CN111263166A - A video image prediction method and device - Google Patents

Abstract

The application provides a video image prediction method and a video image prediction device, which are used for solving the problem of low prediction precision in the prior art. The method comprises the following steps: analyzing candidate motion information and an index identifier from the code stream, wherein the candidate motion information comprises a reference frame index and a candidate motion vector identifier of a block to be processed; when the index mark is a first value, determining a derived reference frame index according to the reference frame index; based on the distance between the reference frame and the current frame and the distance between the derived reference frame and the current frame, scaling the motion vector of the decoded block to obtain a derived motion vector of the candidate motion information; a pixel predictor for the block to be processed is determined based on the candidate motion information, the derived reference frame index, and the derived motion vector. Due to the fact that part of optimal motion information of the HMVP queue is lost due to motion information updating, the derived motion information can make up for the prediction accuracy loss caused by the motion information, and therefore prediction accuracy can be improved.

Description

A video image prediction method and device

This application claims the priority of the Chinese patent application filed on November 30, 2018 with the application number of 201811452886.8 and the invention titled "An Inter-frame Prediction Method and Device", the entire contents of which are incorporated herein by reference middle.

technical field

The present application relates to the technical field of image coding and decoding, and in particular, to an image prediction method and apparatus.

Background technique

With the development of information technology, video services such as 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 advantages of intuition and efficiency. Because 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, and 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 the spatial domain, the time domain and the codeword to remove redundancy as much as possible. The current popular practice is to use a hybrid video coding framework based on image blocks to achieve video coding and 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 adopts 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 existing in the queue. candidate motion information, and store the candidate motion information to be added at the end of the HMVP queue.

For the P frame, only the motion information of the coded block of the forward reference frame can be referred to. When the HMVP queue removes the candidate motion information, it may remove the motion information that can be used for the P frame, resulting in the pending processing of the P frame. When a block is used for inter-frame prediction, there is less motion information that can be referenced, 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 an index identifier from a code stream, where the candidate motion information includes a reference frame index of a block to be processed and a candidate motion vector identifier, 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 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 of the decoded block The vector is scaled to obtain a derived motion vector of the candidate motion information; the pixel predictor 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, the newly generated derivative motion information is also included, 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. Due to the update of motion information in the HMVP queue, part of the optimal motion information is lost, and the derived motion information can compensate 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 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 equal to the to-be-processed value determined only based on the candidate motion information the pixel prediction value of the block is multiplied by a 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 a second weight, The sum of the first weight and the second weight is equal to one.

In the above design, the weighted sum method is used 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 identifier is a second value, determining a pixel prediction value of the image to be processed based only on the candidate motion information.

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

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

MV'=(d0'/d0)MV;

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 The motion vector of the decoded block.

In a possible design, determining a 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, the derived reference frame index is determined to be 0.

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

In a second aspect, the present application provides a method for decoding motion vectors, including:

Parse the code stream to obtain first identification information, 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; parse the code stream to obtain second identification information; When the second identification information is a second numerical 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 a first numerical value, the predicted value of the image block to be processed is obtained according to the first motion vector and the first numerical value. Two motion vectors are obtained to obtain the predicted value of the image block to be processed, wherein the second motion vector is obtained according to the first motion vector and a preset mapping relationship, and the first value and the second value are different.

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

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

determining the coding structure of the sequence in which the image block to be processed is located; and/or,

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

Correspondingly, the parsing of 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 satisfies a preset condition, parsing the code stream to obtain the second identification information.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, the preset condition includes: the prediction mode is a skip mode or a direct (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.

In combination with the second aspect or the first possible implementation manner of the second aspect or the second possible implementation manner, in a 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 temporal 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 temporal 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 a 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 a fifth possible implementation manner of the second aspect, the method further includes: obtaining the second reference according to an 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 implementation manners of the second aspect, in a seventh possible implementation manner of the second aspect, the first motion vector and the second motion vector to obtain the predicted value of the to-be-processed image block, including:

obtaining the first predicted 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 to-be-processed image block 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 slice type of the image where the image block to be processed is located is , and/or, the coding structure of the sequence in which 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, and the method is applied to the encoding side, including:

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 to-be-processed block, and the 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 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, are used in 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 predicted value of the block to be processed corresponding to the first candidate motion information is equal to the smallest sum of absolute transformed difference (SATD) between the first predicted value and the second predicted value the predicted value;

The first predicted value is equal to the pixel predicted value of the block to be processed determined based only on the first candidate motion information, and the second predicted value is equal to the sum of the first weighted value and the second weighted value , the first weighted value is equal to the first predicted value multiplied by the first weighted value, and the second weighted value is equal to the pixel predicted 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 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 one possible design, also include:

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

In a possible design, N pieces of 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:

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

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

Wherein, when the pixel predicted 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 numerical value;

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

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

MV'=(d0'/d0)MV;

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 a 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 further provides a video image prediction device, including:

An entropy decoding unit, configured to parse candidate motion information and an index identifier from the code stream, where the candidate motion information includes a reference frame index of a block to be processed and a candidate motion vector identifier, where the motion vector identifier is used to indicate the to-be-processed block the motion vector of the decoded block referenced by the block;

An inter-frame prediction unit, configured to determine a derived reference frame index according to the reference frame index when the index identifier is 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, the motion vector of the decoded block is scaled to obtain the derived motion vector of the candidate motion information ; determining a pixel predictor 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 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 equal to the to-be-processed value determined only based on the candidate motion information the pixel prediction value of the block is multiplied by a 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 a second weight, The sum of the first weight and the second weight is equal to one.

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

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

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

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

MV'=(d0'/d0)MV;

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 The motion vector of the decoded block.

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

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, the derived reference frame index is determined to be 0.

In a fifth aspect, an embodiment of the present application provides an image prediction apparatus, the apparatus 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, embodiments of the present application provide an image prediction apparatus, the apparatus includes a processor and a memory coupled to the processor; the processor is configured to execute the methods in the 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, where the non-volatile storage medium stores an executable program, and the processor and the non-volatile storage medium store an executable program. The volatile storage media are coupled to each other, and the executable program is executed to implement the method in the first aspect or the second aspect or various implementations 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, where the non-volatile storage medium stores an executable program, the processor and the non-volatile storage medium store an executable program. The volatile storage media are coupled to each other, and the executable program is executed to implement the method in the third aspect or various implementations thereof.

In a ninth aspect, an embodiment of the present application provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the computer-readable storage medium runs on a computer, the computer can execute the first aspect or various implementations thereof. The method in the above-mentioned second aspect or the method in the various implementation manners thereof, or the method in the above-mentioned third aspect or the various implementation manners thereof.

In a tenth aspect, the embodiments of the present application provide a computer program product containing instructions, which, when run on a computer, causes the computer to execute the method in the first aspect or various implementations thereof, or execute the second aspect or methods in its various implementations, or perform the above-mentioned third aspect or the methods in its various implementations.

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 obtained by each aspect and the corresponding implementable design manner are similar, and will not be repeated.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the accompanying drawings required in the embodiments or the background technology of the present application will be described below.

1A is a block diagram of an example of a video encoding and decoding system 10 for implementing embodiments of the present application;

1B is a block diagram of an example of a video coding system 40 for implementing embodiments of the present application;

2 is a block diagram of an example structure of an encoder 20 for implementing an embodiment of the present application;

3 is a block diagram of an example structure of a decoder 30 for implementing an embodiment of the present application;

4 is a block diagram of an example of a video coding apparatus 400 for implementing embodiments of the present application;

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 a reference frame index for implementing an embodiment of the present application.

7 is a schematic diagram of an HMVP queue update mode for implementing an embodiment of the present application;

FIG. 8 is another schematic diagram for realizing the HMVP queue update mode according to the embodiment of the present application;

FIG. 9 is another schematic diagram for realizing the HMVP queue update mode of the embodiment of the present application;

10 is a schematic flowchart of a video image prediction method for implementing an embodiment of the present application;

FIG. 11 is an exemplary schematic diagram for realizing the generation of a derived motion vector according to an embodiment of the present application;

12 is a schematic flowchart of another video image prediction method for implementing an embodiment of the present application;

FIG. 13 is a schematic diagram of a device 1300 for implementing an embodiment of the present application;

FIG. 14 is a schematic diagram of a device 1400 for implementing an embodiment of the present application;

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

Detailed ways

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

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

Video coding generally refers to the processing of sequences of pictures that form a video or video sequence. In the field of video coding, the terms "picture", "frame" or "image" may be used as synonyms. Video encoding as used herein means video encoding or video decoding. Video encoding is performed on the source side and typically involves processing (eg, by compressing) the original video picture to reduce the amount of data required to represent the video picture for more efficient storage and/or transmission. Video decoding is performed on the destination side and typically involves inverse processing relative to the encoder to reconstruct the video pictures. Reference to "encoding" of video pictures in the embodiments should be understood to refer to "encoding" or "decoding" of video sequences. The combination of the encoding part and the decoding part is also called encoding and decoding (encoding and decoding).

A video sequence consists of a series of pictures, which are further divided into slices, which are further divided into blocks. Video coding is performed in units of blocks, and in some new video coding standards, the concept of blocks is further extended. For example, in the H.264 standard, there is a macroblock (MB), and the macroblock can be further divided into a plurality of 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 to divide functionally. A variety of block units are developed, and a new tree-based structure is used to describe them. For example, a CU can be divided into smaller CUs according to a quad-tree, and the smaller CUs can be further divided to form a quad-tree structure. A CU is a basic unit for dividing and coding an encoded image. There is a similar tree structure for PU and TU. PU can correspond to prediction block and is the basic unit of prediction coding. The CU is further divided into a plurality of PUs according to the division mode. The TU may correspond to a transform block and is a 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).

For example, in HEVC, a CTU is split into multiple CUs by using a quad-tree structure represented as a coding tree. The decision whether to encode a picture region using inter-picture (temporal) or intra-picture (spatial) prediction is made at the CU level. Each CU can be further split into one, two or four PUs depending on the PU split type. The same prediction process is applied within a PU and relevant information is transmitted to the decoder on a PU basis. After obtaining the residual block by applying a prediction process based on the PU split type, the CU may be split into transform units (TUs) according to other quad-tree structures similar to the coding tree used for the CU. In the latest development of video compression technology, quad-tree and binary tree (QTBT) are used to segment frames to segment coded blocks. In the QTBT block structure, a CU can be square or rectangular in 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. A decoded image block in the reference image used for prediction of the current block is called a reference block, ie a reference block is a block that provides a reference signal for the current block, wherein the reference signal represents a pixel value within the image block. A block in the reference image that provides a prediction signal for the current block may be a prediction block, where the prediction signal represents a pixel value or a sample value or a sample signal within the prediction block. For example, after traversing multiple reference blocks, the best reference block is found, and the 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, ie 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, further compression is performed by eg quantization to reduce the amount of data required to represent the video picture, and the decoder side cannot fully reconstruct the video picture, i.e. the quality of the reconstructed video picture is compared to the original video picture of lower or poorer quality.

Several video coding standards of H.261 belong to the "lossy hybrid video codec" (ie, combine spatial and temporal prediction in the sample domain with 2D transform coding in the transform domain for applying quantization). Each picture of a video sequence is typically partitioned into sets of non-overlapping blocks, usually encoded at the block level. In other words, the encoder side typically processes i.e. encodes the video at the block (video block) level, eg, by spatial (intra-picture) prediction and temporal (inter-picture) prediction to generate prediction blocks, from the current block (currently processed or to be processed block) subtract the prediction block to obtain the residual block, transform the residual block in the transform domain and quantize the residual block to reduce the amount of data to be transmitted (compressed), while the decoder side will process the inverse relative to the encoder Parts are applied to encoded or compressed blocks to reconstruct the current block for representation. Additionally, the encoder replicates the decoder processing loop such that the encoder and decoder generate the same predictions (eg, intra- and inter-prediction) and/or reconstructions for processing, ie, encoding, subsequent blocks.

The following describes the system architecture to which the embodiments of the present application are applied. Referring to FIG. 1A , FIG. 1A exemplarily shows a schematic block diagram of a video encoding and decoding system 10 to which the embodiments of the present application are applied. As shown in FIG. 1A, video encoding and decoding system 10 may include a source device 12 that produces encoded video data and a destination device 14, which may thus be referred to as a video encoding device. Destination device 14 may decode encoded video data produced by source device 12, and thus destination device 14 may be referred to as a video decoding device. Various implementations of source device 12, destination device 14, or both may include one or more processors and a 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 may be used to store the desired program code in the form of instructions or data structures accessible by a computer, as described herein. Source device 12 and destination device 14 may include various devices including desktop computers, mobile computing devices, notebook (eg, laptop) computers, tablet computers, set-top boxes, telephone handhelds such as so-called "smart" phones, etc. computers, televisions, cameras, display devices, digital media players, video game consoles, in-vehicle computers, wireless communication devices, or the like.

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

A communicative connection may be made between source device 12 and destination device 14 via link 13, via which destination device 14 may receive encoded video data from source device 12. 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, 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 destination device 14 . The one or more communication media may include wireless and/or wired communication media, such as radio frequency (RF) spectrum or one or more physical transmission lines. The one or more communication media may form part of a packet-based network, such as a local area network, a wide area network, or a global network (eg, the Internet). The one or more communication media may include routers, switches, base stations, or other devices that facilitate communication from source device 12 to destination device 14 .

The source device 12 includes an encoder 20 , and optionally, the source device 12 may further 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 software programs in the source device 12 . They are described as follows:

Picture source 16, which may include or may be any kind of picture capture device for, for example, capturing real world pictures, and/or any kind 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 device, for example, a computer graphics processor for generating computer-animated pictures, or for acquiring and/or providing real-world pictures, computer-animated pictures (eg, screen content, virtual reality, VR) pictures), and/or any combination thereof (eg augmented reality (AR) pictures). Picture source 16 may be a camera for capturing pictures or a memory for storing pictures, and picture source 16 may also include any kind of interface (internal or external) that stores previously captured or generated pictures and/or acquires or receives pictures. When the picture source 16 is a camera, the picture source 16 may be, for example, a local or integrated camera integrated in the source device; when the picture source 16 is a memory, the picture source 16 may be local or, for example, an integrated camera integrated in the source device memory. When the picture source 16 includes an interface, the interface may, for example, be an external interface that receives pictures from an external video source, such as an external picture capture device such as a camera, an external memory or an external picture generation device such as For an external computer graphics processor, computer or server. The interface may be any class of interface according to any proprietary or standardized interface protocol, eg wired or wireless interfaces, optical interfaces.

The picture can be regarded as a two-dimensional array or matrix of picture elements. The pixels in the array can also be called sampling points. The number of sampling points in the horizontal and vertical directions (or axes) of an array or picture defines the size and/or resolution of the picture. To represent color, three color components are usually employed, ie a picture can be represented as or contain three arrays of samples. For example in RBG format or color space, a picture includes corresponding arrays of red, green and blue samples. However, in video coding, each pixel is usually represented in a luma/chroma format or color space, for example, for a picture in YUV format, it includes a luma component indicated by Y (sometimes can also be indicated by L) and two components indicated by U and V. chrominance components. The luminance (luma) component Y represents the luminance or gray level intensity (eg, both are the same in a grayscale picture), while the two chroma (chroma) components U and V represent the chrominance or color information components. Accordingly, a picture in YUV format includes a luma sample array of luma sample values (Y), and two chroma sample arrays of chroma values (U and V). Pictures in RGB format can be converted or transformed to YUV format and vice versa, the process is also known as color transformation or conversion. If the picture is black and white, the picture may only include an array of luminance samples. In this embodiment of the present application, the picture transmitted from the picture source 16 to the picture processor may also be referred to as the 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 preprocessing performed by the picture preprocessor 18 may include retouching, color format conversion (eg, from RGB format to YUV format), toning, or denoising.

An encoder 20 (or a video encoder 20) for receiving the pre-processed picture data 19 and processing the pre-processed picture data 19 using a relevant prediction mode (such as the prediction mode in the various embodiments herein), thereby Encoded picture data 21 is provided (the structural details of the encoder 20 will be described further below based on FIG. 2 or FIG. 4 or FIG. 5). In some embodiments, the encoder 20 may be configured to execute various embodiments described later, so as to realize the application of the chroma block prediction method described in this application on the encoding side.

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

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

A communication interface 28 may be used to receive encoded picture data 21 from source device 12 or any other source, such as a storage device, such as an encoded picture data storage device. The communication interface 28 may be used to transmit or receive encoded picture data 21 via the link 13 between the source device 12 and the destination device 14, such as a direct wired or wireless connection, or via any kind of network. Classes of networks are, for example, wired or wireless networks or any combination thereof, or any classes of private and public networks, or any combination thereof. Communication interface 28 may be used, for example, to decapsulate data packets transmitted by communication interface 22 to obtain encoded picture data 21 .

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

Decoder 30 (or referred to as decoder 30 ) for receiving encoded picture data 21 and providing decoded picture data 31 or decoded picture 31 (the function of decoder 30 will be further described below based on FIG. 3 or FIG. 4 or FIG. 5 ) structural details). In some embodiments, the decoder 30 may be configured to execute various embodiments described later, so as to realize the application of the chroma block prediction method described in this application at the decoding side.

A picture post-processor 32 for performing post-processing on 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, which may include color format conversion (eg, from YUV format to RGB format), toning, trimming or resampling, or any other processing, may also be used to convert the post-processed picture data 33 is transmitted to the display device 34 .

A display device 34 for receiving post-processed picture data 33 to display the picture, eg, to a user or viewer. Display device 34 may be or include any type of display for presenting the reconstructed picture, eg, an integrated or external display or monitor. For example, displays may include liquid crystal displays (LCDs), organic light emitting diode (OLED) displays, plasma displays, projectors, micro LED displays, liquid crystal on silicon (LCoS), A digital light processor (DLP) or other display of any kind.

Although FIG. 1A depicts source device 12 and destination device 14 as separate devices, device embodiments may include the functionality of both source device 12 and destination device 14 or both, ie source device 12 or Corresponding functionality and destination device 14 or corresponding functionality. In such embodiments, source device 12 or corresponding functionality and destination device 14 or corresponding functionality may be implemented using the same hardware and/or software, or using separate hardware and/or software, or any combination thereof .

It will be apparent to those skilled in the art based on the description that the functionality of the different units or the existence and (exact) division of the functionality of the source device 12 and/or the destination device 14 shown in FIG. 1A may vary depending on the actual device and application. Source device 12 and destination device 14 may include any of a variety of devices, including any class of handheld or stationary devices, for example, notebook or laptop computers, mobile phones, smartphones, tablet or tablet computers, video cameras, desktops Computers, set-top boxes, televisions, cameras, in-vehicle devices, display devices, digital media players, video game consoles, video streaming devices (such as content serving servers or content distribution servers), broadcast receiver devices, broadcast transmitter devices etc., and can not use or use any kind of operating system.

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

In some cases, the video encoding and decoding system 10 shown in FIG. 1A is merely an example, and the techniques of this application may be applicable to video encoding setups (eg, video encoding or video encoding) that do not necessarily involve any communication of data between encoding and decoding devices. decoding). In other examples, data may be retrieved from local storage, streamed over a network, and the like. A video encoding device may encode and store data to memory, and/or a video decoding device may retrieve and decode data from memory. In some examples, encoding and decoding is performed by devices that do not communicate with each other but only encode data to and/or retrieve data from memory and decode data.

Referring to FIG. 1B , FIG. 1B is an illustrative diagram of an example of a video coding system 40 including encoder 20 of FIG. 2 and/or decoder 30 of FIG. 3 , according to an exemplary embodiment. The video coding system 40 may implement a combination of various techniques of the embodiments of the present application. In the illustrated embodiment, video coding system 40 may include imaging device 41 , encoder 20 , decoder 30 (and/or a video codec implemented by logic 47 of processing unit 46 ), antenna 42 , one or more processors 43 , one or more memories 44 and/or a display device 45 .

As shown in Figure IB, the imaging device 41, antenna 42, processing unit 46, logic circuit 47, encoder 20, decoder 30, processor 43, memory 44 and/or display device 45 can communicate with each other. As discussed, although video coding system 40 is shown with encoder 20 and decoder 30, video coding system 40 may include only encoder 20 or only decoder 30 in different examples.

In some examples, antenna 42 may be used to transmit or receive an encoded bitstream of video data. Additionally, in some instances, display device 45 may be used to present video data. In some instances, logic circuit 47 may be implemented by processing unit 46 . Processing unit 46 may include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, or the like. Video coding system 40 may also include an optional processor 43, which may similarly include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, or the like. In some instances, the logic circuit 47 may be implemented by hardware, such as dedicated hardware for video encoding, etc., and the processor 43 may be implemented by general-purpose software, an operating system, or the like. Additionally, memory 44 may be any type of memory, such as volatile memory (eg, Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), etc.) or non-volatile memory memory (eg, flash memory, etc.), etc. In a non-limiting example, memory 44 may be implemented by cache memory. In some instances, logic circuitry 47 may access memory 44 (eg, for implementing an image buffer). In other examples, logic circuitry 47 and/or processing unit 46 may include memory (eg, cache memory, etc.) for implementing image buffers, and the like.

In some examples, encoder 20 implemented by logic circuitry may include an image buffer (eg, implemented by processing unit 46 or memory 44 ) and a graphics processing unit (eg, implemented by processing unit 46 ). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include encoder 20 implemented by logic circuitry 47 to implement the various modules discussed with reference to FIG. 2 and/or any other encoder system or subsystem described herein. Logic circuits may be used to perform the various operations discussed herein.

In some examples, decoder 30 may be implemented in a similar manner by logic circuit 47 to implement the various modules discussed with reference to decoder 30 of FIG. 3 and/or any other decoder system or subsystem described herein. In some examples, logic-implemented decoder 30 may include an image buffer (implemented by processing unit 2820 or memory 44) and a graphics processing unit (eg, implemented by processing unit 46). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include a decoder 30 implemented by logic circuitry 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., as discussed herein related to encoded video frames, such as data related to encoded partitions (eg, transform coefficients or quantized transform coefficients). , (as discussed) optional indicators, and/or data defining the encoding split). Video coding system 40 may also include decoder 30 coupled to antenna 42 for decoding the encoded bitstream. Display device 45 is used to present video frames.

It should be understood that, for the examples described with reference to the encoder 20 in the embodiments of the present application, the decoder 30 may be used to perform the opposite process. With regard to signaling syntax elements, decoder 30 may be operable to receive and parse such syntax elements, decoding the associated video data accordingly. In some examples, encoder 20 may entropy encode the syntax elements into an encoded video bitstream. In such instances, decoder 30 may parse such syntax elements and decode related video data accordingly.

It should be noted that the methods described in the embodiments of the present application are mainly used for the inter-frame prediction process, and this process exists in both the encoder 20 and the decoder 30. The encoder 20 and the decoder 30 in the embodiments 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 codecs corresponding to next-generation video standard protocols (such as H.266, etc.).

Referring to FIG. 2, FIG. 2 shows a schematic/conceptual block diagram of an example of an encoder 20 for implementing embodiments of the present application. In the example of FIG. 2, encoder 20 includes residual calculation unit 204, transform processing unit 206, quantization unit 208, inverse quantization unit 210, inverse transform processing unit 212, reconstruction unit 214, buffer 216, loop filter Unit 220 , decoded picture buffer (DPB) 230 , prediction processing unit 260 , and entropy encoding unit 270 . Prediction processing unit 260 may include inter prediction unit 244 , intra prediction unit 254 , and mode selection unit 262 . 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 according to a hybrid video codec.

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

The encoder 20 receives a picture 201 or an image block 203 of the picture 201 , eg, a picture in a sequence of pictures forming a video or a video sequence, via eg an input 202 . 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 distinguishing the current picture from other pictures in video coding, other pictures such as the same video sequence) That is, previous encoded and/or decoded pictures in the video sequence of the current picture are also included).

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

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

Like picture 201 , image block 203 is also or can be regarded as a two-dimensional array or matrix of sample points with sample values, although its size is smaller than that of picture 201 . In other words, the image block 203 may comprise, for example, one sample array (eg, a luma array in the case of a black and white picture 201 ) or three sample arrays (eg, one luma array and two chroma arrays in the case of a color picture) or Any other number and/or class of arrays depending on the applied color format. 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 as shown in FIG. 2 is used to encode the picture 201 block by block, eg, performing encoding and prediction for each image block 203 .

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

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

Transform processing unit 206 may be used to apply integer approximations of DCT/DST, such as transforms specified for HEVC/H.265. Compared to the orthogonal DCT transform, this integer approximation is usually scaled by some factor. To maintain the norm of the forward and inversely transformed residual blocks, additional scaling factors are applied as part of the transformation process. The scaling factor is usually chosen based on some constraints, eg, the scaling factor is a power of 2 for the shift operation, the bit depth of the transform coefficients, the trade-off between accuracy and implementation cost, etc. For example, specific scaling factors are specified for the inverse transform at the decoder 30 side by eg inverse transform processing unit 212 (and for the corresponding inverse transform at the encoder 20 side by eg inverse transform processing unit 212), and accordingly, can be at the encoder The 20 side specifies the corresponding scaling factor for the forward transformation through the transformation processing unit 206 .

Quantization unit 208 is used to quantize transform coefficients 207 , eg, by applying scalar quantization or vector quantization, to obtain quantized transform coefficients 209 . The quantized transform coefficients 209 may also be referred to as quantized residual coefficients 209 . The quantization process may reduce the bit depth associated with some or all of the transform coefficients 207 . For example, n-bit transform coefficients may 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. Smaller quantization step sizes correspond to finer quantization, while larger quantization step sizes correspond to coarser quantization. A suitable quantization step size can be indicated by a quantization parameter (QP). For example, the quantization parameter may be an index into a predefined set of suitable quantization step sizes. For example, a smaller quantization parameter may correspond to fine quantization (smaller quantization step size), a larger quantization parameter may correspond to coarse quantization (larger quantization step size), and vice versa. Quantization may involve dividing by the quantization step size and corresponding quantization or inverse quantization, eg, performed by inverse quantization 210, or may involve multiplying by the 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 involving division. Additional scaling factors can be introduced for quantization and inverse quantization to restore the norm of the residual block that may be modified due to the scale used in the fixed-point approximation of the equations for the quantization step size and quantization parameters. In an example embodiment, the inverse transformed and inverse quantized scales may be combined. Alternatively, a custom quantization table can be used and signaled from the encoder to the decoder, eg in a bitstream. Quantization is a lossy operation, where the larger the quantization step size, the larger the loss.

Inverse quantization unit 210 is used to apply the inverse quantization of quantization unit 208 on the quantized coefficients to obtain inverse quantized coefficients 211, eg, based on or using the same quantization step size as quantization unit 208, applying the quantization scheme applied by quantization unit 208 inverse quantization scheme. The inverse quantized coefficients 211 may also be referred to as inverse quantized residual coefficients 211, corresponding to the transform coefficients 207, although the loss due to quantization is generally not the same as the transform coefficients.

The inverse transform processing unit 212 is used to apply the inverse transform of the transform applied by the transform processing unit 206, eg, an inverse discrete cosine transform (DCT) or an inverse discrete sine transform (DST), to obtain in the sample domain Inverse transform block 213 . Inverse transform block 213 may also be referred to as inverse transform inverse quantized block 213 or inverse transform residual block 213 .

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

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

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

Loop filter unit 220 (or simply "loop filter" 220) is used to filter reconstructed block 215 to obtain filtered block 221 for smooth pixel transitions or improved video quality. 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, automatic Adaptive loop filter (ALF), or sharpening or smoothing filter, or collaborative filter. Although loop filter unit 220 is shown in FIG. 2 as an in-loop filter, in other configurations, loop filter unit 220 may be implemented as a post-loop filter. Filtered block 221 may also be referred to as filtered reconstructed block 221 . Decoded picture buffer 230 may store the reconstructed encoded block after loop filter unit 220 performs a filtering operation on the reconstructed encoded block.

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

Decoded picture buffer (DPB) 230 may be a reference picture memory that stores reference picture data for use by encoder 20 to encode video data. DPB 230 may be formed from 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. DPB 230 and buffer 216 may be provided by the same memory device or by separate memory devices. In a certain example, a decoded picture buffer (DPB) 230 is used to store filtered blocks 221 . Decoded picture buffer 230 may further be used to store other previous filtered blocks, such as previously reconstructed and filtered blocks 221, of the same current picture or a different picture, such as a previously reconstructed picture, and may provide a complete previously processed picture. A reconstructed, ie, decoded, picture (and corresponding reference blocks and samples) and/or partially reconstructed current picture (and corresponding reference blocks and samples), eg, for inter prediction. In a certain example, a decoded picture buffer (DPB) 230 is used to store the reconstructed block 215 if the reconstructed block 215 is reconstructed without in-loop filtering.

Prediction processing unit 260, also referred to as block prediction processing unit 260, for receiving or obtaining image block 203 (current image block 203 of current picture 201) and reconstructed picture data, such as the same (current) picture from buffer 216 reference samples and/or reference picture data 231 from one or more previously decoded pictures of decoded picture buffer 230, and used to process such data for prediction, i.e., the provision may be an inter-predicted block 245 or a The prediction block 265 of the intra prediction block 255.

Mode selection unit 262 may be used to select a prediction mode (eg, intra or inter prediction mode) and/or corresponding prediction block 245 or 255 used as prediction block 265 to compute residual block 205 and reconstruct reconstructed blocks 215.

Embodiments of mode selection unit 262 may be used to select a prediction mode (eg, selected from those supported by prediction processing unit 260) that provides the best match or the smallest residual (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 least rate distortion optimization, or select a prediction mode whose relevant rate distortion at least satisfies prediction mode selection criteria .

Prediction processing performed (eg, by prediction processing unit 260 ) and mode selection (eg, by mode selection unit 262 ) are 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 set of prediction modes may include, for example, intra prediction modes and/or inter prediction modes.

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 prediction modes, eg non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in the developing H.266.

In a possible implementation, the set of inter-prediction modes depends on available reference pictures (ie, eg, at least some of the decoded pictures previously stored in DBP 230) and other inter-prediction parameters, eg, on whether to use the entire reference picture or only use a portion of the reference picture, e.g. the search window area surrounding the area of the current block, to search for the best matching reference block, and/or e.g. depending on whether pixel interpolation such as half-pixel and/or quarter-pixel interpolation is applied , the inter prediction mode set may include, for example, an advanced motion vector (Advanced Motion Vector Prediction, AMVP) mode and a merge mode. In a specific implementation, the inter-frame prediction mode set may include the improved control point-based AMVP mode and the improved control point-based merge mode in the embodiments of the present application. In one example, intra-prediction unit 254 may be used to perform any combination of the 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 further be used to partition the image block 203 into smaller block partitions or sub-blocks, eg, by iteratively using quad-tree (QT) partitioning, binary-tree (BT) partitioning or triple-tree (TT) partitioning, or any combination thereof, and for performing prediction, for example, for each of the block partitions or sub-blocks, wherein mode selection includes selecting the tree structure of the partitioned image blocks 203 and selecting an 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 (motion compensation, MC) unit (not shown in FIG. 2 ). A motion estimation unit for receiving or obtaining picture image block 203 (current picture image block 203 of current picture 201) and decoded picture 231, or at least one or more previously reconstructed blocks, eg, one or more other/different The reconstructed block of the previously decoded picture 231 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, or form part of, the sequence of pictures that form the video sequence.

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

The motion compensation unit is used to obtain inter-prediction parameters and perform inter-prediction based on or using the inter-prediction parameters to obtain the inter-prediction block 245 . Motion compensation performed by a motion compensation unit (not shown in Figure 2) may involve fetching or generating a prediction block based on motion/block vectors determined by motion estimation (possibly performing interpolation to sub-pixel accuracy). Interpolative filtering may generate additional pixel samples from known pixel samples, potentially increasing the number of candidate prediction blocks available for encoding a picture block. Once the motion vector for the PU of the current picture block is received, motion compensation unit 246 may locate the prediction block to which the motion vector points in a reference picture list. Motion compensation unit 246 may also generate syntax elements associated with blocks and video slices for use by decoder 30 in decoding picture blocks of the video slice.

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

Intra-prediction unit 254 is used to obtain, eg, receive, picture block 203 (the current picture block) of the same picture and one or more previously reconstructed blocks, eg, 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.

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

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

Specifically, the above-mentioned intra prediction unit 254 may transmit syntax elements to the entropy encoding unit 270, where the syntax elements include intra prediction parameters (such as an intra prediction mode selected for prediction of the current block after traversing multiple intra prediction modes). 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 decoding end 30 may directly use the default prediction mode for decoding.

The entropy coding unit 270 is configured to use an entropy coding algorithm or scheme (eg, variable length coding (VLC) scheme, 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 (syntax-based context-adaptive binary arithmetic coding, SBAC), probability interval partitioning entropy (probability interval partitioningentropy, PIPE) coding or other entropy coding methods or technique) applied to single or all (or none) of the quantized residual coefficients 209, inter-prediction parameters, intra-prediction parameters, and/or loop filter parameters to obtain an output that can be passed through output 272 to, for example, encoded Encoded picture data 21 output in the form of a bitstream 21 . The encoded bitstream may be transmitted to video decoder 30, or archived for transmission or retrieval by video decoder 30 at a later time. Entropy encoding unit 270 may also be used to entropy encode other syntax elements of the current video slice being encoded.

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

Specifically, in this 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 variations of video encoder 20 may be used to encode the video stream. For example, for some image blocks or image frames, video encoder 20 may directly quantize the residual signal without processing by transform processing unit 206 and correspondingly by inverse transform processing unit 212; or, for some 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, the quantization unit 208, the inverse quantization unit 210 and the inverse transform processing unit 212; alternatively, the video encoder 20 may The reconstructed image block is stored directly as a reference block without being processed by filter 220; alternatively, quantization unit 208 and inverse quantization unit 210 in video encoder 20 may be merged together. The loop filter 220 is optional, and for the case of 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-frame prediction unit 244 and the intra-frame prediction unit 254 may be selectively enabled.

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

In the example of FIG. 3, decoder 30 includes entropy decoding unit 304, inverse quantization unit 310, inverse transform processing unit 312, reconstruction unit 314 (eg, summer 314), buffer 316, loop filter 320, a Decoded picture buffer 330 and prediction processing unit 360. Prediction processing unit 360 may include inter prediction unit 344 , intra prediction unit 354 , and mode selection unit 362 . In some examples, video decoder 30 may perform decoding passes that are substantially reciprocal to the encoding passes described with reference to video encoder 20 of FIG. 2 .

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

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

Prediction processing unit 360 may include inter prediction unit 344, which may be functionally similar to inter prediction unit 244, and intra prediction unit 354, which may be functionally similar to intra prediction unit 254 . Prediction processing unit 360 is typically used to perform block prediction and/or obtain prediction blocks 365 from encoded data 21, and to receive or obtain (explicitly or implicitly) prediction-related parameters and/or information about all parameters from, for example, entropy decoding unit 304. Information about the selected prediction mode.

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

Prediction processing unit 360 is operable 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 this application, prediction processing unit 360 uses some of the received syntax elements to determine a prediction mode (eg, intra or inter prediction), an inter prediction slice type ( For example, a B slice, a P slice, or a GPB slice), construction information for one or more of the slice's reference picture list, motion vectors for each inter-coded video block of the slice, Inter-prediction status and other information for each inter-coded video block of the slice to decode the video blocks of the current video slice. In another example of the present disclosure, the syntax elements received by video decoder 30 from the bitstream include receiving an adaptive parameter set (APS), a sequence parameter set (SPS), a picture parameter set (picture parameter set) set, PPS) or syntax elements in one or more of the slice headers.

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

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

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

A loop filter unit 320 is used (during the encoding loop or after the encoding loop) to filter the reconstructed block 315 to obtain a filtered block 321 for smooth pixel transitions or improved video quality. In one example, loop filter unit 320 may be used to perform any combination of the filtering techniques described below. 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, automatic Adaptive loop filter (ALF), or sharpening or smoothing filter, or collaborative filter. Although loop filter unit 320 is shown in FIG. 3 as an in-loop filter, in other configurations, loop filter unit 320 may be implemented as a post-loop filter.

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

Decoder 30 is used to output decoded picture 31, eg, by output 332, for presentation to a user or for viewing by a user.

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

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

It should be understood that, in the encoder 20 and the decoder 30 of the present application, the processing result for a certain link may be further processed and output to the next link, for example, in interpolation filtering, motion vector derivation or loop filtering, etc. After the link, further operations such as Clip or shift are performed 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 be further processed, which is not limited in this application. For example, the value range of the motion vector is constrained to be 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 a power. If bitDepth is 16, the value range is -32768～32767. If bitDepth is 18, the value range is -131072 to 131071. Constraints can be made in 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, which is 32767 obtained by the above formula. 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 processing for 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)

Among them, Clip3 is defined as, indicating that the value of z is clamped to the interval [x, y]:

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

The video coding apparatus 400 includes an ingress port 410 and a receiving unit (Rx) 420 for receiving data, a processor, logic unit or central processing unit (CPU) 430 for processing data, a transmitter unit for transmitting data (Tx) 440 and egress port 450, and, memory 460 for storing data. Video coding apparatus 400 may also include opto-electrical conversion components and electro-optical (EO) components coupled to ingress port 410, receiver unit 420, transmitter unit 440, and egress port 450 for egress or ingress of optical or electrical signals.

The processor 430 is implemented by hardware and software. Processor 430 may be implemented as one or more CPU chips, cores (eg, multi-core processors), FPGAs, ASICs, and DSPs. Processor 430 communicates with ingress port 410 , receiver unit 420 , transmitter unit 440 , egress port 450 and memory 460 . Processor 430 includes a decoding module 470 (eg, encoding module 470 or decoding module 470). The encoding/decoding module 470 implements the embodiments disclosed herein to implement the chroma block prediction method provided by the embodiments of the present application. For example, the encoding/decoding module 470 implements, processes or provides various encoding operations. Thus, a substantial improvement in the functionality of the video coding apparatus 400 is provided by the encoding/decoding module 470, and the transition of the video coding apparatus 400 to different states is affected. Alternatively, the encoding/decoding module 470 is implemented as instructions stored in the memory 460 and executed by the processor 430 .

Memory 460 includes one or more magnetic disks, tape drives, and solid-state drives, and can be used as an overflow data storage device for storing programs as they are selectively executed, and for storing instructions and data read during program execution. 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 may 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 apparatus 500 may implement the techniques 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 present application. The decoding device 500 may include a processor 510 , a memory 530 and a bus system 550 . The processor and the memory are connected through a bus system, the memory is used for storing instructions, and the processor is used for executing the 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. To avoid repetition, detailed description is omitted here.

In this embodiment of the present application, the processor 510 may be a central processing unit (Central Processing Unit, referred to as “CPU” for short), and the processor 510 may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASIC), off-the-shelf programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 530 may comprise a read only memory (ROM) device or a random access memory (RAM) device. Any other suitable type of storage device may also be used as memory 530 . Memory 530 may include code and data 531 accessed by processor 510 using bus 550 . The memory 530 may further include an operating system 533 and an application program 535 including at least one program that allows the processor 510 to perform the video encoding or decoding methods described herein (especially the inter prediction methods described herein). For example, applications 535 may include applications 1 through N, which further include video encoding or decoding applications (referred to as video coding applications) that perform the video encoding or decoding methods described in this application.

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

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

At present, the video coding and decoding technology mainly adopts the hybrid coding architecture, which uses the correlation of the video sequence in the spatial and temporal 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 pixels currently being coded, then calculates the residual between the predicted value and the actual value, 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. The MV and the 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 reference modes. Transform coding refers to transforming the image described in the spatial domain through a specific transform kernel (such as discrete cosine transform, Hadamard transform, etc.) to obtain transform coefficients, so as to change the data distribution and further reduce the amount of data. The inter-frame prediction involved in this application adopts predictive coding.

The inter-frame prediction targeted by the embodiments of the present application is historical motion vector prediction (History-based MotionVector Prediction HMVP).

In the current inter prediction process, a candidate motion vector list or a candidate predicted motion vector list of the current encoding and decoding block, that is, the HMVP list, may be constructed according to the motion information of the reconstructed block encoded or decoded before the current encoding and decoding block. 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 five candidate motion information in the HMVP queue respectively represent motion information corresponding to five modes: skip, B frame forward, B frame backward, B frame bidirectional, and B frame symmetric. When predicting the pixel value of a block to be processed, all candidate motion information is traversed from the generated HMVP queue of the block to be processed and 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 a coded unit is added to the HMVP queue, the HMVP will continuously update the candidate motion information in the HMVP queue. The update rules for candidate motion information in the queue are as follows:

1. If the length of the HMVP queue does not reach the preset maximum length upper limit, 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 FIG. 7 .

2. If the motion information is the same as the candidate motion information that already exists in the HMVP queue, no matter whether the length of the HMVP queue has reached the preset maximum length upper limit 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 FIG. 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 eliminate the candidate motion information that already exists in the HMVP queue. 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-HMVP _L-1 to the left in turn, and add the motion information to be added to the HMVP candidate Items are added at the end of the HMVP queue.

For the P frame, only the motion information of the coded block of the forward reference frame can be referred to. When the HMVP queue removes the candidate motion information, it may remove the motion information that can be used for the P frame, resulting in the pending processing of the P frame. When a block is used for inter-frame prediction, there is less motion information that can be referenced, 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 embodiments of the present application provide a video image prediction method and apparatus. On the basis that the HMVP technology has obtained a queue containing multiple motion information, the embodiments of the present application meet specific requirements for the HMVP queue (such as the currently pending queue). 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 solutions provided by the embodiments of the present application are first described in detail below from the encoding end.

Referring to FIG. 10 , a schematic flowchart of a video image prediction method provided by an embodiment of the present application, the method may be performed by a video image prediction apparatus, for example, the video image prediction apparatus may be the encoder 20 shown in FIG. 2 , Either the inter-frame 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, the HMVP includes N candidate motion vectors, and the video image prediction apparatus traverses each candidate motion vector included in the HMVP queue, and specifically executes the following process:

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

Wherein, the first candidate motion information is one of the historical motion vector prediction queues, for example, may be a candidate motion information traversed by the video image prediction apparatus.

Exemplarily, the first candidate motion information is acquired 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 acquired from the HMVP corresponding to the block to be processed.

After acquiring the first candidate motion information, it is determined whether to execute the derivation process according to the prediction direction of the candidate coded 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 block to be processed 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, the derived reference frame index is 0.

Exemplarily, the inter-frame 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 block to be processed is not skip mode and direct mode, the derivative process is not executed, and only the image to be processed determined based on the first candidate motion information will be 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, determine 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, based on the first candidate motion information, the derived reference frame index, and the derived motion vector, a pixel prediction value of the block to be processed corresponding to the first candidate motion information.

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

The pixel predictor of the block to be processed is determined according to the first candidate motion information, which is called the first predictor for the convenience of description; the pixel predictor of the block to be processed is determined according to the derived motion vector and the derived reference frame index, and for the convenience of description, it is called For the derived pixel predicted value, 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 is determined. 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 possible example, it can also include:

S1005, when the prediction direction is backward or bidirectional, (without executing the derivative process), use the pixel prediction value of the image to be processed determined only based on the first candidate motion information as the corresponding pixel of the first candidate motion information The pixel predicted value of the block to be processed.

In another feasible example, it can also 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, (do not execute the derivative process), use the pixel prediction value of the image to be processed determined only based on the motion information of the first candidate as the pixel prediction value of the to-be-processed image. The pixel prediction value of the block to be processed corresponding to the first candidate motion information.

Illustratively, referring to FIG. 11 , a method for determining a derived motion vector is exemplified.

After obtaining the derived reference frame index, the derived motion vector can be further calculated. Exemplarily, it can be implemented as follows:

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 and the encoded data in the first candidate motion information in the HMVP queue The derived scale factor of the motion vector of the block is d0'/d0, and based on this, the derived motion vector is determined as MV'=(d0'/d0)MV.

Exemplarily, after the derived motion vector is determined, the pending motion 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 predictions for the block:

Based on the above-mentioned derived motion vector and derived reference frame index, a new pixel prediction value, such as a derived pixel prediction value pred0', can be obtained. The pixel prediction value of the block to be processed determined based on the first candidate motion information, for example, is referred to as a first prediction value pred0. The weighted sum of the derived pixel-based predicted value and the first predicted value will be referred to as the second predicted value. The corresponding SATD values are calculated by using the two predicted values (the first predicted value and the second predicted value) and the magnitudes of the SATD values are compared. The predicted value with the smallest SATD value is used as the pixel predicted 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 a second weight (which may be referred to as a second weight), and the first predicted value multiplied by a first weight (which may be referred to as a first weight). and. The sum of the first weight and the second weight is equal to 1, for example, the first weight=the second weight=0.5.

In the embodiment of the present application, after the pixel values corresponding to the candidate motion information in the HMVP queue are determined in the above manner, the pixel prediction value with the smallest rate-distortion cost among the pixel prediction values corresponding to the N candidate motion information may 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 encoded 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, that is, the pixel prediction value corresponding to the second candidate motion information is determined by executing The derivative operation is determined, and 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 Not determined by performing a derivative operation, the index identifier is the second value. For example, the first value is 1 and the second value is 0. In the subsequent description, the first value is 1 and the second value is 0 as an example.

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

The first way is to update while traversing. For example, the HMVP includes N candidate motion information, which are respectively HMVP0-HMVP _N-1 . It is implemented in the manner shown in FIG. 10 .

The following 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 predict the pixel predicted value of the processing block respectively, and calculate SATD according to the two predicted values, and compare the size of the two SATD values:

Specifically, the pixel prediction value calculated by HMVP0 is pred0[0]. Then use this HMVP0 to derive new motion information. Finally, the pixel prediction value is calculated through the derived motion information, and the weighted sum is performed with pred0[0] as a 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 size of the SATD value, and assign an 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 used, and the Flag is set to 1.

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

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

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 smallest 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 the comparison is performed 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 method is: after the traversal of the N candidate motion information included in the HMVP queue is completed, the index identifier is assigned again. For example, it is determined that the predicted value with the smallest rate-distortion cost among the pixel predicted values corresponding to HMVP0-HMVP _N-1 is HMVPk. If the pixel predicted value corresponding to HMVPk does not use a derivative operation, the index flag is assigned a value of 0. If a derivative operation is used, then The index flag is assigned the value 1.

Exemplarily, after the second candidate motion information and the index identifier are determined, 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 by the embodiments of the present application will be described in detail below from the decoding side. The inventive concept adopted on the decoding side and the encoding side is similar, and the repeated parts will not be repeated. For details, please refer to the relevant description of the encoding side.

Referring to FIG. 12 , it 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 may be performed by a video image prediction device, for example, the video image prediction device may be the encoder 30 shown in FIG. 3 , or the inter-frame prediction unit 344 in the encoder 30 , or one or more devices capable of performing decoding processor, or chip or system-on-chip.

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

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

Exemplarily, to determine the candidate motion information and the index identifier, the entropy decoding unit parses the candidate motion information and the index identifier from the code stream, and transmits the candidate motion information and the index identifier to the video image prediction apparatus.

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, determine The motion vectors of the decoded blocks are scaled to obtain derived motion vectors 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 of determining the pixel prediction value of the block to be processed is as follows:

The pixel predictor of the block to be processed is determined according to the candidate motion information, which is called the first predictor for the convenience of description; the pixel predictor of the block to be processed is determined according to the derived motion vector and the derived reference frame index, and is called the first predictor for the convenience of description. For the derived pixel predicted value, 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 pixel predicted value of the block to be processed.

Based on this, the pixel predicted 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 equal to the pixel predicted value of the to-be-processed block determined based only on the candidate motion information Multiplied by a 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 a second weight, the first weight The sum of the value and the second weight is equal to one. For example, the first weight=the second weight=0.5.

In a possible example, it can also include:

S1205, when the index identifier is a second value, determine the pixel prediction value of the to-be-processed image only based on the candidate motion information.

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

MV'=(d0'/d0)MV;

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 The motion vector of the decoded block.

Exemplarily, determining the derived reference frame index according to the reference frame index may 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 , the derived reference frame index is 0.

Based on the same inventive concept as the above method, as shown in FIG. 13 , an embodiment of the present application further provides a device 1300 , where the device 1300 includes an entropy decoding unit 1301 and an inter-frame 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.

An entropy decoding unit 1301, configured to parse candidate motion information and an index identifier from the code stream, where the candidate motion information includes a reference frame index of a block to be processed and a candidate motion vector identifier, where the motion vector identifier is used to indicate the to-be-processed block. processing the motion vectors of the decoded blocks referenced by the block;

The inter-frame prediction unit 1302 is configured to determine a derived reference frame index according to the reference frame index when the index identifier is 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, the motion vector of the decoded block is scaled to obtain the derived motion of the candidate motion information vector; determining a pixel predictor for 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 manner, the pixel prediction value of the block to be processed is equal to a sum of a first weighted value and a second weighted value, and the first weighted value is equal to the to-be-to-be determined only based on the candidate motion information The pixel prediction value of the processing block is multiplied by a first weight, and 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 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 identifier is the second value, the pixel prediction value of the to-be-processed image is determined only based on the candidate motion information.

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

MV'=(d0'/d0)MV;

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 The motion vector of the decoded block.

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

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, the derived reference frame index is determined to be 0.

It should be noted that the entropy decoding unit 1301 and the inter-frame prediction unit 1302 can be applied to the encoding/decoding and/or inter-frame prediction process at the decoding end.

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. 3 . . 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 further provides an apparatus, as shown in FIG. 14 , the apparatus 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 apparatus may include an acquisition unit 1401 and a determination unit 1402 . The obtaining unit 1401 and the determining unit 1402 execute the method steps shown in the embodiment corresponding to FIG. 10 .

This 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 apparatus 1500 may further include a memory 1530. Wherein, the memory 1530 may be provided inside the device, or may be provided outside the device.

Exemplarily, the apparatus 1500 can be applied to the decoding side, and the entropy decoding unit 1301 and the inter-frame prediction unit 1302 shown in FIG. 13 can be implemented by the processor 1520. The processor 1520 sends or receives a video stream or 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 through the hardware integrated logic circuit in the processor 1520 or the instructions in the form of software to complete the method described in FIG. 12 .

Exemplarily, the apparatus 1500 can also be applied to the encoding side, and the obtaining unit 1401 and the determining unit 1402 described in FIG. 14 can be implemented by the processor 1520. The processor 1520 sends or receives a video stream or 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 hardware integrated logic circuit in the processor 1520 or the instructions in the form of software to complete the method described in FIG. 10 .

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

In this embodiment of the present application, the processor 1520 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 may be implemented or executed The methods, steps, and logical block diagrams disclosed in the embodiments of the present application. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of the method disclosed in combination with the embodiments of the present application may be directly embodied as executed by a hardware processor, or executed by a combination of hardware and software units in the processor. The program codes executed by the processor 1520 for implementing the above method may be stored in the memory 1530 . Memory 1530 and 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, which may be in electrical, mechanical or other forms, and is used for information exchange between devices, units or modules.

Processor 1520 may cooperate with 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., and may also be a volatile memory (volatile memory), such as random access memory (random access memory). -access memory, RAM). Memory 1530 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto.

The specific connection medium between the communication interface 1510 , the processor 1520 , and the memory 1530 is not limited in the embodiments of the present application. In the embodiment of the present application, the memory 1530, the processor 1520, and the communication interface 1510 are connected by a bus in FIG. 15. 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 an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in FIG. 15, 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 further provide a computer storage medium, where a software program is stored in the storage medium, and when the software program is read and executed by one or more processors, it can implement any one or more of the above Methods provided by the examples. The computer storage medium may include: a U disk, a removable hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk and other mediums that can store program codes.

Based on the above embodiments, an embodiment of the present application further provides a chip, where 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 information. Optionally, the chip further includes a memory, and the memory is used for necessary program instructions and data to be executed by the processor. The chip may consist of chips, or may include chips and other discrete devices.

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

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

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

The techniques of this application may be implemented in a wide variety of devices or apparatuses, including a wireless handset, an integrated circuit (IC), or a set of ICs (eg, a chip set). Various components, modules, or units are described herein to emphasize functional aspects of means for performing the disclosed techniques, but do not necessarily require realization by different hardware units. Indeed, as described above, the various units may be combined in codec hardware units in conjunction with suitable software and/or firmware, or by interoperating hardware units (including one or more processors as described above) supply.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

The above is only an exemplary embodiment of the present application, but the protection scope of the present application is not limited to this. Substitutions should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims (13)

1. a video image prediction method, is characterized in that, comprises: The candidate motion information and the index identifier are parsed from the code stream, where the candidate motion information includes the reference frame index of the block to be processed and the candidate motion vector identifier, where the motion vector identifier is used to indicate the decoded block referenced by the to-be-processed block the motion vector of ; When the index identifier is the first value, determining 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 scaling the motion vector of the decoded block to obtain a derived motion vector of the candidate motion information; A pixel predictor for 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 of 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, the first weighted value being equal to the motion based only on the candidate The pixel prediction value of the to-be-processed block determined by the information is multiplied by a first weight, and the second weight is equal to the pixel prediction value of the to-be-processed block determined based on the derived motion vector and the derived reference frame index Multiplied by the second weight, the sum of the first weight and the second weight is equal to 1. 3. The method of claim 2, wherein the first weight is equal to the second weight. 4. The method of any one of claims 1-3, further comprising: When the index identifier is the second value, the pixel prediction value of the to-be-processed image is determined only based on the candidate motion information. 5. The method according to any one of claims 1-4, wherein the derived motion vector is obtained according to the following formula: MV'=(d0'/d0)MV; 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 The motion vector of the decoded block. 6. The method according to any one of claims 1-5, 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, the derived reference frame index is determined to be 0. 7. A video image prediction device, comprising: An entropy decoding unit, configured to parse candidate motion information and an index identifier from the code stream, where the candidate motion information includes a reference frame index of a block to be processed and a candidate motion vector identifier, where the motion vector identifier is used to indicate the to-be-processed block the motion vector of the decoded block referenced by the block; An inter-frame prediction unit, configured to determine a derived reference frame index according to the reference frame index when the index identifier is 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, the motion vector of the decoded block is scaled to obtain the derived motion vector of the candidate motion information ; determining a pixel predictor of the block to be processed based on the candidate motion information, the derived reference frame index and the derived motion vector. 8. The apparatus of claim 7, 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, the first weighted value being equal to the motion based only on the candidate The pixel prediction value of the to-be-processed block determined by the information is multiplied by a first weight, and the second weight is equal to the pixel prediction value of the to-be-processed block determined based on the derived motion vector and the derived reference frame index Multiplied by the second weight, the sum of the first weight and the second weight is equal to 1. 9. The apparatus of claim 8, wherein the first weight is equal to the second weight. 10. The apparatus according to any one of claims 7-9, wherein the inter-frame prediction unit is further configured to: When the index identifier is the second value, the pixel prediction value of the to-be-processed image is determined only based on the candidate motion information. 11. The apparatus according to any one of claims 7-10, wherein the derived motion vector is obtained according to the following formula: MV'=(d0'/d0)MV; 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 The motion vector of the decoded block. 12. The apparatus according to any one of claims 7-11, wherein the inter-frame prediction unit, when determining the derived reference frame index according to the reference frame index, is specifically configured to: 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, the derived reference frame index is determined to be 0. 13. A video encoding and decoding device comprising: a non-volatile memory and a processor coupled to each other, the processor calling program code stored in the memory to execute any one of claims 1-6 Methods.

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