Quick reversing display method based on AC8015 platform and FreeRTOs system
By storing the pixel information of the PNG picture as a bin file and packaging it using the MRF multi-file packaging tool, the problems of excessive PNG picture drawing time and loss of chromaticity information in the prior art are solved, and an efficient and serrated reversing display effect is achieved.
Patent Information
- Application Number
- CN202510091625.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2025-06-10
AI Technical Summary
The existing reverse display scheme is too long to draw when processing PNG pictures with transparent backgrounds, which cannot meet the refresh rate requirements; while the JPEG scheme has lost the accuracy of the chromaticity information due to the YUV-encoded chromaticity signal, resulting in obvious serrations and subtle color changes.
The pixel information of PNG pictures is stored in the bin file format, and packaged through the MRF multi-file packaging tool. The invalid data is filtered by using the alpha difference pixel sampling method, and the pixel data is depicted point by point to achieve the same display effect as the original PNG picture.
Reduces the cost and time-consuming of the depiction, meets the refresh rate requirements, and avoids the loss of color accuracy and jagging problems.
Smart Images
Figure CN120123027A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of reverse driving, and in particular to a fast reverse display method based on the AC8015 platform and the FreeRTOs system. Background Art
[0002] In the existing reverse display solutions, a texture mapping scheme is adopted to display pictures. First, pictures in PNG or JPEG format are uniformly packaged into an MRF file using the resource packaging tool provided by AutoChips (hereinafter referred to as the MRF tool). In this process, PNG pictures are parsed into BMP pictures, and JPEG pictures are output in the RGBA8888 format by converting the YUV420 data format through the OMX hard decoding framework. However, there are some problems with these traditional solutions.
[0003] In the texture mapping scheme, for PNG pictures with a transparent background, the MRF tool parses them into BMP pictures, resulting in a drawing time of about 100 milliseconds for each frame during the image rendering and multi-layer fusion processes, which cannot meet the requirements of the refresh rate. For the JPEG scheme, although the YUV420 data is converted into the RGBA8888 format using the OMX hard decoding framework, with a drawing time of about 10 milliseconds per frame, meeting the refresh rate requirements, due to the downsampling of the chrominance signal in the YUV encoding, there will be a loss of chrominance information accuracy when converted into the RGBA8888 format, resulting in obvious jagged edges and subtle color changes, which cannot meet the requirements of the display effect. Summary of the Invention
[0004] The purpose of the present invention is to overcome the above problems existing in the prior art, and to provide a fast reverse display method based on the AC8015 platform and the FreeRTOs system.
[0005] To achieve the above technical objectives and reach the above technical effects, the present invention is realized through the following technical solutions:
[0006] A fast reverse display method based on the AC8015 platform and the FreeRTOs system includes the following steps:
[0007] S1. System initialization: Initialize the relevant hardware controlled by the system and the general-purpose input / output ports, and then load the RTOS operating system. After the RTOS operating system is successfully loaded, start the scheduler of the RTOS operating system;
[0008] S2. Generation of bin map data file: Start the bin file generator program, enter the main function entry. The main function calls the image reading function. The image reading function reads the image data according to the relative path of the png reverse map data, converts the image data into the xyArgb form and stores it in an array. Then, the data in the array is filtered for invalid data using the alpha difference pixel sampling method, and then the valid data is merged and saved as a bin map data file in the bin file format using serialization operations. The bin map data file is then processed for packaging using the mrf multi-file packaging tool;
[0009] S3. Loading of image resources: The packaged bin map data file is directly mounted to a fixed memory area using the memory mapping method;
[0010] S4. Initialize the serial port, ui interface, and video respectively;
[0011] S5. Use the mcu module to parse the vehicle body can message data, split and reorganize the parsed can messages, and transfer them to the freeRTOS system end via serial communication using the protocolbuffer protocol;
[0012] S6. Reverse image interface drawing: After the serial port receives the reverse signal from the mcu, it sends the reverse start status to the maintask task. After receiving the reverse signal, the main task immediately applies for the memory space of the ui buffer, and then fills the layers of the ui buffer according to the steering angle of the reverse and the radar information, and uses the symmetric point plotting image drawing algorithm to flip and fill the data in the uibuffer. After completing the layer filling of the ui buffer, the main task calls the interface for filling the videobuffer memory, applies for a video buffer for storing video stream data, then opens the video camera module, reads the video stream data, and then loads the video stream data into the applied video buffer. After the maintask receives the message that the ui buffer and video buffer data have been successfully filled, it pulls up the bin map data file, the layers of the uibuffer, and the layers of the video buffer to fuse and display the reverse image;
[0013] S7. ui interface display: Transmit the information displayed by the layer to the external display screen through the lvds interface.
[0014] Among them, in step S2, the detailed process of the mrf multi-file packaging tool for packaging processing:
[0015] S21. Place the generated bin files in the same directory;
[0016] S22. Create an XML file describing the MRF file information, and define the location and size information of the MRF file in the XML file.
[0017] S23. Compress the bin file data to save space, perform a packaging operation on the compressed bin file data, and then generate a checksum for the packaged file.
[0018] S24. Ensure that the packaging process is completed correctly and the data is lossless by decompressing and verifying the file content.
[0019] Among them, in step S4, the serial port initialization is specifically as follows: Start a reverse signal monitoring task for a UART serial port. This reverse signal monitoring task monitors the reverse signal sent by the MCU, parses the content of the reverse signal to determine whether to enter the reverse mode. If entering the reverse mode, obtain the latest status of the radar and the auxiliary line.
[0020] Among them, in step S4, the UI interface initialization is specifically as follows: Start a status change monitoring task for the status changes of the radar and the auxiliary line. This status change monitoring task mainly responds in a timely manner to the changes in the reverse radar status and the steering angle auxiliary line, and loads the latest dynamic radar and auxiliary line pictures in real time.
[0021] Among them, in step S4, the Video initialization is specifically as follows: Create a control work task for controlling the video status. This control work task can open or close the video stream data of the video in a timely manner, and can feedback the error status of the video for warning reminders during reverse.
[0022] Among them, the symmetric dot image drawing algorithm is as follows:
[0023] Apply for an idle layer cache area from the UI buffer and fill this layer cache area according to the event information.
[0024] Fill different contents in different areas of the layer cache area. The content of the layer cache area reads the relevant bin map data files from the memory according to the current reverse status. The xy coordinates in the bin map data files are used to determine the coordinate positions at the 1920*720 screen resolution, and the ARGB parameters in the bin map data files are used to draw the colors of the coordinate position points.
[0025] According to the symmetry property of the image, each area is drawn using half of the sampling data, and the other half of each area is directly rotated after symmetry transformation for dot drawing.
[0026] Among them, the specific operation of filling different contents in different areas of the layer cache area is as follows:
[0027] Fill the left half of the layer cache area with radar and car models, and fill the right half of the layer cache area with auxiliary trajectory lines;
[0028] According to the symmetry property of the image, use half of the sampling data to draw half of the radar and half of the car model in the left half of the layer cache area, and then perform symmetry transformation and directly rotate for point plotting;
[0029] According to the symmetry property of the image, use half of the sampling data to draw half of the auxiliary trajectory lines in the right half of the layer cache area, and then perform symmetry transformation and directly rotate for point plotting.
[0030] Among them, the event information includes the steering angle information and radar information during reverse driving.
[0031] The beneficial effects of the present invention are as follows: The present invention stores the pixel point information of PNG pictures in the bin file format and performs packaging through the MRF multi-file packaging tool. The bin file format can read the point plotting data of relevant pictures when needed and perform point-by-point plotting to achieve the same display effect as the original PNG picture. Through this optimized solution, the cost and time consumption of plotting are reduced, the requirements of the refresh rate are met, and at the same time, the loss of color accuracy and the problem of jaggedness are avoided. Description of the Drawings
[0032] The drawings described herein are used to provide a further understanding of the present invention, form a part of this application, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:
[0033] Figure 1 is a flowchart of the fast reverse display method of the present invention based on the AC8015 platform and the FreeRTOs system;
[0034] Figure 2 is a flowchart of the generation of the bin map data file in the present invention;
[0035] Figure 3 is a flowchart of the packaging process by the MRF multi-file packaging tool in the present invention;
[0036] Figure 4 is a schematic diagram of the annotation effect of a reverse image display on the ui interface in the present invention;
[0037] Figure 5 is the main code diagram of the vBackcarUITask() function;
[0038] Figure 6 is the main code diagram of the xUILoadImage() function;
[0039] Figure 7 It is the main code diagram of the copyImageData() function. Specific implementation mode
[0040] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.
[0041] As Figures 1 to 4 shown, a fast reverse display method based on the AC8015 platform and the FreeRTOs system includes the following steps:
[0042] S1. System initialization: Initialize the relevant hardware controlled by the system and the general input / output ports, and then load the RTOS operating system. After the RTOS operating system is successfully loaded, start the scheduler of the RTOS operating system.
[0043] S2. Generation of bin map data file: Start the bin file generator program, enter the main function entry. The main function calls the image reading function. The image reading function reads the image data according to the relative path of the png reverse map data, converts the image data into the xyArgb form and stores it in an array. Then, the data in the array is filtered for invalid data using the alpha difference pixel sampling method, and then the valid data is merged and saved as a bin map data file in the bin file format using serialization operations. The bin map data file is packaged using the mrf multi-file packaging tool;
[0044] Among them, as Figures 5 - 7 shown, in step S2, the main function includes: the vBackcarUITask() function, which is mainly used to monitor reverse-related signals such as the vehicle body steering angle and radar;
[0045] the xUILoadImage() function, which is mainly used to obtain relevant information about the display reverse layer buffer and read the bin file data required for the current reverse display;
[0046] the copyImageData() function, which is used to map the pixel points of the bin file to the target buffer as required, and the ulRotate parameter can also support the mapping method of large data rotation and mirror symmetry.
[0047] Among them, in step S2, the mrf multi-file packaging tool is provided by the ATC company, and the version number is ATC_MRFTool_V2.4.2.
[0048] Among them, in step S2, the detailed process of the mrf multi-file packaging tool for packaging processing:
[0049] S21. Place the generated bin file in the same directory;
[0050] S22. Create an xml file to describe the mrf file information, and define the location and size information of the mrf file in the xml file;
[0051] S23. Compress the bin file data to save space, perform a packaging operation on the compressed bin file data, and then generate a checksum for the packaged file;
[0052] S24. Ensure that the packaging process is completed correctly and the data is lossless by decompressing and verifying the file content.
[0053] S3. Image resource loading: Use the memory mapping method to directly mount the packaged bin image resource file to a fixed memory area.
[0054] S4. Initialize the serial port, ui interface, and video respectively.
[0055] The serial port initialization is specifically as follows: Start a reverse signal monitoring task for the uart serial port. This reverse signal monitoring task monitors the reverse signal sent by the mcu, parses the content of the reverse signal to determine whether to enter the reverse mode. If entering the reverse mode, obtain the latest status of the radar and the auxiliary line.
[0056] The ui interface initialization is specifically as follows: Start a status change monitoring task for the status changes of the radar and the auxiliary line. This status change monitoring task mainly responds in a timely manner to the changes in the reverse radar status and the steering angle auxiliary line, and loads the latest dynamic radar and auxiliary line images in real time.
[0057] The Video initialization is specifically as follows: Create a control work task for controlling the video status. This control work task can open or close the video stream data of the video in a timely manner, and can feedback the error status of the video for warning reminders during reverse.
[0058] S5. Use the mcu module to parse the vehicle body can message data, split and reorganize the parsed can messages, and transfer them to the freeRTOS system end through serial communication using the protocolbuffer protocol.
[0059] S6. Rearview Interface Drawing: After receiving the reverse signal from the MCU through the serial port, send the reverse start status to the maintask. After receiving the reverse signal, the main task immediately applies for the memory space of the ui buffer. Subsequently, fill the layers of the ui buffer according to the steering angle of the reverse and the information of the radar, and use the symmetric point - plotting image drawing algorithm to flip - fill the data in the uibuffer. After completing the layer filling of the ui buffer, the main task calls the interface for filling the videobuffer memory, applies for a video buffer for storing video data, then turns on the video camera module, reads the video stream data, and then loads the video stream data into the applied video buffer. After receiving the message that the ui buffer and the video buffer data have been successfully filled, the main task pulls up the bin graphic file, the layers of the uibuffer, and the layers of the video buffer to fuse and display the reverse image;
[0060] The symmetric point - plotting image drawing algorithm is as follows: Apply for a free layer cache area from the ui buffer and fill this layer cache area according to the event information. Fill different contents in different areas of the layer cache area. The content of the layer cache area reads the relevant bin graphic file from the memory according to the current reverse state. The xy coordinates in the bin graphic file are used to determine the coordinate positions at the 1920 * 720 screen resolution, and the ARGB parameters in the bin graphic file are used to draw the colors of the coordinate position points. According to the symmetry of the image, each area is drawn using half of the sampling data, and the other half of each area is subjected to symmetry transformation and directly rotated for point - plotting.
[0061] Filling different contents in different areas of the layer cache area specifically means: Fill the radar and the car model in the left - hand half area of the layer cache area, and fill the auxiliary trajectory line in the right - hand half of the layer cache area. According to the symmetry of the image, use half of the sampling data to draw half of the radar and half of the car model in the left - hand half area of the layer cache area, and then perform symmetry transformation and directly rotate for point - plotting. According to the symmetry of the image, use half of the sampling data to draw half of the auxiliary trajectory line in the right - hand half area of the layer cache area, and then perform symmetry transformation and directly rotate for point - plotting.
[0062] The event information includes the steering angle information and the radar information of the reverse.
[0063] S7. ui Interface Display: Transmit the information displayed by the layer to the external display screen through the lvds interface.
[0064] The quick reverse display method of this application is implemented based on the AC8015 platform of AutoChips and the FreeRTOS system.
[0065] AC8015 is a new generation of intelligent cockpit application processor chip independently developed by Hefei AutoChips Inc. after 2 years of research and development, and was officially mass-produced for front-loading in March 2021. The CPU of this chip adopts the Cortex A53×4 + R5F×2 architecture, is equipped with a Mali-T820 MP2 GPU, and has 2 high-performance Hi-Fi3 DSPs built-in. It supports Hypervisor virtualization and CPU hard isolation technology, and can implement flexible one-chip multi-screen (IVI + instrument) and one-chip multi-system (Android + Linux & FreeRTOS) intelligent cockpit configuration solutions.
[0066] In AC8015, RVC is divided into two parts: Vehicle RVC and AP RVC. Vehicle RVC is developed based on the FreeRTOS system and provides core reverse functions such as GPIO reverse detection, Video / UI display, and Audio playback; AP RVC is developed based on the Android system and provides reverse assistance functions such as human-computer interaction and Android APP interaction. The solution involved in this article is for Vehicle RVC. Since the Vehicle subsystem starts earlier than the Android system, and since the Vehicle subsystem uses the small real-time operating system FreeRTOS, high response, low latency, and high refresh rate requirements are put forward for the RVC program running on it. This requires a low-latency and low-resource-consuming drawing scheme to meet such requirements.
[0067] The optimization solution provided by the present invention allows PNG images to be displayed in an efficient manner, while maintaining the quality and details of the original images and meeting the refresh rate requirements. This optimization solution is applicable to devices with a large screen resolution, such as a display screen with a resolution of 1920x720, and can effectively improve the display effect and performance of images.
[0068] The above has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all these changes and improvements fall within the scope of the present invention claimed.
Claims
1. A fast reversing display method based on AC8015 platform and FreeRTOs system, characterized in that: The following steps are involved: S1, system initialization: initialize the relevant hardware and general input and output ports of the system control, then load the RTOS operating system, and after the RTOS operating system is loaded normally, start the scheduler of the RTOS operating system; S2. Bin image file generation: Start the bin file generator program and enter the main function entry. The main function calls the image reading function. The image reading function reads the image data according to the relative path of the png reversing image, converts the image data into xyArgb format and stores it in an array. Then, the data in the array is filtered out using the alpha difference pixel sampling method, and then the valid data is merged and saved as a bin image file in the bin file format using the serialization operation. The bin image file is packaged and processed using the mrf multi-file packaging tool; S3, image resource loading: Use the memory mapping method to directly mount the packaged bin image resource file to a fixed memory area; S4, respectively perform serial port initialization, UI interface initialization and video initialization; S5. Use the MCU module to parse the vehicle body CAN message data, split and reassemble the parsed CAN message, and pass it to the FreeRTOS system end through the protocol buffer protocol in the form of serial port communication; S6, reversing interface drawing: after the serial port receives the reversing signal from the mcu, it sends the reversing start status to the main task. After receiving the reversing signal, the main task immediately applies for the memory space of the ui buffer, and then fills the layer of the ui buffer according to the reversing steering angle and radar information, and uses the symmetrical point drawing image drawing algorithm to flip and fill the data in the ui buffer; after completing the filling of the ui buffer layer, the main task calls the video buffer memory filling interface to apply for the video buffer to store the video data, and then opens the video camera module, reads the video stream data, and then loads the video stream data into the applied video buffer. After receiving the message that the uibuffer and video buffer data are successfully filled, the main task pulls up the bin image file, the ui buffer layer and the video buffer layer to merge and display the reversing picture; S7, UI interface display: The information displayed on the layer is transmitted to the external display screen through the LVDS interface.
2. The fast reversing display method based on the AC8015 platform and the FreeRTOs system according to claim 1 is characterized in that: In step S2, the detailed process of the mrf multi-file packaging tool for packaging is as follows: S21. Put the generated bin file into the same directory; S22, create an XML file describing the mrf file information, and define the location and size information describing the mrf file in the XML file; S23, compressing the bin file data to save space, packaging the compressed bin file data, and then generating a checksum for the packaged file; S24. Ensure that the packaging process is completed correctly and the data is intact by decompressing and verifying the file contents.
3. The fast reversing display method based on AC8015 platform and FreeRTOs system according to claim 1 is characterized in that: In step S4, the serial port initialization is specifically: starting a reversing signal monitoring task of a uart serial port, the reversing signal monitoring task monitors the reversing signal sent by the mcu, and parses the content of the reversing signal to determine whether to enter the reversing mode, if entering the reversing mode, then obtain the latest status of the radar and auxiliary line.
4. The fast reversing display method based on AC8015 platform and FreeRTOs system according to claim 1 is characterized in that: In step S4, the UI interface initialization is specifically as follows: starting a state change monitoring task for radar and auxiliary line state changes. The state change monitoring task mainly responds to changes in the reversing radar state and steering angle auxiliary line in a timely manner, and loads the latest dynamic radar and auxiliary line images in real time.
5. The fast reversing display method based on AC8015 platform and FreeRTOs system according to claim 1 is characterized in that: In step S4, the video initialization is specifically to create a control task for controlling the video state, which can timely open or close the video stream data of the video and provide feedback on the error state of the video so as to provide a warning reminder when reversing.
6. The fast reversing display method based on AC8015 platform and FreeRTOs system according to claim 1 is characterized in that: The symmetrical point drawing image drawing algorithm is: Apply for a free layer cache area from UI buffer and fill it with event information. Different content is filled in different areas of the layer cache area. The content of the layer cache area reads the relevant bin file from the memory according to the current reversing state. The xy coordinates in the bin file are used to determine the coordinate position under the 1920*720 screen resolution. The ARGB parameters in the bin file are used to draw the color of the coordinate position point. According to the symmetry property of the image, half of the sampling data is used to draw each area, and the other half of each area is directly rotated for point drawing after symmetry transformation.
7. The fast reversing display method based on AC8015 platform and FreeRTOs system according to claim 1 is characterized in that: The specific method of filling different contents in different areas of the layer cache area is as follows: Fill the left half of the layer cache area with radar and car models, and fill the right half of the layer cache area with auxiliary track lines; According to the symmetry of the image, half of the sampling data is used to draw half of the radar and half of the car model in the left half of the layer cache area, and then the symmetry transformation is performed to directly rotate and draw points; According to the symmetry of the image, half of the sampling data is used to draw half of the auxiliary trajectory line in the right half of the layer cache area, and then the symmetry transformation is performed to directly rotate and draw points.
8. The fast reversing display method based on AC8015 platform and FreeRTOs system according to claim 1 is characterized in that: The event information includes steering angle information and radar information of reversing.