Method and device for synchronously playing back test data of full vehicle

Abstract

The invention discloses a method and a device for synchronously playing back full-quantity whole vehicle test data, and the method comprises the steps: when a user initiates a playback request of the whole vehicle test data, a video service platform transmits the received playback request to a corresponding whole vehicle collection system; after receiving a playback request, the whole vehicle acquisition system acquires a corresponding target historical video file from a local storage, determines a key frame serving as a video playing first frame based on a playback starting moment and a whole vehicle acquisition system moment value corresponding to each key frame in the target historical video file, and plays the video according to the key frame. Determining a data caching time length based on a whole vehicle acquisition system moment value of a video playing first frame and a playback starting moment, and sending video data in the target historical video file to a video service platform by taking the video playing first frame as a starting frame; and the video service platform sends the corresponding video data to a user display interface according to a preset rule based on the data caching duration. The method is simple in logic and easy to implement; operation is convenient and accuracy is high; and the application range is wide without any limitation.

Description

Technical Field

[0001] The present invention relates to the field of audio and video streaming media, and in particular to a method and device for synchronous playback of full vehicle test data. Background Art

[0002] In recent years, with the rapid development of Internet of Things technology and artificial intelligence technology, test vehicles need to collect data including but not limited to bus data, data collected by acquisition terminals, GPS data, audio data, video data, analog signals, fault data, CCP / XCP, and custom data uploaded by vehicle control devices for local storage. Full data collection supports test monitoring, playback, analysis, mining and other needs. The video data collected by the whole vehicle is stored locally as a historical video file. The video frame data stored in each historical video file abandons the system time information of the data acquisition system, and the timestamps are reassigned based on the value 0, which is equivalent to the video data breaking the synchronization link with other types of data. At the same time, due to the encoding characteristics of the video stream, not all video frames can be played directly as the starting frame, which will also aggravate the problem of asynchronous playback of the whole vehicle test data. In addition, in order to smoothly send video data, the video service platform may set up data cache, which has a great impact on data playback synchronization. The above objective realities will lead to the inability to synchronize the playback of the whole vehicle test data, which is unacceptable to users. Summary of the invention

[0003] In view of the technical defects and technical drawbacks in the prior art, the embodiments of the present invention provide a method for overcoming the above problems or at least partially solving the above problems. The specific solution is as follows:

[0004] As a first aspect of the present invention, a method for synchronous playback of full vehicle test data is provided, the method comprising:

[0005] Step 1: When the user initiates a playback request for vehicle test data, the video service platform sends the received playback request to the corresponding vehicle acquisition system;

[0006] Step 2: After receiving the playback request, the vehicle acquisition system obtains the corresponding target historical video file from the local storage, determines the key frame as the first frame of the video playback based on the playback start time in the playback request and the vehicle acquisition system time value corresponding to each key frame in the target historical video file, and determines the data cache duration based on the vehicle acquisition system time value of the first frame of the video playback and the playback start time;

[0007] Step 3: The vehicle acquisition system takes the first frame of the video playback as the starting frame and sends the corresponding video data in the target historical video file to the video service platform in an orderly manner; the video service platform sends the corresponding video data to the user display interface according to the preset rules based on the data cache duration.

[0008] Furthermore, in step 1, the playback request includes the vehicle number, data type, and start and end times of the data to be played back, and the video service platform sends the playback request to the corresponding vehicle collection system through the vehicle number in the playback request.

[0009] Furthermore, the method further comprises: when the vehicle acquisition system saves the acquired video data as a historical video file, for each historical video file, marking the start and end time of the file recording on the corresponding file name, and writing the vehicle acquisition system time values ​​corresponding to all key frames of the corresponding historical video file into the file designated area of ​​the historical video file;

[0010] In step 2, the vehicle collection system matches the starting time of the data to be played back in the playback request with the start and end times of each historical video file recorded locally to determine the corresponding target historical video file, and obtains the vehicle collection system time value corresponding to each key frame in the target historical video file in the specified area of ​​the file.

[0011] Further, in step 2, based on the playback start time in the playback request and the vehicle acquisition system time value corresponding to each key frame in the target historical video file, the key frame as the first frame of the video playback is determined, and based on the vehicle acquisition system time value of the first frame of the video playback and the playback start time, the data cache duration is determined specifically including:

[0012] When the playback start time in the playback request is exactly the same as the vehicle acquisition system time value corresponding to a key frame in the target historical video file, the corresponding key frame is used as the first frame of the video playback, and the data cache duration is set to 0;

[0013] When the playback start time in the playback request is between the vehicle acquisition system time values ​​corresponding to two key frames in the target historical video file, calculating the difference between the playback start time and the vehicle acquisition system time values ​​corresponding to the two key frames, specifically including:

[0014] Let the two key frames be the i-th key frame and the i+1-th key frame, and the corresponding vehicle acquisition system time value is T i and T i+1 , let the playback start time T in the playback request be s , then the difference between the playback start time and the vehicle acquisition system corresponding to the i-th key frame is (T s -T i ), the difference between the playback start time and the vehicle acquisition system corresponding to the i+1th key frame is (T s -T i+1 );

[0015] Compare(Ts -T i ) and (T s -T i+1 ) is the absolute value of (T s -T i ) is less than the absolute value of (T s -T i+1 ), the i-th key frame is used as the first frame of the video playback, and the data cache duration is set to (T s -T i ) absolute value; if (T s -T i ) is less than or equal to (T s -T i+1 ), the i+1th key frame is used as the first frame of the video playback, and the data cache duration value is set to 0.

[0016] Furthermore, in step 3, the vehicle acquisition system takes the first frame of the video playback as the starting frame and sends the corresponding video data in the target historical video file to the video service platform in an orderly manner, specifically including:

[0017] After determining the data cache duration, the vehicle acquisition system immediately sends the data cache duration to the video service platform, and determines whether the data cache duration is equal to 0 or greater than 0;

[0018] If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame and immediately and orderly sends the corresponding video data to the video service platform;

[0019] If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame, and sends the corresponding video data to the video service platform in an orderly manner after a certain delay, where the delay time is equal to the data cache duration.

[0020] Further, in step 3, the video service platform sends the corresponding video data to the user display interface according to the preset rules based on the data cache duration, specifically including:

[0021] If the data cache duration is 0, the video service platform directly forwards the received video data to the user display page;

[0022] If the data cache duration is not equal to 0, the video service platform caches the received video data, and when the cached video duration is equal to the data cache duration, clears the cached video data, and forwards each frame of video data received thereafter to the user display page.

[0023] As a second aspect of the present invention, a device for synchronous playback of full vehicle test data is also provided, the device comprising a video service platform and a vehicle acquisition system;

[0024] The video service platform is used to receive a playback request for vehicle test data initiated by a user, send the playback request to the corresponding vehicle acquisition system, receive the video data and data cache duration returned by the vehicle acquisition system, and send the corresponding video data to the user display interface according to a preset rule based on the data cache duration;

[0025] The whole vehicle acquisition system is used to obtain the corresponding target historical video file from the local storage after receiving the playback request, determine the key frame as the first frame of the video playback based on the playback start time in the playback request and the whole vehicle acquisition system time value corresponding to each key frame in the target historical video file, and determine the data cache duration based on the whole vehicle acquisition system time value of the first frame of the video playback and the playback start time, take the first frame of the video playback as the starting frame, and send the corresponding video data in the target historical video file to the video service platform in an orderly manner.

[0026] Furthermore, the whole vehicle acquisition system is also used to mark the start and end time of file recording on the corresponding file name for each historical video file when saving the collected video data as a historical video file, and when generating the historical video file, write the whole vehicle acquisition system time values ​​corresponding to all key frames of the corresponding historical video file into the file designated area of ​​the historical video file;

[0027] The whole vehicle collection system matches the starting time of the data to be played back in the playback request with the start and end times of each historical video file recorded locally to determine the corresponding target historical video file, and queries and obtains the whole vehicle collection system time value corresponding to each key frame in the target historical video file in the specified area of ​​the file.

[0028] Further, the vehicle acquisition system determines the key frame as the first frame of the video playback based on the playback start time in the playback request and the vehicle acquisition system time value corresponding to each key frame in the target historical video file, and determines the data cache duration based on the vehicle acquisition system time value of the first frame of the video playback and the playback start time, specifically including:

[0029] When the playback start time in the playback request is exactly the same as the vehicle acquisition system time value corresponding to a key frame in the target historical video file, the corresponding key frame is used as the first frame of the video playback, and the data cache duration is set to 0;

[0030] When the playback start time in the playback request is between the vehicle acquisition system time values ​​corresponding to two key frames in the target historical video file, calculating the difference between the playback start time and the vehicle acquisition system time values ​​corresponding to the two key frames, specifically including:

[0031] Let the two key frames be the i-th key frame and the i+1-th key frame, and the corresponding vehicle acquisition system time value is T i and T i+1 , let the playback start time T in the playback request be s , then the difference between the playback start time and the vehicle acquisition system corresponding to the i-th key frame is (T s -T i ), the difference between the playback start time and the vehicle acquisition system corresponding to the i+1th key frame is (T s -T i+1 );

[0032] Compare(T s -T i ) and (T s -T i+1 ) is the absolute value of (T s -T i ) is less than the absolute value of (T s -T i+1 ), the i-th key frame is used as the first frame of the video playback, and the data cache duration is set to (T s -T i ) absolute value; if (T s -T i ) is less than or equal to (T s -T i+1 ), the i+1th key frame is used as the first frame of the video playback, and the data cache duration value is set to 0.

[0033] Furthermore, the vehicle acquisition system takes the first frame of the video playback as the starting frame and sends the corresponding video data in the target historical video file to the video service platform in an orderly manner, specifically including:

[0034] After determining the data cache duration, the vehicle acquisition system immediately sends the data cache duration to the video service platform, and determines whether the data cache duration is equal to 0 or greater than 0;

[0035] If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame and immediately and orderly sends the corresponding video data to the video service platform;

[0036] If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame, and sends the corresponding video data to the video service platform in order after a certain delay, where the delay time is equal to the data cache duration;

[0037] The video service platform sends the corresponding video data to the user display interface according to the preset rules based on the data cache duration, including:

[0038] If the data cache duration is 0, the video service platform directly forwards the received video data to the user display page;

[0039] If the data cache duration is not equal to 0, the video service platform caches the received video data, and when the cached video duration is equal to the data cache duration, clears the cached video data, and forwards each frame of video data received thereafter to the user display page.

[0040] The present invention has the following beneficial effects:

[0041] 1. In view of the problem that many factors may affect the video screen synchronization during the playback of vehicle test data, the present invention proposes a method for synchronous playback of all vehicle test data. All types of playback data use the system timestamp of the acquisition system as the first reference, and the position of the video key frame and the delay caused by the video playback method as the second reference. A reasonable video frame is selected from the vehicle historical video file as the starting frame of the video playback, thereby ensuring the synchronization of the vehicle test data playback at the source. This method closely links the originally relatively isolated historical video data with the system timestamp of the vehicle acquisition system based on the encapsulation characteristics of the historical video file. After comprehensively considering all factors that affect the synchronization of the historical video, a reasonable and feasible optimization method is given to ensure that the source of the test data playback is definitely synchronized.

[0042] 2. The logic of the present invention is simple and easy to implement; it is easy to operate and has high accuracy; it has a wide range of practical applications and is not subject to any restrictions. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic flow chart of a method for synchronous playback of full vehicle test data provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] like Figure 1 As shown, the method for synchronous playback of full vehicle test data provided by an embodiment of the present invention includes:

[0046] Step 1: When the user initiates a playback request for vehicle test data, the video service platform sends the received playback request to the corresponding vehicle acquisition system;

[0047] Step 2: After receiving the playback request, the vehicle acquisition system obtains the corresponding target historical video file from the local storage, determines the key frame as the first frame of the video playback based on the playback start time in the playback request and the vehicle acquisition system time value corresponding to each key frame in the target historical video file, and determines the data cache duration based on the vehicle acquisition system time value of the first frame of the video playback and the playback start time;

[0048] Step 3: The vehicle acquisition system takes the first frame of the video playback as the starting frame and sends the corresponding video data in the target historical video file to the video service platform in an orderly manner; the video service platform sends the corresponding video data to the user display interface according to the preset rules based on the data cache duration.

[0049] The playback request includes the vehicle number, data type, and start and end time of the data to be played back. The video service platform sends the playback request to the corresponding vehicle collection system through the vehicle number in the playback request.

[0050] In the above embodiment, when the user wants to view the historical vehicle data collected by any vehicle, he selects the vehicle number and the start and end time information of the playback on the operation page, clicks the OK button, and the user's demand instructions are conveyed to the specific vehicle through the video service platform.

[0051] For example: the user needs to view the historical data collected for the vehicle with vehicle number 010 and Vin number LBV8V3106GMG03526. The playback start time is 09:10 on August 30, 2024, and the playback end time is 09:40 on August 30, 2024. The user selects the above information, clicks the OK button, and waits to watch.

[0052] In some embodiments, the method also includes that when the whole vehicle acquisition system saves the collected video data as a historical video file, for each historical video file, the start and end time of the file recording is marked on the corresponding file name, and the whole vehicle acquisition system time values ​​corresponding to all key frames of the corresponding historical video file are written into the file specified area of ​​the historical video file; in step 2, the whole vehicle acquisition system matches the playback start time of the data to be played back in the playback request with the start and end time of each historical video file recorded locally to determine the corresponding target historical video file, and obtains the whole vehicle acquisition system time value corresponding to each key frame in the target historical video file in the specified file area.

[0053] Optionally, the vehicle data collection system determines whether the playback start time of the data to be played back in the playback request is between the start time and the end time of the recording of each historical video file stored locally. If the playback start time is between the start time and the end time of the recording of a historical video file, then the historical video file is the corresponding target historical video file.

[0054] For example: the vehicle acquisition system finds a file named 20240830090327-20240830091535.mp4 from the historical video files stored locally. The 20240830090327 in the file name means that the acquisition system starts recording the video at 09:03:27 on August 30, 2024, and the 20240830091535 in the file name means that the video recording ends at 09:15:35 on August 30, 2024. The starting time that the user expects to play back, 09:10:00 on August 30, 2024, is between the start and end times of the historical video file recording, indicating that this file is the target file being found. The vehicle acquisition system reads the content of the specified area in the mp4 file, which sequentially stores the serial number of each key frame in the historical video file and the corresponding system time value of the vehicle acquisition system.

[0055] In some embodiments,

[0056] In step 2, based on the playback start time in the playback request and the vehicle acquisition system time value corresponding to each key frame in the target historical video file, the key frame as the first frame of the video playback is determined, and based on the vehicle acquisition system time value of the first frame of the video playback and the playback start time, the data cache duration is determined specifically including:

[0057] When the playback start time in the playback request is exactly the same as the vehicle acquisition system time value corresponding to a key frame in the target historical video file, the corresponding key frame is used as the first frame of the video playback, and the data cache duration is set to 0;

[0058] When the playback start time in the playback request is between the vehicle acquisition system time values ​​corresponding to two key frames in the target historical video file, calculating the difference between the playback start time and the vehicle acquisition system time values ​​corresponding to the two key frames, specifically including:

[0059] Let the two key frames be the i-th key frame and the i+1-th key frame, and the corresponding vehicle acquisition system time value is T i and T i+1 , let the playback start time T in the playback request be s , then the difference between the playback start time and the vehicle acquisition system corresponding to the i-th key frame is (T s -T i ), the difference between the playback start time and the vehicle acquisition system corresponding to the i+1th key frame is (T s -T i+1 );

[0060] Compare(T s -T i ) and (Ts -T i+1 ) is the absolute value of (T s -T i ) is less than the absolute value of (T s -T i+1 ), the i-th key frame is used as the first frame of the video playback, and the data cache duration is set to (T s -T i ) absolute value; if (T s -T i ) is less than or equal to (T s -T i+1 ), the i+1th key frame is used as the first frame of the video playback, and the data cache duration value is set to 0.

[0061] For example, the system time value corresponding to the 98th key frame is 09:09:58:328 milliseconds on August 30, 2024, and the system time value corresponding to the 99th key frame is 09:10:00:574 milliseconds on August 30, 2024, that is, the 98th frame is the key frame before the time value at which the user expects to start playback, and the 99th frame is the key frame after the time value at which the user expects to start playback. The absolute value of the difference between the starting time 09:10:00 on August 30, 2024 and the 98th key frame is 1 second 672 milliseconds, and the difference with the 99th key frame is 0 second 574 milliseconds. The smaller value is the selected key frame, that is, it is sent starting from the 99th frame, and the video delay value VideoDelayValue notified to the video service platform is 0, that is, the data cache duration is 0.

[0062] In step 3, the vehicle acquisition system takes the first frame of the video playback as the starting frame and sends the corresponding video data in the target historical video file to the video service platform in an orderly manner, including:

[0063] After determining the data cache duration, the vehicle collection system immediately sends the data cache duration to the video service platform, and at the same time, based on the data cache duration being equal to 0 or greater than 0, performs the following data sending process;

[0064] If the data cache duration is greater than 0, the first frame of the video playback is used as the starting frame, and the corresponding video data is immediately and orderly sent to the video service platform;

[0065] If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame, and sends the corresponding video data to the video service platform in an orderly manner after a certain delay, where the delay time is equal to the data cache duration.

[0066] In the above embodiment, the video data is sent to the video service platform in an orderly manner frame by frame in the form of a video stream.

[0067] In step 3, the video service platform sends the corresponding video data to the user display interface according to the preset rules based on the data cache duration, which specifically includes:

[0068] If the data cache duration is 0, the video service platform directly forwards the received video stream to the user display page;

[0069] If the data cache duration is not equal to 0, the video service platform will cache the received video stream, and when the cached video duration is equal to the data cache duration, the cached video data will be cleared, and each frame of the video stream received thereafter will be directly forwarded to the user display page.

[0070] In view of the problem that many factors may affect the video screen asynchronism during the playback of whole vehicle test data, the present invention proposes a method for synchronous playback of full vehicle test data. All types of playback data use the system timestamp of the acquisition system as the first reference, and the position of the video key frame and the delay caused by the video playback method as the second reference. A reasonable video frame is selected from the whole vehicle historical video file as the starting frame of the video playback, thereby ensuring the synchronization of the whole vehicle test data during playback at the source. This method closely links the originally relatively isolated historical video data with the system timestamp of the whole vehicle acquisition system based on the encapsulation characteristics of the historical video file. After comprehensively considering all factors affecting the synchronization of historical videos, a reasonable and feasible optimization method is given to ensure that the source of the test data playback is definitely synchronized.

[0071] In addition, an embodiment of the present invention further provides a device for synchronous playback of full vehicle test data, the device comprising a video service platform and a vehicle acquisition system;

[0072] The video service platform is used to receive a playback request for vehicle test data initiated by a user, send the playback request to the corresponding vehicle acquisition system, receive the video data and data cache duration returned by the vehicle acquisition system, and send the corresponding video data to the user display interface according to a preset rule based on the data cache duration;

[0073] The whole vehicle acquisition system is used to obtain the corresponding target historical video file from the local storage after receiving the playback request, determine the key frame as the first frame of the video playback based on the playback start time in the playback request and the whole vehicle acquisition system time value corresponding to each key frame in the target historical video file, and determine the data cache duration based on the whole vehicle acquisition system time value of the first frame of the video playback and the playback start time, take the first frame of the video playback as the starting frame, and send the corresponding video data in the target historical video file to the video service platform in an orderly manner.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for synchronous playback of full vehicle test data, characterized in that: The method comprises: Step 1: When the user initiates a playback request for vehicle test data, the video service platform sends the received playback request to the corresponding vehicle acquisition system; Step 2: After receiving the playback request, the vehicle acquisition system obtains the corresponding target historical video file from the local storage, determines the key frame as the first frame of the video playback based on the playback start time in the playback request and the vehicle acquisition system time value corresponding to each key frame in the target historical video file, and determines the data cache duration based on the vehicle acquisition system time value of the first frame of the video playback and the playback start time; Step 3: The vehicle acquisition system takes the first frame of the video playback as the starting frame and sends the corresponding video data in the target historical video file to the video service platform in an orderly manner; the video service platform sends the corresponding video data to the user display interface according to the preset rules based on the data cache duration.

2. The method for synchronous playback of full vehicle test data according to claim 1 is characterized in that: In step 1, the playback request includes the vehicle number, data type, and start and end times of the data to be played back. The video service platform sends the playback request to the corresponding vehicle acquisition system through the vehicle number in the playback request.

3. The method for synchronous playback of full vehicle test data according to claim 1 is characterized in that: The method further comprises: when the vehicle acquisition system saves the collected video data as a historical video file, for each historical video file, marking the start and end time of the file recording on the corresponding file name, and writing the vehicle acquisition system time values ​​corresponding to all key frames of the corresponding historical video file into the file designated area of ​​the historical video file; In step 2, the vehicle collection system matches the playback start time of the data to be played back in the playback request with the start and end times of each historical video file recorded locally to determine the corresponding target historical video file, and obtains the vehicle collection system time value corresponding to each key frame in the target historical video file in the specified area of ​​the file.

4. The method for synchronous playback of full vehicle test data according to claim 1, characterized in that: In step 2, based on the playback start time in the playback request and the vehicle acquisition system time value corresponding to each key frame in the target historical video file, the key frame as the first frame of the video playback is determined, and based on the vehicle acquisition system time value of the first frame of the video playback and the playback start time, the data cache duration is determined specifically including: When the playback start time in the playback request is exactly the same as the vehicle acquisition system time value corresponding to a key frame in the target historical video file, the corresponding key frame is used as the first frame of the video playback, and the data cache duration is set to 0; When the playback start time in the playback request is between the vehicle acquisition system time values ​​corresponding to two key frames in the target historical video file, calculating the difference between the playback start time and the vehicle acquisition system time values ​​corresponding to the two key frames, specifically including: Let the two key frames be the i-th key frame and the i+1-th key frame, and the corresponding vehicle acquisition system time value is T i and T i+1 , let the playback start time T in the playback request be s , then the difference between the playback start time and the vehicle acquisition system corresponding to the i-th key frame is (T s -T i ), the difference between the playback start time and the vehicle acquisition system corresponding to the i+1th key frame is (T s -T i+1 ); Compare(T s -T i ) and (T s -T i+1 ) is the absolute value of (T s -T i ) is less than the absolute value of (T s -T i+1 ), the i-th key frame is used as the first frame of the video playback, and the data cache duration is set to (T s -T i ) absolute value; if (T s -T i ) is less than or equal to (T s -T i+1 ), the i+1th key frame is used as the first frame of the video playback, and the data cache duration value is set to 0.

5. The method for synchronous playback of full vehicle test data according to claim 1, characterized in that: In step 3, the vehicle acquisition system takes the first frame of the video playback as the starting frame and sends the corresponding video data in the target historical video file to the video service platform in an orderly manner, including: After determining the data cache duration, the vehicle acquisition system immediately sends the data cache duration to the video service platform, and determines whether the data cache duration is equal to 0 or greater than 0; If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame and immediately and orderly sends the corresponding video data to the video service platform; If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame, and sends the corresponding video data to the video service platform in an orderly manner after a certain delay, where the delay time is equal to the data cache duration.

6. The method for synchronous playback of full vehicle test data according to claim 1, characterized in that: In step 3, the video service platform sends the corresponding video data to the user display interface according to the preset rules based on the data cache duration, which specifically includes: If the data cache duration is 0, the video service platform directly forwards the received video data to the user display page; If the data cache duration is not equal to 0, the video service platform caches the received video data, and when the cached video duration is equal to the data cache duration, clears the cached video data, and forwards each frame of video data received thereafter to the user display page.

7. A device for synchronous playback of full vehicle test data, characterized in that: The device includes a video service platform and a vehicle collection system; The video service platform is used to receive a playback request for vehicle test data initiated by a user, send the playback request to the corresponding vehicle acquisition system, receive the video data and data cache duration returned by the vehicle acquisition system, and send the corresponding video data to the user display interface according to a preset rule based on the data cache duration; The whole vehicle acquisition system is used to obtain the corresponding target historical video file from the local storage after receiving the playback request, determine the key frame as the first frame of the video playback based on the playback start time in the playback request and the whole vehicle acquisition system time value corresponding to each key frame in the target historical video file, and determine the data cache duration based on the whole vehicle acquisition system time value of the first frame of the video playback and the playback start time, take the first frame of the video playback as the starting frame, and send the corresponding video data in the target historical video file to the video service platform in an orderly manner.

8. The device for synchronous playback of full vehicle test data according to claim 7, characterized in that: The whole vehicle acquisition system is also used to mark the start and end time of file recording on the corresponding file name for each historical video file when saving the collected video data as a historical video file, and write the whole vehicle acquisition system time values ​​corresponding to all key frames of the corresponding historical video file into the file designated area of ​​the historical video file when generating the historical video file; The whole vehicle collection system matches the starting time of the data to be played back in the playback request with the start and end times of each historical video file recorded locally to determine the corresponding target historical video file, and queries and obtains the whole vehicle collection system time value corresponding to each key frame in the target historical video file in the specified area of ​​the file.

9. The device for synchronous playback of full vehicle test data according to claim 7, characterized in that: The vehicle acquisition system determines the key frame as the first frame of the video playback based on the playback start time in the playback request and the vehicle acquisition system time value corresponding to each key frame in the target historical video file, and determines the data cache duration based on the vehicle acquisition system time value of the first frame of the video playback and the playback start time. Specifically, it includes: When the playback start time in the playback request is exactly the same as the vehicle acquisition system time value corresponding to a key frame in the target historical video file, the corresponding key frame is used as the first frame of the video playback, and the data cache duration is set to 0; When the playback start time in the playback request is between the vehicle acquisition system time values ​​corresponding to two key frames in the target historical video file, calculating the difference between the playback start time and the vehicle acquisition system time values ​​corresponding to the two key frames, specifically including: Let the two key frames be the i-th key frame and the i+1-th key frame, and the corresponding vehicle acquisition system time value is T i and T i+1 , let the playback start time T in the playback request be s , then the difference between the playback start time and the vehicle acquisition system corresponding to the i-th key frame is (T s -T i ), the difference between the playback start time and the vehicle acquisition system corresponding to the i+1th key frame is (T s -T i+1 ); Compare(T s -T i ) and (T s -T i+1 ) is the absolute value of (T s -T i ) is less than the absolute value of (T s -T i+1 ), the i-th key frame is used as the first frame of the video playback, and the data cache duration is set to (T s -T i ) absolute value; if (T s -T i ) is less than or equal to (T s -T i+1 ), the i+1th key frame is used as the first frame of the video playback, and the data cache duration value is set to 0.

10. The device for synchronous playback of full vehicle test data according to claim 8, characterized in that: The vehicle acquisition system takes the first frame of the video playback as the starting frame and sends the corresponding video data in the target historical video file to the video service platform in an orderly manner. Specifically, it includes: After determining the data cache duration, the vehicle acquisition system immediately sends the data cache duration to the video service platform, and determines whether the data cache duration is equal to 0 or greater than 0; If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame and immediately and orderly sends the corresponding video data to the video service platform; If the data cache duration is greater than 0, the vehicle acquisition system takes the first frame of the video playback as the starting frame, and sends the corresponding video data to the video service platform in order after a certain delay, where the delay time is equal to the data cache duration; The video service platform sends the corresponding video data to the user display interface according to the preset rules based on the data cache duration, including: If the data cache duration is 0, the video service platform directly forwards the received video data to the user display page; If the data cache duration is not equal to 0, the video service platform caches the received video data, and when the cached video duration is equal to the data cache duration, clears the cached video data, and forwards each frame of video data received thereafter to the user display page.

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