VR system application in the inheritance of intangible cultural heritage gongs and drums based on video simulation

In recent years, with the rapid popularization of Internet technology and the development of a large number of smart terminal devices for the Internet of Things, Internet of Things systems and devices have become more and more popular in people’s daily lives, and the types and numbers of smart Internet of Things applications are constantly increasing. In VR, more and more input devices and more and more data and information directly affect the depth of embedding. In the era of big data, data storage is overvalued, and a reasonable solution to data storage strategies is needed. When sending video simulation applications, the emergence of VR technology has played a huge role in the inheritance of intangible cultural heritage. Through immersive virtual reality or interactive virtual reality, it has injected new blood of the times into excellent traditional culture and has become an intangible help. The list of intangible cultural heritage protection includes many traditional folk music with unique local characteristics. The gong and drum music in a certain place is one of them. This thesis analyzes the problems in depth from the development status of gongs and drums in a certain place and the problems faced in the later period, and explores executable inheritance and protection strategies.


Introduction
In the process of protection and inheritance of intangible cultural heritage of gongs and drums, due to historical, cultural, social habits, and other reasons, most of the inheritors mainly inherited through oral inheritance, content recitation, language, and behavior (Lenzerini 2011). However, there are relatively few records about them, and the content is incomplete, has the characteristics of original ecology, easy to lose, and easy to change. Especially with the aging of the inheritors and the lack of market demand, many skills have been forgotten by people, and even gradually no one learns, and the inheritance is lost (Barrio et al. 2012). This makes it difficult to inherit intangible cultural heritage, and related protection work is also difficult. Under the new concept of protection and inheritance, modern digital technology is used to record, inherit, promote, and sell intangible cultural heritage projects (Kanduti and Kopač 2021). The development of modern digital technology provides a broader space for the collection, preservation, display, and popularization of intangible cultural heritage gongs and drums (Galla 2018). The Internet of Things is an important part of the new generation of information technology and an important development stage in the ''information'' age. It has a very wide range of uses, whether it is daily living environment monitoring, security work, smart home, transportation, and other aspects (Sundmaeker et al. 2010). This technology uses a computer to generate an interactive three-dimensional dynamic view. Through the physical action simulation system, the user can be gradually brought into a virtual environment. VR is not only used in the field of computer imagery, but also participates in research and development in a wide range of fields such as video conferencing, network technology, decentralized computing technology, and decentralized virtual reality development (Said and Masud 2013). Virtual reality technology is also an important means of current new product design and development. It is mainly used for product simulation in the product design stage to help people understand the design concept more clearly (Li et al. 2017). Intangible cultural heritage of gongs and drums is an important part of national history in Chinese culture, and it is also a witness of national development. It has become an important branch of Chinese culture. However, with the development and changes of society, the inheritance and development of intangible cultural heritage is facing more and more severe tests, and more and more new protection concepts and methods need to be continuously explored (Xue et al. 2019). This article takes virtual reality technology as an important way to discuss its application and use in the protection of intangible cultural heritage. Research-related technical methods and cultural protection strategies analyze their important role in the inheritance and development of traditional culture, so as to provide help for the protection of intangible cultural heritage (Chen 2022).

Related work
If there is no limit, the speed of the performer will determine the value of the predicted speed according to a Gaussian distribution with an average of 1.34 m/s and a standard deviation of 0.26 m/s. Based on the above method, the article first uses the existing research to calibrate several parameters that cannot be obtained from the observation data set and are difficult to directly calibrate (Tan et al. 2020). On the other hand, through the obtained performer observation data, several parameters with poor portability are corrected. The literature pointed out that compared with other intangible cultural heritages of ethnic minority art, the research results of ''silk strings and gongs and drums'' have received less attention in academic circles (Esfehani and Albrecht 2018). A lot of information has not been discovered, checked, and updated. For the inheritance and protection of ''silk strings and gongs and drums,'' on the one hand, we can further study history. On the other hand, it can conduct detailed and systematic investigations on its historical inheritance mode, inheritance mechanism, and inheritance characteristics (Melis and Chambers 2021). The literature research on cluster movement and action rules can scientifically predict public activities, thereby providing a basis for land use planning and cluster management, effectively ensuring public safety, and minimizing damage to the environment (Zhang et al. 2012). This has become the focus of current research in related fields. As simulation increasingly replaces experimental induction and model inference, it has gradually become one of the commonly used scientific research methods, also known as the third paradigm. More and more people are beginning to use computer simulation technology to simulate the complexities of crowd actions (Liu and Huang 2015). When the culture ushered in a new era, ''silk strings and gongs and drums'' are also facing new development opportunities. The ''Sixian gongs and drums'' promoted by the government were declared as new intangible cultural heritage (Jacobs 2014). Through cultural inheritance, selection of relevant inheritors, and organization of related personnel to perform performances, the previous cultural materials were sorted, and a batch of ''silk strings'' was created. ''Gongs and drums'' performance project, they often participate in various exhibitions and art activities, and have won many awards and high praise.
The core of the protection of intangible cultural heritage is the protection of the inheritors. In order to protect the intangible cultural heritage, clarifying the responsibilities and obligations of the inheritors and determining the beneficiaries and responsible persons are important prerequisites for protection. The government should emphasize or recognize the responsibilities of the inheritor in the work of heritage protection, give certain recognition, and provide corresponding help at the same time, and pay attention to the contribution and feelings of the inheritor. In order to increase the enthusiasm and enthusiasm of the inheritors for the inheritance of skills, it is necessary to ensure that their rights are not affected, so as to form a good group protection and inheritance atmosphere.
3 The video simulation algorithm design of the big data VR system 3.1 Big data VR system algorithm VR system based on super-high-resolution panoramic video as shown in Fig. 1. As shown in Fig. 1, the video playback process uses the super-high-resolution panoramic video to be pre-divided into slices at the same time. The video encoding copy and the normal resolution are less than 8 k, which is used to enlarge the circular super-high-resolution video area. In addition to the magnified area, two hardware decoders are used to decode them, so that they are presented in normal resolution video. For ultra-high-resolution videos, it is necessary to calculate the tiles covered by the magnified area according to the position of the current viewpoint, and load the corresponding code streams of these tiles. In the current system, the VR head display operates in 3DOF mode, and the position of the head display is consistent with the origin of the world coordinate system and the spherical model coordinate system. The VR head display device used in this system is HTCVVEPro. By calling the interface provided by the OpenVR SDK, a 4 9 4 matrix of the same kind can be returned in real time. This corresponds to the OpenGL observation matrix, which includes the position information and direction information of the display. The matrix returned by the header display is usually shown in formula (1). In 3DOF mode, the parallel movement vector is equal to the zero vector.
As shown in formula (2), the rotation matrix can be used to calculate the current direction to ori (omitted form of oricontion).
The center point of the sub-image is equivalent to the projection of the viewpoint on the plane, and the calculation process is as follows: First, as shown in Eq. (3), the spherical orthogonal coordinates are converted into spherical coordinates.
Then, as shown in Eq. (4), the spherical coordinates are converted into texture coordinates.
Finally, as shown in formula (5), the texture coordinates are converted into pixel coordinates to obtain the pixel coordinates (s, t) of the center of the sub-image.
As shown in Fig. 2, the sub-image does not cross the boundary but is located within the range of the panoramic image. If you know the center coordinate P of the subimage and the length of the side, you can calculate the coordinates of the four corners and their corresponding tiles.
For example, as shown in Eq. (6), the coordinates of point A in the upper left corner are equal to the coordinates of point P in the center minus half the length of the side.
After the video is divided into 24 9 48 tiles, each tile has its own coordinate range. As shown in formulas (7) and (8), you can calculate the row number and column number  of the tile with a dot A, and then calculate the serial number of the tile.
In the above formula, row and col are the row number and column number of the tile where point A is placed. TileOrder is the sequence number of the tiles placed at point A, 1280 is the tile length, and 48 is the number of tiles in each row. The row number, column number, and sequence number are numbers starting from 0. Similarly, the serial numbers of B, C, and D are calculated as expressions (9), (10), and (11).
The corresponding relationship between vertex coordinates and texture coordinates depends on the projection form of the panoramic image and the ERP projection method used in the system. The apex of the ball is produced by the intersection of the vertical and horizontal lines. When the radius of the sphere is r, the angle between adjacent vertical lines and horizontal lines changes, and when the angle between adjacent vertical lines changes, the intersection of the i-th latitude line and the J warp line becomes the spherical coordinate. As shown in formula (12), the spherical coordinates are converted into spatial Cartesian coordinates.
According to the ERP mapping, the texture coordinates corresponding to the vertices are calculated as shown in Eq. (13).
The formula (14) expresses the calculation formula of the texture coordinate conversion process of the magnified area.
The texture coordinate of the center of the square subimage of the texture object.
Calculation process: In the load code flow calculation and sub-image overlapping tiles, the pixel coordinates of the upper left corner of the sub-image can be calculated according to the center of the sub-image, and then, the subsequent decoded output image fusion of the angle point of the top tile is calculated, calculated as (15).
To maximize the use of sub-images, make the circle inside the square when the magnification is equal. Therefore, the normalized value is calculated as shown in formula (16).
As shown in Table 1, first, from the perspective of transmission, analyze the bandwidth efficiency of the tile transmission method based on the amount of code stream after video encoding. Then, the display effect before and after zooming, the normal resolution, and the super-high resolution were set, the display clarity of the video zooming was compared, and the advantages and disadvantages of various zooming modes were summarized.
As shown in Table 2, the magnification modes will be compared from three aspects: bidirectionality, area of interest, and vertigo, so that two different magnification modes and full-screen magnification modes can be obtained. These four magnifying glass modes are dynamic effects and cannot be reflected in the screenshots of the static system.

IOT video simulation algorithm
The inter-frame difference method based on the video image sequence in the difference operation of two adjacent frames is used to obtain the contour of the moving target. The test result is discontinuous and low in accuracy, and it is difficult to extract the whole moving target area. The optical flow method of each pixel in the image provides a motion vector (image of the optical flow field) by analyzing the changes in the detection of moving objects. Its biggest advantage is that it supports camera movement, and the algorithm is complex, but a large number of calculations and poor anti-noise performance can no longer meet the requirements of 3D real-time video surveillance. The background difference method can be used to obtain the foreground moved by the difference operation between the current image and the background image. This has the advantage that the algorithm complexity is low, and the moving objects are completely segmented. The successful operation of this method is to correctly describe the background of the image, construct a background model that can adapt to changes in the scene environment, and construct a relatively correct and firm background model. However, using the Gaussian mixture model can simulate complex multi-modal backgrounds and high adaptability.
When X is used to represent the pixel observation value at time t, as shown in formula (17), it is determined as the probability density function of the background model.
Here, the weight value of the Gaussian distribution at time t is as follows: g represents the probability density of the Gaussian distribution at time t Here n represents the dimension of the observations, and the average matrix of the Gaussian distribution at time t is as follows: It is assumed that the RGB components of each pixel are independent of each other and are considered to have the same dispersion. X Here r is the standard deviation, and I is the identity matrix.
In the initial stage of GMM, the same weight value is used for the K Gaussian distribution.
When inputting subsequent images in the video, the parameters of the GMM must be continuously updated to adapt the model to the height of the background. The observed value of each pixel of the new frame image is consistent with the existing K Gaussian distribution. If the judgment condition of Eq. (22) is satisfied, X can be regarded as consistent with the Gaussian distribution.
During the update process, the weight of the Gaussian distribution will be updated according to formula (23). The average and variance of the consistent Gaussian distribution are updated according to formulas (24) and (25), but the average and variance of the inconsistent Gaussian distribution will not change.
In the above formula, a is the update rate of the weight, and q is the update rate of the parameter.
If the observed value of the pixel is inconsistent with all the Gaussian distributions of the GMM, a new Gaussian distribution must be created according to formula (27), and the Gaussian distribution must be replaced with the lowest priority. k k;t ¼ x k;t =r k;t k ¼ 1; 2; . . .; K ð Þ ð 27Þ  In order to determine the best Gaussian distribution that can be used to describe the background model after the parameter update, this survey sorts the K Gaussian distribution from high to low according to the priority and selects the first M Gaussian distribution to generate the background model: As shown in Fig. 3, the process of the background difference algorithm improved by the Gaussian mixture model is as follows.
Video preprocessing: The input cluster video is processed by video resampling and filtering. As a result, the amount of calculation and image noise are greatly reduced, and the detection performance of background differences is improved.
Background modeling of mixed Gaussian model: The mixed Gaussian model is initialized according to the first K frame of the video input, and the background model will be updated when a new image frame is input.
Median filter: The foreground image obtained by the difference operation will be filtered by the median to remove impulse interference and descrambling noise in the foreground.
Morphological operation: Set the morphological threshold, remove isolated noise outside the target, and smooth the target boundary through erosion and expansion operations or opening operations.
Histogram threshold processing: By setting the gray histogram threshold, the redundant target foreground with less color change is eliminated.
Extraction and filling configuration: First, through connectivity analysis, multiple daily markers in the foreground are separated, and then, contour extraction and filling methods are used to extract the complete area of multiple targets.
As shown in Fig. 4, through the implementation of the algorithm, the background subtraction proposed by the Gaussian mixture model-based performer's moving target detection method can perform simple and efficient multiple moving target detection results on a static camera group. It is the fixed camera of the original video image, (b) is used to establish the background image, the Gaussian mixture model (c) is not an improved GMM algorithm for detecting

Project overall planning
This VR system is a VR application for VR glasses for smartphones based on the Win10 mobile phone system. Smartphones, VR glasses, and VR applications are the three important parts of this system. VR glasses for mobile communication devices provide a basic VR environment. The lens of the VR glasses matches the image of the human eye, and the right and left sides of the phone screen are close to the viewpoint of the human eye, forming a sense of immersion. In addition, the VR application program is composed of a rendering architecture package layer, a VRLauncer module, a VR video player, a VR image browser, a VR content storage module, and a pre-tracking algorithm module. The packaging layer of the rendering architecture is encapsulated in the Direct 3D 11 graphics rendering interface below, simplifying the logic of the upper function coding, and facilitating future expansion and maintenance. The image list page is exactly the same as the VR video playback interface, so it will not be explained here. In the image browsing page, the image format selected by the user can be automatically distinguished. Two-dimensional images and panoramic images adopt different forms of reproduction. The 2D image shows a simple rectangular frame, while the panoramic image is a special format and must be displayed in a sphere. The image browser of the control is relatively simple, the user clicks the button to confirm. The screen jumps to the next image. The image can be played in a loop. If the current image is the last image, please click the button to jump. Take the first photo directly. When the user clicks the back button, the page will return to the image list.

System requirement analysis
As shown in Fig. 5, the overall function of the system is divided into VRLauncer module, VR video player module, VR image browser module, and VR storage module. As a real-time presentation VR system, system performance, stability, and ease of use are also necessary conditions. From the point of view of stability, the system proposes a method of header aggregation. For ease of use, the system provides a variety of user control input methods. The following will focus on the requirements of the following modules for detailed description. VRLauncer is composed of multiple scenes, each scene includes the functions required by the system, and each scene includes the following contents: The main interface of VRLauncer. The main interface includes buttons for the VR video player module, VR image browser buttons, start interface buttons for beginners, setting interface buttons, and other input buttons for other modules. The main screen also displays the current system time and battery, as well as the background of the sphere behind the main screen.
Beginner's startup interface is as follows: Beginners guide new users from the buttons of VR glasses and headsets to guide new users to confirm the input of the message and the way of replying to the message, notify the user of the matters needing attention in the use of the system, and prompt the display in the storage directory. There is also a system guidance function. When starting the VR system for the first time, the system first enters the startup interface and then enters the main interface.
VR system setting interface is as follows: The setting function includes whether to use the system volume setting, screen brightness setting, and user control mode setting, that is, the Hover selection function to control the system.
In addition, VRLauncer also provides system startup pendant function. Using VR Picture Browser, users can display common images and panoramic images from inside the phone in a VR environment. It has the same interface as the VR in the design of the video player that uses the same design as the VR image browser. It has an image viewing page and a list, and then, the image list is scanned by the phone to capture the type of image, so that you can skip supporting users. The thumbnail of the image is finally added to the list interface.
The VR storage module is a module independent of the system. Unlike other modules, this module is a standalone 2D application.
As shown in Fig. 6, this is the overall architecture of the VR system. The system abstracts the basic presentation logic, packs the presentation layer of Direct 3D 11, and is designed to solve the event monitoring mechanism controlled by the user to trigger the response. The head tracking algorithm provides data for rendering, and the system determines the presented image based on the head posture information. By combining the posture information provided by the presentation architecture and the head tracking algorithm, a complete set of presentation and logic functions is realized.

VR system implementation
The VR encapsulation layer encapsulates many program details, greatly promotes the upper-level logic code, eliminates the separation of the upper-level business logic layer and basic graphics presentation, logic layer and rendering, and becomes the basis for implementation. When creating business logic, you do not need to consider graphics rendering and coding. It will be greatly simplified, and the logic will become clear. The system also abstracts some necessary function points and categories, such as timers, interface UI, event monitoring functions, and provides more tool categories for the upper layer, making the description of the upper layer logic more convenient and clear.
As shown in Table 3, the methods and functions of the Application class will be described in detail. The application inherits the IFrameworkView class of the UWP framework and manages the entire life cycle of the application, such as startup, suspension, background execution, and recovery. Open OnActivated () is called when the application starts or starts and contains a number of logic for activating the application. The On Suspending() method is called when the application pauses and reaches the background. This provides the logic to be processed when the application reaches the background. The onResuming() method is called when the application reaches the background, and the processing logic can be edited.
Some of the important methods and attributes of the System class are shown in Table 4. When the application starts, the system creates system objects and uses all objects in the initialization system.
The detailed information of the MediaPlayer class is shown in Table 5. The player interface contains controls for controlling the video display area and playback.

Inheritance path of intangible cultural heritage gongs and drums
For the inheritance of intangible cultural heritage, due to the changes of the times, people's attitudes toward culture have also changed, resulting in the loss of the inheritance of related skills, the imperfect identification and training mechanism of the inheritors, and the lack of related management. The overall effect of inheritance has declined, coupled with the shortage of professional researchers, the shortage of research investment, and the inadequate storage of relevant materials, which has caused major problems for the inheritance of intangible cultural heritage. The protection of ''silk strings and gongs and drums'' is a systematic project. In order to ensure that the project can be passed on for a longer time, it is necessary to achieve the following points in the future protection work: The vitality of intangible cultural heritage is reflected in the continuous inheritance of skills. Only when it can be passed down for a long time, intangible cultural heritage will gain vitality. ''As the Chinese proverb says, ''Art only exists when people live. When people are dead, then art will disappear.'' Only the skills and content of ''silk strings and gongs and drums'' are all handed over to the inheritors so that they can master them skillfully. And by keeping it in mind, more people can appreciate the charm of ''silk strings and gongs and drums.'' The first step to protect inheritors is to establish scientific identification standards. In the case of a specific inheritor, the following things need to be done. Strict standards should be established. Non-genetic inheritors Fig. 6 The overall architecture of the VR system   refer to natural persons or group networks who learn excellent skills and directly participate in the production and execution of inheritance activities during the inheritance process, and can teach the students. From this point of view, the inheritor of Jianshi's ''Sixian Gong and Drum'' must meet the following conditions: He has mastered a large number of tunes and can perform proficiently; directly participates in the performance during the inheritance process; is willing to teach others to learn; or is already teaching others learn. In addition, the moral quality of the inheritor is also very important. Cultural space is ''a place or a series of places where traditional or folk culture is regularly expressed.'' ''The core value and theoretical basis of existence is to present intangible cultural heritage and lifestyle in a complete, comprehensive, and realistic ecological form.'' Intangible cultural heritage is formed in a specific cultural space, and then separated, will face the risk of change and alienation. Therefore, in order to protect the intangible cultural heritage, we must follow the principles of authenticity and life, and strengthen the protection of cultural space. Intangible cultural heritage policy plays an important guiding role in inheriting intangible cultural heritage, inheriting collective creativity and actions. The promulgation and implementation of the law stipulate the preservation, inheritance, and protection of intangible cultural heritage. Subsequently, local governments have issued local regulations and policy documents, which will be specifically reflected in the following points on the basis of maintaining the degree of innovation: Through continuous improvement of the management system and the improvement of the supervision system, it can ensure that the intangible cultural heritage is obtained effective protection.
Fund raising is an inevitable issue in terms of inheritance, and whether the funds are complete is directly related to the smooth development of inheritance activities. Most artists need to survive. Under the high attention of the government, the cultural awareness of artists is aroused. However, due to limited inheritance funds, public activities such as public performances or lectures cannot be effectively carried out. Now, lack of professional talents is the bottleneck of work. Many artists have not received enough education, have limited thinking, are not sensitive to changes in the times, and have low adaptability to the environment. Because of insufficient guidance from experts, their inheritance is insufficient. Therefore, how to ensure the maximum use of human resources has become an inevitable topic in the process of construction and protection. At present, the number of professional research institutions in the field of China's intangible cultural heritage is increasing, providing strong academic guarantees and professional support for the protection and inheritance of intangible cultural heritage. The involvement of experts and scholars can promote the improvement of the quality of national music, help the inheritors change their thinking, and improve their fashion and aesthetics. When there are insufficient experts in the government's cultural department, they can also make up for it by seeking help from universities in related fields.

Conclusion
The Internet of Things (IoT) is a vast network that combines a huge number of sensing devices and the Internet. On the Internet, large sensing devices always collect data and send it to the data center. With the continuous development of perception technology and network technology, data show huge characteristics, forming the big data of the Internet of Things. Aiming at the current popularity of virtual reality in the market, we will integrate the current VR functions, continue to develop VR systems, and expand the market. The system is based on the Win10 mobile phone system, uses the UWP frame structure, and uses the Direct 3D 11 graphics rendering library to achieve all the expected functions. At present, crowd simulation technology has become a research hotspot in public security, military training, computer animation, artificial intelligence, and other fields. Through a detailed investigation of the development of cluster action modeling, data-driven, and software computing at home and abroad, this article will study the video data-driven intelligent cluster simulation method. Regarding the intangible cultural heritage gongs and drums after the transformation, on the one hand, he frequently participated in various exhibitions and performances, and repeatedly made commercial attempts. Some of them are promoted by the government, and some are explored by folk artists in search of change. According to the changes of the times, the inheritance model of intangible cultural heritage gongs and drums is evolving. This is an opportunity as well as a challenge. Changes in the field of inheritance, non-scientific identification and management mechanisms of inheritors, lack of experts in cultural departments, insufficient funds, and unscientific preservation and management of intangible cultural heritage materials are all dilemmas in the inheritance and protection of intangible cultural heritage. In order to better