Inter-frame fast mode selection method, system and device for HEVC (High Efficiency Video Coding) and medium

Abstract

The invention discloses an inter-frame fast mode selection method, system and device for HEVC and a medium. The method comprises the steps that whether a current prediction unit is in an SKIP mode or a Merge mode is judged according to the absolute difference sum of the current prediction unit and a DCT conversion coefficient; determining an inter-frame first optimal mode of the current prediction unit according to a judgment result; judging whether to skip selection of an intra-frame mode or not based on the coding block mark of the inter-frame first optimal mode; and if the intra-frame mode is not skipped, selecting the mode with the minimum rate-distortion cost value as a second inter-frame optimal mode according to the rate-distortion cost value of the first inter-frame optimal mode and the rate-distortion cost value of the intra-frame mode. The mode decision is realized by fully utilizing the prediction information and the transformation information, and the inter-frame mode selection complexity is effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of video coding, and in particular to a HEVC inter-frame fast mode selection method, system, device and medium. Background Art

[0002] HEVC (high efficiency video coding) is a new generation of video coding standard. Due to the introduction of large-size quadtree segmentation, higher prediction accuracy, 35 intra-frame prediction modes, rate-distortion optimization technology, sample adaptive offset technology and other new technologies in HEVC, the coding complexity is extremely high. In order to reduce the complexity of coding, the existing technology estimates the depth prediction range of the current coding tree unit, mode selection and early termination of the coding unit from the perspective of temporal and spatial domain correlation. However, this method does not consider the correlation and fast decision between the prediction modes of the prediction unit itself, has limitations for PU mode selection and reducing coding complexity, and cannot effectively reduce the complexity of inter-frame mode selection. Therefore, how to effectively reduce the complexity of inter-frame mode selection is a problem to be solved. Summary of the invention

[0003] The main purpose of the present application is to overcome the shortcomings and deficiencies of the prior art and to provide a method, system, device and medium for fast inter-frame mode selection of HEVC, which effectively reduces the complexity of inter-frame mode selection by making full use of prediction information and transformation information to realize mode decision.

[0004] In order to achieve the above objectives, this application adopts the following technical solutions:

[0005] In a first aspect, the present application provides a method for selecting an inter-frame fast mode of HEVC, comprising the following steps:

[0006] Determine whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference and DCT transform coefficient of the current prediction unit;

[0007] According to the result of the judgment, determining the first inter-frame optimal mode of the current prediction unit;

[0008] Determining whether to skip the selection of the intra-frame mode based on the coding block flag of the first optimal inter-frame mode;

[0009] If the selection of the intra mode is not skipped, the mode with the smallest rate-distortion cost value is selected as the second optimal inter mode according to the rate-distortion cost value of the first optimal inter mode and the rate-distortion cost value of the intra mode.

[0010] As a preferred technical solution, before judging whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference sum and DCT transform coefficient of the current prediction unit, the method further includes:

[0011] Acquire multiple motion vector predictors in Merge mode, and select a preset number of motion vector predictors from the multiple motion vector predictors as candidate motion vector predictors;

[0012] Luminance component interpolation and chrominance component interpolation are performed on the candidate motion vector predictor to obtain a complete prediction unit including luminance and chrominance.

[0013] As a preferred technical solution, the interpolation of luminance components and chrominance components of the candidate motion vector predictor is performed to obtain a complete prediction unit including luminance and chrominance, including:

[0014] Calculating the luminance rate distortion cost value of the candidate motion vector predictor, and selecting the candidate motion vector predictor with the minimum luminance rate distortion cost value as the optimal motion vector predictor;

[0015] The optimal motion vector predictor is interpolated for chrominance components to obtain a complete prediction unit including luminance and chrominance.

[0016] As a preferred technical solution, it also includes:

[0017] If, during the process of calculating the luminance rate distortion cost value, the luminance rate distortion cost value is less than a first preset threshold, the candidate motion vector predictor of the luminance rate distortion cost value is used as the optimal motion vector predictor, and the candidate selection process is exited in advance.

[0018] As a preferred technical solution, judging whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference and DCT transform coefficient of the current prediction unit includes:

[0019] Calculate the absolute difference sum of each 8x8 sub-block of the current prediction unit;

[0020] If the sum of the absolute differences of the 8x8 sub-blocks of the current prediction unit is greater than a second preset threshold related to the quantization parameter, the current prediction unit is in Merge mode;

[0021] Otherwise, the residual of the 8x8 sub-block with the largest absolute difference is calculated, and the DCT transform coefficient of the 8x8 sub-block is calculated;

[0022] If the absolute values ​​of all transform coefficients of the 8x8 sub-block are less than or equal to a third preset threshold related to the quantization parameter, the current prediction unit is in SKIP mode, otherwise it is in Merge mode.

[0023] As a preferred technical solution, determining the first inter-frame optimal mode of the current prediction unit according to the result of the judgment includes:

[0024] If the first optimal inter-frame mode of the current prediction unit is the Merge mode, then calculating the absolute difference sum of the Merge mode;

[0025] Perform Inter mode motion search on the current prediction unit to obtain the optimal motion vector and calculate the absolute difference of the optimal motion vector;

[0026] Comparing the absolute difference sum of the Merge mode and the absolute difference sum of the optimal motion vector, if the absolute difference sum of the Merge mode is less than the absolute difference sum of the optimal motion vector of the Inter mode, the inter-frame first optimal mode of the current prediction unit is the Merge mode, otherwise the inter-frame first optimal mode of the current prediction unit is the Inter mode;

[0027] The rate-distortion optimization is performed on the first inter-frame optimal mode of the current prediction unit to obtain a rate-distortion cost value of the first inter-frame optimal mode.

[0028] As a preferred technical solution, the determining whether to skip the selection of the intra-frame mode based on the coding block flag of the first optimal inter-frame mode includes:

[0029] If the luminance coding block flag and the chrominance coding block flag of the first optimal mode of the current frame are both zero, the selection of the intra-frame mode is skipped; otherwise, the intra-frame mode is selected, and the absolute difference sum of all intra-frame modes is calculated, and the absolute difference sum of the intra-frame mode with the smallest absolute difference is selected as the absolute difference sum of the optimal mode of the intra-frame;

[0030] If the absolute difference of the optimal mode within the frame is greater than the preset multiple of the absolute difference of the optimal motion vector between frames, the rate-distortion optimization and chrominance prediction process of luminance is skipped;

[0031] If the absolute difference of the optimal mode within the frame is less than the preset multiple of the absolute difference of the optimal motion vector between frames, the rate-distortion optimization of brightness is performed, and the rate-distortion cost value of brightness is obtained;

[0032] If the optimal rate-distortion cost value of luminance is greater than or equal to the rate-distortion cost value of the optimal mode of the current inter-frame, the chrominance prediction process is skipped;

[0033] If the optimal rate-distortion cost value of brightness is less than the rate-distortion cost value of the first optimal mode in the current inter-frame, the rate-distortion cost value of the entire intra-frame mode is calculated.

[0034] In a second aspect, the present application provides an inter-frame fast mode selection system of HEVC, which is applied to an inter-frame fast mode selection method of HEVC, including a first judgment module, a first optimal mode module, a second judgment module and a second optimal mode module;

[0035] The first judgment module is used to judge whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference sum and DCT transformation coefficient of the current prediction unit;

[0036] The first optimal mode module is used to determine the first inter-frame optimal mode of the current prediction unit according to the result of the judgment;

[0037] The second judgment module is used to judge whether to skip the selection of the intra-frame mode based on the coding block flag of the first optimal inter-frame mode;

[0038] The second optimal mode module is used to select the mode with the smallest rate-distortion cost value as the second optimal inter-frame mode according to the rate-distortion cost value of the first optimal inter-frame mode and the rate-distortion cost value of the intra-frame mode if the selection of the intra-frame mode is not skipped.

[0039] In a third aspect, the present application provides an electronic device, the electronic device comprising:

[0040] at least one processor; and a memory communicatively coupled to the at least one processor;

[0041] The memory stores computer program instructions that can be executed by the at least one processor, and the computer program instructions are executed by the at least one processor so that the at least one processor can execute the HEVC inter-frame fast mode selection method.

[0042] In a fourth aspect, the present application provides a computer-readable storage medium storing a program, which, when executed by a processor, implements the HEVC inter-frame fast mode selection method.

[0043] In summary, compared with the prior art, the effective effects brought about by the technical solution provided by this application include at least:

[0044] The present application proposes a fast inter-frame mode selection method for HEVC, which determines whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference and DCT transform coefficient of the current prediction unit; determines the first inter-frame optimal mode of the current prediction unit according to the result of the determination; determines whether to skip the selection of the intra-frame mode based on the coding block flag of the first inter-frame optimal mode, and if the intra-frame mode is not skipped, performs intra-frame mode selection; if the selection of the intra-frame mode is not skipped, selects the mode with the smallest rate-distortion cost value as the second inter-frame optimal mode according to the rate-distortion cost value of the first inter-frame optimal mode and the rate-distortion cost value of the intra-frame mode. The present application makes full use of prediction information and transformation information for fast mode decision-making, and uses the correlation and information between different prediction modes for early judgment, effectively reducing the complexity of inter-frame mode selection. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 A flowchart of a HEVC inter-frame fast mode selection method provided by an embodiment of the present application;

[0047] Figure 2 A block diagram of an inter-frame fast mode selection system of HEVC provided for one embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0049] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0050] The Merge mode (motion merge mode), SKIP mode (skip mode) and Inter mode in this application are all inter-frame modes.

[0051] Among them, Merge mode (motion merge mode): does not directly transmit the motion vector of the current block, but tries to select an optimal one from the motion vectors of adjacent blocks as the motion vector of the current block. Since there is no need to transmit the motion vector itself, the amount of encoded data can be further reduced.

[0052] SKIP mode (skip mode): If the motion vector of the current block is exactly the same as the motion vector of a neighboring block, and the prediction residual is very small (usually below a certain threshold), the encoder can directly skip the encoding process of the current block without transmitting any information about the current block (including motion vector and prediction residual).

[0053] Inter mode: uses the information already encoded in the previous frame or previous frames to predict the content of the current frame, and only transmits the prediction error (that is, the difference between the actual frame and the predicted frame) and necessary motion information (such as motion vectors), rather than the data of the entire frame.

[0054] See also Figure 1 In one embodiment of the present application, a method for selecting an inter-frame fast mode of HEVC is provided, comprising the following steps:

[0055] S1. Determine whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference sum and DCT transform coefficient of the current prediction unit.

[0056] Further, before judging whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference sum and DCT transform coefficient of the current prediction unit, the method further includes:

[0057] Acquire multiple motion vector predictors in Merge mode, and select a preset number of motion vector predictors from the multiple motion vector predictors as candidate motion vector predictors; wherein the preset number is 3;

[0058] Performing luminance component interpolation and chrominance component interpolation on the candidate motion vector predictor to obtain a complete prediction unit including luminance and chrominance, the specific steps of which include:

[0059] Calculate the brightness rate-distortion cost value of the candidate motion vector predictor, and select the candidate motion vector predictor with the smallest brightness rate-distortion cost value as the optimal motion vector predictor; wherein, if, in the process of calculating the brightness rate-distortion cost value, the brightness rate-distortion cost value is less than a first preset threshold value, then the candidate motion vector predictor with the brightness rate-distortion cost value is used as the optimal motion vector predictor, and the candidate selection process is exited early.

[0060] Furthermore, luminance component interpolation refers to the process of performing motion compensation on a motion vector predictor to obtain a corresponding predicted image, and calculating a luminance rate-distortion cost value based on the original image and the predicted image, that is, the process of obtaining a predicted image based on the reconstructed image and the corresponding MVP interpolation.

[0061] The optimal motion vector predictor is interpolated for chrominance components to obtain a complete prediction unit including luminance and chrominance.

[0062] Specifically, judging whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference and DCT transform coefficient of the current prediction unit includes:

[0063] Calculate the absolute difference sum of each 8x8 sub-block of the current prediction unit;

[0064] If the sum of the absolute differences of the 8x8 sub-blocks of the current prediction unit is greater than a second preset threshold THR1 related to the quantization parameter (qp), the current prediction unit is in Merge mode;

[0065] Otherwise, the residual of the 8x8 sub-block with the largest absolute difference is calculated, and the DCT transform coefficient of the 8x8 sub-block is calculated;

[0066] If the absolute values ​​of all transform coefficients of the 8x8 sub-block are less than or equal to a third preset threshold THR2 related to the quantization parameter (qp), the current prediction unit is in SKIP mode, otherwise it is in Merge mode.

[0067] The second preset threshold THR1 and the third preset threshold THR2 related to the quantization parameter (qp) are determined according to experiments.

[0068] The DCT transform coefficients in this embodiment refer to discrete cosine transform coefficients.

[0069] S2. Determine a first inter-frame optimal mode of the current prediction unit according to the SKIP mode or the Merge mode of the current prediction unit.

[0070] Further, according to the mode of the current prediction unit, determining the first optimal inter-frame mode of the current prediction unit includes the following steps:

[0071] If the first optimal inter-frame mode of the current prediction unit is the Merge mode, then calculating the absolute difference sum of the Merge mode;

[0072] Perform Inter mode motion search on the current prediction unit to obtain the optimal motion vector (MV), and calculate the absolute difference sum of the optimal motion vector;

[0073] Compare the absolute difference sum of the Merge mode and the absolute difference sum of the optimal motion vector, if the absolute difference sum of the Merge mode is less than the absolute difference sum of the optimal motion vector of the Inter mode, then the first inter-frame optimal mode of the current prediction unit is the Merge mode, otherwise the first inter-frame optimal mode of the current prediction unit is the Inter mode;

[0074] The rate-distortion optimization is performed on the inter-frame first optimal mode of the current prediction unit to obtain the rate-distortion cost value of the inter-frame first optimal mode.

[0075] S3 determines whether to skip the selection of the intra-frame mode based on the coding block flag of the first optimal inter-frame mode; the steps include:

[0076] If the luminance coding block flag and the chrominance coding block flag of the first optimal mode of the current inter-frame are both zero, it is an all-zero block (an all-zero block refers to a coding block in which the residual coefficient is 0 after the residual coefficient is transformed and quantized), and the selection of the intra-frame mode is skipped; otherwise, the intra-frame mode is selected, the absolute difference sum of all intra-frame modes is calculated, and the absolute difference sum of the intra-frame mode with the smallest absolute difference is selected as the absolute difference sum of the optimal mode in the frame;

[0077] If the absolute difference of the optimal mode within the frame is greater than the preset multiple of the absolute difference of the optimal motion vector (MV) between frames, the rate-distortion optimization and chrominance prediction process of luminance is skipped;

[0078] If the absolute difference of the optimal mode within the frame is less than a preset multiple of the absolute difference of the optimal motion vector (MV) between frames, the rate-distortion optimization of brightness is performed, and the brightness rate-distortion cost value is obtained;

[0079] If the optimal rate-distortion cost value of luminance is greater than or equal to the rate-distortion cost value of the optimal mode of the current inter-frame, the chrominance prediction process is skipped;

[0080] If the optimal rate-distortion cost value of brightness is less than the rate-distortion cost value of the first optimal mode in the current inter-frame, the rate-distortion cost value of the entire intra-frame mode is calculated.

[0081] S4. If the selection of the intra-frame mode is not skipped, then according to the rate-distortion cost value of the first optimal inter-frame mode and the rate-distortion cost value of the intra-frame mode, the mode with the smallest rate-distortion cost value is selected as the second optimal inter-frame mode.

[0082] Furthermore, if the selection of the intra-frame mode is skipped, the first optimal inter-frame mode determined in step S2 is used as the second optimal inter-frame mode.

[0083] In summary, the present application firstly makes a quick decision on the SKIP mode and the Merge mode based on the absolute difference and the DCT transform coefficient, so as to realize the early termination of the SKIP mode; then makes a decision on the Merge mode and the Inter mode based on the absolute difference, thereby saving a lot of rate-distortion optimization calculations; finally, the intra-frame mode calculation is quickly skipped, and the optimal inter-frame mode is determined according to the rate-distortion optimization criterion. The present application makes full use of the prediction information and the transformation information to realize the mode decision, and effectively reduces the complexity of the inter-frame mode selection.

[0084] It should be noted that, for the sake of convenience of description, the aforementioned method embodiments are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited to the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously.

[0085] Based on the same idea as the inter-frame fast mode selection method of HEVC in the above-mentioned embodiment, the present application also provides an inter-frame fast mode selection system of HEVC, which can be used to execute the above-mentioned inter-frame fast mode selection method of HEVC. For ease of explanation, the structural diagram of an embodiment of an inter-frame fast mode selection method of HEVC only shows the parts related to the embodiment of the present application. Those skilled in the art can understand that the illustrated structure does not constitute a limitation on the system, and may include more or fewer components than the illustrated structure, or combine certain components, or arrange the components differently.

[0086] See also Figure 2 In another embodiment of the present application, a HEVC inter-frame fast mode selection system is provided, the system comprising a first judgment module 101, a first optimal mode module 102, a second judgment module 103 and a second optimal mode module 104;

[0087] The first judgment module 101 is used to judge whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference sum and DCT transformation coefficient of the current prediction unit;

[0088] The first optimal mode module 102 is used to determine the first inter-frame optimal mode of the current prediction unit according to the result of the judgment;

[0089] The second judgment module 103 is used to judge whether to skip the selection of the intra-frame mode based on the coding block flag of the first optimal inter-frame mode;

[0090] The second optimal mode module 104 is configured to select the mode with the smallest rate-distortion cost value as the second optimal inter-frame mode according to the rate-distortion cost value of the first optimal inter-frame mode and the rate-distortion cost value of the intra-frame mode if the selection of the intra-frame mode is not skipped.

[0091] It should be noted that an inter-frame fast mode selection system of HEVC in the present application corresponds one-to-one to an inter-frame fast mode selection method of HEVC in the present application. The technical features and beneficial effects described in the embodiment of the above-mentioned inter-frame fast mode selection method of HEVC are applicable to the embodiment of an inter-frame fast mode selection system of HEVC. For specific contents, please refer to the description in the embodiment of the method of the present application, which will not be repeated here. This is hereby declared.

[0092] In addition, in the implementation of an inter-frame fast mode selection system of HEVC in the above-mentioned embodiment, the logical division of each program module is only an example. In actual applications, the above-mentioned functions can be assigned to different program modules as needed, for example, for the configuration requirements of the corresponding hardware or the convenience of software implementation. That is, the internal structure of the inter-frame fast mode selection system of HEVC is divided into different program modules to complete all or part of the functions described above.

[0093] In another embodiment, an electronic device for implementing an inter-frame fast mode selection method of HEVC is provided, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor; when the processor executes the computer program, an inter-frame fast mode selection method of HEVC of any embodiment of the present application is implemented.

[0094] Exemplarily, in this embodiment, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present application. The one or more module elements may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program in the device.

[0095] The device may be a computing device such as a desktop computer, a notebook, a palm computer, a cloud server, etc. The device may include, but is not limited to, a processor and a memory.

[0096] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the device, and various interfaces and lines are used to connect various parts of the entire device.

[0097] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the device by running or executing the computer program and / or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; in addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0098] Accordingly, the present application also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute an inter-frame fast mode selection method of HEVC as described in any one of the above embodiments.

[0099] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0100] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The above embodiments are preferred implementation modes of the present application, but the implementation modes of the present application are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present application should be equivalent replacement methods and are included in the protection scope of the present application.

Claims

1. A method for selecting an inter-frame fast mode of HEVC, characterized in that: The steps include: Determine whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference and DCT transform coefficient of the current prediction unit; According to the result of the judgment, determining the first inter-frame optimal mode of the current prediction unit; Determining whether to skip the selection of the intra-frame mode based on the coding block flag of the first optimal inter-frame mode; If the selection of the intra mode is not skipped, the mode with the smallest rate-distortion cost value is selected as the second optimal inter mode according to the rate-distortion cost value of the first optimal inter mode and the rate-distortion cost value of the intra mode.

2. The method for selecting an inter-frame fast mode of HEVC according to claim 1, characterized in that: Before judging whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference and DCT transform coefficient of the current prediction unit, the method further includes: Acquire multiple motion vector predictors in Merge mode, and select a preset number of motion vector predictors from the multiple motion vector predictors as candidate motion vector predictors; Luminance component interpolation and chrominance component interpolation are performed on the candidate motion vector predictor to obtain a complete prediction unit including luminance and chrominance.

3. The method for selecting an inter-frame fast mode of HEVC according to claim 2, characterized in that: The step of performing luminance component interpolation and chrominance component interpolation on the candidate motion vector predictor to obtain a complete prediction unit including luminance and chrominance includes: Calculating the luminance rate distortion cost value of the candidate motion vector predictor, and selecting the candidate motion vector predictor with the minimum luminance rate distortion cost value as the optimal motion vector predictor; The optimal motion vector predictor is interpolated for chrominance components to obtain a complete prediction unit including luminance and chrominance.

4. The method for selecting an inter-frame fast mode of HEVC according to claim 3, characterized in that: Also includes: If, during the process of calculating the luminance rate distortion cost value, the luminance rate distortion cost value is less than a first preset threshold, the candidate motion vector predictor of the luminance rate distortion cost value is used as the optimal motion vector predictor, and the candidate selection process is exited in advance.

5. The method for selecting an inter-frame fast mode of HEVC according to claim 1, characterized in that: The step of judging whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference and DCT transform coefficient of the current prediction unit includes: Calculate the absolute difference sum of each 8x8 sub-block of the current prediction unit; If the sum of the absolute differences of the 8x8 sub-blocks of the current prediction unit is greater than a second preset threshold related to the quantization parameter, the current prediction unit is in Merge mode; Otherwise, the residual of the 8x8 sub-block with the largest absolute difference is calculated, and the DCT transform coefficient of the 8x8 sub-block is calculated; If the absolute values ​​of all transform coefficients of the 8x8 sub-block are less than or equal to a third preset threshold related to the quantization parameter, the current prediction unit is in SKIP mode, otherwise it is in Merge mode.

6. The method for selecting an inter-frame fast mode of HEVC according to claim 5, characterized in that: The determining, according to the result of the judgment, a first optimal inter-frame mode of the current prediction unit includes: If the first optimal inter-frame mode of the current prediction unit is the Merge mode, then calculating the absolute difference sum of the Merge mode; Perform Inter mode motion search on the current prediction unit to obtain the optimal motion vector and calculate the absolute difference of the optimal motion vector; Comparing the absolute difference sum of the Merge mode and the absolute difference sum of the optimal motion vector, if the absolute difference sum of the Merge mode is less than the absolute difference sum of the optimal motion vector of the Inter mode, the inter-frame first optimal mode of the current prediction unit is the Merge mode, otherwise the inter-frame first optimal mode of the current prediction unit is the Inter mode; The rate-distortion optimization is performed on the first inter-frame optimal mode of the current prediction unit to obtain a rate-distortion cost value of the first inter-frame optimal mode.

7. The method for selecting an inter-frame fast mode of HEVC according to claim 6, characterized in that: The determining whether to skip the selection of the intra-frame mode based on the coding block flag of the first optimal inter-frame mode includes: If the luminance coding block flag and the chrominance coding block flag of the first optimal mode of the current frame are both zero, the selection of the intra-frame mode is skipped; otherwise, the intra-frame mode is selected, the absolute difference sum of all intra-frame modes is calculated, and the absolute difference sum of the intra-frame mode with the smallest absolute difference is selected as the absolute difference sum of the optimal mode of the intra-frame; If the absolute difference of the optimal mode within the frame is greater than the preset multiple of the absolute difference of the optimal motion vector between frames, the rate-distortion optimization and chrominance prediction process of luminance is skipped; If the absolute difference of the optimal mode within the frame is less than the preset multiple of the absolute difference of the optimal motion vector between frames, the rate-distortion optimization of brightness is performed, and the rate-distortion cost value of brightness is obtained; If the optimal rate-distortion cost value of luminance is greater than or equal to the rate-distortion cost value of the optimal mode of the current inter-frame, the chrominance prediction process is skipped; If the optimal rate-distortion cost value of brightness is less than the rate-distortion cost value of the first optimal mode in the current inter-frame, the rate-distortion cost value of the entire intra-frame mode is calculated.

8. A HEVC inter-frame fast mode selection system, characterized in that: An inter-frame fast mode selection method of HEVC applied to any one of claims 1-7, comprising a first judgment module, a first optimal mode module, a second judgment module and a second optimal mode module; The first judgment module is used to judge whether the current prediction unit is in SKIP mode or Merge mode according to the absolute difference sum and DCT transformation coefficient of the current prediction unit; The first optimal mode module is used to determine the first inter-frame optimal mode of the current prediction unit according to the result of the judgment; The second judgment module is used to judge whether to skip the selection of the intra-frame mode based on the coding block flag of the first optimal inter-frame mode; The second optimal mode module is used to select the mode with the smallest rate-distortion cost value as the second optimal inter-frame mode according to the rate-distortion cost value of the first optimal inter-frame mode and the rate-distortion cost value of the intra-frame mode if the selection of the intra-frame mode is not skipped.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively coupled to the at least one processor; The memory stores computer program instructions that can be executed by the at least one processor, and the computer program instructions are executed by the at least one processor so that the at least one processor can execute an inter-frame fast mode selection method of HEVC as described in any one of claims 1-7.

10. A computer-readable storage medium storing a program, characterized in that: When the program is executed by a processor, an inter-frame fast mode selection method of HEVC as described in any one of claims 1 to 7 is implemented.

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