WO2020211642A1

WO2020211642A1 - Code block prediction method and apparatus, and code block decoding method and apparatus

Info

Publication number: WO2020211642A1
Application number: PCT/CN2020/082689
Authority: WO
Inventors: 李振纲; 梁俊辉; 王宁; 曾幸
Original assignee: 中兴通讯股份有限公司; 华中科技大学
Priority date: 2019-04-15
Filing date: 2020-04-01
Publication date: 2020-10-22
Also published as: CN111836043A

Abstract

The present application provides a code block prediction method and apparatus, and a code block decoding method and apparatus. The code block prediction method comprises: an encoding means divides coded blocks subjected to intra-frame prediction, selects a reference pixel from reconstructed pixels in the divided subblocks; the encoding means performs iterative prediction on each subblock by using the reference pixel to obtain coded blocks subjected to iterative prediction; the encoding means compares distortion parameters of the coded blocks subjected to intra-frame prediction with distortion parameters of the coded blocks subjected to iterative prediction, determines a prediction mode of the coded blocks, and configures a corresponding flag bit; the encoding means sends the coded blocks corresponding to the prediction mode and the flag bit to a decoding device.

Description

Method and device for predicting and decoding code block

Technical field

The present disclosure relates to but is not limited to the field of communications.

Background technique

Video coding is a video compression technology that achieves the purpose of video compression by eliminating redundant information such as temporal redundancy, spatial redundancy, and coding redundancy in the video sequence.

Prediction technology is an important part of video coding technology, divided into intra-frame prediction and inter-frame prediction. Intra prediction is mainly used to eliminate the spatial redundancy information in the video sequence. When performing intra prediction on the current block, first obtain the adjacent reconstructed pixels of the current block as reference pixels, and then obtain the reference pixels according to different prediction modes The pixel value of the current block, and the optimal prediction mode is selected by calculating the rate-distortion cost in different prediction modes, and finally the prediction residual block of the current block is transformed, quantized, and entropy-coded and then transmitted to the decoding end. The decoding end can obtain the prediction mode used by the encoding end and the corresponding residual block by decoding the code stream, and then obtain the prediction block according to the prediction mode, and further add the residual block to obtain the reconstructed block, and finally reconstruct all the codes Blocks can reconstruct the entire video sequence. However, the intra-frame prediction method in the related art causes inaccurate prediction and large prediction residual due to the limitation of reference pixels.

Summary of the invention

According to an embodiment of the present disclosure, a method for predicting a code block is provided, which includes: an encoding device divides an intra-predicted encoding block, and selects reference pixels from reconstructed pixels in the divided sub-blocks; The encoding device uses the reference pixels to perform iterative prediction on each of the sub-blocks to obtain an iteratively predicted encoding block; the encoding device compares the intra-frame prediction encoding block with the iteratively predicted encoding block The distortion parameter determines the prediction mode of the coding block and sets the corresponding flag bit; the coding device sends the coding block corresponding to the prediction mode and the flag bit to the decoding device.

According to another embodiment of the present disclosure, there is provided a method for decoding a code block, which includes: a decoding device receives a prediction block and a flag sent by an encoding device; and the decoding device compares all data according to the prediction mode carried in the flag. The prediction block is decoded, wherein the prediction mode includes: an intra prediction mode and an iterative prediction mode.

According to another embodiment of the present disclosure, there is provided a code block prediction device, which is located in the coding device, and includes: a selection module for dividing an intra-frame predicted coding block, from among the divided sub-blocks A reference pixel is selected from the reconstructed pixels; a prediction module is used to perform iterative prediction on each of the sub-blocks using the reference pixels to obtain an iteratively predicted coding block; a determination module is used to compare the coding after the intra-frame prediction Block and the distortion parameters of the coded block after the iterative prediction, determine the prediction mode of the coded block and set the corresponding flag bit; the sending module is used to send the coded block corresponding to the prediction mode and the flag bit to the decoding device .

According to another embodiment of the present disclosure, a device for decoding code blocks is provided, which is characterized in that it includes: a receiving module for receiving prediction blocks and flag bits sent by an encoding device; The prediction mode carried in the bit decodes the prediction block, where the prediction mode includes: an intra prediction mode and an iterative prediction mode.

According to yet another embodiment of the present disclosure, there is also provided a storage medium in which a computer program is stored, wherein the computer program is configured to execute the steps in any one of the above method embodiments when running.

According to another embodiment of the present disclosure, there is also provided an electronic device, including a memory and a processor, the memory stores a computer program, and the processor is configured to run the computer program to execute any one of the foregoing Steps in the method embodiment.

Description of the drawings

The drawings described here are used to provide a further understanding of the present disclosure and constitute a part of the present application. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure, and do not constitute an improper limitation of the present disclosure. In the attached picture:

Fig. 1 is a flowchart of a method for predicting a code block according to an embodiment of the present disclosure;

Fig. 2 is a schematic diagram of dividing a coding block according to an embodiment of the present disclosure;

Fig. 3 is a schematic diagram of a sub-block according to an embodiment of the present disclosure;

Fig. 4 is a schematic diagram of a bidirectional prediction according to an embodiment of the present disclosure;

Fig. 5 is a flowchart of a method for decoding code blocks according to an embodiment of the present disclosure;

Fig. 6 is a structural block diagram of a code block prediction apparatus according to an embodiment of the present disclosure;

Fig. 7 is a structural block diagram of a code block decoding device according to an embodiment of the present disclosure;

Figure 8 shows an original coding block;

9A to 9D show the process of traditional prediction and reconstruction;

10A to 10H show the iterative prediction and reconstruction process;

FIG. 11A shows the coefficient block after transform and quantization of the residual block in the traditional intra mode;

FIG. 11B shows the coefficient block after transform and quantization of the residual block corresponding to the iterative prediction mode.

detailed description

Hereinafter, the present disclosure will be described in detail with reference to the drawings and in conjunction with embodiments. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other if there is no conflict.

It should be noted that the terms "first" and "second" in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence.

In some embodiments, a method for predicting code blocks is provided. Fig. 1 is a flowchart of a method for predicting code blocks according to an embodiment of the present disclosure. As shown in Fig. 1, the process includes the following steps: Step S102: The coding device divides the code block after intra-frame prediction. Select reference pixels from the reconstructed pixels in the subsequent sub-blocks; step S104, the encoding device uses the reference pixels to perform iterative prediction on each of the sub-blocks to obtain an iteratively predicted encoding block; step S106, the encoding The device compares the distortion parameters of the coding block after intra-frame prediction and the coding block after iterative prediction, determines the prediction mode of the coding block and sets the corresponding flag bit; step S108, the coding device corresponds the prediction mode The coding block and the flag bit are sent to the decoding device.

In one embodiment, when performing intra-frame prediction, the encoding device uses original reference pixels of the coded block to perform intra-frame prediction and reconstruction of the coded block.

In an embodiment, the division method includes one of the following: no division is performed on the coding block, and N division division is performed on the coding block, where N is a positive integer greater than or equal to 2.

Fig. 2 is a schematic diagram of dividing a coding block according to an embodiment of the present disclosure. As shown in Figure 2, Figure 2 shows several examples of N-division.

Of course, other division methods are also within the protection scope of the present disclosure, such as non-equal division, division according to a certain special ratio, division according to a certain graph, and other division methods are also within the protection scope of the present disclosure. I won't go into details here.

In an embodiment, the encoding device selecting reference pixels from the divided sub-blocks includes: the encoding device selecting boundary pixels in the sub-blocks as the reference pixels.

Fig. 3 is a schematic diagram of a sub-block according to an embodiment of the present disclosure. As shown in FIG. 3, the pixels at the outermost part of the sub-block are regarded as reference pixels (lattice area) of the sub-block. Take Fig. 3 as an example, in the case of a sub-block of size W*H in Fig. 3, take 1 as the width, W as the length of the upper and lower border pixel sets, take 1 as the length and H as the left border of the width The set of pixels on the right and right boundary is regarded as the boundary pixels of the sub-block.

In an embodiment, the encoding device uses the reference pixels to perform iterative prediction on each of the sub-blocks to obtain an iteratively predicted encoding block, including: the encoding device uses the reference pixels to perform each of the The internal pixels in the reconstructed pixels in the sub-blocks are iteratively predicted to obtain the predicted value of the internal pixels.

Taking FIG. 3 as an example, the reconstructed pixels excluding the aforementioned boundary pixels in the sub-block are all internal pixels.

In an embodiment, the encoding device uses the reference pixels to iteratively predict the internal pixels in each sub-block to obtain the predicted value of the internal pixels, including: the encoding device according to the reference The value of the pixel and the distance between the predicted pixel in the internal pixel and the reference pixel determine the predicted value of the predicted pixel; the encoding device predicts the predicted pixel according to the pixel order of the internal pixel The results are arranged to obtain the predicted value of the internal pixels.

In one embodiment, the first reference pixel is the reference pixel in the upper left corner, and the second reference pixel is the reference pixel in the lower right corner. The predicted value of the predicted pixel is realized by at least the following formula: P=(α×d _β +β×d _α )÷(d _α +d _β ), where α is the value of the first reference pixel in the reference pixels , Β is the value of the second reference pixel in the reference pixel, d _α is the distance between the predicted pixel and the first reference pixel, d _β is the distance between the predicted pixel and the second reference pixel P is the predicted value of the predicted pixel.

Fig. 4 is a schematic diagram of a bidirectional prediction according to an embodiment of the present disclosure. As shown in FIG. 4, in the sub-block in FIG. 4, the horizontal line filled area is the predicted pixel, the white pixel is the unpredicted pixel, the diagonal line filled area is the reference pixel, and the vertical line filled area is the predicted pixel. In order to facilitate calculations, in the process of selecting the first reference pixel and the second reference pixel, a method of placing the predicted pixel on the connecting line between the two reference pixels can be considered. In this case, it is only necessary to calculate the vertical or horizontal distance, that is, the distance between the prediction pixel in FIG. 4 and the first reference pixel (pixel value α) and the second reference pixel (pixel value β). In addition, taking Figure 4 as an example, in the subsequent calculation process, if the unpredicted pixel corresponding to the white color on the right side of the vertical line filled area in Figure 4 is calculated, then only the current first reference pixel (pixel value α) needs to be selected The pixel on the right is used as the new first reference pixel, and then the pixel above the current second reference pixel (the pixel value is β) is selected as the new second reference pixel. However, the distance between the predicted pixel and the new first reference pixel and the new second reference pixel in the vertical or horizontal direction can be calculated. The prediction calculation methods corresponding to other pixels are also similar, and will not be repeated here.

The bidirectional prediction used in FIG. 4 is only a method for calculating the predicted value of the predicted pixel in the embodiment of the present disclosure. Other prediction methods, such as learning through a neural network to achieve prediction, are also within the protection scope of the present disclosure, and will not be repeated here.

It should be noted that, for the method of selecting reference pixels, the foregoing embodiment provides a method of using boundary pixels in the reconstructed pixels. Of course, other ways of selecting some pixels from the reconstructed pixels as reference pixels are also within the protection scope of the present disclosure. For example, because the sub-blocks are obtained through division. Therefore, there must be adjacent pixels between multiple adjacent sub-blocks. It is also within the protection scope of the present disclosure to select common pixels from these adjacent pixels as reference pixels. For example, take the binary division of Figure 2 as an example. The lowermost boundary pixel of the upper sub-block can be used as the reference pixel of the lower sub-block. Conversely, the uppermost boundary pixel of the lower sub-block can also be used as the reference pixel of the upper sub-block. In this way, for the entire coding block, since it is not necessary to select all the boundary pixels of each sub-block, the time for determining the reference pixels can be saved, thereby improving the calculation efficiency. At the same time, since the selected reference pixels in addition to the common pixels are different in each individual sub-block, the position of the other reference pixels can be used to facilitate matching by the encoding device in the subsequent stitching process.

Of course, other reference pixel selection methods that can overcome the shortcoming of inaccurate prediction of the part of the coding block farther from the reference pixel in the intra prediction technology are also within the protection scope of the present disclosure, and will not be described in detail here.

In an embodiment, the method further includes: the encoding device determines that the predicted value of the boundary pixel after iterative prediction is the predicted value of the boundary pixel after intra prediction; the encoding device is based on the sub-block According to the pixel position relationship of, the iterative prediction block of the sub-block is generated through the predicted value of the boundary pixel and the predicted value of the internal pixel.

In an embodiment, the encoding device splices the iterative prediction blocks of the sub-blocks according to the positional relationship between the sub-blocks to obtain the iteratively predicted encoding block.

In an embodiment, the distortion parameter at least includes: a rate-distortion cost, wherein the rate-distortion cost is determined by adding the bit and distortion of the code block after the flag bit is added.

It should be pointed out that the rate-distortion cost is only one of the distortion parameters listed in the present disclosure, and other distortion parameters, such as the size of the coding block and the distortion size of the intra-frame prediction mode, are also within the protection scope of the present disclosure.

In an embodiment, calculating the bits of the coding block after the iterative prediction after adding the flag bit includes: the coding device according to the bits required by the coefficient block, the bits required by the flag bit, and the frame The bits required for the coding block after intra-prediction are calculated for the bits corresponding to the coding block after iterative prediction; wherein, the coefficient block is determined according to the uncoded code block and the coding block after the iterative prediction.

In an embodiment, the coefficient block is determined in the following manner: the uncoded code block is subtracted from the coded block after iterative prediction to obtain the residual block. However, a change operation (for example, a change mode determined by the coding framework, such as DCT transform) on the residual block is performed to obtain a transform block. The transform block is obtained, and then the transform block is quantized, that is, the value in the transform block is divided by the quantization step to obtain the coefficient block. It should be noted that the bits required by the coefficient block refer to the bits required for entropy coding of the coefficient block.

In one embodiment, calculating the distortion of the coding block after the iterative prediction after the flag bit is added includes: the coding device performs a calculation on the difference between the code block before coding and the coding block after the iterative prediction. Quantization operation to obtain a distortion residual block; the coding device determines an intermediate reconstruction block according to the distortion residual block and the intra-frame predicted coding block; the coding device iteratively predicts the intermediate reconstruction block to obtain An intermediate prediction block and determine a final reconstruction block with the distortion residual block; the encoding device calculates the distortion between the final reconstruction block and the code block before encoding according to a preset distortion calculation criterion.

In an embodiment, the intermediate reconstruction block may be determined by the sum of the distortion residual block and the coded block after intra-frame prediction.

It should be noted that the method for determining the intermediate reconstruction block and the final reconstruction block is not limited to the above-mentioned method, and other acquisition methods are also within the protection scope of the present disclosure, and will not be repeated here. For example, the preset distortion calculation criterion includes, but is not limited to, the Mean Squared Error (MSE) criterion.

In one embodiment, calculating the distortion of the intra-frame predicted coding block after the flag bit is added includes: the coding device calculates the intra-frame predicted coding block and the intra-frame prediction according to a preset distortion calculation criterion. Distortion between code blocks before encoding.

In an embodiment, when the encoding device determines that the rate-distortion cost corresponding to the encoding block after intra-frame prediction is not greater than the rate-distortion cost corresponding to the encoding block after iterative prediction, the encoding device determines the The prediction mode of the coding block is intra prediction, and the mark position is the value corresponding to the intra prediction; when the coding device determines that the rate distortion cost corresponding to the coding block after intra prediction is greater than the iteration When predicting the rate-distortion cost corresponding to the coded block after prediction, the coding device determines that the prediction mode of the coded block is an iterative prediction mode, and sets the flag position to a value corresponding to the iterative prediction mode.

Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is Better implementation. Based on this understanding, the technical solution of the present disclosure essentially or the part that contributes to the existing technology can be embodied in the form of a software product, and the computer software product is stored in a storage medium (such as ROM/RAM, magnetic disk, The optical disc) includes several instructions to enable a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the method described in each embodiment of the present disclosure.

In some embodiments, a method for decoding code blocks is provided. Fig. 5 is a flowchart of a method for decoding a code block according to an embodiment of the present disclosure. As shown in Fig. 5, the process includes the following steps: step S502, the decoding device receives the prediction block and the flag sent by the encoding device; S504. The decoding device decodes the prediction block according to the prediction mode carried in the flag bit, where the prediction mode includes: an intra prediction mode and an iterative prediction mode.

In an embodiment, the decoding device decodes the prediction block according to the prediction mode carried in the flag bit, including: the decoding device determines the final reconstruction according to the residual block obtained from the code stream and the prediction mode Block and decode the final reconstructed block.

In an embodiment, the decoding device determines the final reconstructed block according to the residual block obtained from the bitstream and the prediction mode, including: when the prediction mode is the intra prediction mode, the intra prediction mode is used to obtain Prediction block, the decoding device obtains the final reconstructed block according to the residual block obtained from the code stream and the prediction block corresponding to the intra prediction mode.

In one embodiment, the decoding device determines the final reconstruction block according to the residual block obtained from the code stream and the prediction mode, including: when the prediction mode is an iterative prediction mode, the decoding device The residual block obtained in the stream and the prediction block generated by the intra prediction mode are used to obtain the intermediate reconstruction block; the decoding device obtains the intermediate prediction block after iterative prediction on the intermediate reconstruction block; the decoding device obtains the intermediate prediction block according to the intermediate prediction The block and the residual block obtained from the code stream determine the final reconstruction block.

In one embodiment, the iterative prediction of the intermediate reconstruction block by the decoding device includes: the decoding device divides the intermediate reconstruction block and selects reference pixels from the divided sub-blocks; the encoding device uses The reference pixels perform iterative prediction on each of the sub-blocks to obtain a coded block after iterative prediction.

In order to better understand the solutions recorded in the foregoing embodiments, the following scenarios are also provided in this embodiment. It should be noted that in the following scenario, the length and width are both 4, no division is performed, and a coding block in a diagonal prediction mode is used as an example. Of course, coding blocks of other sizes and other prediction methods are also within the protection scope of this embodiment, and will not be repeated here.

Figure 8 depicts an original coding block. As shown in Fig. 8, the left and upper pixels in the coding block are used as reference pixels (gray areas). The other areas are the values of the original coding block (white areas).

Figures 9A to 9D show the process of traditional prediction and reconstruction.

First, as shown in FIG. 9A, the value of the original coded block is intra-predicted by the traditional intra-frame 45-degree prediction mode, and the corresponding prediction block is obtained.

Then, the prediction block after intra prediction is subtracted from the value of the original block to obtain the residual block, as shown in FIG. 9B.

Then, the residual block is subjected to a series of quantization operations (for example, inverse quantization and inverse transformation after transform and quantization) to obtain the distorted residual block, as shown in FIG. 9C.

Finally, the distorted residual block and the prediction block are added to obtain the reconstructed block after intra-frame prediction, as shown in FIG. 9D.

Figures 10A to 10H are the iterative prediction and reconstruction process.

First, after obtaining the prediction block and reconstruction block for intra prediction, iterative prediction is needed next. It should be pointed out that the external pixel prediction value is the same as the traditional intra mode. That is, as shown in FIG. 10A, the parts not shown in FIG. 10A are internal pixels in the subsequent iterative prediction.

Secondly, when performing 45-degree bidirectional prediction of internal pixels, all surrounding reference pixels are available (gray area), where the right and bottom reference pixels come from the reconstructed pixels obtained by traditional intra mode prediction, and the middle part is the intra prediction value, such as Shown in Figure 10B.

After splicing the inner pixels and outer pixels, the prediction block after iterative prediction is obtained, as shown in FIG. 10C.

In the reconstruction process, first, the value of the original coding block is used to subtract the prediction block after iterative prediction to obtain the residual block, as shown in FIG. 10D.

Then, the residual block is subjected to a series of quantization operations (for example, inverse quantization and inverse transformation after transform and quantization) to obtain the distorted residual block, as shown in FIG. 10E.

Then, unlike the reconstruction in intra prediction, in the iterative prediction process, the distorted residual block needs to be added to the prediction block after intra prediction to obtain an intermediate reconstruction block, as shown in FIG. 10F.

Then iteratively predict the intermediate reconstruction block. The external prediction value is still the same as the intra mode, but when the internal prediction is performed, the right and lower reference pixels are from the lower right boundary pixel of the middle reconstruction block, and the final internal prediction value is shown in Figure 10G.

Finally, the internal prediction value and the external prediction value are spliced and then added to the distortion residual block in Fig. 10E to obtain the final reconstructed block, as shown in Fig. 10H.

When determining the selected test mode, the distortion and code rate of the intra-frame prediction mode and iterative prediction mode are calculated.

If the MSE criterion is adopted, the distortion of the traditional intra mode is the MSE value of the corresponding pixel block in Figure 9D and Figure 8, which is 60.06, and the distortion of the iterative prediction mode is the MSE value of the corresponding pixel block in Figure 10H and Figure 8, which is 58.00 , It can be seen that the distortion of the iterative prediction mode is smaller.

When calculating the code rate, the coefficient block after transform and quantization of the residual block in the traditional intra mode is shown in FIG. 11A.

The number of bits required for entropy coding of the coefficient block in the scanning order is 12, and a total of 13 bits are required for adding the flag bit.

The coefficient block after transformation and quantization of the residual block corresponding to the iterative prediction mode is shown in FIG. 11B.

Entropy coding of the coefficient block requires only 2 bits, and a total of 3 bits are required for adding the flag bit.

It can be seen that the MSE distortion of iterative prediction is less than that of the traditional mode, and the required bit rate is also less than that of the traditional mode. Therefore, the final rate-distortion cost is also less than the traditional model.

In some embodiments, a device for predicting code blocks is also provided, and the device is used to implement the above-mentioned embodiments and implementations, and those that have been explained will not be repeated. As used below, the term "module" can implement a combination of software and/or hardware with predetermined functions. Although the devices described in the following embodiments are implemented by software, hardware or a combination of software and hardware is also possible and conceived.

Fig. 6 is a structural block diagram of a code block prediction device according to an embodiment of the present disclosure. As shown in Fig. 6, the device includes: a selection module 62 configured to divide the code block after intra-frame prediction. Reference pixels are selected from the reconstructed pixels in the sub-blocks; the prediction module 64 is configured to use the reference pixels to perform iterative prediction on each of the sub-blocks to obtain an iteratively predicted encoding block; the determination module 66 is configured to compare all The distortion parameters of the coding block after intra-frame prediction and the coding block after iterative prediction, determining the prediction mode of the coding block and setting the corresponding flag bit; the sending module 68 is configured to configure the coding block corresponding to the prediction mode and The flag bit is sent to the decoding device.

It should be noted that each of the above modules can be implemented by software or hardware. For the latter, it can be implemented in the following manner, but not limited to this: the above modules are all located in the same processor; or, the above modules are combined in any combination The forms are located in different processors.

In some embodiments, a device for decoding code blocks is also provided, and the device is used to implement the above-mentioned embodiments and implementations, and those that have been explained will not be repeated. As used below, the term "module" can implement a combination of software and/or hardware with predetermined functions. Although the devices described in the following embodiments are implemented by software, hardware or a combination of software and hardware is also possible and conceived.

Fig. 7 is a structural block diagram of a code block decoding device according to an embodiment of the present disclosure. As shown in Fig. 7, the device includes: a receiving module 72 configured to receive a prediction block and a flag bit sent by an encoding device; a decoding module 74. It is configured to decode the prediction block according to the prediction mode carried in the flag bit, where the prediction mode includes: an intra prediction mode and an iterative prediction mode.

In some embodiments, a storage medium is further provided, and the storage medium stores a computer program, wherein the computer program is configured to execute the steps in any one of the foregoing method embodiments when running.

In an embodiment, the above-mentioned storage medium may be configured to store a computer program for performing the following steps: Step S1, the encoding device divides the coded block after intra-frame prediction, from the reconstructed pixels in the divided sub-blocks Select reference pixels; step S2, the encoding device uses the reference pixels to perform iterative prediction on each of the sub-blocks to obtain an iteratively predicted encoding block; step S3, the encoding device compares the intra-frame predicted Distortion parameters of the coding block and the coding block after the iterative prediction, determining the prediction mode of the coding block and setting the corresponding flag bit; step S4, the coding device sends the coding block corresponding to the prediction mode and the flag bit To the decoding device.

In an embodiment, the above-mentioned storage medium may be configured to store a computer program for performing the following steps: step S1, the decoding device receives the prediction block and the flag bit sent by the encoding device; step S2, the decoding device according to the The prediction mode carried in the flag bit decodes the prediction block, where the prediction mode includes: an intra prediction mode and an iterative prediction mode.

The above-mentioned storage media may include but are not limited to: U disk, Read-Only Memory (Read-Only Memory, ROM for short), Random Access Memory (RAM for short), mobile hard disk, magnetic disk or optical disk, etc. A medium that can store a computer program.

In some embodiments, an electronic device is also provided, including a memory and a processor, the memory stores a computer program, and the processor is configured to run the computer program to execute the steps in any one of the foregoing method embodiments.

In one embodiment, the above electronic device may further include a transmission device and an input/output device, wherein the transmission device is connected to the above processor, and the input/output device is connected to the above processor.

In an embodiment, the above-mentioned processor may be configured to execute the following steps through a computer program: Step S1, the encoding device divides the coded block after intra-frame prediction, and selects reference pixels from the reconstructed pixels in the divided sub-blocks Step S2, the encoding device uses the reference pixels to perform iterative prediction on each of the sub-blocks to obtain an iteratively predicted encoding block; Step S3, the encoding device compares the intra-frame predicted encoding block and The distortion parameter of the coding block after the iterative prediction is determined, the prediction mode of the coding block is determined, and the corresponding flag bit is set; step S4, the coding device sends the coding block corresponding to the prediction mode and the flag bit to the decoding device .

In one embodiment, the above-mentioned processor may be configured to execute the following steps through a computer program: step S1, the decoding device receives the prediction block and the flag bit sent by the encoding device; step S2, the decoding device according to the flag bit The carried prediction mode decodes the prediction block, where the prediction mode includes: an intra prediction mode and an iterative prediction mode.

For specific examples in this embodiment, reference may be made to the examples described in the above-mentioned embodiments and implementation manners, and this embodiment will not be repeated here.

Through the present disclosure, on the basis of the traditional prediction mode, an iterative prediction mode is also provided, and the prediction mode selects reference pixels as needed in the part after the current block is divided, instead of adjacent to the current block in the traditional prediction mode The reconstructed pixels are used as reference pixels. Therefore, the intra-frame prediction method in the related art can solve the problem of inaccurate prediction and large prediction residual due to the limitation of the reference pixel, and achieve the effect of simple implementation process, low coding complexity, and improved prediction performance.

Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present disclosure can be implemented by a general computing device, and they can be concentrated on a single computing device or distributed in a network composed of multiple computing devices. Above, alternatively, they can be implemented with program codes executable by the computing device, so that they can be stored in the storage device for execution by the computing device, and in some cases, can be executed in a different order than here. Perform the steps shown or described, or fabricate them into individual integrated circuit modules, or fabricate multiple modules or steps of them into a single integrated circuit module to achieve. In this way, the present disclosure is not limited to any specific hardware and software combination.

The above descriptions are only exemplary embodiments of the present disclosure, and are not used to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

A method for predicting code blocks, including:

The coding device divides the coding block after intra-frame prediction, and selects reference pixels from the reconstructed pixels in the divided sub-blocks;

The encoding device uses the reference pixels to perform iterative prediction on each of the sub-blocks to obtain a coded block after iterative prediction;

The coding device compares the distortion parameters of the coding block after the intra-frame prediction and the coding block after the iterative prediction, determines the prediction mode of the coding block, and sets a corresponding flag bit;

The encoding device sends the encoding block corresponding to the prediction mode and the flag bit to a decoding device.
The method according to claim 1, wherein the method of dividing comprises one of the following: not dividing the coding block, and dividing the coding block with N branches, where N is a positive integer greater than or equal to 2.
The method according to claim 1, wherein the encoding device selects reference pixels from the divided sub-blocks, comprising:

The encoding device selects boundary pixels in the sub-block as the reference pixels.
The method according to claim 1, wherein the encoding device uses the reference pixels to perform iterative prediction on each of the sub-blocks to obtain an encoded block after iterative prediction, comprising:

The encoding device uses the reference pixels to iteratively predict the internal pixels in the reconstructed pixels in each of the sub-blocks to obtain the predicted value of the internal pixels.
The method according to claim 4, wherein the encoding device uses the reference pixels to iteratively predict the internal pixels in the reconstructed pixels in each of the sub-blocks to obtain the predicted values of the internal pixels, include:

The encoding device determines the predicted value of the predicted pixel according to the value of the reference pixel and the distance between the predicted pixel in the internal pixel and the reference pixel;

The encoding device arranges the prediction results of the prediction pixels according to the pixel order of the internal pixels to obtain the prediction values of the internal pixels.
The method according to claim 5, wherein the predicted value of the predicted pixel is realized by at least the following formula:

P=(α×d β +β×d α )÷(d α +d β )

Where α is the value of the first reference pixel in the reference pixel, β is the value of the second reference pixel in the reference pixel, d α is the distance between the predicted pixel and the first reference pixel, d β is the distance between the predicted pixel and the second reference pixel, and P is the predicted value of the predicted pixel.
The method according to claim 4, further comprising:

Determining, by the encoding device, the predicted value of the boundary pixel after iterative prediction is the predicted value of the boundary pixel after intra prediction;

The encoding device generates an iterative prediction block of the sub-block by using the predicted value of the boundary pixel and the predicted value of the internal pixel according to the pixel position relationship of the sub-block.
The method according to claim 7, further comprising:

The coding device splices the iterative prediction blocks of the sub-blocks according to the position relationship between the sub-blocks to obtain the coding block after the iterative prediction.
The method according to claim 1, wherein the distortion parameter includes at least a rate-distortion cost, wherein the rate-distortion cost is determined by adding the bit and distortion of the code block after the flag bit.
The method according to claim 9, wherein calculating the bits of the coding block after the iterative prediction after adding the flag bit comprises:

The coding device calculates the bits corresponding to the coding block after iterative prediction according to the bits required by the coefficient block, the bits required by the flag bit, and the bits required by the coding block after the intra-frame prediction; wherein, The coefficient block is determined according to the uncoded code block and the coded block after the iterative prediction.
The method according to claim 9, wherein calculating the distortion of the coding block after the iterative prediction after adding the flag bit comprises:

The encoding device obtains a distorted residual block by performing a quantization operation on the difference between the code block before encoding and the code block after iterative prediction;

The encoding device determines an intermediate reconstruction block according to the distortion residual block and the intra-frame predicted encoding block;

The encoding device iteratively predicts the intermediate reconstruction block to obtain the intermediate prediction block, and determines a final reconstruction block with the distortion residual block;

The encoding device calculates the distortion between the final reconstructed block and the code block before encoding according to a preset distortion calculation criterion.
The method according to claim 9, wherein calculating the distortion of the coding block after the intra-frame prediction after adding the flag bit comprises:

The coding device calculates the distortion between the code block after intra-frame prediction and the code block before coding according to a preset distortion calculation criterion.
The method according to claim 9, further comprising:

When the encoding device determines that the rate-distortion cost corresponding to the encoding block after intra-frame prediction is not greater than the rate-distortion cost corresponding to the encoding block after iterative prediction, the encoding device determines that the prediction mode of the encoding block is Intra-frame prediction, and setting the mark position to a value corresponding to the intra-frame prediction;

When the encoding device determines that the rate-distortion cost corresponding to the encoding block after intra-frame prediction is greater than the rate-distortion cost corresponding to the encoding block after iterative prediction, the encoding device determines that the prediction mode of the encoding block is iterative Prediction mode, and the mark position is the value corresponding to the iterative prediction mode.
A method for decoding code blocks includes:

The decoding device receives the prediction block and the flag bit sent by the encoding device;

The decoding device decodes the prediction block according to the prediction mode carried in the flag bit, where the prediction mode includes: an intra prediction mode and an iterative prediction mode.
The method according to claim 14, wherein the decoding device decodes the prediction block according to the prediction mode carried in the flag bit, comprising:

The decoding device determines a final reconstruction block according to the residual block obtained from the code stream and the prediction mode, and decodes the final reconstruction block.
The method according to claim 15, wherein the decoding device determines the final reconstruction block according to the residual block obtained from the code stream and the prediction mode, comprising:

When the prediction mode is the intra prediction mode, the intra prediction mode is used to obtain the prediction block, and the decoding device obtains the final reconstructed block according to the residual block obtained from the code stream and the prediction block corresponding to the intra prediction mode .
The method according to claim 15, wherein the decoding device determines the final reconstruction block according to the residual block obtained from the code stream and the prediction mode, comprising:

When the prediction mode is an iterative prediction mode, the decoding device obtains an intermediate reconstruction block according to the residual block obtained from the code stream and the prediction block generated using the intra prediction mode;

The decoding device obtains the intermediate prediction block after iteratively predicting the intermediate reconstruction block;

The decoding device determines the final reconstruction block according to the intermediate prediction block and the residual block obtained from the code stream.
The method according to claim 17, wherein the iterative prediction of the intermediate reconstruction block by the decoding device comprises:

The decoding device divides the intermediate reconstruction block, and selects reference pixels from the divided sub-blocks;

The encoding device uses the reference pixels to perform iterative prediction on each of the sub-blocks to obtain an encoded block after iterative prediction.
A code block prediction device, located in an encoding device, includes:

The selecting module is configured to divide the coded block after intra-frame prediction, and select reference pixels from the reconstructed pixels in the divided sub-blocks;

A prediction module configured to perform iterative prediction on each of the sub-blocks by using the reference pixels to obtain a coded block after iterative prediction;

A determining module, configured to compare the distortion parameters of the coded block after intra-frame prediction and the coded block after iterative prediction, determine the prediction mode of the coded block, and set corresponding flag bits;

The sending module is configured to send the coding block corresponding to the prediction mode and the flag bit to the decoding device.
A decoding device for code blocks includes:

A receiving module, configured to receive the prediction block and the flag bit sent by the encoding device;

The decoding module is configured to decode the prediction block according to the prediction mode carried in the flag bit, where the prediction mode includes: an intra prediction mode and an iterative prediction mode.
A storage medium in which a computer program is stored, and the computer program is configured to execute the method described in any one of claims 1-18 when running.
An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the method described in any one of claims 1-18.