Encoding and decoding method, code stream, encoder, decoder and storage medium

Abstract

The embodiment of the invention discloses a coding and decoding method, a code stream, a coder, a decoder and a storage medium, and the method comprises the steps: determining a candidate data processing mode based on a first preset condition; determining a data processing mode parameter corresponding to the syntax element to be decoded; based on the candidate data processing modes, determining a target data processing mode according to the data processing mode parameters; and decoding the syntax element to be decoded according to the target data processing mode, and determining the value of the syntax element to be decoded. Therefore, the method can save the code rate, improve the coding and decoding efficiency, and further improve the coding and decoding performance.

Description

Coding and decoding method, code stream, encoder, decoder and storage medium Technical Field The embodiments of the present application relate to the field of point cloud encoding and decoding technology, and in particular, to an encoding and decoding method, a bit stream, an encoder, a decoder, and a storage medium. Background Art In the geometry-based point cloud compression (G-PCC) codec framework, the geometry information of the point cloud and the attribute information corresponding to the points in the point cloud are encoded separately. Among them, for the G-PCC codec framework, the geometry codec part can be divided into octree-based geometry codec and prediction tree-based geometry codec. In the related art, some parameter information of the encoder is not set reasonably, and because the probability value and index mapping table of the encoder have an update process, it is impossible to select the most matching encoder for encoding during the encoding process, which reduces the encoding and decoding efficiency. Summary of the invention The embodiments of the present application provide a coding and decoding method, a bit stream, an encoder, a decoder and a storage medium, which can save bit rate, improve coding and decoding efficiency, and thus improve coding and decoding performance. The technical solution of the embodiment of the present application can be implemented as follows: In a first aspect, an embodiment of the present application provides a decoding method, which is applied to a decoder, and the method includes: Based on the first preset condition, determining a candidate data processing mode; Determining a data processing mode parameter corresponding to a syntax element to be decoded; Based on the candidate data processing modes, determining a target data processing mode according to the data processing mode parameters; The syntax element to be decoded is decoded according to the target data processing mode, and the value of the syntax element to be decoded is determined. In a second aspect, an embodiment of the present application provides an encoding method, which is applied to an encoder, and the method includes: Based on the first preset condition, determining a candidate data processing mode; Determining a data processing mode parameter corresponding to a syntax element to be encoded; Based on the candidate data processing modes, determining a target data processing mode according to the data processing mode parameters; The values ​​of the syntax elements to be encoded are encoded according to the target data processing mode, and the obtained encoded bits are written into the bitstream. In a third aspect, an embodiment of the present application provides a code stream, which is generated by bit encoding based on information to be encoded; wherein the information to be encoded includes at least: the value of the syntax element to be encoded. In a fourth aspect, an embodiment of the present application provides an encoder, the encoder comprising a first determining unit and an encoding unit; wherein, A first determining unit, configured to determine a candidate data processing mode based on a first preset condition; and determine a data processing mode parameter corresponding to a syntax element to be encoded; The first determination unit is further configured to determine a target data processing mode according to the data processing mode parameters based on the candidate data processing modes; The encoding unit is configured to encode the value of the syntax element to be encoded according to the target data processing mode, and write the obtained encoded bits into the bit stream. In a fifth aspect, an embodiment of the present application provides an encoder, the encoder comprising a first memory and a first processor; wherein, A first memory, for storing a computer program that can be run on the first processor; The first processor is used to execute the method described in the second aspect when running a computer program. In a sixth aspect, an embodiment of the present application provides a decoder, the decoder comprising a second determining unit and a decoding unit; wherein, A second determination unit is configured to determine a candidate data processing mode based on a first preset condition; and determine a data processing mode parameter corresponding to a syntax element to be decoded; The second determination unit is further configured to determine the target data processing mode according to the data processing mode parameters based on the candidate data processing modes; The decoding unit is configured to decode the syntax element to be decoded according to the target data processing mode and determine the value of the syntax element to be decoded. In a seventh aspect, an embodiment of the present application provides a decoder, the decoder comprising a second memory and a second processor; wherein: A second memory for storing a computer program that can be run on a second processor; The second processor is used to execute the method described in the first aspect when running a computer program. In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed, it implements the method described in the first aspect, or implements the method described in the second aspect. The embodiment of the present application provides a coding and decoding method, a code stream, an encoder, a decoder and a storage medium. At the encoding end, based on a first preset condition, a candidate data processing mode is determined; a data processing mode parameter corresponding to a syntax element to be encoded is determined; based on the candidate data processing mode, a target data processing mode is determined according to the data processing mode parameter; the value of the syntax element to be encoded is encoded according to the target data processing mode, and the obtained encoded bits are written into the code stream. At the decoding end, based on the first preset condition, a candidate data processing mode is determined; a data processing mode parameter corresponding to a syntax element to be decoded is determined; based on the candidate data processing mode, a target data processing mode is determined according to the data processing mode parameter; the syntax element to be decoded is decoded according to the target data processing mode, and the value of the syntax element to be decoded is determined. In this way, both the encoding end and the decoding end determine the candidate data processing mode based on the first preset condition; then determine the corresponding data processing mode parameters based on the syntax elements to be encoded or the syntax elements to be decoded, and then determine the target data processing mode, and finally encode and decode the syntax elements according to the target data processing mode; in this way, since the candidate data processing modes meet the first preset condition, the best target encoder can be selected from these candidate data processing modes for encoding during the encoding process, thereby saving bit rate, improving encoding and decoding efficiency, and thus improving encoding and decoding performance. BRIEF DESCRIPTION OF THE DRAWINGS FIG1 is a schematic diagram of a network architecture for point cloud encoding and decoding; FIG. 2 is a schematic diagram of a composition framework of a G-PCC encoder; FIG3 is a schematic diagram of a composition framework of a G-PCC decoder; FIG4 is a schematic diagram of a flow chart of a decoding method provided in an embodiment of the present application; FIG5 is a schematic diagram of a flow chart of an encoding method provided in an embodiment of the present application; FIG6 is a schematic diagram of a detailed flow chart of an encoding method provided in an embodiment of the present application; FIG7 is a schematic diagram of a scanning order of an octree node provided in an embodiment of the present application; FIG8 is a schematic diagram of the distribution of child neighbor nodes and coplanar parent neighbor nodes of a child node 0 provided in an embodiment of the present application; FIG9 is a schematic diagram of the distribution order of 20 parent neighbor nodes of a child node 0 provided in an embodiment of the present application; FIG10A is a schematic diagram of the distribution of subnodes of a current node provided in an embodiment of the present application; FIG10B is a schematic diagram of another sub-node distribution of a current node provided in an embodiment of the present application; FIG11 is a schematic diagram of the distribution of child neighbor nodes and coplanar parent neighbor nodes of a child node 1 provided in an embodiment of the present application; FIG12 is a schematic diagram of the distribution order of 20 parent neighbor nodes of a child node 1 provided in an embodiment of the present application; FIG13 is a schematic diagram of a detailed flow chart of another encoding method provided in an embodiment of the present application; FIG14 is a schematic diagram of the composition structure of an encoder provided in an embodiment of the present application; FIG15 is a schematic diagram of a specific hardware structure of an encoder provided in an embodiment of the present application; FIG16 is a schematic diagram of the structure of a decoder provided in an embodiment of the present application; FIG17 is a schematic diagram of a specific hardware structure of a decoder provided in an embodiment of the present application; FIG. 18 is a schematic diagram of the composition structure of a coding and decoding system provided in an embodiment of the present application. DETAILED DESCRIPTION In order to enable a more detailed understanding of the features and technical contents of the embodiments of the present application, the implementation of the embodiments of the present application is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application. In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments, but it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict. It should also be noted that the terms "first\second\third" involved in the embodiments of the present application are only used to distinguish similar objects and do not represent a specific ordering of the objects. It is understandable that "first\second\third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. Before further describing the embodiments of the present application in detail, the nouns and terms involved in the embodiments of the present application are described first. The nouns and terms involved in the embodiments of the present application are subject to the following interpretations: Point Cloud Compression (PCC); Geometry-based Point Cloud Compression (G-PCC or GPCC); Video-based Point Cloud Compression (V-PCC or VPCC); Octree; Triangle soup (Trisoup); Intra Prediction; Look Up Table (LUT); Red-Green-Blue (RGB); Luminance-Chrominance (YUV); Level of Detail (LOD); Predicting Transform; Lifting Transform; Region Adaptive Hierarchal Transform (RAHT); Context-based Adaptive Binary Arithmetic Coding (CABAC) based on context model. It can be understood that point cloud is a three-dimensional representation of the surface of an object. Point cloud (data) of the surface of an object can be collected through acquisition equipment such as photoelectric radar, lidar, laser scanner, multi-view camera, etc. In addition, a point cloud refers to a collection of massive three-dimensional points, and the points in the point cloud may include the location information of the points and the attribute information of the points. For example, the location information of the points may be the three-dimensional coordinate information of the points. The location information of the points may also be referred to as the geometric information of the points. For example, the attribute information of the points may include color information and / or reflectivity, etc. For example, the color information may be information on any color space. For example, the color information may be RGB information. Among them, R represents red (Red, R), G represents green (Green, G), and B represents blue (Blue, B). For another example, the color information may be brightness and chromaticity (YCbCr, YUV) information. Among them, Y represents brightness, Cb (U) represents blue chromaticity, and Cr (V) represents red chromaticity. For a point cloud obtained according to the principle of laser measurement, the points in the point cloud may include the three-dimensional coordinate information of the points and the laser reflection intensity (reflectance) of the points. For another example, for a point cloud obtained according to the principle of photogrammetry, the points in the point cloud may include the three-dimensional coordinate information of the points and the color information of the points. For another example, a point cloud obtained by combining the principles of laser measurement and photogrammetry may include the three-dimensional coordinate information of the points, the laser reflection intensity (reflectance) of the points, and the color information of the points. Point clouds can be divided into the following categories according to the way they are obtained: The first type of static point cloud: the object is stationary, and the device that obtains the point cloud is also stationary; The second type of dynamic point cloud: the object is moving, but the device that obtains the point cloud is stationary; The third type of dynamic point cloud acquisition: the device that acquires the point cloud is moving. For example, point clouds can be divided into two categories according to their usage: Category 1: Machine perception point cloud, which can be used in autonomous navigation systems, real-time inspection systems, geographic information systems, visual sorting robots, disaster relief robots, etc. Category 2: Point cloud perceived by the human eye, which can be used in point cloud application scenarios such as digital cultural heritage, free viewpoint broadcasting, 3D immersive communication, and 3D immersive interaction. Since point clouds are a collection of massive points, storing point clouds not only consumes a lot of memory, but is also not conducive to transmission. There is also not enough bandwidth to support direct transmission of point clouds at the network layer without compression. Therefore, point clouds need to be compressed. Up to now, the point cloud coding framework that can compress the point cloud can be the G-PCC codec framework or the V-PCC codec framework provided by the Moving Picture Experts Group (MPEG), or the AVS-PCC codec framework provided by the Audio Video Standard (AVS). Among them, the G-PCC codec framework can be used to compress the first type of static point cloud and the third type of dynamically acquired point cloud, and the V-PCC codec framework can be used to compress the second type of dynamic point cloud. In the embodiment of the present application, the G-PCC codec framework is mainly described here. The embodiment of the present application provides a network architecture of a point cloud encoding and decoding system including a decoding method and an encoding method. FIG1 is a schematic diagram of a network architecture of a point cloud encoding and decoding provided by the embodiment of the present application. As shown in FIG1 , the network architecture includes one or more electronic devices 13 to 1N and a communication network 01, wherein the electronic devices 13 to 1N can perform video interaction through the communication network 01. During the implementation process, the electronic device can be various types of devices with point cloud encoding and decoding functions. For example, the electronic device can include a mobile phone, a tablet computer, a personal computer, a personal digital assistant, a navigator, a digital phone, a video phone, a television, a sensor device, a server, etc., which is not limited by the embodiment of the present application. Among them, the decoder or encoder in the embodiment of the present application can be the above-mentioned electronic device. Among them, the electronic device in the embodiment of the present application has a point cloud encoding and decoding function, generally including a point cloud encoder (ie, encoder) and a point cloud decoder (ie, decoder). The following uses the G-PCC codec framework as an example to illustrate the relevant technology. It can be understood that in the point cloud G-PCC encoding and decoding framework, for the point cloud data to be encoded, the point cloud data is first divided into multiple slices by slice division. In each slice, the geometric information of the point cloud and the attribute information corresponding to each point cloud are encoded separately. FIG2 shows a schematic diagram of the composition framework of a G-PCC encoder. As shown in FIG2, in the geometric encoding process, the geometric information is transformed so that all point clouds are contained in a bounding box, and then quantized. This step of quantization mainly plays a role in scaling. Due to the quantization rounding, the geometric information of a part of the point cloud is the same, so whether to remove duplicate points is determined based on parameters. The process of quantization and removal of duplicate points is also called voxelization. Then, the Bounding Box is divided into octrees or a prediction tree is constructed. In this process, arithmetic coding is performed on the points in the leaf nodes of the division to generate a binary geometric bit stream; or, arithmetic coding is performed on the intersection points (Vertex) generated by the division (surface fitting is performed based on the intersection points) to generate a binary geometric bit stream. In the attribute encoding process, after the geometric encoding is completed and the geometric information is reconstructed, color conversion is required first to convert the color information (i.e., attribute information) from the RGB color space to the YUV color space. Then, the point cloud is recolored using the reconstructed geometric information so that the uncoded attribute information corresponds to the reconstructed geometric information. Attribute encoding is mainly performed on color information. In the process of color information encoding, there are two main transformation methods. One is the distance-based lifting transformation that relies on LOD division, and the other is direct RAHT transformation. Both methods convert color information from the spatial domain to the frequency domain, and obtain high-frequency coefficients and low-frequency coefficients through transformation. Finally, the coefficients are quantized and then arithmetic coding is performed on the quantized coefficients to generate a binary attribute bit stream. FIG3 shows a schematic diagram of the composition framework of a G-PCC decoder. As shown in FIG3, for the acquired binary bit stream, the geometric bit stream and the attribute bit stream in the binary bit stream are first decoded independently. When decoding the geometric bit stream, the geometric information of the point cloud is obtained through arithmetic decoding-reconstruction of the octree / reconstruction of the prediction tree-reconstruction of the geometry-coordinate inverse conversion; when decoding the attribute bit stream, the attribute information of the point cloud is obtained through arithmetic decoding-inverse quantization-LOD partitioning / RAHT-color inverse conversion, and the point cloud data to be encoded (i.e., the output point cloud) is restored based on the geometric information and attribute information. It should be noted that, as shown in FIG. 2 or FIG. 3 , the current geometric coding of G-PCC can be divided into octree-based geometric coding (marked by a dotted box) and prediction tree-based geometric coding (marked by a dotted box). For octree-based geometry encoding (OctGeomEnc), octree-based geometry encoding includes: first, coordinate transformation of geometric information so that all point clouds are contained in a Bounding Box. Then quantization is performed. This step of quantization mainly plays a role of scaling. Due to quantization rounding, the geometric information of some points is the same. Whether to remove duplicate points is determined based on parameters. The process of quantization and removal of duplicate points is also called voxelization. Next, the Bounding Box is continuously divided into trees (such as octrees, quadtrees, binary trees, etc.) in the order of breadth-first traversal. For the child nodes generated by the division, a bit is used to indicate whether the corresponding rectangular block of the node in space contains a point, which is called a "placeholder code". The placeholder code of each node is encoded. In the geometric coding framework based on octree, the bounding box is divided into child nodes in sequence, and the non-empty child nodes (including points in the point cloud) are divided until the leaf node obtained by division is a 1×1×1 unit cube. Then the number of points contained in the leaf node is encoded, and finally the encoding of the geometric octree is completed to generate a binary code stream. In the geometric coding framework based on triangle face sets, octree division must also be performed first, but different from the geometric information encoding based on octree, this method does not need to divide the point cloud into unit cubes with a side length of 1×1×1 step by step, but stops dividing when the side length of the sub-block (Block) is W. Based on the surface formed by the distribution of the point cloud in each Block, the surface and the twelve edges of the Block are obtained. The Vertex coordinates of each Block are encoded in sequence to generate a binary code stream. For octree-based geometric decoding, the decoding end obtains the placeholder code of each node by continuously parsing in the order of breadth-first traversal, and continuously divides the nodes in turn until a 1×1×1 unit cube is obtained. The number of points contained in each leaf node is parsed, and finally the geometric reconstructed point cloud information is restored. For Predictive geometry coding (PredGeomTree), the Predictive geometry coding includes: first, sorting the input point cloud. The currently used sorting methods include disorder, Morton order, azimuth order and radial distance order. At the encoding end, the prediction tree structure is established by using two different methods, including: high-latency slow mode (KD-Tree, KD tree) and low-latency fast mode (using laser radar calibration information, each point is divided into different lasers (Laser), and the prediction tree structure is established according to different Lasers). Next, based on the structure of the prediction tree, each node in the prediction tree is traversed, and the geometric position information of the node is predicted by selecting different prediction modes to obtain the geometric prediction residual, and the geometric prediction residual is quantized using the quantization parameter. Finally, through continuous iteration, the prediction residual of the prediction tree node position information, the prediction tree structure and the quantization parameters are encoded to generate a binary code stream. For geometric decoding based on the prediction tree, the decoding end reconstructs the prediction tree structure by continuously parsing the bit stream, and then obtains the geometric position prediction residual information and quantization parameters of each prediction node through parsing, and dequantizes the prediction residual to recover the reconstructed geometric position information of each node, and finally completes the geometric reconstruction of the decoding end. In the related art, a dynamic update optimal binarization (Optimal Binarization with Update on the Fly, OBUF) technology is proposed for octree coding. The dynamic OBUF process is divided into two stages: (1) obtaining the context information of the placeholder code to be encoded and reducing the context information, and the information to be reduced each time will be dynamically adjusted during the encoding process; (2) mapping the reduced context information to a smaller set of binary encoders, and after each placeholder code encoding is completed, its index mapping relationship will also be updated. In the above process, the purpose of updating the index mapping table is to find an encoder that is closer to the probability for the current context state. The relevant technical approach is to assume that the probability value maintained by the encoder will monotonically increase or decrease with the encoder index value. However, during the encoding process, some parameter information of the encoder is not set reasonably. For example, the initial probability value of the encoder is 0.5 (if 16-bit bit accuracy is taken as an example, it corresponds to 32768). Moreover, since the probability value and index mapping table maintained by the encoder are updated, the probability value maintained by the encoder at any time may not necessarily increase or decrease monotonically with the encoder index value, resulting in the inability to select the most matching encoder for encoding during the encoding process, reducing the encoding and decoding efficiency. An embodiment of the present application provides a coding method, which determines a candidate data processing mode based on a first preset condition; determines a data processing mode parameter corresponding to a syntax element to be encoded; based on the candidate data processing mode, determines a target data processing mode according to the data processing mode parameter; encodes the value of the syntax element to be encoded according to the target data processing mode, and writes the obtained coded bits into a bitstream. An embodiment of the present application also provides a decoding method, which determines a candidate data processing mode based on a first preset condition; determines a data processing mode parameter corresponding to a syntax element to be decoded; based on the candidate data processing mode, determines a target data processing mode according to the data processing mode parameter; decodes the syntax element to be decoded according to the target data processing mode, and determines the value of the syntax element to be decoded. In this way, both the encoding end and the decoding end determine the candidate data processing mode based on the first preset condition; then determine the corresponding data processing mode parameters based on the syntax elements to be encoded or the syntax elements to be decoded, and then determine the target data processing mode, and finally encode and decode the syntax elements according to the target data processing mode; in this way, since the candidate data processing modes meet the first preset condition, the best target encoder can be selected from these candidate data processing modes for encoding during the encoding process, thereby saving bit rate, improving encoding and decoding efficiency, and thus improving encoding and decoding performance. The embodiments of the present application will be described in detail below with reference to the accompanying drawings. In one embodiment of the present application, referring to FIG4 , a schematic flow chart of a decoding method provided by an embodiment of the present application is shown. As shown in FIG4 , the method may include: S401: Determine a candidate data processing mode based on a first preset condition. It should be noted that the decoding method of the embodiment of the present application is applied to a decoder (or referred to as an "entropy decoder"). In addition, the decoding method may specifically refer to a point cloud decoding method, or a point cloud entropy decoding method. Based on this method, the decoding process of the syntax element to be decoded can be implemented, and the bit rate can be saved. It should also be noted that in the embodiment of the present application, the data processing mode may be used to implement a decoding function. That is, the data processing mode here may be regarded as a decoding method / entropy decoding method, or may also be regarded as a decoder / entropy decoder. It should be understood that in the embodiment of the present application, there may be multiple candidate data processing modes, that is, there may be multiple candidate decoders; subsequently, a target decoder is selected from the multiple candidate decoders, and the selected target decoder is used to decode the syntax element to be decoded. In addition, in the embodiment of the present application, there may be only one candidate data processing mode, that is, there is only one candidate decoder; at this time, different configuration parameters of the candidate decoders may be set, and then the decoder corresponding to the target configuration parameters may be used to decode the syntax element to be decoded, and no limitation is made to this. It should also be understood that in an embodiment of the present application, the first preset condition may be related to an initialization parameter, or the first preset condition may be related to a threshold parameter (such as an upper threshold parameter and / or a lower threshold parameter). The candidate data processing mode determined by the first preset condition can improve decoding efficiency during the decoding process. In some embodiments, determining the candidate data processing mode based on the first preset condition may include: determining an initialization parameter of the candidate data processing mode according to the first preset condition. It should be noted that, in the embodiment of the present application, the initialization parameter may indicate the probability value of the candidate data processing mode. That is, the embodiment of the present application may set the probability initial value of the candidate data processing mode so that the probability initial value of the candidate data processing mode can satisfy the decreasing or increasing order. Further, in some embodiments, determining the initialization parameter of the candidate data processing mode according to the first preset condition may include: determining a first sorting indication parameter according to the initialization parameter of the candidate data processing mode. It should also be noted that, in an embodiment of the present application, the value of the first sort indication parameter may include a first preset value and a second preset value; wherein the first preset value indicates the descending order of the initialization parameter, and the second preset value indicates the ascending order of the initialization parameter. For example, it is assumed that there are K candidate data processing modes, and the initialization parameters of the K candidate data processing modes are T0, T1, ..., T i …T K-1 , then for the first preset value, the order of decreasing initialization parameters is: T0≥T1≥…≥T i ≥…≥T K-1 ; For the second preset value, the order of increasing initialization parameters is: T0≤T1≤…≤T i ≤…≤T K-1 . In a possible implementation, the method may further include: determining a third preset value and a fourth preset value of the candidate data processing mode; and determining a value of the first sorting indication parameter according to the third preset value and the fourth preset value. It should be understood that in the embodiment of the present application, the third preset value indicates the update order of the probability values ​​of the candidate data processing modes, and the fourth preset value indicates the update order of the index values ​​of the candidate data processing modes. That is, the third preset value can indicate the candidate decoder probability update direction, and the fourth preset value can indicate the candidate decoder index mapping table update direction. In this way, according to the candidate decoder probability update direction and the candidate decoder index mapping table update direction, it can be determined whether the initialization parameters are in descending order or ascending order. In a specific embodiment, determining the value of the first sorting indication parameter according to the third preset value and the fourth preset value may include: If the third preset value and the fourth preset value are different, determining that the value of the first sorting indication parameter is the first preset value; If the third preset value is the same as the fourth preset value, it is determined that the value of the first sorting indication parameter is the second preset value. It should also be understood that in the embodiments of the present application, for the third preset value and the fourth preset value, in one possible implementation method, if the value of the third preset value is equal to 1, it indicates that the candidate decoder probability update direction is a decreasing direction; if the value of the third preset value is equal to 0, it indicates that the candidate decoder probability update direction is an increasing direction; and if the value of the fourth preset value is equal to 1, it indicates that the candidate decoder index mapping table update direction is a decreasing direction; if the value of the third preset value is equal to 0, it indicates that the candidate decoder index mapping table update direction is an increasing direction. In another possible implementation, if the value of the third preset value is equal to 0, it indicates that the candidate decoder probability update direction is in a decreasing direction; if the value of the third preset value is equal to 1, it indicates that the candidate decoder probability update direction is in an increasing direction; and if the value of the fourth preset value is equal to 0, it indicates that the candidate decoder index mapping table update direction is in a decreasing direction; if the value of the third preset value is equal to 1, it indicates that the candidate decoder index mapping table update direction is in an increasing direction. In this way, if the third preset value and the fourth preset value are different, it means that the candidate decoder probability update direction is opposite to the candidate decoder index mapping table update direction. At this time, the value of the first sorting indication parameter is the first preset value, that is, the first sorting indication parameter indicates the descending order of the initialization parameter, specifically: T0≥T1≥…≥T i ≥…≥T K-1 ; If the third preset value is the same as the fourth preset value, it means that the candidate decoder probability update direction is the same as the candidate decoder index mapping table update direction. At this time, the value of the first sorting indication parameter is the second preset value, that is, the first sorting indication parameter indicates the order of increasing initialization parameters, specifically: T0≤T1≤…≤T i ≤…≤T K-1. It should also be understood that in an embodiment of the present application, if the probability value of the candidate decoder and the corresponding index value in the index mapping table both increase (or remain unchanged) or both decrease (or remain unchanged), then it can be determined that the update direction of the candidate decoder probability is the same as the update direction of the candidate decoder index mapping table; otherwise, it is determined that the update direction of the candidate decoder probability is opposite to the update direction of the candidate decoder index mapping table. In another possible implementation, the method may further include: determining a first parameter corresponding to the candidate data processing mode; and determining a value of a first sorting indication parameter according to the first parameter. It should be understood that in the embodiment of the present application, the first parameter corresponding to the candidate data processing mode may refer to the symbol corresponding to the probability value stored by the candidate decoder. Exemplarily, the first parameter may indicate a specific value, such as a value of 0 or 1; or the first parameter may also indicate a symbol of binary arithmetic coding, such as a symbol of 0 or 1, which is not limited here. In a specific embodiment, determining the value of the first sorting indication parameter according to the first parameter may include: If the first parameter indicates the first data, determining that the value of the first sort indication parameter is a first preset value; If the first parameter indicates the second data, the value of the first sort indication parameter is determined to be a second preset value. It should also be understood that in the embodiment of the present application, the first data may be the symbol "0" and the second data may be the symbol "1". Exemplarily, if the probability value stored by the candidate decoder is the probability value of the symbol "0" with 16-bit precision, then the value of the first sorting indication parameter is the first preset value, that is, the first sorting indication parameter indicates the descending order of the initialization parameter, specifically: T0≥T1≥…≥T i ≥…≥T K-1 If the probability value stored by the candidate decoder is the probability value of the symbol "1" with 16-bit precision, then the value of the first sorting indication parameter is the second preset value, that is, the first sorting indication parameter indicates the order of increasing initialization parameters, specifically: T0≤T1≤…≤T i ≤…≤T K-1 . In this way, not only can we determine whether the initialization parameters are in descending or ascending order based on the candidate decoder probability update direction and the candidate decoder index mapping table update direction; in addition, based on the symbol (Symbol) corresponding to the probability value stored in the candidate decoder, we can also determine whether the initialization parameters are in descending or ascending order. In yet another possible implementation, the method may further include: When the value of the first sorting indication parameter is the first preset value, T i-1Greater than or equal to T i ; When the value of the first sorting indication parameter is the second preset value, T i-1 Less than or equal to T i ; Among them, T i is the initialization parameter of the candidate data processing mode, i=1,2,…,K-1, K represents the number of candidate data processing modes. Exemplarily, when the value of the first ranking indication parameter is the first preset value, T0≥T1≥…≥T i ≥…≥T K-1 ; When the value of the first sorting indication parameter is the second preset value, T0≤T1≤…≤T i ≤…≤T K-1 . In other embodiments, determining the candidate data processing mode based on the first preset condition may include: determining a threshold parameter of the candidate data processing mode according to the first preset condition. It should be noted that, in the embodiment of the present application, the threshold parameter may indicate the probability threshold value of the candidate data processing mode, wherein the probability threshold value includes: the probability upper limit value and / or the probability lower limit value. That is, the embodiment of the present application may set the probability threshold value of the candidate data processing mode so that the probability threshold value of the candidate data processing mode can satisfy the decreasing or increasing order. Further, in some embodiments, determining a threshold parameter of a candidate data processing mode according to a first preset condition may include: determining a second ranking indication parameter according to the threshold parameter of the candidate data processing mode. It should also be noted that, in the embodiment of the present application, the value of the second sort indication parameter includes a fifth preset value and a sixth preset value; wherein the fifth preset value indicates the descending order of the threshold parameter, and the sixth preset value indicates the ascending order of the threshold parameter. Exemplarily, assuming that there are K candidate data processing modes, the lower limit threshold parameters of the K candidate data processing modes are L0, L1, ..., L i …L K-1 , then for the fifth preset value, the order of decreasing lower limit threshold parameters is: L0≥L1≥…≥L i ≥…≥L K-1 ; For the sixth preset value, the order of increasing the lower threshold parameter is: L0≤L1≤…≤L i ≤…≤L K-1 The upper threshold parameters of the K candidate data processing modes are U0, U1…U i …U K-1 , then for the fifth preset value, the order of decreasing upper threshold parameters is: U0≥U1≥…≥U i≥…≥U K-1 ; For the sixth preset value, the order of increasing the upper threshold parameter is: U0≤U1≤…≤U i ≤…≤U K-1 . In a possible implementation, the method may further include: determining a third preset value and a fourth preset value of the candidate data processing mode; and determining a value of the second sorting indication parameter according to the third preset value and the fourth preset value. It should be understood that in the embodiment of the present application, the third preset value indicates the update order of the probability values ​​of the candidate data processing modes, and the fourth preset value indicates the update order of the index values ​​of the candidate data processing modes. That is, the third preset value may indicate the candidate decoder probability update direction, and the fourth preset value may indicate the candidate decoder index mapping table update direction. In this way, according to the candidate decoder probability update direction and the candidate decoder index mapping table update direction, it is possible to determine whether the threshold parameters (such as the lower threshold parameter, the upper threshold parameter, etc.) are in descending order or in increasing order. In a specific embodiment, determining the value of the second sorting indication parameter according to the third preset value and the fourth preset value may include: If the third preset value is different from the fourth preset value, determining that the value of the second sorting indication parameter is the fifth preset value; If the third preset value is the same as the fourth preset value, it is determined that the value of the second sorting indication parameter is the sixth preset value. It should be noted that in the embodiment of the present application, the values ​​of the third preset value and the fourth preset value can be found in the above content and will not be described in detail here. It should also be noted that, in the embodiment of the present application, if the third preset value is different from the fourth preset value, it means that the candidate decoder probability update direction is opposite to the candidate decoder index mapping table update direction. At this time, the value of the second sorting indication parameter is the fifth preset value, that is, the second sorting indication parameter indicates the order of decreasing threshold parameters, specifically L0≥L1≥…≥L i ≥…≥L K-1 , U0≥U1≥…≥U i ≥…≥U K-1 ; If the third preset value is the same as the fourth preset value, it means that the candidate decoder probability update direction is the same as the candidate decoder index mapping table update direction, and the value of the second sorting indication parameter is the sixth preset value, that is, the second sorting indication parameter indicates the order of increasing threshold parameters, specifically: L0≤L1≤…≤L i ≤…≤L K-1 ,U0≤U1≤…≤U i ≤…≤U K-1 . In another possible implementation, the method may further include: determining a first parameter corresponding to the candidate data processing mode; and determining a value of a second sorting indication parameter based on the first parameter. In a specific embodiment, determining the value of the second sorting indication parameter according to the first parameter may include: If the first parameter indicates the first data, determining that the value of the second sort indication parameter is a fifth preset value; If the first parameter indicates the second data, the value of the second sort indication parameter is determined to be a sixth preset value. It should be noted that, in the embodiments of the present application, the description of the first parameter can refer to the aforementioned content and will not be described in detail here. Exemplarily, the first data may be the symbol "0" and the second data may be the symbol "1". For example, if the probability value stored by the candidate decoder is the probability value of the symbol "0" with 16-bit precision, then the value of the second sorting indication parameter is the fifth preset value, that is, the fifth sorting indication parameter can indicate the order in which the lower limit threshold parameter decreases, specifically: L0≥L1≥…≥L i ≥…≥L K-1 , and the order in which the upper threshold parameters are decreased, specifically: U0≥U1≥…≥U i ≥…≥U K-1 If the probability value stored by the candidate decoder is the probability value of the symbol "1" with 16-bit precision, then the value of the second sorting indication parameter is the sixth preset value, that is, the sixth sorting indication parameter can indicate the order in which the lower limit threshold parameter increases, specifically: L0≤L1≤…≤L i ≤…≤L K-1 , and the order in which the upper threshold parameters are increased, specifically: U0≤U1≤…≤U i ≤…≤U K-1 . In this way, not only can it be determined whether the threshold parameters are in descending order or ascending order according to the candidate decoder probability update direction and the candidate decoder index mapping table update direction; in addition, according to the symbol (Symbol) corresponding to the probability value stored by the candidate decoder, it can also be determined whether the threshold parameters are in descending order or ascending order. In addition, the threshold parameters here may include a lower threshold parameter (such as a probability lower limit value) and / or an upper threshold parameter (such as a probability upper limit value). In another possible implementation, the method may further include: when the value of the second sorting indication parameter is a fifth preset value, if the threshold parameter is a lower threshold parameter, then L i-1 Greater than or equal to L i ; If the threshold parameter is the upper threshold parameter, then U i-1 Greater than or equal to U i ; When the value of the second sorting indication parameter is the sixth preset value, if the threshold parameter is the lower threshold parameter, then L i-1 Less than or equal to L i ; If the threshold parameter is the upper threshold parameter, then U i-1 Less than or equal to U i . In the present embodiment, L i is the lower threshold parameter of the candidate data processing mode, U i is the upper limit threshold parameter of the candidate data processing mode, i=1, 2, ..., K-1, and K represents the number of candidate data processing modes. Exemplarily, when the value of the second ranking indication parameter is the fifth preset value, L0≥L1≥…≥L i ≥…≥L K-1 , U0≥U1≥…≥U i ≥…≥U K-1 When the value of the second sorting indication parameter is the sixth preset value, L0≤L1≤…≤L i ≤…≤L K-1 ,U0≤U1≤…≤U i ≤…≤U K-1 . In another possible implementation, the method may further include: among the candidate data processing modes, determining that the lower threshold parameter of the current candidate data processing mode is the same as the upper threshold parameter of the adjacent candidate data processing mode, and determining that the upper threshold parameter of the current candidate data processing mode is the same as the lower threshold parameter of the adjacent candidate data processing mode. In a specific embodiment, if the third preset value and the fourth preset value are different, then L is determined. i-1 =U i If the third preset value is the same as the fourth preset value, then determine U i-1 =L i . In an embodiment of the present application, for the upper threshold parameter and the lower threshold parameter in the candidate decoder, it is necessary to satisfy: the lower threshold parameter of the current candidate decoder is the same as the upper threshold parameter of the adjacent candidate decoder, and the upper threshold parameter of the current candidate decoder is the same as the lower threshold parameter of the adjacent candidate decoder. Exemplarily, if the candidate decoder probability update direction is opposite to the candidate decoder index mapping table update direction, then L i-1 with U i Should meet: L i-1 =U i ; If the candidate decoder probability update direction is the same as the candidate decoder index mapping table update direction, then L i-1 with U i Should meet: Ui-1 =L i . In yet another possible implementation, the method may further include: adjusting a threshold parameter of the candidate data processing mode to determine an adjusted threshold parameter of the candidate data processing mode; Among them, when the value of the second sorting indication parameter is the fifth preset value, the second sorting indication parameter indicates the descending order of the adjustment threshold parameter; when the value of the second sorting indication parameter is the sixth preset value, the second sorting indication parameter indicates the ascending order of the adjustment threshold parameter. In the embodiment of the present application, the upper threshold parameter and the lower threshold parameter in the candidate decoder can be dynamically updated and adjusted, and it is only necessary to ensure that the upper threshold parameter and the lower threshold parameter after the update can still meet: L0≥L1≥…≥L i ≥…≥L K-1 , U0≥U1≥…≥U i ≥…≥U K-1 ; or, L0≤L1≤…≤L i ≤…≤L K-1 ,U0≤U1≤…≤U i ≤…≤U K-1 . S402: Determine a data processing mode parameter corresponding to a syntax element to be decoded. S403: Based on the candidate data processing modes, determine the target data processing mode according to the data processing mode parameters. It should be noted that in the embodiment of the present application, the syntax element to be decoded specifically refers to the syntax element to be decoded by the decoding end. The syntax element here can refer to a binary arithmetic coded symbol or any syntax element written into the bitstream, and no limitation is made here. It should also be noted that, in the embodiments of the present application, the data processing mode parameter specifically refers to the index value corresponding to the candidate data processing mode. In some embodiments, determining the data processing mode parameter corresponding to the syntax element to be decoded may include: determining context information of the syntax element to be decoded; and determining the data processing mode parameter according to the context information and a preset mapping table. Further, in some embodiments, determining data processing mode parameters according to context information and a preset mapping table may include: determining a context state of a syntax element to be decoded according to the context information; and determining data processing mode parameters according to the context state and a preset mapping table. It should be noted that, in the embodiment of the present application, the preset mapping table can be used to characterize the mapping relationship between the context state and the data processing mode parameters. It should also be noted that in an embodiment of the present application, context information can be divided into primary information and secondary information according to the importance of the information. Among them, for primary information, it will not be reduced; while for secondary information, it is possible to be reduced. After the context information has undergone a dynamic reduction process, the result is a context state (represented by D) composed of context information that has not been reduced. Each context state D will have a counter N to record the number of times the current state D has been accessed. If N is greater than a preset threshold, the dynamic reduction process will be updated, that is, subsequent grammatical elements to be encoded will consider more secondary information to form a new context state D. In this way, after determining the context state D, the data processing mode parameters corresponding to the syntax element to be decoded can be determined through the preset mapping table. The preset mapping table records the mapping relationship between multiple sets of context states and data processing mode parameters, and the data processing mode parameters and the data processing mode also have a corresponding relationship, so that the target data processing mode (i.e., the target decoder) corresponding to the syntax element to be decoded can be determined. Furthermore, in some embodiments, the method may further include: updating a preset mapping table according to the value of the syntax element to be decoded. In a specific embodiment, updating the preset mapping table may include: If the value of the syntax element to be decoded is the seventh preset value, reducing the data processing mode parameter in the preset mapping table; If the value of the syntax element to be decoded is the eighth preset value, the data processing mode parameter in the preset mapping table is increased. It should be noted that, in the embodiment of the present application, the seventh preset value is different from the eighth preset value, and the seventh preset value and the eighth preset value can be in parameter form or in digital form. Specifically, the syntax element to be decoded can be a parameter written in the profile or a value of a flag, which is not specifically limited here. Exemplarily, the seventh preset value may be set to 1, and the eighth preset value may be set to 0; or, the seventh preset value may be set to 0, and the eighth preset value may be set to 1; or, the seventh preset value may be set to true, and the eighth preset value may be set to false; or, the seventh preset value may be set to false, and the eighth preset value may be set to true. In the embodiment of the present application, the seventh preset value is 0, and the eighth preset value is 1, but this is not specifically limited. It should also be noted that, in the embodiment of the present application, after each decoding of a syntax element is completed, the data processing mode parameter in the preset mapping table can also be adjusted according to the value of the syntax element. For example, if the value of the currently decoded syntax element is 0, the data processing mode parameter can be reduced (or unchanged); if the value of the currently decoded syntax element is 1, the data processing mode parameter can be increased (or unchanged) to achieve the update of the preset mapping table. S404: Decode the syntax element to be decoded according to the target data processing mode, and determine the value of the syntax element to be decoded. It should be noted that, in the embodiment of the present application, after the target data processing mode (ie, the target decoder) is determined, the syntax element to be decoded can be decoded according to the target data processing mode to obtain the value of the syntax element to be decoded. It should also be noted that, in the embodiment of the present application, after decoding the syntax element to be decoded, it is also necessary to determine the probability value corresponding to the target decoder and update the probability value. Therefore, in some embodiments, the method may also include: determining a first probability value of the target data processing mode according to the value of the syntax element to be decoded; updating the first probability value of the target data processing mode, and determining a second probability value of the target data processing mode. In some embodiments, updating a first probability value of a target data processing mode to determine a second probability value of the target data processing mode may include: determining a second parameter corresponding to the target data processing mode; updating the first probability value of the target data processing mode according to the second parameter and the value of a syntax element to be decoded, and determining the second probability value of the target data processing mode. It should be understood that in the embodiment of the present application, the second parameter corresponding to the target data processing mode may refer to the symbol (Symbol) corresponding to the probability value stored by the target decoder. Exemplarily, the second parameter may indicate a specific value, such as a value of 0 or 1; or the second parameter may also indicate a symbol of binary arithmetic coding, such as a symbol of 0 or 1, which is not limited here. It should also be understood that in an embodiment of the present application, after decoding the syntax element to be decoded, if the probability value of the target decoder represents the probability of the second parameter, then the probability value of the target decoder can be increased or decreased according to the data indicated by the second parameter. In a possible implementation manner, updating the first probability value of the target data processing mode according to the second parameter and the value of the syntax element to be decoded may include: If the second parameter indicates the first data, and the value of the syntax element to be decoded is the seventh preset value, increasing the first probability value of the target data processing mode; If the second parameter indicates the first data, and the value of the syntax element to be decoded is an eighth preset value, then the first probability value of the target data processing mode is reduced. Alternatively, in another possible implementation manner, updating the first probability value of the target data processing mode according to the second parameter and the value of the syntax element to be decoded may include: If the second parameter indicates the second data, and the sign of the syntax element to be decoded is a seventh preset value, reducing the first probability value of the target data processing mode; If the second parameter indicates the second data, and the sign of the syntax element to be decoded is an eighth preset value, then the first probability value of the target data processing mode is increased. Exemplarily, if the probability value of the target decoder represents the probability of the symbol "0", then when the currently decoded syntax element is 0, the probability value of the target decoder is increased (or unchanged), and when the currently decoded syntax element is 1, the probability value of the target decoder is decreased (or unchanged); if the probability value of the encoder represents the probability of the symbol "1", then when the currently decoded syntax element is 0, the probability value of the target decoder is decreased (or unchanged), and when the currently decoded syntax element is 0, the probability value of the target decoder is increased (or unchanged). Furthermore, in some embodiments, the method may also include: correcting the second probability value of the target data processing mode to determine a target probability value of the target data processing mode. In a specific embodiment, correcting the second probability value of the target data processing mode to determine the target probability value of the target data processing mode may include: If the second probability value is less than the probability lower limit value, the target probability value is set to the probability lower limit value; If the second probability value is greater than the probability upper limit value, the target probability value is set to the probability upper limit value; If the second probability value is greater than or equal to the probability lower limit value and less than or equal to the probability upper limit value, the target probability value is set to the second probability value. It should be noted that, in the embodiment of the present application, the second probability value of the target data processing mode can be expressed as P i It means that, then for P i Two threshold values ​​can be set: probability upper limit (high threshold) U i And the probability lower limit (lower threshold) L i , should satisfy L i ≤U i After performing the probability update, it is also necessary to perform P k =Clip3(L i ,U i ,P i ), where Clip3(x,y,z) is the truncation calculation function, and its calculation formula is as follows: Wherein, i=0, 1, 2, ..., K-1, and K represents the number of candidate data processing modes. In short, in an embodiment of the present application, a group of candidate decoders having initialization parameters in ascending (increasing) or descending (decreasing) order are proposed, and the ascending (increasing) or descending (decreasing) order can be determined by the sign corresponding to the probability value of the decoder; and this group of candidate decoders is also a decoder with upper threshold parameters and lower threshold parameters. This embodiment provides a decoding method, firstly determining a candidate data processing mode according to a first preset condition, then determining a corresponding data processing mode parameter according to a syntax element to be decoded, and then determining a target data processing mode from these candidate data processing modes, and finally decoding the syntax element according to the target data processing mode. In this way, since the candidate data processing mode satisfies the first preset conditions such as the initialization parameter, the upper threshold parameter, and the lower threshold parameter, the best target decoder can be selected from these candidate data processing modes for decoding during the decoding process, thereby saving bit rate, improving encoding and decoding efficiency, and thus improving encoding and decoding performance. In another embodiment of the present application, referring to FIG5 , a schematic diagram of a flow chart of an encoding method provided in an embodiment of the present application is shown. As shown in FIG5 , the method may include: S501: Determine a candidate data processing mode based on a first preset condition. It should be noted that the encoding method of the embodiment of the present application is applied to an encoder (or referred to as an "entropy encoder"). In addition, the encoding method may specifically refer to a point cloud encoding method, or a point cloud entropy encoding method. Based on this method, the encoding process of the syntax element to be encoded can be implemented, and the bit rate can be saved. It should also be noted that in the embodiment of the present application, the data processing mode may be used to implement the encoding function. That is, the data processing mode here can be regarded as an encoding method / entropy encoding method, or can also be regarded as an encoder / entropy encoder. It should be understood that in the embodiment of the present application, there may be multiple candidate data processing modes, that is, there may be multiple candidate encoders; subsequently, a target encoder is selected from the multiple candidate encoders, and the selected target encoder is used to encode the value of the grammatical element to be encoded. In addition, in the embodiment of the present application, there may be only one candidate data processing mode, that is, there is only one candidate encoder; in this case, different configuration parameters of the candidate encoders may be set, and then the encoder corresponding to the target configuration parameters may be used to encode the value of the grammatical element to be encoded, and no limitation is made to this. It should also be understood that in an embodiment of the present application, the first preset condition may be related to an initialization parameter, or the first preset condition may be related to a threshold parameter (such as an upper threshold parameter and / or a lower threshold parameter). The candidate data processing mode determined by the first preset condition can improve the encoding efficiency during the encoding process. In some embodiments, determining the candidate data processing mode based on the first preset condition may include: determining an initialization parameter of the candidate data processing mode according to the first preset condition. It should be noted that, in the embodiment of the present application, the initialization parameter may indicate the probability value of the candidate data processing mode. That is, the embodiment of the present application may set the probability initial value of the candidate data processing mode so that the probability initial value of the candidate data processing mode can satisfy the decreasing or increasing order. Further, in some embodiments, determining the initialization parameter of the candidate data processing mode according to the first preset condition may include: determining a first sorting indication parameter according to the initialization parameter of the candidate data processing mode. It should also be noted that, in an embodiment of the present application, the value of the first sort indication parameter may include a first preset value and a second preset value; wherein the first preset value indicates the descending order of the initialization parameter, and the second preset value indicates the ascending order of the initialization parameter. In a possible implementation, the method may further include: determining a third preset value and a fourth preset value of the candidate data processing mode; and determining a value of the first sorting indication parameter according to the third preset value and the fourth preset value. It should be understood that in the embodiment of the present application, the third preset value indicates the update order of the probability values ​​of the candidate data processing modes, and the fourth preset value indicates the update order of the index values ​​of the candidate data processing modes. That is, the third preset value may indicate the candidate encoder probability update direction, and the fourth preset value may indicate the candidate encoder index mapping table update direction. In this way, according to the candidate encoder probability update direction and the candidate encoder index mapping table update direction, it is possible to determine whether the initialization parameters are in descending order or ascending order. In a specific embodiment, determining the value of the first sorting indication parameter according to the third preset value and the fourth preset value may include: If the third preset value and the fourth preset value are different, determining that the value of the first sorting indication parameter is the first preset value; If the third preset value is the same as the fourth preset value, it is determined that the value of the first sorting indication parameter is the second preset value. It should be noted that in the embodiment of the present application, the values ​​of the third preset value and the fourth preset value can be found in the above content and will not be described in detail here. It should also be noted that, in the embodiment of the present application, if the third preset value and the fourth preset value are different, it means that the candidate encoder probability update direction is opposite to the candidate encoder index mapping table update direction. At this time, the value of the first sorting indication parameter is the first preset value, that is, the first sorting indication parameter indicates the order of decreasing initialization parameters, specifically: T0≥T i ≥…≥T i ≥…≥T K-1 ; If the third preset value is the same as the fourth preset value, it means that the candidate encoder probability update direction is the same as the candidate encoder index mapping table update direction. At this time, the value of the first sorting indication parameter is the second preset value, that is, the first sorting indication parameter indicates the order of increasing initialization parameters, specifically: T0≤T1≤…≤T i ≤…≤T K-1 . It should also be understood that in an embodiment of the present application, if the probability value of the candidate encoder and the corresponding index value in the index mapping table both increase (or remain unchanged) or both decrease (or remain unchanged), then it can be determined that the update direction of the candidate encoder probability is the same as the update direction of the candidate encoder index mapping table; otherwise, it is determined that the update direction of the candidate encoder probability is opposite to the update direction of the candidate encoder index mapping table. In another possible implementation, the method may further include: determining a first parameter corresponding to the candidate data processing mode; and determining a value of a first sorting indication parameter according to the first parameter. In a specific embodiment, determining the value of the first sorting indication parameter according to the first parameter may include: If the first parameter indicates the first data, determining that the value of the first sort indication parameter is a first preset value; If the first parameter indicates the second data, the value of the first sort indication parameter is determined to be a second preset value. It should also be understood that in the embodiment of the present application, the first data may be the symbol "0" and the second data may be the symbol "1". Exemplarily, if the probability value stored by the candidate encoder is the probability value of the symbol "0" with 16-bit precision, then the value of the first sorting indication parameter is the first preset value, that is, the first sorting indication parameter indicates the descending order of the initialization parameter, specifically: T0≥T1≥…≥T i ≥…≥T K-1 If the probability value stored by the candidate encoder is the probability value of the symbol "1" with 16-bit precision, then the value of the first sorting indication parameter is the second preset value, that is, the first sorting indication parameter indicates the order of increasing initialization parameters, specifically: T0≤T1≤…≤T i ≤…≤T K-1 . In this way, not only can we determine whether the initialization parameters are in descending or ascending order based on the candidate encoder probability update direction and the candidate encoder index mapping table update direction; in addition, based on the symbol (Symbol) corresponding to the probability value stored by the candidate encoder, we can also determine whether the initialization parameters are in descending or ascending order. In yet another possible implementation, the method may further include: When the value of the first sorting indication parameter is the first preset value, T i-1 Greater than or equal to T i ; When the value of the first sorting indication parameter is the second preset value, T i-1 Less than or equal to T i . Among them, T i is the initialization parameter of the candidate data processing mode, i=1, 2, ..., K-1, K represents the number of candidate data processing modes. Exemplarily, when the value of the first ranking indication parameter is the first preset value, T0≥T1≥...≥T i ≥…≥T K-1 ; When the value of the first sorting indication parameter is the second preset value, T0≤T1≤…≤T i ≤…≤T K-1 . In other embodiments, determining the candidate data processing mode based on the first preset condition may include: determining a threshold parameter of the candidate data processing mode according to the first preset condition. It should be noted that, in the embodiment of the present application, the threshold parameter may indicate the probability threshold value of the candidate data processing mode, wherein the probability threshold value includes: the probability upper limit value and / or the probability lower limit value. That is, the embodiment of the present application may set the probability threshold value of the candidate data processing mode so that the probability threshold value of the candidate data processing mode can satisfy the decreasing or increasing order. Further, in some embodiments, determining a threshold parameter of a candidate data processing mode according to a first preset condition may include: determining a second ranking indication parameter according to the threshold parameter of the candidate data processing mode. It should also be noted that, in the embodiment of the present application, the value of the second sort indication parameter includes a fifth preset value and a sixth preset value; wherein the fifth preset value indicates the descending order of the threshold parameter, and the sixth preset value indicates the ascending order of the threshold parameter. In a possible implementation, the method may further include: determining a third preset value and a fourth preset value of the candidate data processing mode; and determining a value of the second sorting indication parameter according to the third preset value and the fourth preset value. It should be understood that in the embodiment of the present application, the third preset value indicates the update order of the probability values ​​of the candidate data processing modes, and the fourth preset value indicates the update order of the index values ​​of the candidate data processing modes. That is, the third preset value may indicate the candidate encoder probability update direction, and the fourth preset value may indicate the candidate encoder index mapping table update direction. In this way, according to the candidate encoder probability update direction and the candidate encoder index mapping table update direction, it is possible to determine whether the threshold parameters (such as the lower threshold parameter, the upper threshold parameter, etc.) are in descending order or in increasing order. In a specific embodiment, determining the value of the second sorting indication parameter according to the third preset value and the fourth preset value may include: If the third preset value is different from the fourth preset value, determining that the value of the second sorting indication parameter is the fifth preset value; If the third preset value is the same as the fourth preset value, it is determined that the value of the second sorting indication parameter is the sixth preset value. It should be noted that in the embodiment of the present application, the values ​​of the third preset value and the fourth preset value can be found in the above content and will not be described in detail here. It should also be noted that, in the embodiment of the present application, if the third preset value is different from the fourth preset value, it means that the candidate encoder probability update direction is opposite to the candidate encoder index mapping table update direction. At this time, the value of the second sorting indication parameter is the fifth preset value, that is, the second sorting indication parameter indicates the order of decreasing threshold parameters, specifically L0≥L1≥…≥L i ≥…≥L K-1 , U0≥U1≥…≥U i ≥…≥U K-1 ; If the third preset value is the same as the fourth preset value, it means that the candidate encoder probability update direction is the same as the candidate encoder index mapping table update direction, and the value of the second sorting indication parameter is the sixth preset value, that is, the second sorting indication parameter indicates the order of increasing threshold parameters, specifically: L0≤L1≤…≤L i ≤…≤L K-1 ,U0≤U1≤…≤U i ≤…≤U K-1 . In another possible implementation, the method may further include: determining a first parameter corresponding to the candidate data processing mode; and determining a value of a second sorting indication parameter based on the first parameter. In a specific embodiment, determining the value of the second sorting indication parameter according to the first parameter may include: If the first parameter indicates the first data, determining that the value of the second sort indication parameter is a fifth preset value; If the first parameter indicates the second data, the value of the second sort indication parameter is determined to be a sixth preset value. It should be noted that, in the embodiments of the present application, the description of the first parameter can refer to the aforementioned content and will not be described in detail here. Exemplarily, the first data may be the symbol "0" and the second data may be the symbol "1". For example, if the probability value stored by the candidate encoder is the probability value of the symbol "0" with 16-bit precision, then the value of the second sorting indication parameter is the fifth preset value, that is, the fifth sorting indication parameter can indicate the order in which the lower limit threshold parameter decreases, specifically: L0≥L1≥…≥L i ≥…≥L K-1 , and the order in which the upper threshold parameters are decreased, specifically: U0≥U1≥…≥U i ≥…≥U K-1 If the probability value stored by the candidate encoder is the probability value of the symbol "1" with 16-bit precision, then the value of the second sorting indication parameter is the sixth preset value, that is, the sixth sorting indication parameter can indicate the order in which the lower limit threshold parameter increases, specifically: L0≤L1≤…≤L i ≤…≤L K-1 , and the order in which the upper threshold parameters are increased, specifically: U0≤U1≤…≤U i ≤…≤U K-1 . In this way, not only can it be determined whether the threshold parameters are in descending order or ascending order according to the candidate encoder probability update direction and the candidate encoder index mapping table update direction; in addition, according to the symbol (Symbol) corresponding to the probability value stored by the candidate encoder, it can also be determined whether the threshold parameters are in descending order or ascending order. In addition, the threshold parameters here may include a lower threshold parameter (such as a probability lower limit value) and / or an upper threshold parameter (such as a probability upper limit value). In another possible implementation, the method may further include: when the value of the second sorting indication parameter is a fifth preset value, if the threshold parameter is a lower threshold parameter, then L i-1 Greater than or equal to L i ; If the threshold parameter is the upper threshold parameter, then U i-1 Greater than or equal to U i ; When the value of the second sorting indication parameter is the sixth preset value, if the threshold parameter is the lower threshold parameter, then L i-1 Less than or equal to L i ; If the threshold parameter is the upper threshold parameter, then U i-1 Less than or equal to U i . In the present embodiment, L i is the lower threshold parameter of the candidate data processing mode, U iis the upper limit threshold parameter of the candidate data processing mode, i=1, 2, ..., K-1, and K represents the number of candidate data processing modes. Exemplarily, when the value of the second ranking indication parameter is the fifth preset value, L0≥L1≥…≥L i ≥…≥L K-1 , U0≥U1≥…≥U i ≥…≥U K-1 When the value of the second sorting indication parameter is the sixth preset value, L0≤L1≤…≤L i ≤…≤L K-1 ,U0≤U1≤…≤U i ≤…≤U K-1 . In another possible implementation, the method may further include: among the candidate data processing modes, determining that the lower threshold parameter of the current candidate data processing mode is the same as the upper threshold parameter of the adjacent candidate data processing mode, and determining that the upper threshold parameter of the current candidate data processing mode is the same as the lower threshold parameter of the adjacent candidate data processing mode. In a specific embodiment, if the third preset value and the fourth preset value are different, then L is determined. i-1 =U i If the third preset value is the same as the fourth preset value, then determine U i-1 =L i . In an embodiment of the present application, for the upper threshold parameter and the lower threshold parameter in the candidate encoder, it is necessary to satisfy: the lower threshold parameter of the current candidate encoder is the same as the upper threshold parameter of the adjacent candidate encoder, and the upper threshold parameter of the current candidate encoder is the same as the lower threshold parameter of the adjacent candidate encoder. For example, if the candidate encoder probability update direction is opposite to the candidate encoder index mapping table update direction, then L i-1 with U i Should meet: L i-1 =U i ; If the candidate encoder probability update direction is the same as the candidate encoder index mapping table update direction, then L i-1 with U i Should meet: U i-1 =L i . In yet another possible implementation, the method may further include: adjusting a threshold parameter of the candidate data processing mode to determine an adjusted threshold parameter of the candidate data processing mode; Among them, when the value of the second sorting indication parameter is the fifth preset value, the second sorting indication parameter indicates the descending order of the adjustment threshold parameter; when the value of the second sorting indication parameter is the sixth preset value, the second sorting indication parameter indicates the ascending order of the adjustment threshold parameter. In the embodiment of the present application, the upper threshold parameter and the lower threshold parameter in the candidate encoder can be dynamically updated and adjusted, and it is only necessary to ensure that the upper threshold parameter and the lower threshold parameter after the update can still meet: L0≥L1≥…≥L i ≥…≥L K-1 , U0≥U1≥…≥U i ≥…≥U K-1 ; or, L0≤L1≤…≤L i ≤…≤L K-1 ,U0≤U1≤…≤U i ≤…≤U K-1 . S502: Determine a data processing mode parameter corresponding to a syntax element to be encoded. S503: Based on the candidate data processing modes, determine the target data processing mode according to the data processing mode parameters. It should be noted that in the embodiment of the present application, the syntax element to be encoded specifically refers to the syntax element to be encoded by the encoder. The syntax element here can refer to a symbol of binary arithmetic coding or any syntax element written into the bitstream, and no limitation is made here. It should also be noted that, in the embodiments of the present application, the data processing mode parameter specifically refers to the index value corresponding to the candidate data processing mode. In some embodiments, determining the data processing mode parameter corresponding to the syntax element to be encoded may include: determining context information of the syntax element to be encoded; and determining the data processing mode parameter according to the context information and a preset mapping table. Further, in some embodiments, determining data processing mode parameters according to context information and a preset mapping table may include: determining a context state of a syntax element to be encoded according to the context information; and determining data processing mode parameters according to the context state and a preset mapping table. It should be noted that, in the embodiment of the present application, the preset mapping table can be used to characterize the mapping relationship between the context state and the data processing mode parameters. It should also be noted that in an embodiment of the present application, context information can be divided into primary information and secondary information according to the importance of the information. Among them, for primary information, it will not be reduced; while for secondary information, it is possible to be reduced. After the context information has undergone a dynamic reduction process, the result is a context state (represented by D) composed of context information that has not been reduced. Each context state D will have a counter N to record the number of times the current state D has been accessed. If N is greater than a preset threshold, the dynamic reduction process will be updated, that is, subsequent grammatical elements to be encoded will consider more secondary information to form a new context state D. In this way, after determining the context state D, the data processing mode parameters corresponding to the syntax element to be encoded can be determined through the preset mapping table. The preset mapping table records the mapping relationship between multiple sets of context states and data processing mode parameters, and the data processing mode parameters and the data processing mode also have a corresponding relationship, so that the target data processing mode (i.e., the target encoder) corresponding to the syntax element to be encoded can be determined. Furthermore, in some embodiments, the method may further include: updating a preset mapping table according to the value of the syntax element to be encoded. In a specific embodiment, updating the preset mapping table may include: If the value of the syntax element to be encoded is the seventh preset value, reducing the data processing mode parameter in the preset mapping table; If the value of the syntax element to be encoded is the eighth preset value, the data processing mode parameter in the preset mapping table is increased. It should be noted that, in the embodiment of the present application, the seventh preset value is different from the eighth preset value, and the seventh preset value and the eighth preset value can be in parameter form or in digital form. Specifically, the syntax element to be encoded can be a parameter written in the profile or a value of a flag, which is not specifically limited here. Exemplarily, the seventh preset value may be set to 1, and the eighth preset value may be set to 0; or, the seventh preset value may be set to 0, and the eighth preset value may be set to 1; or, the seventh preset value may be set to true, and the eighth preset value may be set to false; or, the seventh preset value may be set to false, and the eighth preset value may be set to true. In the embodiment of the present application, the seventh preset value is 0, and the eighth preset value is 1, but this is not specifically limited. It should also be noted that, in the embodiment of the present application, after each encoding of a syntax element is completed, the data processing mode parameter in the preset mapping table can also be adjusted according to the value of the syntax element. For example, if the value of the currently encoded syntax element is 0, the data processing mode parameter can be reduced (or unchanged); if the value of the currently encoded syntax element is 1, the data processing mode parameter can be increased (or unchanged) to achieve the update of the preset mapping table. S504: Encode the value of the syntax element to be encoded according to the target data processing mode, and write the obtained encoded bits into the bitstream. It should be noted that in the embodiment of the present application, after the target data processing mode (ie, the target encoder) is determined, the value of the syntax element to be encoded can be encoded according to the target data processing mode, and the obtained encoded bits can be written into the bitstream. It should also be noted that, in the embodiment of the present application, after encoding the syntax element to be encoded, it is also necessary to determine the probability value corresponding to the target encoder and update the probability value. Therefore, in some embodiments, the method may also include: determining a first probability value of the target data processing mode according to the value of the syntax element to be encoded; updating the first probability value of the target data processing mode, and determining a second probability value of the target data processing mode. In some embodiments, updating a first probability value of a target data processing mode to determine a second probability value of the target data processing mode may include: determining a second parameter corresponding to the target data processing mode; updating the first probability value of the target data processing mode according to the second parameter and the value of a syntax element to be encoded, and determining the second probability value of the target data processing mode. It should be understood that in the embodiment of the present application, the second parameter corresponding to the target data processing mode may refer to the symbol (Symbol) corresponding to the probability value stored by the target encoder. Exemplarily, the second parameter may indicate a specific value, such as a value of 0 or 1; or the second parameter may also indicate a symbol of binary arithmetic coding, such as a symbol of 0 or 1, which is not limited here. It should also be understood that in an embodiment of the present application, after encoding the syntax element to be encoded, if the probability value of the target encoder represents the probability of the second parameter, then the probability value of the target encoder can be increased or decreased according to the data indicated by the second parameter. In a possible implementation manner, updating the first probability value of the target data processing mode according to the second parameter and the value of the syntax element to be encoded may include: If the second parameter indicates the first data, and the value of the syntax element to be encoded is the seventh preset value, increasing the first probability value of the target data processing mode; If the second parameter indicates the first data, and the value of the syntax element to be encoded is an eighth preset value, then the first probability value of the target data processing mode is reduced. Alternatively, in another possible implementation manner, updating the first probability value of the target data processing mode according to the second parameter and the value of the syntax element to be encoded may include: If the second parameter indicates the second data, and the sign of the syntax element to be encoded is a seventh preset value, reducing the first probability value of the target data processing mode; If the second parameter indicates the second data, and the sign of the syntax element to be encoded is an eighth preset value, then the first probability value of the target data processing mode is increased. Exemplarily, if the probability value of the target encoder represents the probability of the symbol "0", then when the currently encoded syntax element is 0, the probability value of the target encoder is increased (or unchanged), and when the currently encoded syntax element is 1, the probability value of the target encoder is decreased (or unchanged); if the probability value of the encoder represents the probability of the symbol "1", then when the currently encoded syntax element is 0, the probability value of the target encoder is decreased (or unchanged), and when the currently encoded syntax element is 0, the probability value of the target encoder is increased (or unchanged). Furthermore, in some embodiments, the method may also include: correcting the second probability value of the target data processing mode to determine a target probability value of the target data processing mode. In a specific embodiment, correcting the second probability value of the target data processing mode to determine the target probability value of the target data processing mode may include: If the second probability value is less than the probability lower limit value, the target probability value is set to the probability lower limit value; If the second probability value is greater than the probability upper limit value, the target probability value is set to the probability upper limit value; If the second probability value is greater than or equal to the probability lower limit value and less than or equal to the probability upper limit value, the target probability value is set to the second probability value. It should be noted that, in the embodiment of the present application, the second probability value of the target data processing mode can be expressed as P i It means that, then for P i Two threshold values ​​can be set: probability upper limit (high threshold) U i And the probability lower limit (lower threshold) L i , should satisfy L i ≤U i After performing the probability update, it is also necessary to perform P k =Clip3(L i ,U i ,P i ), where Clip3(x, y, z) is a truncation calculation function, and its calculation formula is shown in the above formula (1). In short, in an embodiment of the present application, a group of candidate encoders with ascending (increasing) or descending (decrease) initialization parameters are proposed, and the ascending (increasing) or descending (decrease) order can be determined by the sign corresponding to the probability value of the encoder; and this group of candidate encoders is also an encoder with upper threshold parameters and lower threshold parameters. Furthermore, an embodiment of the present application also provides a code stream, wherein the code stream is generated by bit encoding according to information to be encoded; wherein the information to be encoded includes at least: a value of a syntax element to be encoded. It should also be noted that, in the embodiment of the present application, for the syntax element to be encoded, the encoding end can encode it and write it into the bit stream; subsequently, the value of the syntax element can be determined by decoding at the decoding end, so that the decoding end can use the value of the syntax element to perform related decoding operations. This embodiment provides a coding method, firstly determining a candidate data processing mode according to a first preset condition, then determining a corresponding data processing mode parameter according to a syntax element to be coded, and then determining a target data processing mode from these candidate data processing modes, and finally coding the syntax element according to the target data processing mode. In this way, since the candidate data processing mode satisfies the first preset conditions such as the initialization parameter, the upper threshold parameter, and the lower threshold parameter, the best target encoder can be selected from these candidate data processing modes for coding during the coding process, thereby saving bit rate, improving coding and decoding efficiency, and thus improving coding and decoding performance. In another embodiment of the present application, based on the encoding method and decoding method described in the above embodiments, the technical solution of the embodiment of the present application can be applied to the dynamic OBUF process. Among them, for the dynamic OBUF process, it can be applied to the decoding end, it can also be applied to the encoding end, and it can even be applied to the encoding end and the decoding end at the same time, without specific limitation. Taking the encoding end as an example, Figure 6 is a detailed flow diagram of an encoding method provided in an embodiment of the present application. As shown in Figure 6, the detailed flow may include: S601: Determine a current syntax element to be encoded. S602: Determine context information. S603: Dynamically reduce the context information to determine a context state after the dynamic reduction. S604: Determine an encoder index value based on the index mapping table. S605: After determining the target encoder according to the encoder index value, use the target encoder to encode the current syntax element and update the probability value of the target encoder. It should be noted that, in the embodiment of the present application, after the probability value of the target encoder is updated, the following update process may also be performed: S606: Update the dynamic reduction process. S607: Go to the next syntax element. Here, the context information is the input of OBUF, which is composed of encoded syntax elements and can be divided into primary information and secondary information according to the importance of the information. Some of the secondary information will be reduced during the dynamic reduction process. In addition, the primary information will not be reduced, but the secondary information may be reduced. After the dynamic reduction process of the context information, the context state composed of the non-reduced context information is obtained. Each context state will have a counter N to record the number of times the current context state is accessed. If N is greater than the preset threshold, the dynamic reduction process will be updated, that is, the subsequent syntax elements to be encoded will consider more secondary information to form a new context state, which means that the reduced secondary information is dynamically adjusted. It should also be noted that, in the embodiment of the present application, for the encoder index mapping table, the following update process can be performed: S608: Update the index mapping table. Here, the index mapping table is the preset mapping table described in the above embodiment. At the encoding end, the index mapping table may specifically refer to an encoder index mapping table, which provides a mapping relationship between context states and encoder index values. Through this mapping table, the encoder index value that should be used for the grammatical element to be encoded in any context state can be obtained. After each grammatical element is encoded, the mapping relationship between the context state and the encoder index value in the mapping table is adjusted according to the result of the grammatical element. In a specific embodiment, the process shown in FIG6 is described below: (1) Determination of context information. It should be understood that the context information is the input of OBUF, which is composed of encoded syntax elements and can be divided into primary information and secondary information according to the importance of the information, wherein part of the secondary information will be reduced in the process of dynamic reduction. Based on the octree coding framework, the occupancy information of the current coding node is represented by an eight-bit binary code (placeholder code). The order of these eight bits indicates the occupancy of the child node at a certain position of the current node, where occupied is 1 and unoccupied is 0. Since the encoder currently used by GPCC is the context-based binary arithmetic coder (CABAC), the current coding symbol (bin) and the context model for updating the probability need to be input during encoding, so each bit of the 8-bit placeholder code of the current node, that is, the occupancy information of the child node of the current node, is encoded separately each time. The context of the child node to be encoded can be determined by the following types of information: the local sparsity of the child node to be encoded, the position information of the child node to be encoded and the occupancy of its encoded sibling nodes, the occupancy of the 6 coplanar neighbors of the current node, and the occupancy of the other 20 co-edge and co-point neighbors of the current node. The above context information is converted into a binary stream (bins), where the information with a stronger correlation with the current child node is located in the high position of the bins as the main information; the information with a weak correlation with the current child node is located in the low position of the bins as the secondary information. The order of these context information arranged by importance can be: the encoded sibling nodes of the current child node> the encoded coplanar child node neighbors of the current child node> the encoded co-edge child node neighbors of the current child node> the encoded co-point child node neighbors of the current child node> the encoded other child node neighbors of the current child node> the encoded coplanar parent node neighbors of the current child node> the encoded co-edge parent node neighbors of the current child node> the other 20 encoded parent node neighbors. When constructing context information, different context models are first constructed for the sub-nodes to be encoded at different positions of the current node according to the scanning order. The scanning order is shown in Figure 7. As the number of encoded sub-nodes in the current node increases, the effective context information that can be referenced by the unencoded sub-nodes will also change. In addition, there are different local sparsity determination methods for the eight sub-nodes of the current node, so each sub-node has its own context bins. The following takes sub-node 0 and sub-node 1 as examples to describe the process of establishing context information in detail. For child node 0: Here, there are child node neighbors with the same plane, edge, and point, no encoded sibling nodes, parent node neighbors with the same plane, and 20 other encoded neighbor nodes that can be referenced. When it is judged to be sparse, the context bins is 19 bits, with a maximum of 2 19 states, with the upper 6 bits as the main information and the lower 13 bits as the unreduced secondary information; when it is judged to be non-sparse, the context bins are 16 bits, with a maximum of 2 16 states, with the upper 4 bits as the main information and the lower 12 bits as the unreduced secondary information. Local sparsity can be established according to the number of occupations (NN) of the 12 encoded child nodes in the negative directions of x, y, and z adjacent to the current child node in Figure 8, where the number of occupations NN>1 is non-sparse, and the number of occupations NN<1 is sparse. The bins in each state will have corresponding identification bits. Exemplarily, Figure 8 shows a distribution diagram of the child neighbor nodes and coplanar parent neighbor nodes of child node 0, and Figure 9 shows a distribution order diagram of the 20 parent neighbor nodes of child node 0. Among them, numbers such as 1, 2, 4, 8, 16, and 32 represent the numbers of neighbor nodes. In addition, Table 1 shows the meaning of the bins value corresponding to child node 0, that is, the interpretation of each bit of context information in the bins. The order from the highest bit to the lowest bit reflects the importance of the information. Among them, gray filling 1 or 0 indicates the flag bit. In addition, it also involves coplanar child nodes, co-edge child nodes, co-point child nodes, clamped edge child nodes and co-position child nodes. In Table 1, B (Bottom), F (Front), and L (left) are the parent neighbor nodes of the six neighbors numbered 16, 4, and 2 that are coplanar with the current node in Figure 8. Since these three encoded nodes are located in the negative direction of the current node coordinate axis, their child node occupancy information can be obtained. Therefore, Table 1 lists the child nodes that are coplanar, co-edge, and co-point with the current encoded child node in these three directions one by one; Top, Back, and Right are the parent neighbor nodes of the six neighbors numbered 32, 8, and 1 that are coplanar with the current node in Figure 8. Since these three encoded nodes are located in the positive direction of the current node coordinate axis, their child node occupancy information cannot be obtained, and their correlation is weaker than the above-mentioned 12 child neighbor nodes; other numbers such as 9, 4, 1, and 2 in Table 1 are the serial numbers of the 20 co-edge / co-point neighbors of the current node except the six coplanar parent neighbors shown in Figure 9. It can be understood that for the "co-located" child node information in Table 1, there is also a child node numbered 0 in the encoded Bottom, Front, and Left nodes, and this node is called the co-located child node; the two letters LF, LB, and FB in Table 1 respectively represent the occupancy information of the two child nodes sandwiched between the Left direction and the Front direction that share the same edge with the current child node (obtained by the No. 1 placeholder code among the 20 neighbors), the occupancy information of the two child nodes sandwiched between the Left direction and the Bottom direction that share the same edge with the current child node (obtained by the No. 8 placeholder code among the 20 neighbors), and the occupancy information of the two child nodes sandwiched between the Front direction and the Bottom direction that share the same edge with the current child node (obtained by the No. 3 placeholder code among the 20 neighbors). Table 1 Furthermore, through the available placeholder codes of the parent neighbor nodes that are coplanar with the negative directions of the three coordinate axes of the current child node, the occupation information of its 3*8=24 child nodes can be obtained. Among these 24 child node information, 21 bits are used to construct the context information of the child node bit0. These 21 nodes can be divided into the following five categories (3+6+3+3+6=21) according to the degree of relevance to the child node 0: 1) The child nodes that are coplanar with the current node have one position each in the Bottom, Front, and Left directions, and use B face 、F face , L face express; 2) The child nodes that share the same edge with the current node have two bits in each of the three directions: Bottom, Front, and Left. The order of these two bits is determined by the scanning order. Use B 2 edge , B 1 edge 、F 2 face 、F 1 face , L 2 face , L 1 face express; 3) The child nodes that share the same point with the current node have one position in each of the three directions: Bottom, Front, and Left. Use B vertex 、F vertex , L vertex express; 4) The child nodes in the same position as the current node, that is, the child nodes with internal sequence number 0 in the bottom, front and left directions, use B bit0 、F bit0 , L bit0 10A and 10B , where the current node is represented by b0; 5) The child nodes that are coplanar with the co-located child nodes of the current node, that is, the unclassified child nodes that are coplanar with the co-located node in the three directions of Bottom, Front and Left. Each direction has two bits, and is represented by B 2 far , B 1 far 、F 2 far 、F 1 far , L 2 far , L 1 far express. Furthermore, the 26 parent neighbor nodes adjacent to the current node can be divided into the following five categories (3+3+3+n+17-n) according to their relevance to child node 0: 1) Three nodes that are coplanar with the current node and located in the negative direction of the coordinate axis are represented by Bottom, Front, and Left; 2) Three nodes that are coplanar with the current node and located in the positive direction of the coordinate axis, represented by Top, Back, and Right; 3) The three nodes that share the same edge with the current node and are located in the negative direction of the coordinate axis are numbered 1, 3, and 8 in the 20-neighborhood graph. The placeholder codes of these three nodes can be used to calculate the information of another type of child nodes that share the same edge with the current node. Each of these three nodes has two bits, and 1 is between Left and Front, 3 is between Left and Bottom, and 8 is between Front and Bottom. Therefore, LF is used. 2 1. LF 1 1. LB 2 3. LB 1 3. FB 2 8. Facebook 1 8 represents these 6 bits of information; 4) Other parent neighbors participating in the construction of context information, select n bits from the remaining 17 bits; 5) Unused parent neighbor information, that is, it does not participate in predicting the current child node occupancy, a total of 17-n bits. For child node 1: Here, there are child node neighbors with the same plane, edge, and point, there is one encoded sibling node bit0, there are parent node neighbors with the same plane, and 20 other encoded neighbor nodes that can be referenced. When it is judged to be sparse, the context bins is 19 bits, with a maximum of 2 19 states, with the upper 6 bits as the main information and the lower 13 bits as the unreduced secondary information; when it is judged to be non-sparse, the context bins is 19 bits, with a maximum of 2 19 states, with the upper 7 bits as the main information and the lower 12 bits as the unreduced secondary information. Local sparsity is established according to the number of occupancy (NN) of the 4 encoded child nodes in the negative y direction adjacent to the current child node in Figure 11, where the number of occupancy NN>0 is non-sparse, and the number of occupancy NN=0 is sparse. Exemplarily, Figure 11 shows a distribution diagram of the child neighbor nodes and coplanar parent neighbor nodes of child node 1, and Figure 12 shows a distribution order diagram of the 20 parent neighbor nodes of child node 1. Among them, numbers such as 1, 2, 4, 8, 16, 32 represent the numbers of neighbor nodes. In addition, Table 2 shows the meaning of the bins value corresponding to child node 1, that is, the interpretation of each bit of context information in the bins. According to Table 2, it can be seen that the encoded sibling node 0 occupies the highest importance of information and is located in the highest bit of the bins. Table 2 (2) Dynamic reduction / update dynamic reduction process. In the context information, the main information will not be reduced, but the secondary information may be reduced. After the context information is dynamically reduced, the result is a context state D composed of the context information that will not be reduced. Each context state D will have a counter N to record the number of times the current state D is accessed. If N is greater than the set threshold, the dynamic reduction process will be updated, that is, the subsequent syntax elements to be encoded will consider more secondary information to form a new context state D, which means that the reduced secondary information is dynamically adjusted. In summary, the initial number of bits in the context bins is very large, generally 16 to 19 bits. If the number of context states is not reduced, it will be a lot, causing storage burden. However, if the number of context states D is reduced by simply canceling part of the context information, the accuracy of probability estimation will be reduced. Therefore, it is necessary to dynamically reduce the context information. The idea is to implicitly activate some states D. These states D[i1][i2'] are the reorganized contexts of the fixed-bit main information i1 and the truncated kbit secondary information i2' in the original context bins. The reorganized context and the current encoded symbol are sent to the encoder to update the probability of these states. When the number of visits to these states D is greater than the preset threshold (the establishment of the preset threshold is related to the probability update of the encoder), the truncated kbit secondary information in the original context bins is changed to truncated (k-1)bit secondary information and then the context is reorganized again to activate the new state. This method of dynamically reducing the number of states adaptively activates, uses and updates some of the states D while retaining all valid contexts. Since in this process, it is necessary to introduce k[i1][i2'] to record the number of bits of secondary information truncation and counter N[i1][i2'] to record the frequency of use of the reorganized context, which will introduce a large memory overhead, the embodiment of the present application proposes a simplified process, that is, when the number of bits of secondary information retention is greater than a certain value d max When the secondary information is updated, the simplified counter N[i1] is used, that is, only the frequency of use of the main information is used as the basis for updating and truncating the secondary information, and k[i1] is used to record the number of truncated bits of the secondary information of this type of main information. This hybrid dynamic reduction scheme reduces the implementation complexity while retaining the original accuracy. (3) Encoder index mapping table and mapping table update. Here, the encoder index mapping table provides a mapping relationship between context states and encoder index values. Through this mapping table, the encoder index value that should be used for the syntax element to be encoded in any context state can be obtained. After each syntax element is encoded, the mapping relationship between the context state D and the encoder index value in the mapping table will be adjusted according to the result of the syntax element. In the GPCC coding framework, the encoder index mapping table can store an 8-bit encoder index value. When the current coded symbol is "1", the encoder index value is increased (or unchanged); when the current coded symbol is "0", the encoder index value is decreased (or unchanged). The specific update method is as follows, where stateVal is the encoder index value, CtxMap is the encoder index mapping table, ctxMapIdx is the context state D, and binVal is the current coded symbol. ctxMapTransition is a query table, as shown in Table 3, which shows the value of ctxMapTransition[i]. For example, the specific update process is described as follows: Table 3 i0123456789101112131415 value 0112479111416192322222015 After obtaining stateVal, the encoder corresponding to the currently encoded symbol can be obtained, and the encoder index value can correspond to the encoder one by one; it can also be further mapped, and multiple encoder index values ​​correspond to one encoder to obtain the final encoder index value. Exemplarily, in the GPCC encoding framework, stateVal needs to be shifted right by 2 bits to obtain the final encoder index value. Exemplarily, as shown in Figure 13, the process can specifically include: S1301: Input the current syntax element bin to be encoded. S1302: Constructing a context state index to be encoded. Specifically, in the embodiment of the present application, S1=1< <userBitS1,1<<userBitS2);i2’=i2> >k; idx=i2'*S2+i1. S1303: Determine whether counter[idx]>th. S1304: Execute k=k', i2'=i2>>k, idx=i2'*S2+i1. S1305: Execute ctxMapldx=idx, stateVal=CtxMap[ctxMapldx]. S1306: Determine binVal=1. S1307: Determine value and CtxMap[ctxMapldx] according to the first calculation model. S1308: Determine value and CtxMap[ctxMapldx] according to the second calculation model. S1309: Execute counter[idx]++, model=CtxMap[ctxMapldx]>>2. S1310: Send the bin to be encoded and the model model to the encoder to update the probability of the model encode(bin,model). Specifically, in the embodiment of the present application, for S1306, if the judgment result is yes, S1307 is executed, and the first calculation model at this time is: value = ctxMapTransition[(255-stateVal)>>4], CtxMap[ctxMapldx] = CtxMap[ctxMapldx]+value; if the judgment result is no, S1308 is executed, and the second calculation model at this time is: value = ctxMapTransition[(255-stateVal)>>4], CtxMap[ctxMapldx] = CtxMap[ctxMapldx]-value. (4) Encoder probability update. After encoding a binary syntax element, the probability value of the corresponding encoder is also updated. If the probability value of the encoder represents the probability of the symbol "0", when the current encoded binary syntax element is 0, the probability value of the encoder is increased (or unchanged); when the current encoded binary syntax element is 1, the probability value of the encoder is decreased (or unchanged); or, if the probability value of the encoder represents the probability of the symbol "1", when the current encoded binary syntax element is 0, the probability value of the encoder is decreased (or unchanged); when the current encoded binary syntax element is 0, the probability value of the encoder is increased (or unchanged). In the GPCC coding framework, the probability value of the encoder represents the probability of the symbol "0". After encoding the symbol "0", its probability value increases (or remains unchanged), and after encoding the symbol "1", its probability value decreases (or remains unchanged). The specific updating method is as follows, where binVal represents the encoded symbol, pro represents the probability value stored by the encoder, and CtxUpdateDelta is a lookup table, as shown in Table 4, which shows the value of CtxUpdateDelta[i+j]. For example, the specific update process is described as follows: if(binVal) pro-=CtxUpdateDelta[pro>>8]; else pro+=CtxUpdateDelta[255-(pro>>8)]. Table 4 Further, in the embodiment of the present application, in the encoder index mapping table, there are multiple encoders, and each encoder index value can correspond to an encoder. For the multiple encoders used (assuming the number is K), their index values ​​are 0 to K-1, and the probability values ​​of these K encoders are given initial values ​​T_0, T1...T i …T K-1 , the initial value represents a number in the range of [0 to 1]. If a 16-bit unsigned integer is used for representation and storage, the value range is 0 to 65535. When encoding binary symbols, the probability value of the corresponding encoder and the corresponding index in the mapping table are both increased (or unchanged) or decreased (or unchanged), that is, the encoder probability update direction is considered to be the same as the index mapping table update direction, otherwise the update direction is considered to be opposite. If the encoder probability update direction is opposite to the index mapping table update direction, the initial value should satisfy T0≥T i ≥…≥T i ≥…≥T K-2 ≥T K-1 ; If the encoder probability update direction is the same as the index mapping table update direction, the initial value should satisfy the initial value should satisfy: T0≤T1≤…≤T i ≤…≤T K-2 ≤T K-1 . In the prior art, namely the universal test software TMC13v19 of G-PCC, the value of K is 64, and the encoder probability update direction is opposite to the index mapping table update direction, so the probability values ​​of the 64 encoders can be set to the initial values ​​as follows: int coder_init_pro

[0064] ={ 65517,65444,65294,65066,64761,64379,63922,63390,62783,62104,61355,60537,59653,58704,57692, 56620,55490,54305,53068,51782,50451,49076,47663,46213,44731,43220,41683,40124,38548,36958, 35357,33750,32141,30533,28930,27335,25754,24190,22646,21127,19635,18175,16750,15364,14020, 12721,11470,10270,9125,8038,7009,6042,5140,4305,3540,2845,2222,1674,1202,806,488,249,91,16 }; Furthermore, in the embodiment of the present application, a threshold parameter may also be set for the probability value of the encoder. (a) For the K encoders used, the probability value P k Set two threshold values: low threshold L i And the high threshold U i , should satisfy L i ≤U i The encoder's probability value P k Add another step P after performing the probability update k =Clip3(L i ,U i ,P i ), where Clip3(x, y, z) is a truncation calculation function, and its calculation formula is shown in the above formula (1). (b) The lower threshold L of K encoders i And the high threshold value U i Also need to meet: If the encoder probability update direction is opposite to the index mapping table update direction, then L0≥L1≥…≥L i ≥…≥L K-2 ≥L K-1 、U0≥U1≥…≥U i ≥…≥U K-2 ≥U K-1 ; If the encoder probability update direction is the same as the index mapping table update direction, then L0≤L1≤…≤L i ≤…≤L K-2 ≤L K-1 、U0≤U1≤…≤U i ≤…≤U K-2 ≤U K-1 . In the related art, namely the universal test software TMC13v19 of G-PCC, the probability value stored by the encoder is the probability value of the symbol "0" with 16-bit precision. Therefore, the lower threshold L i And the high threshold U i Should satisfy L0≥L1≥…≥L i ≥…≥L K-2 ≥L K-1 、U0≥U1≥…≥U i ≥…≥U K-2 ≥U K-1 . (c) The high threshold and low threshold of the K encoders should satisfy that the high threshold of the encoder is the same as the low threshold of the adjacent encoder, and the low threshold of the encoder is the same as the high threshold of the adjacent encoder, as follows: If the encoder probability update direction is opposite to the index mapping table update direction, then L i , U i Should meet: L i =U i+1 (0≤i≤K-2); If the encoder probability update direction is the same as the index mapping table update direction, then L k , U k Should meet: U i =L i+1 (0≤i≤K-2). Combining the above three points, the high threshold and low threshold of 64 encoders can be set as follows: int coder_bound

[0064] [2]={ {65500,65535},{65388,65500},{65200,65388},{64933,65388}, {64590,64933},{64169,64590},{63675,64169},{63105,63675}, {62462,63105},{61747,62462},{60963,61747},{60112,60963}, {59194,60112},{58214,59194},{57171,58214},{56069,57171}, {54911,56069},{53699,54911},{52437,53699},{51128,52437}, {49774,51128},{48379,49774},{46947,48379},{45480,46947}, {43983,45480},{42458,43983},{40908,42458},{39340,40908}, {37756,39340},{36160,37756},{34555,36160},{32946,34555}, {31336,32946},{29730,31336},{28130,29730},{26541,28130}, {24967,26541},{23413,24967},{21880,23413},{20374,21880}, {18897,20374},{17454,18897},{16047,17454},{14681,16047}, {13359,14681},{12083,13359},{10857,12083},{9684,10857}, {8567,9684},{7509,8567},{6510,7509},{5575,6510}, {4706,5575},{3905,4706},{3175,3905},{2515,3175}, {1930,2515},{1419,1930},{985,1419},{627,985}, {349,627},{150,349},{32,150},{0,32}}; (d) The upper threshold U of each encoder i , low threshold L i It can also be dynamically updated and adjusted, as long as L0≥L1≥…≥L is maintained after the update i ≥…≥L K-2 ≥L K-1 、U0≥U1≥…≥U i ≥…≥U K-2 ≥U K-1 Or L0≤L1≤…≤L i ≤…≤L K-2 ≤L K-1 、U0≤U1≤…≤U i ≤…≤U K-2 ≤U K-1 That's it. Thus, based on the general test software TMC13V19 of G-PCC, the set probability initial value and the high and low threshold values ​​are shown in the technical solution of the embodiment of the present application. Compared with TMC13v19 of the related art, the geometric part code stream performance comparison of the present technical solution under lossless conditions is shown in Table 5. It can be seen from Table 5 that the present technical solution has an average gain of about 1.1% on the geometric code stream on these data, which saves coding bits. Table 5 Sequence bpip ratio [%] basketball_player_vox11_0000020098.9% dancer_vox11_0000000198.8% facade_00064_vox1198.8% longdress_vox10_130098.8% loot_vox10_120098.7% queen_020098.8%redandblack_vox10_155099.3%soldier_vox10_069098.7%thaidancer_viewdep_vox1299.2%average 98.9% In the embodiments of the present application, the specific implementation of the aforementioned embodiments is elaborated in detail through the above embodiments. It can be seen that according to the technical scheme of the aforementioned embodiments, since the candidate data processing mode satisfies the first preset conditions such as the initialization parameters, the upper threshold parameters and the lower threshold parameters, the best target encoder can be selected from these candidate data processing modes for encoding during the encoding process, thereby saving bit rate, improving encoding and decoding efficiency, and further improving encoding and decoding performance. In another embodiment of the present application, based on the same inventive concept as the above-mentioned embodiment, see FIG14, which shows a schematic diagram of the composition structure of an encoder 140 provided in an embodiment of the present application. As shown in FIG14, the encoder 140 may include: a first determining unit 1401 and an encoding unit 1402; wherein, The first determining unit 1401 is configured to determine a candidate data processing mode based on a first preset condition; and determine a data processing mode parameter corresponding to a syntax element to be encoded; The first determining unit 1401 is further configured to determine a target data processing mode according to the data processing mode parameters based on the candidate data processing modes; The encoding unit 1402 is configured to encode the value of the syntax element to be encoded according to the target data processing mode, and write the obtained encoding bits into the bitstream. It should be noted that, in the embodiment of the present application, the encoder 140 can also be regarded as a data processing mode (or "entropy encoder"), which is used to encode the values ​​of the encoded syntax elements. In some embodiments, the first determination unit 1401 is further configured to determine an initialization parameter of the candidate data processing mode according to the first preset condition. In some embodiments, the initialization parameters indicate probability values ​​of candidate data processing modes. In some embodiments, the first determination unit 1401 is further configured to determine a threshold parameter of the candidate data processing mode according to a first preset condition. In some embodiments, the threshold parameter indicates a probability threshold value of the candidate data processing mode, wherein the probability threshold value includes: an upper probability limit value and / or a lower probability limit value. In some embodiments, the first determining unit 1401 is further configured to determine a first sorting indication parameter according to an initialization parameter of the candidate data processing mode. In some embodiments, the value of the first sort indication parameter includes a first preset value and a second preset value; wherein the first preset value indicates a decreasing order of the initialization parameter, and the second preset value indicates an increasing order of the initialization parameter. In some embodiments, the first determination unit 1401 is also configured to determine a third preset value and a fourth preset value of the candidate data processing mode; and determine a value of the first sorting indication parameter based on the third preset value and the fourth preset value; wherein the third preset value indicates an update order of probability values ​​of the candidate data processing mode, and the fourth preset value indicates an update order of index values ​​of the candidate data processing mode. In some embodiments, the first determination unit 1401 is further configured to determine that the value of the first sorting indication parameter is the first preset value if the third preset value and the fourth preset value are different; if the third preset value and the fourth preset value are the same, determine that the value of the first sorting indication parameter is the second preset value. In some embodiments, the first determination unit 1401 is further configured to determine a first parameter corresponding to the candidate data processing mode; and determine a value of the first sort indication parameter according to the first parameter. In some embodiments, the first determination unit 1401 is further configured to determine that the value of the first sort indication parameter is a first preset value if the first parameter indicates first data; and to determine that the value of the first sort indication parameter is a second preset value if the first parameter indicates second data. In some embodiments, the first determining unit 1401 is further configured to, when the value of the first sorting indication parameter is a first preset value, T i-1 Greater than or equal to T i ; When the value of the first sorting indication parameter is the second preset value, T i-1 Less than or equal to T i ; Among them, T i is the initialization parameter of the candidate data processing mode, i=1,2,…,K-1, K represents the number of candidate data processing modes. In some embodiments, the first determining unit 1401 is further configured to determine a second sorting indication parameter according to a threshold parameter of the candidate data processing mode. In some embodiments, the value of the second sort indication parameter includes a fifth preset value and a sixth preset value; wherein the fifth preset value indicates a decreasing order of the threshold parameter, and the sixth preset value indicates an increasing order of the threshold parameter. In some embodiments, the first determination unit 1401 is also configured to determine a third preset value and a fourth preset value of the candidate data processing mode; and determine the value of the second sorting indication parameter based on the third preset value and the fourth preset value; wherein the third preset value indicates the probability value update order of the candidate data processing mode, and the fourth preset value indicates the index value update order of the candidate data processing mode. In some embodiments, the first determination unit 1401 is further configured to determine that the value of the second sorting indication parameter is the fifth preset value if the third preset value is different from the fourth preset value; if the third preset value is the same as the fourth preset value, determine that the value of the second sorting indication parameter is the sixth preset value. In some embodiments, the first determination unit 1401 is further configured to determine a first parameter corresponding to the candidate data processing mode; and determine a value of the second sort indication parameter according to the first parameter. In some embodiments, the first determination unit 1401 is further configured to determine that the value of the second sort indication parameter is a fifth preset value if the first parameter indicates the first data; and to determine that the value of the second sort indication parameter is a sixth preset value if the first parameter indicates the second data. In some embodiments, the first determining unit 1401 is further configured to, when the value of the second ranking indication parameter is the fifth preset value, if the threshold parameter is the lower threshold parameter, then L i-1 Greater than or equal to L i ; If the threshold parameter is the upper threshold parameter, then U i-1 Greater than or equal to U i ; and when the value of the second sorting indication parameter is the sixth preset value, if the threshold parameter is the lower threshold parameter, then L i-1 Less than or equal to L i ; If the threshold parameter is the upper threshold parameter, then U i-1 Less than or equal to U i Among them, L i is the lower threshold parameter of the candidate data processing mode, U i is the upper limit threshold parameter of the candidate data processing mode, i=1, 2, ..., K-1, and K represents the number of candidate data processing modes. In some embodiments, the first determination unit 1401 is also configured to, in the candidate data processing mode, determine that the lower limit threshold parameter of the current candidate data processing mode is the same as the upper limit threshold parameter of the adjacent candidate data processing mode, and determine that the upper limit threshold parameter of the current candidate data processing mode is the same as the lower limit threshold parameter of the adjacent candidate data processing mode. In some embodiments, the first determining unit 1401 is further configured to determine L if the third preset value and the fourth preset value are different. i-1 =U iIf the third preset value is the same as the fourth preset value, then determine U i-1 =L i . In some embodiments, referring to FIG. 14 , the encoder 140 may further include a first updating unit 1403, configured to adjust the threshold parameters of the candidate data processing mode and determine the adjusted threshold parameters of the candidate data processing mode; wherein, when the value of the second sorting indication parameter is the fifth preset value, the second sorting indication parameter indicates the descending order of the adjustment threshold parameters; and when the value of the second sorting indication parameter is the sixth preset value, the second sorting indication parameter indicates the ascending order of the adjustment threshold parameters. In some embodiments, the first determining unit 1401 is further configured to determine context information of the syntax element to be encoded; and determine a data processing mode parameter according to the context information and a preset mapping table. In some embodiments, the first determination unit 1401 is also configured to determine the context state of the syntax element to be encoded based on the context information; and determine the data processing mode parameters based on the context state and a preset mapping table; wherein the preset mapping table is used to characterize the mapping relationship between the context state and the data processing mode parameters. In some embodiments, the first updating unit 1403 is further configured to update a preset mapping table according to the value of the syntax element to be encoded. In some embodiments, the first update unit 1403 is further configured to reduce the data processing mode parameter in the preset mapping table if the value of the syntax element to be encoded is the seventh preset value; if the value of the syntax element to be encoded is the eighth preset value, increase the data processing mode parameter in the preset mapping table. In some embodiments, the first updating unit 1403 is further configured to determine a first probability value of the target data processing mode according to the value of the syntax element to be encoded; and to update the first probability value of the target data processing mode to determine a second probability value of the target data processing mode. In some embodiments, the first determining unit 1401 is further configured to determine a second parameter corresponding to the target data processing mode; The first updating unit 1403 is further configured to update the first probability value of the target data processing mode according to the second parameter and the value of the syntax element to be encoded, and determine the second probability value of the target data processing mode. In some embodiments, the first updating unit 1403 is further configured to increase the first probability value of the target data processing mode if the second parameter indicates the first data and the value of the syntax element to be encoded is the seventh preset value; decrease the first probability value of the target data processing mode if the second parameter indicates the first data and the value of the syntax element to be encoded is the eighth preset value; or decrease the first probability value of the target data processing mode if the second parameter indicates the second data and the symbol of the syntax element to be encoded is the seventh preset value; increase the first probability value of the target data processing mode if the second parameter indicates the second data and the symbol of the syntax element to be encoded is the eighth preset value. In some embodiments, the first determination unit 1401 is further configured to correct the second probability value of the target data processing mode to determine a target probability value of the target data processing mode. In some embodiments, the first determination unit 1401 is further configured to set the target probability value to the lower probability limit value if the second probability value is less than the lower probability limit value; to set the target probability value to the upper probability limit value if the second probability value is greater than the upper probability limit value; and to set the target probability value to the second probability value if the second probability value is greater than or equal to the lower probability limit value and less than or equal to the upper probability limit value. It is understandable that in the embodiments of the present application, a "unit" may be a part of a circuit, a part of a processor, a part of a program or software, etc., and of course, it may be a module, or it may be non-modular. Moreover, the components in the present embodiment may be integrated into a processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of a software functional module. If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially or the part that contributes to the prior art or the whole or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) or a processor to perform all or part of the steps of the method described in this embodiment. The aforementioned storage medium includes: U disk, mobile hard disk, read only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes. Therefore, an embodiment of the present application provides a computer-readable storage medium, which is applied to the encoder 140. The computer-readable storage medium stores a computer program. When the computer program is executed by the first processor, it implements the encoding method described in any one of the aforementioned embodiments. Based on the composition of the encoder 140 and the computer-readable storage medium, refer to Figure 15, which shows a specific hardware structure diagram of the encoder 140 provided in an embodiment of the present application. As shown in Figure 15, the encoder 140 may include: a first communication interface 1501, a first memory 1502 and a first processor 1503; each component is coupled together through a first bus system 1504. It can be understood that the first bus system 1504 is used to achieve connection and communication between these components. In addition to the data bus, the first bus system 1504 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity, various buses are labeled as the first bus system 1504 in Figure 15. Among them, The first communication interface 1501 is used for receiving and sending signals during the process of sending and receiving information with other external network elements; A first memory 1502, used to store a computer program that can be run on the first processor 1503; The first processor 1503 is configured to, when running the computer program, execute: Based on the first preset condition, determining a candidate data processing mode; Determining a data processing mode parameter corresponding to a syntax element to be encoded; Based on the candidate data processing modes, determining a target data processing mode according to the data processing mode parameters; The value of the syntax element to be encoded is encoded according to the target data processing mode, and the obtained encoding bits are written into a bitstream. It can be understood that the first memory 1502 in the embodiment of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct memory bus random access memory (DRRAM). The first memory 1502 of the systems and methods described in the present application is intended to include, but is not limited to, these and any other suitable types of memory. The first processor 1503 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the first processor 1503. The above-mentioned first processor 1503 can be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor to execute, or the hardware and software modules in the decoding processor are combined and executed. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the first memory 1502, and the first processor 1503 reads the information in the first memory 1502 and completes the steps of the above method in combination with its hardware. It is to be understood that these embodiments described in the present application can be implemented with hardware, software, firmware, middleware, microcode or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application specific integrated circuits (Application Specific Integrated Circuits, ASIC), digital signal processors (Digital Signal Processing, DSP), digital signal processing equipment (DSP Device, DSPD), programmable logic devices (Programmable Logic Device, PLD), field programmable gate arrays (Field-Programmable Gate Array, FPGA), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units or combinations thereof for performing functions described in the present application. For software implementation, the technology described in the present application can be implemented by the module (such as process, function, etc.) performing the functions described in the present application. The software code can be stored in a memory and executed by a processor. The memory can be implemented in a processor or outside a processor. Optionally, as another embodiment, the first processor 1503 is further configured to execute the encoding method described in any one of the aforementioned embodiments when running the computer program. The present embodiment provides an encoder, in which, since the candidate data processing modes satisfy first preset conditions such as initialization parameters, upper threshold parameters and lower threshold parameters, an optimal target encoder can be selected from these candidate data processing modes for encoding during the encoding process, thereby saving bit rate, improving encoding and decoding efficiency, and further improving encoding and decoding performance. In another embodiment of the present application, based on the same inventive concept as the above-mentioned embodiment, refer to FIG16, which shows a schematic diagram of the composition structure of a decoder 160 provided in an embodiment of the present application. As shown in FIG16, the decoder 160 may include: a second determination unit 1601 and a decoding unit 1602; wherein, The second determining unit 1601 is configured to determine a candidate data processing mode based on a first preset condition; and determine a data processing mode parameter corresponding to a syntax element to be decoded; The second determining unit 1601 is further configured to determine a target data processing mode according to the data processing mode parameters based on the candidate data processing modes; The decoding unit 1602 is configured to decode the syntax element to be decoded according to the target data processing mode, and determine the value of the syntax element to be decoded. It should be noted that, in the embodiment of the present application, the decoder 160 can also be regarded as a data processing mode (or "entropy decoder"), which is used to decode the values ​​of the syntax elements to be decoded. In some embodiments, the second determining unit 1601 is further configured to determine the initialization parameters of the candidate data processing mode according to the first preset condition. In some embodiments, the initialization parameters indicate probability values ​​of candidate data processing modes. In some embodiments, the second determination unit 1601 is further configured to determine a threshold parameter of the candidate data processing mode according to the first preset condition. In some embodiments, the threshold parameter indicates a probability threshold value of the candidate data processing mode, wherein the probability threshold value includes: an upper probability limit value and / or a lower probability limit value. In some embodiments, the second determining unit 1601 is further configured to determine the first sorting indication parameter according to the initialization parameter of the candidate data processing mode. In some embodiments, the value of the first sort indication parameter includes a first preset value and a second preset value; wherein the first preset value indicates a decreasing order of the initialization parameter, and the second preset value indicates an increasing order of the initialization parameter. In some embodiments, the second determination unit 1601 is further configured to determine a third preset value and a fourth preset value of the candidate data processing mode; and determine the value of the first sorting indication parameter based on the third preset value and the fourth preset value; wherein the third preset value indicates the probability value update order of the candidate data processing mode, and the fourth preset value indicates the index value update order of the candidate data processing mode. In some embodiments, the second determination unit 1601 is further configured to determine that the value of the first sorting indication parameter is the first preset value if the third preset value and the fourth preset value are different; if the third preset value and the fourth preset value are the same, determine that the value of the first sorting indication parameter is the second preset value. In some embodiments, the second determination unit 1601 is further configured to determine a first parameter corresponding to the candidate data processing mode; and determine a value of the first sort indication parameter according to the first parameter. In some embodiments, the second determination unit 1601 is further configured to determine that the value of the first sort indication parameter is a first preset value if the first parameter indicates first data; and to determine that the value of the first sort indication parameter is a second preset value if the first parameter indicates second data. In some embodiments, the second determining unit 1601 is further configured to, when the value of the first sorting indication parameter is a first preset value, T i-1 Greater than or equal to T i ; and when the value of the first sorting indication parameter is the second preset value, T i-1 Less than or equal to T i ; Among them, T i is the initialization parameter of the candidate data processing mode, i=1,2,…,K-1, K represents the number of candidate data processing modes. In some embodiments, the second determining unit 1601 is further configured to determine a second sorting indication parameter according to a threshold parameter of the candidate data processing mode. In some embodiments, the value of the second sort indication parameter includes a fifth preset value and a sixth preset value; wherein the fifth preset value indicates a decreasing order of the threshold parameter, and the sixth preset value indicates an increasing order of the threshold parameter. In some embodiments, the second determination unit 1601 is also configured to determine a third preset value and a fourth preset value of the candidate data processing mode; and determine the value of the second sorting indication parameter based on the third preset value and the fourth preset value; wherein the third preset value indicates the probability value update order of the candidate data processing mode, and the fourth preset value indicates the index value update order of the candidate data processing mode. In some embodiments, the second determination unit 1601 is further configured to determine that the value of the second sorting indication parameter is the fifth preset value if the third preset value is different from the fourth preset value; if the third preset value is the same as the fourth preset value, determine that the value of the second sorting indication parameter is the sixth preset value. In some embodiments, the second determination unit 1601 is further configured to determine a first parameter corresponding to the candidate data processing mode; and determine a value of the second sort indication parameter according to the first parameter. In some embodiments, the second determination unit 1601 is further configured to determine that the value of the second sort indication parameter is a fifth preset value if the first parameter indicates the first data; and to determine that the value of the second sort indication parameter is a sixth preset value if the first parameter indicates the second data. In some embodiments, the second determining unit 1601 is further configured to, when the value of the second ranking indication parameter is the fifth preset value, if the threshold parameter is the lower threshold parameter, then L i-1 Greater than or equal to L i ; If the threshold parameter is the upper threshold parameter, then U i-1 Greater than or equal to U i ; and when the value of the second sorting indication parameter is the sixth preset value, if the threshold parameter is the lower threshold parameter, then L i-1 Less than or equal to L i ; If the threshold parameter is the upper threshold parameter, then U i-1 Less than or equal to U i Among them, L i is the lower threshold parameter of the candidate data processing mode, U i is the upper limit threshold parameter of the candidate data processing mode, i=1, 2, ..., K-1, and K represents the number of candidate data processing modes. In some embodiments, the second determination unit 1601 is further configured to, in the candidate data processing mode, determine that the lower limit threshold parameter of the current candidate data processing mode is the same as the upper limit threshold parameter of the adjacent candidate data processing mode, and determine that the upper limit threshold parameter of the current candidate data processing mode is the same as the lower limit threshold parameter of the adjacent candidate data processing mode. In some embodiments, the second determining unit 1601 is further configured to determine L if the third preset value is different from the fourth preset value. i-1 =U i If the third preset value is the same as the fourth preset value, then determine U i-1 =L i . In some embodiments, referring to FIG. 16 , the decoder 160 may further include a second updating unit 1603, configured to adjust the threshold parameters of the candidate data processing mode and determine the adjusted threshold parameters of the candidate data processing mode; wherein, when the value of the second sorting indication parameter is the fifth preset value, the second sorting indication parameter indicates the descending order of the adjustment threshold parameters; and when the value of the second sorting indication parameter is the sixth preset value, the second sorting indication parameter indicates the ascending order of the adjustment threshold parameters. In some embodiments, the second determining unit 1601 is further configured to determine context information of the syntax element to be decoded; and determine the data processing mode parameter according to the context information and a preset mapping table. In some embodiments, the second determination unit 1601 is further configured to determine the context state of the syntax element to be decoded based on the context information; and determine the data processing mode parameters based on the context state and a preset mapping table; wherein the preset mapping table is used to characterize the mapping relationship between the context state and the data processing mode parameters. In some embodiments, the second updating unit 1603 is further configured to update the preset mapping table according to the value of the syntax element to be decoded. In some embodiments, the second update unit 1603 is further configured to reduce the data processing mode parameter in the preset mapping table if the value of the syntax element to be decoded is the seventh preset value; if the value of the syntax element to be decoded is the eighth preset value, increase the data processing mode parameter in the preset mapping table. In some embodiments, the second updating unit 1603 is further configured to determine a first probability value of the target data processing mode according to the value of the syntax element to be decoded; and to update the first probability value of the target data processing mode to determine a second probability value of the target data processing mode. In some embodiments, the second determining unit 1601 is further configured to determine a second parameter corresponding to the target data processing mode; The second updating unit 1603 is further configured to update the first probability value of the target data processing mode according to the second parameter and the value of the syntax element to be decoded, and determine the second probability value of the target data processing mode. In some embodiments, the second updating unit 1603 is further configured to increase the first probability value of the target data processing mode if the second parameter indicates the first data and the value of the syntax element to be decoded is the seventh preset value; decrease the first probability value of the target data processing mode if the second parameter indicates the first data and the value of the syntax element to be decoded is the eighth preset value; or decrease the first probability value of the target data processing mode if the second parameter indicates the second data and the symbol of the syntax element to be decoded is the seventh preset value; increase the first probability value of the target data processing mode if the second parameter indicates the second data and the symbol of the syntax element to be decoded is the eighth preset value. In some embodiments, the second determination unit 1601 is further configured to correct the second probability value of the target data processing mode to determine the target probability value of the target data processing mode. In some embodiments, the second determination unit 1601 is further configured to set the target probability value to the lower probability limit value if the second probability value is less than the lower probability limit value; to set the target probability value to the upper probability limit value if the second probability value is greater than the upper probability limit value; and to set the target probability value to the second probability value if the second probability value is greater than or equal to the lower probability limit value and less than or equal to the upper probability limit value. It can be understood that in this embodiment, a "unit" can be a part of a circuit, a part of a processor, a part of a program or software, etc., and of course it can also be a module, or it can be non-modular. Moreover, the components in this embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional module. If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, this embodiment provides a computer-readable storage medium, which is applied to the decoder 160, and the computer-readable storage medium stores a computer program. When the computer program is executed by the second processor, the method described in any one of the above embodiments is implemented. Based on the composition of the decoder 160 and the computer-readable storage medium, refer to Figure 17, which shows a specific hardware structure diagram of the decoder 160 provided in an embodiment of the present application. As shown in Figure 17, the decoder 160 may include: a second communication interface 1701, a second memory 1702 and a second processor 1703; each component is coupled together through a second bus system 1704. It can be understood that the second bus system 1704 is used to achieve connection and communication between these components. In addition to the data bus, the second bus system 1704 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity, various buses are marked as the second bus system 1704 in Figure 17. Among them, The second communication interface 1701 is used for receiving and sending signals during the process of sending and receiving information with other external network elements; The second memory 1702 is used to store a computer program that can be run on the second processor 1703; The second processor 1703 is configured to, when running the computer program, execute: Based on the first preset condition, determining a candidate data processing mode; Determining a data processing mode parameter corresponding to a syntax element to be decoded; Based on the candidate data processing modes, determining a target data processing mode according to the data processing mode parameters; The syntax element to be decoded is decoded according to the target data processing mode, and the value of the syntax element to be decoded is determined. Optionally, as another embodiment, the second processor 1703 is further configured to execute any one of the methods described in the foregoing embodiments when running the computer program. It can be understood that the hardware functions of the second memory 1702 and the first memory 1502 are similar, and the hardware functions of the second processor 1703 and the first processor 1503 are similar; they will not be described in detail here. The present embodiment provides a decoder, in which, since the candidate data processing modes satisfy the first preset conditions such as the initialization parameters, the upper threshold parameters and the lower threshold parameters, the best target decoder can be selected from these candidate data processing modes for decoding during the decoding process, thereby saving bit rate, improving encoding and decoding efficiency, and further improving encoding and decoding performance. In yet another embodiment of the present application, referring to FIG18 , a schematic diagram of the composition structure of a coding and decoding system provided in an embodiment of the present application is shown. As shown in FIG18 , the coding and decoding system 180 may include an encoder 1801 and a decoder 1802 . In the embodiment of the present application, the encoder 1801 may be the encoder described in any one of the aforementioned embodiments, and the decoder 1802 may be the decoder described in any one of the aforementioned embodiments. It should be noted that, in this application, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element. The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments. The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments. The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments. The features disclosed in several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments. The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims. Industrial Applicability In the embodiment of the present application, at the encoding end, based on the first preset condition, a candidate data processing mode is determined; a data processing mode parameter corresponding to the syntax element to be encoded is determined; based on the candidate data processing mode, a target data processing mode is determined according to the data processing mode parameter; the value of the syntax element to be encoded is encoded according to the target data processing mode, and the obtained encoded bits are written into the bitstream. At the decoding end, based on the first preset condition, a candidate data processing mode is determined; a data processing mode parameter corresponding to the syntax element to be decoded is determined; based on the candidate data processing mode, a target data processing mode is determined according to the data processing mode parameter; the syntax element to be decoded is decoded according to the target data processing mode, and the value of the syntax element to be decoded is determined. In this way, both the encoding end and the decoding end determine the candidate data processing mode based on the first preset condition; then determine the corresponding data processing mode parameters based on the syntax elements to be encoded or the syntax elements to be decoded, and then determine the target data processing mode, and finally encode and decode the syntax elements according to the target data processing mode; in this way, since the candidate data processing modes meet the first preset condition, the best target encoder can be selected from these candidate data processing modes for encoding during the encoding process, thereby saving bit rate, improving encoding and decoding efficiency, and thus improving encoding and decoding performance.

Claims

1. A decoding method, applied to a decoder, the method comprising: Based on the first preset condition, determining a candidate data processing mode; Determining a data processing mode parameter corresponding to a syntax element to be decoded; Based on the candidate data processing modes, determining a target data processing mode according to the data processing mode parameters; The syntax element to be decoded is decoded according to the target data processing mode, and a value of the syntax element to be decoded is determined.

2. The method according to claim 1, wherein: The determining of the candidate data processing mode based on the first preset condition includes: According to the first preset condition, initialization parameters of the candidate data processing mode are determined.

3. The method according to claim 2, wherein: The initialization parameter indicates a probability value of the candidate data processing mode.

4. The method according to claim 1 or 2, wherein: The determining of the candidate data processing mode based on the first preset condition includes: According to the first preset condition, a threshold parameter of the candidate data processing mode is determined.

5. The method according to claim 4, wherein: The threshold parameter indicates a probability threshold value of the candidate data processing mode, wherein the probability threshold value includes: a probability upper limit value and / or a probability lower limit value.

6. The method according to claim 2, wherein: The step of determining the initialization parameters of the candidate data processing mode according to the first preset condition includes: A first sorting indication parameter is determined according to the initialization parameter of the candidate data processing mode.

7. The method according to claim 6, wherein: The value of the first sorting indication parameter includes a first preset value and a second preset value; The first preset value indicates a decreasing order of the initialization parameter, and the second preset value indicates an increasing order of the initialization parameter.

8. The method according to claim 7, wherein: The method further comprises: Determining a third preset value and a fourth preset value of the candidate data processing mode; Determining a value of the first sorting indication parameter according to the third preset value and the fourth preset value; The third preset value indicates an update order of probability values ​​of the candidate data processing modes, and the fourth preset value indicates an update order of index values ​​of the candidate data processing modes.

9. The method according to claim 8, wherein: The determining, according to the third preset value and the fourth preset value, a value of the first sorting indication parameter includes: If the third preset value is different from the fourth preset value, determining that the value of the first sorting indication parameter is the first preset value; If the third preset value is the same as the fourth preset value, it is determined that the value of the first sorting indication parameter is the second preset value.

10. The method according to claim 7, wherein: The method further comprises: Determining a first parameter corresponding to the candidate data processing mode; A value of the first sorting indication parameter is determined according to the first parameter.

11. The method according to claim 10, wherein: The determining, according to the first parameter, a value of the first sort indication parameter includes: If the first parameter indicates first data, determining that the value of the first sort indication parameter is the first preset value; If the first parameter indicates second data, the value of the first sort indication parameter is determined to be the second preset value.

12. The method according to claim 7, wherein: The method further comprises: When the value of the first sorting indication parameter is the first preset value, T i-1 Greater than or equal to T i ; When the value of the first sorting indication parameter is the second preset value, T i-1 Less than or equal to T i ; Among them, T i is the initialization parameter of the candidate data processing mode, i=1, 2, ..., K-1, K represents the number of the candidate data processing modes.

13. The method according to claim 4, wherein: The step of determining the threshold parameter of the candidate data processing mode according to the first preset condition includes: A second sorting indication parameter is determined according to the threshold parameter of the candidate data processing mode.

14. The method according to claim 13, wherein: The value of the second sorting indication parameter includes a fifth preset value and a sixth preset value; The fifth preset value indicates a decreasing order of the threshold parameters, and the sixth preset value indicates an increasing order of the threshold parameters.

15. The method according to claim 14, wherein: The method further comprises: Determining a third preset value and a fourth preset value of the candidate data processing mode; Determining a value of the second sorting indication parameter according to the third preset value and the fourth preset value; The third preset value indicates an update order of probability values ​​of the candidate data processing modes, and the fourth preset value indicates an update order of index values ​​of the candidate data processing modes.

16. The method according to claim 15, wherein: The determining, according to the third preset value and the fourth preset value, a value of the second sorting indication parameter includes: If the third preset value is different from the fourth preset value, determining that the value of the second sorting indication parameter is the fifth preset value; If the third preset value is the same as the fourth preset value, it is determined that the value of the second sorting indication parameter is the sixth preset value.

17. The method according to claim 14, wherein: The method further comprises: Determining a first parameter corresponding to the candidate data processing mode; A value of the second sort indication parameter is determined according to the first parameter.

18. The method according to claim 17, wherein: The determining, according to the first parameter, a value of the second sort indication parameter includes: If the first parameter indicates first data, determining that the value of the second sort indication parameter is the fifth preset value; If the first parameter indicates the second data, it is determined that the value of the second sort indication parameter is the sixth preset value.

19. The method according to claim 15, wherein: The method further comprises: When the value of the second sorting indication parameter is the fifth preset value, if the threshold parameter is a lower threshold parameter, then L i-1 Greater than or equal to L i ; If the threshold parameter is an upper threshold parameter, then U i-1 Greater than or equal to U i ; When the value of the second sorting indication parameter is the sixth preset value, if the threshold parameter is a lower threshold parameter, then L i-1 Less than or equal to L i ; If the threshold parameter is an upper threshold parameter, then U i-1 Less than or equal to U i ; Among them, L i is the lower limit threshold parameter of the candidate data processing mode, U i is the upper limit threshold parameter of the candidate data processing mode, i=1, 2, ..., K-1, and K represents the number of the candidate data processing modes.

20. The method according to claim 19, wherein: The method further comprises: In the candidate data processing mode, it is determined that the lower threshold parameter of the current candidate data processing mode is the same as the upper threshold parameter of the adjacent candidate data processing mode, and it is determined that the upper threshold parameter of the current candidate data processing mode is the same as the lower threshold parameter of the adjacent candidate data processing mode.

21. The method according to claim 20, wherein: The method further comprises: If the third preset value is different from the fourth preset value, then determine L i-1 =U i ; If the third preset value is the same as the fourth preset value, then determine U i-1 =L i .

22. The method according to claim 14, wherein: The method further comprises: Adjusting the threshold parameter of the candidate data processing mode to determine the adjusted threshold parameter of the candidate data processing mode; Wherein, when the value of the second sorting indication parameter is the fifth preset value, the second sorting indication parameter indicates the descending order of the adjustment threshold parameters; When the value of the second sorting indication parameter is the sixth preset value, the second sorting indication parameter indicates the increasing order of the adjustment threshold parameters.

23. The method according to claim 1, wherein: The determining of the data processing mode parameter corresponding to the syntax element to be decoded includes: Determining context information of the syntax element to be decoded; The data processing mode parameters are determined according to the context information and a preset mapping table.

24. The method according to claim 23, wherein: The determining the data processing mode parameter according to the context information and the preset mapping table includes: Determining, according to the context information, a context state of the syntax element to be decoded; Determining the data processing mode parameters according to the context state and the preset mapping table; The preset mapping table is used to represent the mapping relationship between the context state and the data processing mode parameters.

25. The method according to claim 23, wherein: The method further comprises: The preset mapping table is updated according to the value of the syntax element to be decoded.

26. The method according to claim 25, wherein: The updating of the preset mapping table includes: If the value of the syntax element to be decoded is the seventh preset value, reducing the data processing mode parameter in the preset mapping table; If the value of the syntax element to be decoded is the eighth preset value, the data processing mode parameter in the preset mapping table is increased.

27. The method according to claim 5, wherein: The method further comprises: Determining a first probability value of the target data processing mode according to a value of the syntax element to be decoded; The first probability value of the target data processing mode is updated to determine a second probability value of the target data processing mode.

28. The method according to claim 27, wherein: The updating of the first probability value of the target data processing mode to determine the second probability value of the target data processing mode includes: Determining a second parameter corresponding to the target data processing mode; The first probability value of the target data processing mode is updated according to the second parameter and the value of the syntax element to be decoded, and the second probability value of the target data processing mode is determined.

29. The method according to claim 28, wherein: The updating the first probability value of the target data processing mode according to the second parameter and the value of the syntax element to be decoded includes: If the second parameter indicates the first data, and the value of the syntax element to be decoded is a seventh preset value, increasing the first probability value of the target data processing mode; If the second parameter indicates the first data, and the value of the syntax element to be decoded is an eighth preset value, reducing the first probability value of the target data processing mode; or, If the second parameter indicates second data, and the sign of the syntax element to be decoded is a seventh preset value, reducing the first probability value of the target data processing mode; If the second parameter indicates second data, and the sign of the syntax element to be decoded is an eighth preset value, then increasing the first probability value of the target data processing mode.

30. The method of claim 27, wherein: The method further comprises: The second probability value of the target data processing mode is corrected to determine a target probability value of the target data processing mode.

31. The method according to claim 30, wherein: The step of correcting the second probability value of the target data processing mode to determine the target probability value of the target data processing mode includes: If the second probability value is less than the probability lower limit value, setting the target probability value to the probability lower limit value; If the second probability value is greater than the probability upper limit value, setting the target probability value to the probability upper limit value; If the second probability value is greater than or equal to the probability lower limit value and less than or equal to the probability upper limit value, the target probability value is set to the second probability value.

32. A coding method, applied to an encoder, the method comprising: Based on the first preset condition, determining a candidate data processing mode; Determining a data processing mode parameter corresponding to a syntax element to be encoded; Based on the candidate data processing modes, determining a target data processing mode according to the data processing mode parameters; The value of the syntax element to be encoded is encoded according to the target data processing mode, and the obtained encoding bits are written into a bitstream.

33. The method of claim 32, wherein: The determining of the candidate data processing mode based on the first preset condition includes: According to the first preset condition, initialization parameters of the candidate data processing mode are determined.

34. The method of claim 33, wherein: The initialization parameter indicates a probability value of the candidate data processing mode.

35. The method according to claim 32 or 33, wherein: The determining of the candidate data processing mode based on the first preset condition includes: According to the first preset condition, a threshold parameter of the candidate data processing mode is determined.

36. The method of claim 35, wherein: The threshold parameter indicates a probability threshold value of the candidate data processing mode, wherein the probability threshold value includes: a probability upper limit value and / or a probability lower limit value.

37. The method of claim 33, wherein: The step of determining the initialization parameters of the candidate data processing mode according to the first preset condition includes: A first sorting indication parameter is determined according to the initialization parameter of the candidate data processing mode.

38. The method of claim 37, wherein: The value of the first sorting indication parameter includes a first preset value and a second preset value; The first preset value indicates a decreasing order of the initialization parameter, and the second preset value indicates an increasing order of the initialization parameter.

39. The method of claim 38, wherein: The method further comprises: Determining a third preset value and a fourth preset value of the candidate data processing mode; Determining a value of the first sorting indication parameter according to the third preset value and the fourth preset value; The third preset value indicates an update order of probability values ​​of the candidate data processing modes, and the fourth preset value indicates an update order of index values ​​of the candidate data processing modes.

40. The method of claim 39, wherein: The determining, according to the third preset value and the fourth preset value, a value of the first sorting indication parameter includes: If the third preset value is different from the fourth preset value, determining that the value of the first sorting indication parameter is the first preset value; If the third preset value is the same as the fourth preset value, it is determined that the value of the first sorting indication parameter is the second preset value.

41. The method of claim 38, wherein: The method further comprises: Determining a first parameter corresponding to the candidate data processing mode; A value of the first sorting indication parameter is determined according to the first parameter.

42. The method according to claim 41, wherein: The determining, according to the first parameter, a value of the first sort indication parameter includes: If the first parameter indicates first data, determining that the value of the first sort indication parameter is the first preset value; If the first parameter indicates second data, the value of the first sort indication parameter is determined to be the second preset value.

43. The method of claim 38, wherein: The method further comprises: When the value of the first sorting indication parameter is the first preset value, T i-1 Greater than or equal to T i ; When the value of the first sorting indication parameter is the second preset value, T i-1 Less than or equal to T i ; Among them, T i is the initialization parameter of the candidate data processing mode, i=1, 2, ..., K-1, K represents the number of the candidate data processing modes.

44. The method of claim 35, wherein: The step of determining the threshold parameter of the candidate data processing mode according to the first preset condition includes: A second sorting indication parameter is determined according to the threshold parameter of the candidate data processing mode.

45. The method of claim 44, wherein: The value of the second sorting indication parameter includes a fifth preset value and a sixth preset value; The fifth preset value indicates a decreasing order of the threshold parameters, and the sixth preset value indicates an increasing order of the threshold parameters.

46. ​​The method of claim 45, wherein: The method further comprises: Determining a third preset value and a fourth preset value of the candidate data processing mode; Determining a value of the second sorting indication parameter according to the third preset value and the fourth preset value; The third preset value indicates an update order of probability values ​​of the candidate data processing modes, and the fourth preset value indicates an update order of index values ​​of the candidate data processing modes.

47. The method of claim 46, wherein: The determining, according to the third preset value and the fourth preset value, a value of the second sorting indication parameter includes: If the third preset value is different from the fourth preset value, determining that the value of the second sorting indication parameter is the fifth preset value; If the third preset value is the same as the fourth preset value, it is determined that the value of the second sorting indication parameter is the sixth preset value.

48. The method of claim 45, wherein: The method further comprises: Determining a first parameter corresponding to the candidate data processing mode; A value of the second sort indication parameter is determined according to the first parameter.

49. The method of claim 48, wherein: The determining, according to the first parameter, a value of the second sort indication parameter includes: If the first parameter indicates first data, determining that the value of the second sort indication parameter is the fifth preset value; If the first parameter indicates the second data, it is determined that the value of the second sort indication parameter is the sixth preset value.

50. The method of claim 46, wherein: The method further comprises: When the value of the second sorting indication parameter is the fifth preset value, if the threshold parameter is a lower threshold parameter, then L i-1 Greater than or equal to L i ; If the threshold parameter is an upper threshold parameter, then U i-1 Greater than or equal to U i ; When the value of the second sorting indication parameter is the sixth preset value, if the threshold parameter is a lower threshold parameter, then L i-1 Less than or equal to L i ; If the threshold parameter is an upper threshold parameter, then U i-1 Less than or equal to U i ; Among them, L i is the lower limit threshold parameter of the candidate data processing mode, U i is the upper limit threshold parameter of the candidate data processing mode, i=1, 2, ..., K-1, and K represents the number of the candidate data processing modes.

51. The method of claim 50, wherein: The method further comprises: In the candidate data processing mode, it is determined that the lower threshold parameter of the current candidate data processing mode is the same as the upper threshold parameter of the adjacent candidate data processing mode, and it is determined that the upper threshold parameter of the current candidate data processing mode is the same as the lower threshold parameter of the adjacent candidate data processing mode.

52. The method of claim 51, wherein: The method further comprises: If the third preset value is different from the fourth preset value, then determine L i-1 =U i ; If the third preset value is the same as the fourth preset value, then determine U i-1 =L i .

53. The method of claim 45, wherein: The method further comprises: Adjusting the threshold parameter of the candidate data processing mode to determine the adjusted threshold parameter of the candidate data processing mode; Wherein, when the value of the second sorting indication parameter is the fifth preset value, the second sorting indication parameter indicates the descending order of the adjustment threshold parameters; When the value of the second sorting indication parameter is the sixth preset value, the second sorting indication parameter indicates the increasing order of the adjustment threshold parameters.

54. The method of claim 32, wherein: The determining of the data processing mode parameter corresponding to the syntax element to be encoded includes: Determining context information of the syntax element to be encoded; The data processing mode parameters are determined according to the context information and a preset mapping table.

55. The method of claim 54, wherein: The determining the data processing mode parameter according to the context information and the preset mapping table includes: Determining, according to the context information, a context state of the syntax element to be encoded; Determining the data processing mode parameters according to the context state and the preset mapping table; The preset mapping table is used to represent the mapping relationship between the context state and the data processing mode parameters.

56. The method of claim 54, wherein: The method further comprises: The preset mapping table is updated according to the value of the syntax element to be encoded.

57. The method of claim 56, wherein: The updating of the preset mapping table includes: If the value of the syntax element to be encoded is the seventh preset value, reducing the data processing mode parameter in the preset mapping table; If the value of the syntax element to be encoded is the eighth preset value, the data processing mode parameter in the preset mapping table is increased.

58. The method of claim 36, wherein: The method further comprises: Determining a first probability value of the target data processing mode according to a value of the syntax element to be encoded; The first probability value of the target data processing mode is updated to determine a second probability value of the target data processing mode.

59. The method of claim 58, wherein: The updating of the first probability value of the target data processing mode to determine the second probability value of the target data processing mode includes: Determining a second parameter corresponding to the target data processing mode; The first probability value of the target data processing mode is updated according to the second parameter and the value of the syntax element to be encoded, and the second probability value of the target data processing mode is determined.

60. The method of claim 59, wherein: The updating the first probability value of the target data processing mode according to the second parameter and the value of the syntax element to be encoded includes: If the second parameter indicates the first data, and the value of the syntax element to be encoded is a seventh preset value, increasing the first probability value of the target data processing mode; If the second parameter indicates the first data, and the value of the syntax element to be encoded is an eighth preset value, reducing the first probability value of the target data processing mode; or, If the second parameter indicates second data, and the sign of the syntax element to be encoded is a seventh preset value, reducing the first probability value of the target data processing mode; If the second parameter indicates second data, and the sign of the syntax element to be encoded is an eighth preset value, then increasing the first probability value of the target data processing mode.

61. The method of claim 58, wherein: The method further comprises: The second probability value of the target data processing mode is corrected to determine a target probability value of the target data processing mode.

62. The method of claim 61, wherein: The step of correcting the second probability value of the target data processing mode to determine the target probability value of the target data processing mode includes: If the second probability value is less than the probability lower limit value, setting the target probability value to the probability lower limit value; If the second probability value is greater than the probability upper limit value, setting the target probability value to the probability upper limit value; If the second probability value is greater than or equal to the probability lower limit value and less than or equal to the probability upper limit value, the target probability value is set to the second probability value.

63. A code stream, wherein The code stream is generated by bit coding according to the information to be coded; wherein the information to be coded at least includes: the value of the syntax element to be coded.

64. An encoder, comprising a first determining unit and an encoding unit; wherein: The first determining unit is configured to determine a candidate data processing mode based on a first preset condition; and determining a data processing mode parameter corresponding to the syntax element to be encoded; The first determination unit is further configured to determine a target data processing mode based on the candidate data processing modes and according to the data processing mode parameters; The encoding unit is configured to encode the value of the syntax element to be encoded according to the target data processing mode, and write the obtained encoding bits into the bitstream.

65. An encoder, comprising a first memory and a first processor; wherein: The first memory is used to store a computer program that can be run on the first processor; The first processor is configured to execute the method according to any one of claims 31 to 62 when running the computer program.

66. A decoder, comprising a second determining unit and a decoding unit; wherein: The second determining unit is configured to determine a candidate data processing mode based on the first preset condition; and determining a data processing mode parameter corresponding to a syntax element to be decoded; The second determination unit is further configured to determine a target data processing mode according to the data processing mode parameters based on the candidate data processing modes; The decoding unit is configured to decode the syntax element to be decoded according to the target data processing mode, and determine the value of the syntax element to be decoded.

67. A decoder, comprising a second memory and a second processor; wherein: The second memory is used to store a computer program that can be run on the second processor; The second processor is configured to execute the method according to any one of claims 1 to 31 when running the computer program.

68. A computer-readable storage medium, wherein: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 31 is implemented, or the method according to any one of claims 32 to 62 is implemented.

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