transform coding refers to the image described in the spatial domain through a specific transformation kernel (such as discrete cosine transform, Hadamard transform, etc.) to obtain transform coefficients, so as to achieve the purpose of changing the data distribution and further reducing the amount of data. The inter-frame prediction involved in this application uses predictive coding.

The inter-frame prediction in this embodiment of the application is historical motion vector prediction (History-based Motion Vector Prediction HMVP).

In the current inter-frame prediction process, the candidate motion vector list or the candidate motion vector predictor list of the current codec block can be constructed according to the motion information of the reconstructed block that is encoded or decoded before the current codec block, that is, the HMVP list. The HMVP list stores candidate motion information in the form of a queue. The candidate motion information includes information such as the MV of the coded unit, the prediction direction, and the reference frame index. Generally, the maximum length of the HMVP queue is set to 13. The first 5 candidate motion information in the HMVP queue respectively represent the motion information corresponding to the five modes of time domain skip (skip), B frame forward, B frame backward, B frame bidirectional, and B frame symmetry. When predicting the pixel value of a block to be processed, all candidate motion information is traversed from the HMVP queue of the block to be processed and the RDO is calculated, and the motion information represented by the smallest RDO is selected as the motion information of the block to be processed.

It should be noted that HMVP is only used in skip/direct mode.

In addition, when the motion information of an encoded unit is added to the HMVP queue, HMVP will continuously update the candidate motion information in the HMVP queue. The update rules of candidate motion information in the queue are as follows:

1. If the length of the HMVP queue does not reach the upper limit of the preset maximum length, and the motion information is different from the candidate motion information in the HMVP queue, the motion information is stored at the end of the HMVP queue, as shown in Figure 7.

2. If the motion information is the same as the candidate motion information that already exists in the HMVP queue, regardless of whether the length of the HMVP queue has reached the upper limit of the preset maximum length of the HMVP queue, remove the candidate motion that already exists in the HMVP queue with the same motion information Information, and store the motion information at the end of the HMVP queue as candidate motion information, as shown in Figure 8.

3. If the number of candidate motion information in the HMVP queue reaches or exceeds the preset maximum length limit, regardless of whether the motion information is the same as the candidate motion information in the HMVP queue, the FIFO principle is used to remove the candidate motion information that already exists in the HMVP queue. And store the motion information at the end of the HMVP queue as candidate motion information, as shown in Figure 9, remove HMVP0 in the HMVP queue, move HMVP1-HMVPL-1 to the left in turn, and add the motion information HMVP candidates to be added Added at the end of the HMVP queue.

For P frames, it can only refer to the motion information of the coded blocks of the forward reference frame. When the HMVP queue eliminates candidate motion information, it may eliminate the motion information that can be used for P frames, resulting in pending processing for P frames When the block is subjected to inter-frame prediction, there is less motion information that can be referred to, resulting in lower prediction accuracy. In addition, the pixel value of the current block to be processed estimated from the motion information existing in the HMVP queue may not be the optimal motion information, and there is still room for improvement in motion information extraction.

In order to improve the prediction accuracy, the embodiment of the application provides a video image prediction method and device. On the basis that the HMVP technology has obtained a queue containing multiple motion information, the embodiment of the application requires that the HMVP queue meets specific requirements (such as currently waiting The reference direction of the processing block is forward) for each candidate motion information, and an additional motion information is derived to provide more candidate motion information.

The following first describes the solution provided by the embodiment of the present application in detail from the encoding end.

Refer to FIG. 10, which is a schematic flowchart of a video image prediction method provided by an embodiment of this application. The method may be executed by a video image prediction device. For example, the video image prediction device may be the encoder 20 shown in FIG. Either the inter prediction unit 244 in the encoder 20, or one or more processors capable of performing encoding, or a chip or a chip system.

For example, HMVP includes N candidate motion vectors, and the video image prediction device traverses each candidate motion vector included in the HMVP queue, and specifically executes the following process:

S1001. Obtain first candidate motion information from the historical motion vector prediction queue corresponding to the block to be processed, where the first candidate motion information includes the prediction direction of the candidate coded block, the reference frame index of the block to be processed, and the coded candidate The motion vector of the block.

Wherein, the first candidate motion information is one in the historical motion vector prediction queue, for example, it may be one candidate motion information traversed by the video image prediction device.

Exemplarily, the first candidate motion information is obtained from the historical motion vector prediction queue corresponding to the block to be processed, that is, the first candidate motion information corresponding to the currently traversed index is obtained from the HMVP corresponding to the block to be processed.

After the first candidate motion information is acquired, it is determined whether to perform the derivation process according to the prediction direction of the candidate encoded block included in the first candidate motion information.

S1002: When the prediction direction is forward and the number of reference frames included in the reference frame list corresponding to the to-be-processed block is greater than 1, determine a derived reference frame index according to the reference frame index.

As an example, the relationship between the reference frame index and the derived reference frame index is:

If the current reference frame index is 0, then the derived reference frame index is 1; or,

If the current reference frame index is not 0, then the derived reference frame index is 0.

Exemplarily, the inter prediction mode adopted by the block to be processed is skip mode or direct mode.

In a feasible example, if the inter-frame prediction mode adopted by the to-be-processed block is not skip mode and direct mode, the derivation process is not executed, and only the image to be processed determined based on the first candidate motion information The pixel prediction value is used as the pixel prediction value of the block to be processed corresponding to the first candidate motion information.

S1003, based on the distance between the reference frame indicated by the reference frame index and the current frame where the block to be processed is located, and the distance between the derived reference frame indicated by the derived reference frame index and the current frame, The motion vector included in the first candidate motion information is scaled to obtain a derived motion vector of the first candidate motion information.

It should be noted that the distance between different frames is defined as: the absolute position of the current frame in the video sequence minus the absolute position of the reference frame in the video sequence is the distance between the current frame and the reference frame.

S1004: Determine a pixel prediction value of the block to be processed corresponding to the first candidate motion information based on the first candidate motion information, the derived reference frame index, and the derived motion vector.

An example of an implementation manner of determining the pixel prediction value of the block to be processed corresponding to the first candidate motion information is as follows:

Determine the pixel prediction value of the block to be processed according to the first candidate motion information, which is called the first prediction value for the convenience of description; determine the pixel prediction value of the block to be processed according to the derived motion vector and the derived reference frame index, for the convenience of description, Is the predicted value of the derived pixel, and then determine the sum of the first predicted value multiplied by the first weight and the derived pixel predicted value multiplied by the second weight as the second predicted value, and the SATD value in the first predicted value and the second predicted value The smallest predicted value is used as the pixel predicted value of the block to be processed corresponding to the first candidate motion information.

In a feasible example, it can also include:

S1005: When the prediction direction is backward or bidirectional, (without performing the derivation process), use the pixel prediction value of the image to be processed determined based only on the first candidate motion information as the all corresponding to the first candidate motion information. The pixel prediction value of the block to be processed.

In another feasible example, it may further include:

S1006: When the number of reference frames included in the reference frame list corresponding to the block to be processed is equal to 1, (the derivation process is not performed), the pixel prediction value of the image to be processed determined based only on the first candidate motion information is taken as The pixel prediction value of the block to be processed corresponding to the first candidate motion information.

Exemplarily, refer to FIG. 11 for an example of a method for determining a derived motion vector.

After obtaining the derived reference frame index, the derived motion vector can be further calculated. Exemplarily, it can be implemented in the following manner:

Assuming that the distance between the derived reference frame and the current frame is d0', and the distance between the reference frame of the first candidate motion information and the current frame is d0, then the derived motion vector is encoded with the first candidate motion information in the HMVP queue The derived scale coefficient of the motion vector of the block is d0'/d0. Based on this, it is determined that the derived motion vector is MV'=(d0'/d0)MV.

Exemplarily, after determining the derived motion vector, the to-be-processed corresponding to the first candidate motion information may be determined according to the first candidate motion information, the derived reference frame index, and the derived motion vector in the following manner Pixel prediction value of the block:

Based on the above-mentioned derived motion vector and derived reference frame index, a new pixel prediction value can be obtained, for example, the derived pixel prediction value pred0'. The pixel prediction value of the block to be processed determined based on the first candidate motion information is referred to as the first prediction value pred0, for example. The weighted sum of the predicted value based on the derivative pixel and the first predicted value is called the second predicted value. The two predicted values (the first predicted value and the second predicted value) are used to calculate the corresponding SATD values and compare the SATD values. The prediction value with the smallest SATD value is used as the pixel prediction value of the block to be processed corresponding to the first candidate motion information.

Exemplarily, the second predicted value is equal to the derived pixel predicted value multiplied by the second weight value (may be referred to as the second weighted value), and the first predicted value multiplied by the first weighted value (may be referred to as the first weighted value) with. The sum of the first weight value and the second weight value is equal to 1, for example, the first weight value=the second weight value=0.5.

In this embodiment of the application, after the pixel value corresponding to the candidate motion information in the HMVP queue is determined by the above method, the pixel prediction value with the smallest rate distortion cost among the pixel prediction values corresponding to the N candidate motion information can be selected, and the rate distortion The second candidate motion information and the index identifier corresponding to the pixel prediction value with the least cost are incorporated into the bitstream. Wherein, when the pixel prediction value corresponding to the second candidate motion information is determined based on the second candidate motion information and the derived motion vector of the second candidate motion information, that is, the pixel prediction value corresponding to the second candidate motion information is determined by executing The derivation operation determines that the index is identified as the first value; when the pixel prediction value corresponding to the second candidate motion information is determined only based on the second candidate motion information, that is, the pixel prediction value corresponding to the second candidate motion information It is not determined by performing a derivative operation, and the index is identified as the second value. For example, the first value is 1, and the second value is 0. In the following description, the first value is 1 and the second value is 0 as an example.

As an example, when selecting the pixel prediction value with the smallest rate-distortion cost among the pixel prediction values corresponding to the N candidate motion information, and determining the index identifier, it can be implemented in the following manner:

The first method is to use the method of updating while traversing. For example, HMVP includes N candidate motion information, respectively HMVP0-HMVPN-1. This is achieved in the manner shown in Figure 10.

Here is an example of traversing two HMVP0 and HMVP1:

A1, traverse to HMVP0 in the HMVP queue, and determine whether HMVP0 performs a derivative operation. If yes, perform A2, if not, predict the pixel prediction value of the block to be processed based on HMVP0 as pred0[0].

A2: Use two kinds of motion information to respectively predict the pixel prediction value of the processing block, and calculate SATD according to the two prediction values, and compare the magnitude of the two SATD values:

Specifically, HMVP0 calculates the pixel prediction value as pred0[0]. Then use the HMVP0 to derive new movement information. Finally, the pixel prediction value is calculated through the derived motion information, and weighted and summed with pred0[0], as the new pixel prediction value pred0[1]. Calculate the SATD values SATD0[0] and SATD0[1] corresponding to the pixel prediction values pred0[0] and pred0[1], respectively.

A3: Determine the pixel prediction value of the block to be processed according to the SATD value, and assign the index flag Flag.

For example, if SATD0[0]≤SATD0[1], the pixel prediction value is pred0[0], that is, no derivative operation is used, and Flag is set to 0; if SATD0[0]>SATD0[1], the pixel prediction value is pred0[ 1], that is, the derivative operation is adopted, and Flag is set to 1.

As an example, taking Flag as 1 as an example, continue to traverse HMVP1 in the above manner.

For example, the pixel prediction value corresponding to HMVP1 is pred1[1], that is, the derivative operation is used as an example, if it is determined that the pixel prediction value pred0[1] corresponding to HMVP0 and the pixel prediction value pred1[1] corresponding to HMVP1 have the smallest rate distortion cost If the predicted value is pred1[1], the Flag value remains unchanged, and it is still 1, continue to traverse the next HMVP2, and so on, and for HMVP2, when performing comparisons, determine the pixel predicted values pred0[1] and HMVP1 corresponding to HMVP0 Among the corresponding pixel predicted values pred1[1], the predicted value pred1[1] with the smallest rate-distortion cost is compared. If it is determined that the prediction value of the pixel prediction value pred0[1] corresponding to HMVP0 and the prediction value of the pixel prediction value pred1[1] corresponding to HMVP1 is pred0[1], then the Flag value remains unchanged and remains 1, so continue to traverse. One HMVP2, and when performing comparison for HMVP2, compare the pixel prediction value pred0[1] corresponding to the determined HMVP0 and the pixel prediction value pred1[1] corresponding to HMVP1 among the prediction value pred0[1] with the smallest rate-distortion cost.

For example, the pixel prediction value corresponding to HMVP1 is pred1[0], that is, the derivative operation is not used as an example. If it is determined that the pixel prediction value pred0[1] corresponding to HMVP0 and the pixel prediction value pred0[1] corresponding to HMVP1 have the least rate distortion cost The predicted value of is pred1[0], then the Flag value is updated, updated to 0, and continues to traverse the next HMVP2, and so on. And when performing comparison for HMVP2, the pixel prediction value pred0[1] corresponding to the determined HMVP0 and the pixel prediction value pred1[1] corresponding to HMVP1 are compared with the prediction value pred1[0] with the smallest rate-distortion cost.

The second way is: after the traversal of the N candidate motion information included in the HMVP queue is completed, an index identifier is assigned. For example, it is determined that the predicted value of the pixel prediction value corresponding to HMVP0-HMVPN-1 with the smallest rate-distortion cost is HMVPk. If the pixel prediction value corresponding to HMVPk does not use a derivative operation, the index identifier is assigned a value of 0. If a derivative operation is used, the index The identification value is 1.

Exemplarily, after determining the second candidate motion information and the index identifier, the second candidate motion information (or the identifier of the second candidate motion information) and the index identifier are transmitted to the decoding side.

The video image prediction method provided in the embodiments of the present application will be described in detail below from the decoding side. The inventive concept adopted by the decoding side and the encoding side is similar, and the repetition will not be repeated. For details, refer to the relevant description on the encoding side.

Refer to FIG. 12, which is a schematic flowchart of a video image prediction method provided by an embodiment of the present application corresponding to the decoding side. The method can be performed by a video image prediction device. For example, the video image prediction device can be the encoder 30 shown in FIG. 3, or the inter prediction unit 344 in the encoder 30, or one or more capable of performing decoding. Processor, or chip or chip system.

S1201: Determine candidate motion information and an index identifier, where the candidate motion information includes a reference frame index of the block to be processed and a candidate motion vector identifier, and the motion vector identifier is used to indicate the motion of the decoded block referenced by the block to be processed Vector.

It should be noted that, if it corresponds to the coding side, the candidate motion information here is the second candidate motion information.

Exemplarily, the determination of the candidate motion information and the index identifier may be performed by the entropy decoding unit to parse the candidate motion information and the index identifier from the code stream, and then transmit the candidate motion information and the index identifier to the video image prediction device.

S1202: When the index identifier is a first value, determine a derived reference frame index according to the reference frame index.

S1203, based on the distance between the reference frame indicated by the reference frame index and the current frame where the block to be processed is located, and the distance between the derived reference frame indicated by the derived reference frame index and the current frame, The motion vector of the decoded block is scaled to obtain a derived motion vector of the candidate motion information.

S1204: Determine a pixel prediction value of the block to be processed based on the candidate motion information, the derived reference frame index, and the derived motion vector.

An example of an implementation manner of determining the pixel prediction value of the block to be processed is as follows:

The pixel prediction value of the block to be processed is determined according to the candidate motion information, which is called the first prediction value for the convenience of description; the pixel prediction value of the block to be processed is determined according to the derived motion vector and the derived reference frame index, which is called Is the derived pixel predicted value, and then the sum of the first predicted value multiplied by the first weight and the derived pixel predicted value multiplied by the second weight is determined as the pixel predicted value of the block to be processed.

Based on this, the pixel prediction value of the to-be-processed block is equal to the sum of a first weighted value and a second weighted value, and the first weighted value is equal to the pixel-predicted value of the to-be-processed block determined based only on the candidate motion information Multiplied by the first weight, the second weight is equal to the pixel prediction value of the block to be processed determined based on the derived motion vector and the derived reference frame index multiplied by the second weight, the first weight The sum of the value and the second weight is equal to 1. For example, the first weight=the second weight=0.5.

In a feasible example, it can also include:

S1205: When the index is identified as a second value, determine the pixel prediction value of the image to be processed based only on the candidate motion information.

Exemplarily, the derivative motion vector is obtained according to the following formula:

MV'=(d0'/d0)MV;

Wherein, MV' represents the derived motion vector, d0' represents the distance between the derived reference frame and the current frame, d0 represents the distance between the reference frame and the current frame, and MV represents the distance between the reference frame and the current frame. The motion vector of the decoded block.

Exemplarily, determining the derived reference frame index according to the reference frame index can be implemented in the following manner: when the reference frame index is zero, the derived reference frame index is 1; when the reference frame index is non-zero When the time, the derived reference frame index is 0.

Based on the same inventive concept as the foregoing method, as shown in FIG. 13, an embodiment of the present application further provides a device 1300 including an entropy decoding unit 1301 and an inter prediction unit 1302. The device 1300 may specifically be a processor in a video decoder, or a chip or a chip system, or one or more modules in a video decoder.

The entropy decoding unit 1301 is used to parse candidate motion information and index identifiers from the code stream. The candidate motion information includes the reference frame index of the block to be processed and the candidate motion vector identifier, and the motion vector identifier is used to indicate the to-be-processed block. The motion vector of the decoded block referenced by the processing block;

The inter prediction unit 1302 is configured to determine a derived reference frame index according to the reference frame index when the index is identified as a first value; based on the reference frame indicated by the reference frame index and the current block where the block to be processed is located The distance between frames, and the distance between the derived reference frame indicated by the derived reference frame index and the current frame, and the motion vector of the decoded block is scaled to obtain the derived motion of the candidate motion information Vector; determining the pixel prediction value of the block to be processed based on the candidate motion information, the derived reference frame index, and the derived motion vector.

In a possible implementation, the pixel prediction value of the to-be-processed block is equal to the sum of a first weighted value and a second weighted value, and the first weighted value is equal to the to-be-processed value determined based only on the candidate motion information. The pixel prediction value of the processing block is multiplied by a first weight value, and the second weight value is equal to the pixel prediction value of the block to be processed determined based on the derived motion vector and the derived reference frame index multiplied by a second weight value , The sum of the first weight and the second weight is equal to 1.

In a possible implementation manner, the first weight is equal to the second weight.

In a possible implementation manner, the inter-frame prediction unit 1302 is further configured to:

When the index is identified as a second value, the pixel prediction value of the image to be processed is determined based only on the candidate motion information.

In a possible implementation manner, the derivative motion vector is obtained according to the following formula:

MV'=(d0'/d0)MV;

Wherein, MV' represents the derived motion vector, d0' represents the distance between the derived reference frame and the current frame, d0 represents the distance between the reference frame and the current frame, and MV represents the distance between the reference frame and the current frame. The motion vector of the decoded block.

In a possible implementation manner, the inter prediction unit 1302 is specifically configured to: when determining the derived reference frame index according to the reference frame index:

When the reference frame index is zero, it is determined that the derived reference frame index is 1; or,

When the reference frame index is non-zero, it is determined that the derived reference frame index is 0.

It should be noted that the above-mentioned entropy decoding unit 1301 and inter-frame prediction unit 1302 may be applied to the encoding and decoding and/or inter-frame prediction processes of the decoder.

Exemplarily, at the decoding end, in FIG. 13, the position of the entropy decoding unit 1301 corresponds to the position of the entropy decoding unit 304 in FIG. 3. In other words, the function of the entropy decoding unit 1301 can be completed by the entropy decoding unit 304 in FIG. . The position of the inter prediction unit 1302 corresponds to the position of the inter prediction unit 344 in FIG. 3. In other words, the function of the inter prediction unit 1302 can be performed by the inter prediction unit 344 in FIG. 3.

Based on the same inventive concept as the method embodiment, the embodiment of the present application also provides a device. As shown in FIG. 14, the device 1400 may specifically be a processor in a video encoder, or a chip or a chip system, or a video A module in the encoder, such as the inter prediction unit 244.

Illustratively, the device may include an acquiring unit 1401 and a determining unit 1402. The obtaining unit 1401 and the determining unit 1402 execute the method steps shown in the embodiment corresponding to FIG. 10.

The embodiment of the present application also provides another structure of the apparatus for a decoder. As shown in FIG. 15, the apparatus 1500 may include a communication interface 1510 and a processor 1520. Optionally, the device 1500 may further include a memory 1530. Wherein, the memory 1530 may be provided inside the device or outside the device.

Exemplarily, the device 1500 can be applied to the decoding side, and the entropy decoding unit 1301 and the inter prediction unit 1302 shown in FIG. 13 can be implemented by the processor 1520. The processor 1520 sends or receives a video stream or a code stream through the communication interface 1510, and is used to implement the method described in FIG. 12. In the implementation process, each step of the processing flow can be implemented by the integrated logic circuit of hardware in the processor 1520 or instructions in the form of software to complete the method described in FIG. 12.

Exemplarily, the device 1500 can also be applied to the encoding side, and the acquisition unit 1401 and the determination unit 1402 described in FIG. 14 can be implemented by the processor 1520. The processor 1520 sends or receives a video stream or a code stream through the communication interface 1510, and is used to implement the method described in FIG. 12. In the implementation process, each step of the processing flow may be implemented by the integrated logic circuit of hardware in the processor 1520 or instructions in the form of software to complete the method described in FIG. 10.

The communication interface 1510 in the embodiment of the present application may be a circuit, a bus, a transceiver, or any other device that can be used for information exchange. Wherein, for example, the other device may be a device connected to the device 1500, for example, when the device is a video decoder, the other device may be a video encoder.

The processor 1520 in the embodiment of the present application may be a general-purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, which can implement or execute The methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application may be directly embodied as being executed and completed by a hardware processor, or executed and completed by a combination of hardware and software units in the processor. The program code executed by the processor 1520 for implementing the foregoing method may be stored in the memory 1530. The memory 1530 and the processor 1520 are coupled.

The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units or modules, and may be in electrical, mechanical or other forms, and is used for information exchange between devices, units or modules.

The processor 1520 may operate in cooperation with the memory 1530. The memory 1530 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), etc., or a volatile memory, such as random access memory (random access memory). -access memory, RAM). The memory 1530 is any other medium that can be used to carry or store desired program codes in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto.

The embodiment of the present application does not limit the specific connection medium between the communication interface 1510, the processor 1520, and the memory 1530. In the embodiment of the present application, in FIG. 15, the memory 1530, the processor 1520, and the communication interface 1510 are connected by a bus. The bus is represented by a thick line in FIG. 15. The connection mode between other components is only for schematic illustration. It is not limited. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, only one thick line is used in FIG. 15 to represent, but it does not mean that there is only one bus or one type of bus.

Based on the above embodiments, the embodiments of the present application also provide a computer storage medium, the storage medium stores a software program, and when the software program is read and executed by one or more processors, any one or more of the above The method provided by the embodiment. The computer storage medium may include: U disk, mobile hard disk, read-only memory, random access memory, magnetic disk or optical disk and other media that can store program codes.

Based on the above embodiments, the embodiments of the present application also provide a chip. The chip includes a processor for implementing the functions involved in any one or more of the above embodiments, such as acquiring or processing the information involved in the above method or news. Optionally, the chip further includes a memory, and the memory is used for necessary program instructions and data executed by the processor. The chip can be composed of a chip, or it can include a chip and other discrete devices.

Those skilled in the art can understand that the functions described in conjunction with the various illustrative logical blocks, modules, and algorithm steps disclosed herein can be implemented by hardware, software, firmware, or any combination thereof. If implemented in software, the functions described by various illustrative logical blocks, modules, and steps can be stored or transmitted as one or more instructions or codes on a computer-readable medium, and executed by a hardware-based processing unit. The computer-readable medium may include a computer-readable storage medium, which corresponds to a tangible medium, such as a data storage medium, or a communication medium that includes any medium that facilitates the transfer of a computer program from one place to another (for example, 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, codes, and/or data structures for implementing 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 structures that can be used to store instructions or data Any other media that can be accessed by the computer in the form of desired program code. And, any connection is properly termed a computer-readable medium. For example, if you use coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology such as infrared, radio, and microwave 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 disks include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVD) and Blu-ray disks, where disks usually reproduce data magnetically, while optical disks use lasers to reproduce data optically data. The combination of the above items should also be included in the scope of computer-readable media.

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

The technology of this application can be implemented in a variety of devices or devices, including wireless handsets, integrated circuits (ICs), or a set of ICs (for example, 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 they do not necessarily need to be implemented by different hardware units. In fact, as described above, various units can be combined with appropriate software and/or firmware in the codec hardware unit, or by interoperating hardware units (including one or more processors as described above). provide.

In the above-mentioned embodiments, the description of each embodiment has its own focus. For a part that is not described in detail in an embodiment, reference may be made to related descriptions of other embodiments.

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

Claims (13)

1. A video image prediction method, characterized in that it comprises:

   The candidate motion information and the index identifier are parsed from the code stream. The candidate motion information includes the reference frame index and candidate motion vector identifier of the block to be processed. The motion vector identifier is used to indicate the decoded block referenced by the block to be processed Motion vector

   When the index is identified as a first value, determine a derived reference frame index according to the reference frame index;

   Based on the distance between the reference frame indicated by the reference frame index and the current frame where the block to be processed is located, and the distance between the derived reference frame indicated by the derived reference frame index and the current frame, the Performing scaling processing on the motion vector of the decoded block to obtain the derived motion vector of the candidate motion information;

   The pixel prediction value of the block to be processed is determined based on the candidate motion information, the derived reference frame index, and the derived motion vector.
2. The method according to claim 1, wherein the pixel prediction value of the block to be processed is equal to the sum of a first weighted value and a second weighted value, and the first weighted value is determined based on only the candidate motion information. The pixel prediction value of the block to be processed is multiplied by a first weight value, and the second weight value is equal to the pixel prediction value of the block to be processed determined based on the derived motion vector and the derived reference frame index multiplied by The second weight value, the sum of the first weight value and the second weight value is equal to 1.
3. 3. The method of claim 2, wherein the first weight is equal to the second weight.
4. The method according to any one of claims 1 to 3, further comprising:

   When the index is identified as a second value, the pixel prediction value of the image to be processed is determined based only on the candidate motion information.
5. The method according to any one of claims 1-4, wherein the derivative motion vector is obtained according to the following formula:

   MV'=(d0'/d0)MV;

   Wherein, MV' represents the derived motion vector, d0' represents the distance between the derived reference frame and the current frame, d0 represents the distance between the reference frame and the current frame, and MV represents the distance between the reference frame and the current frame. The motion vector of the decoded block.
6. The method according to any one of claims 1 to 5, wherein determining a derived reference frame index according to the reference frame index comprises:

   When the reference frame index is zero, determine that the derived reference frame index is 1;

   When the reference frame index is non-zero, it is determined that the derived reference frame index is 0.
7. A video image prediction device, characterized by comprising:

   The entropy decoding unit is used to parse candidate motion information and index identification from the code stream. The candidate motion information includes the reference frame index of the block to be processed and the candidate motion vector identification, and the motion vector identification is used to indicate the to-be-processed block. The motion vector of the decoded block referenced by the block;

   An inter prediction unit, configured to determine a derived reference frame index according to the reference frame index when the index is identified as a first value; based on the reference frame indicated by the reference frame index and the current frame where the block to be processed is located And the distance between the derived reference frame indicated by the derived reference frame index and the current frame, and the motion vector of the decoded block is scaled to obtain the derived motion vector of the candidate motion information ; Determine the pixel prediction value of the block to be processed based on the candidate motion information, the derived reference frame index and the derived motion vector.
8. The device according to claim 7, wherein the pixel prediction value of the to-be-processed block is equal to the sum of a first weighted value and a second weighted value, and the first weighted value is determined based on only the candidate motion information The pixel prediction value of the block to be processed is multiplied by a first weight value, and the second weight value is equal to the pixel prediction value of the block to be processed determined based on the derived motion vector and the derived reference frame index multiplied by The second weight value, the sum of the first weight value and the second weight value is equal to 1.
9. The device of claim 8, wherein the first weight is equal to the second weight.
10. 9. The apparatus according to any one of claims 7-9, wherein the inter-frame prediction unit is further configured to:

    When the index is identified as a second value, the pixel prediction value of the image to be processed is determined based only on the candidate motion information.
11. The apparatus according to any one of claims 7-10, wherein the derivative motion vector is obtained according to the following formula:

    MV'=(d0'/d0)MV;

    Wherein, MV' represents the derived motion vector, d0' represents the distance between the derived reference frame and the current frame, d0 represents the distance between the reference frame and the current frame, and MV represents the distance between the reference frame and the current frame. The motion vector of the decoded block.
12. The apparatus according to any one of claims 7-11, wherein the inter-frame prediction unit is specifically configured to: when determining a derived reference frame index according to the reference frame index:

    When the reference frame index is zero, it is determined that the derived reference frame index is 1; or,

    When the reference frame index is non-zero, it is determined that the derived reference frame index is 0.
13. A video encoding and decoding device, comprising: a non-volatile memory and a processor coupled with each other, the processor calls the program code stored in the memory to execute any one of claims 1-6 The method described.

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