A method for transmitting and processing in - vehicle audio - video data

Abstract

The present invention discloses a transmission and processing method for vehicle-mounted audio and video data. First, each frame of audio and video data, timing and clock signals are obtained at the transmitting end of the audio and video data source, and each frame of audio and video data is compressed and encoded to obtain compressed encoded data; the compressed encoded data is added with an anti-interference factor and a scrambling code, and then the timing information and clock information are encoded to obtain transmission encoded data; the transmission encoded data is converted into three-way data, and then the three-way data is converted into serial data; the serial data is received at the receiving end of the vehicle-mounted audio and video device and converted into three-way parallel data; the three-way parallel data are processed separately and then integrated to obtain transmission encoded data; the transmission encoded data is decoded, descrambled, and decompressed, and then assembled based on the timing and clock to obtain complete audio and video data. The present invention has a controllable bit rate and a wide redundancy range.

Description

Technical Field

[0001] The present invention relates to the field of audio and video data transmission methods, and in particular to a transmission processing method for vehicle-mounted audio and video data. Background Art

[0002] With the advancement of technology, ultra-high-definition and high-definition audio and video applications are becoming increasingly widespread, and the demand for ultra-high-definition and high-definition audio and video equipment is also gradually increasing. The transmission of ultra-high-definition and high-definition audio and video data generally involves compression and encoding at the data source, transmission from the data source to the device, and decompression and decoding on the device, ultimately resulting in the ultra-high-definition and high-definition audio and video data from the data source being received by the device.

[0003] To ensure the reliability and stability of data transmission after compression encoding, the data source usually encodes the audio and video data for transmission, and then uses audio and video SerDes technology and the LVDS transmission format to transmit the data in two channels at the analog end (that is, convert the data into an analog signal for transmission). After the device performs serial-to-parallel conversion on the two channels of data, it recovers the clock signal, audio and video data signal, and communication signal from the LVDS data, and then decodes the transmitted data to obtain the final audio and video data.

[0004] This dual-channel transmission architecture has the advantages of simple design and strong legacy. However, it has the following issues: 1. It is not very resistant to electromagnetic interference; 2. High-definition video requires 4.5 Gbps, and ultra-high-definition video requires 18 Gbps. This high transmission rate results in excessive power consumption and a high bit error rate for data recovery; 3. The dual-channel architecture, with one active and one standby channel, lacks sufficient redundancy. Summary of the Invention The purpose of the present invention is to provide a method for transmitting and processing vehicle-mounted audio and video data, so as to solve the problem of insufficient redundancy in the two-way transmission architecture of audio and video data in the prior art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for transmitting and processing vehicle-mounted audio and video data includes the following steps:

[0007] Step 1: At the transmitting end of the audio and video data source, obtain each frame of audio and video data, clock information and timing information of each frame of audio and video data, and compress and encode each frame of audio and video data to obtain compressed encoded data;

[0008] Step 2: At the transmitting end of the audio and video data source, the compressed coded data obtained in step 1 is scrambled after adding an anti-interference factor. The scrambled data is then encoded together with the timing information and clock information obtained in step 1 to obtain transmission coded data.

[0009] Step 3: At the transmitting end of the audio and video data source, the transmission coded data obtained in step 2 is sent to three data processing channels for processing, and three data channels, namely high-frequency data, medium-frequency data, and low-frequency data, are obtained, where:

[0010] The first data processing channel includes a high-pass filter, a high-frequency protection circuit, and an escape compensation circuit. The transmission coded data is filtered by the high-pass filter, subjected to aliasing gain processing by the high-frequency protection circuit, and subjected to bit compensation by the escape compensation circuit in sequence to obtain high-frequency data.

[0011] The second data processing channel includes a bandpass filter, a synchronous delay circuit, and an escape compensation circuit. The transmission coded data is filtered by the bandpass filter, synchronized with the high-frequency data by the synchronous delay circuit, and bit-compensated by the escape compensation circuit to obtain intermediate frequency data.

[0012] The third data processing channel includes a low-pass filter, a synchronous delay circuit, and an escape compensation circuit. The transmission coded data is filtered by the low-pass filter, synchronized with the high-frequency data by the synchronous delay circuit, and bit-compensated by the escape compensation circuit to obtain low-frequency data.

[0013] Step 4: At the transmitting end of the audio and video data source, the high-frequency data, the intermediate-frequency data, and the low-frequency data obtained in step 3 are synchronized, and then the synchronized three-way data is converted into serial data using a parallel-to-serial method;

[0014] Step 5: The audio and video data source transmitting end transmits the serial data obtained in step 4 to the vehicle-mounted audio and video device receiving end;

[0015] Step 6: Receive the serial data at the receiving end of the vehicle-mounted audio and video device, and convert the serial data into three parallel data paths, namely, high-frequency data, medium-frequency data, and low-frequency data, by using a serial-to-parallel conversion method;

[0016] Step 7: At the receiving end of the vehicle-mounted audio and video equipment, three data inverse processing channels are used to process the three parallel data obtained in step 6 respectively, where:

[0017] The first data inverse processing channel includes an escape compensation reverse circuit, a high-frequency protection reverse circuit, and a high-pass filter. The high-frequency data is sequentially decompensated by the escape compensation reverse circuit, de-aliased by the high-frequency protection reverse circuit, and filtered by the high-pass filter to obtain the high-frequency part of the transmission coded data;

[0018] The second data inverse processing channel includes an escape compensation inverse circuit, a synchronous delay circuit, and a bandpass filter. The intermediate frequency data is sequentially decompensated by the escape compensation inverse circuit, synchronized with the high frequency part of the transmission coded data by the synchronous delay circuit, and filtered by the bandpass filter to obtain the intermediate frequency part of the transmission coded data;

[0019] The third data inverse processing channel includes an escape compensation inverse circuit, a synchronization delay circuit, and a low-pass filter. The low-frequency data is sequentially decompensated by the escape compensation inverse circuit, synchronized with the high-frequency portion of the transmission coded data by the synchronization delay circuit, and filtered by the low-pass filter to obtain the low-frequency portion of the transmission coded data.

[0020] Step 8: Integrate the high-frequency part, the intermediate-frequency part, and the low-frequency part of the transmission coded data obtained in step 7, and calculate the integrated data using the formula Q = A*X + B*Y + C*Z, which is the transmission coded data, wherein: A, B, and C are the gain constants of the high-frequency part, the intermediate-frequency part, and the low-frequency part, respectively; X, Y, and Z are the high-frequency part, the intermediate-frequency part, and the low-frequency part of the transmission coded data, respectively; and Q is the final single-channel data after integration;

[0021] Step 9: Decode the transmission coded data obtained in step 8 to obtain the compressed coded data, timing information of each frame of audio and video data, and clock information;

[0022] Step 10: Descramble and remove the anti-interference factor of the compressed coded data obtained in step 9, and then decode and decompress it to obtain each frame of audio and video data. Then, based on the timing information and clock information of each frame of audio and video data, assemble each frame of audio and video data into complete audio and video data.

[0023] Furthermore, the compression encoding in step 1 is lossless compression encoding.

[0024] Furthermore, in step 4, a data buffer is used to synchronize the high-frequency data, the medium-frequency data, and the low-frequency data obtained in step 3.

[0025] Furthermore, in step 4, a 12-bit deep in-phase frequency multiplication method is used to realize parallel-to-serial conversion.

[0026] Furthermore, in step 5, the audio and video data source sending end also sends transmission clock information to the vehicle-mounted audio and video device receiving end; in step 6, the vehicle-mounted audio and video device receiving end also receives the transmission clock information, and the vehicle-mounted audio and video device receiving end self-tests the transmission clock information of the serial data and compares it with the received transmission clock information to obtain the correct transmission clock information.

[0027] Furthermore, in step 5, the audio and video data source transmitting end uses a frequency division method to send the transmission clock information; in step 6, the vehicle-mounted audio and video device receiving end uses a frequency multiplication method to restore the transmission clock information.

[0028] Furthermore, in step 7, in step 6, the serial data is passed through a voltage equalizer to remove power ripple and stabilize the voltage, and then converted from serial to parallel.

[0029] Compared with the prior art, the advantages of the present invention are:

[0030] 1. The present invention adopts lossless compression to obtain compressed coded data, which can reduce the transmission rate and bit error rate. Then, anti-interference factors and scrambling processing are added to the compressed coded data, which can significantly improve the anti-electromagnetic interference ability of the data to be transmitted.

[0031] 2. The present invention adopts the method of reducing the clock frequency for transmission and then restoring the high frequency later. That is, in step 5, the transmission clock information is sent by frequency division, and then in step 6, the receiving end uses the frequency multiplication method to restore the transmission clock information. In this way, the clock information can be transmitted normally while reducing the transmission rate. Under normal circumstances, the clock frequency is more than twice the data frequency. Taking 4K ultra-high definition as an example, the frequency of normal data is 300MHz, while the frequency of the clock is 600MHz. The normal transmission clock frequency must reach 1.2GHz to correctly recover the clock information. Through the above method of the present invention, the clock information can be transmitted at the same frequency as the data, thereby reducing the overall transmission rate.

[0032] 3. The present invention adopts a three-way data processing channel architecture at the transmitting end and a corresponding three-way data reverse processing channel architecture at the receiving end, thereby forming three channels of high frequency, medium frequency and low frequency data. In the entire design, special filtering and protection circuit mechanisms are adopted for high frequency and low frequency that are easily interfered with, thereby enhancing the anti-interference ability and also enhancing the stability and reliability of audio and video data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flowchart of the method of the present invention.

[0034] Figure 2 It is a flowchart of the lossless compression encoding process of the present invention.

[0035] Figure 3 It is a flow chart of forming a three-way architecture of the present invention.

[0036] Figure 4 It is a sending flow chart of the audio and video data source sending end of the present invention.

[0037] Figure 5 It is a receiving flow chart of the receiving end of the vehicle-mounted audio and video equipment of the present invention.

[0038] Figure 6 It is a processing flow chart of the three-way data inverse processing channel of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described below with reference to the accompanying drawings and examples.

[0040] like Figure 1 As shown, an embodiment of the present invention provides a method for transmitting and processing in-vehicle audio and video data, including the following steps:

[0041] Step 1: During the transmission phase, each frame of audio and video data, along with its timing and clock information, is obtained from the audio and video data source. Each frame of audio and video data is then losslessly compressed to produce compressed data. Prior to compression, the video data must undergo a color space conversion, converting the RGB format to YCbCr.

[0042] The present invention takes the lossless compression encoding process of video data as an example to illustrate the process. Figure 2 First, each frame of video data is divided into multiple sub-pictures of equal size according to the relationship between the clock signal frequency of each frame of video data, the clock frequency of the video embedded timing coding method, the processing rate, and the compression ratio.

[0043] Then, each sub-image is subjected to lossless compression coding to obtain the lossless compression coding sub-data corresponding to each sub-image. The data processing process of the lossless compression coding processing unit is as follows: Figure 2 As shown, a frame of input video data is first divided into multiple processing units (of equal width and height), each with its own dedicated data path. Within each processing unit, each row of pixels is divided into equal numbers of pixel data and processed separately, based on the YCoCg color space. If the input is RGB or YCbCr data, it is first converted to YCoCg format. Pixels are then reconstructed using pixel prediction data or a history lookup table. A variable-length code (VLC) or entropy coding module determines whether to use pixel prediction or a history lookup table. The entropy coding module constructs independent syntax units for each sub-data stream, Y, Co, or Cg. Each syntax unit contains the redundancy value used for prediction and reconstruction and an index into the history lookup table. Each independent syntax unit is written to a separate equalization buffer, and its corresponding size is also written to the corresponding syntax unit size buffer. After a certain processing delay, the sub-data streams are reselected according to a specific order and rules to form a new sub-coded bit stream, which is then written to each independent rate buffer. Each independent rate buffer is then read out sequentially to form the output bit stream for the entire video lossless compression encoding.

[0044] Step 2: The compressed coded data obtained in step 1 is added with an anti-interference factor and then scrambled to obtain data with strong electromagnetic interference resistance. The scrambled data is then Gray-encoded along with the timing information and clock information obtained in step 1, as well as the communication interface data used by the transmitting end of the audio and video data source, to obtain the transmission-encoded data.

[0045] In the present invention, due to the vibration and bumps of the vehicle, as well as the electromagnetic interference of the motor inside the vehicle, an anti-interference factor and scrambling processing are added to the compressed coded data. The anti-interference factor refers to giving different gain variables to each different data, and then multiplying it with the signal to increase the anti-interference ability.

[0046] Increasing the anti-interference factor is mainly to prevent high-frequency ripple and low-frequency interference waves from causing power fluctuations and data changes. Scrambling is a common EMI anti-interference method.

[0047] In addition, CRC check data may be added in step 2 so that data transmission verification can be performed based on the CRC check data later.

[0048] In the present invention, because the transmitting end of the audio and video data source uses a pair of twisted-pair differential lines to send the transmission coded data to the receiving end of the audio and video equipment, this requires that during the transmission process, the specific audio and video data, as well as clock information, timing information, communication interface data, etc. are all transmitted by the same pair of differential lines. Therefore, it is necessary to encode these information data as a whole to become one kind of data for transmission.

[0049] Step 3: Convert the transmission coded data from single channel to three channel data.

[0050] Prior to step 3, all signal processing involved digital signal processing, resulting in relatively stable voltages, minimal power ripple, and a stable signal that was less susceptible to interference. However, after step 3, the analog circuitry (converting data to analog for transmission) significantly increases the likelihood of interference from various external sources. To ensure signal stability, integrity, and reliability, starting with step 3, a three-channel architecture will be used to process and transmit data.

[0051] The process of forming a three-way architecture is as follows Figure 3 As shown:

[0052] At the transmitting end of the audio and video data source, the transmission coded data obtained in step 2 is sent to three data processing channels for processing, and three data channels, namely high-frequency data, medium-frequency data, and low-frequency data, are obtained.

[0053] The first data processing channel includes a high-pass filter, a high-frequency protection circuit, and an escape compensation circuit. The transmitted coded data is filtered by the high-pass filter, subjected to aliasing gain processing by the high-frequency protection circuit, and bit-compensated by the escape compensation circuit to obtain high-frequency data.

[0054] The second data processing channel includes a bandpass filter, a synchronous delay circuit, and an escape compensation circuit. The transmitted coded data is filtered by the bandpass filter, synchronized with the high-frequency data by the synchronous delay circuit, and bit-compensated by the escape compensation circuit to obtain the intermediate frequency data.

[0055] The third data processing channel includes a low-pass filter, a synchronous delay circuit, and an escape compensation circuit. The transmitted coded data is filtered by the low-pass filter, synchronized with the high-frequency data by the synchronous delay circuit, and bit compensated by the escape compensation circuit to obtain low-frequency data.

[0056] In this step 3, high-frequency filtering, intermediate-frequency filtering, and low-frequency filtering are performed respectively through a high-pass filter, a band-pass filter, and a low-pass filter. For high-frequency data, due to the relatively large interference from electromagnetic interference and noise, an aliasing factor is added to the data through a high-frequency protection circuit. This multiplies the transmission coded data output after filtering by the high-pass filter by a certain gain, thereby increasing the value of the actual signal. For low-frequency and intermediate-frequency data, due to the relatively small interference, a synchronization delay circuit is provided to synchronize them with the high-frequency data. To prevent the escape or loss of some data or bits, escape compensation circuits are provided in all three data processing channels. Bit compensation is performed through the escape compensation circuits, and finally three data channels are obtained: high-frequency data, intermediate-frequency data, and low-frequency data. These three data channels then enter the subsequent simulation process.

[0057] Step 4: At the transmitting end of the audio and video data source, synchronize the high-frequency data, intermediate-frequency data, and low-frequency data obtained in step 3, and then convert the synchronized three-way data into serial data using a parallel-to-serial method. The specific process is as follows:

[0058] like Figure 4 As shown, in step 4, the three data paths must be synchronized before transmission. Therefore, this step uses a small storage buffer to achieve synchronization. Specifically, the high-frequency data, medium-frequency data, and low-frequency data are first stored in a 32-bit wide buffer with an 8- to 16-level depth. Then, using the same clock, the data is read from the three buffers simultaneously, achieving synchronization.

[0059] Then, the three parallel data paths of high-frequency data, intermediate-frequency data, and low-frequency data are converted into serial data. Currently, the common methods used in the market for parallel-to-serial conversion are 6-bit, 8-bit, 10-bit, or 12-bit in-phase frequency multiplication. In the present invention, a 12-bit in-phase frequency multiplication method is preferably used to convert the three parallel data paths into serial data, thereby increasing the amount of data transmitted.

[0060] Since the transmitting end of the audio and video data source uses a pair of differential twisted-pair lines to transmit data to the receiving end of the in-vehicle audio and video equipment, the transmission clock information and serial data are combined together for transmission in step 5. The transmission clock information includes parameters such as the frequency, period, phase, and duty cycle of the transmission clock. In order to accurately restore the transmission clock information at the receiving end of the in-vehicle audio and video equipment, a special data segment is set to transmit the parameters of these transmission clock information.

[0061] Specifically, when sending transmission clock information, since the transmission clock frequency of high-definition video is 148.5MHz and the transmission clock frequency of ultra-high definition is 600MHz, in order to effectively transmit serial data and transmission clock information, and enable the receiving end of the on-board audio and video equipment to effectively and accurately recover the clock signal, based on the transmission characteristics of the present invention that supports ultra-high-definition 4K*2K@60Hz, the present invention uses a four-division frequency method to send transmission clock information at the sending end of the video data source.

[0062] At the same time, the present invention also adds CRC check data to the serial data to facilitate the vehicle-mounted audio and video equipment receiving end to perform data verification based on the CRC check method. According to different bit transmission modes, CRC checks of different bit widths can be used.

[0063] Step 5: Instruct the audio and video data source transmitter to transmit the serial data obtained in step 4 to the vehicle-mounted audio and video device receiver.

[0064] During specific transmission, in order to increase the driving performance of the differential signal during transmission and solve problems such as signal attenuation that occur during transmission, this step 5 adds transmission drive processing at the transmitting end of the audio and video data source. Specifically, the H-bridge differential drive architecture, charge pump and current control method are used for transmission drive processing, and overcurrent and low-current protection mechanisms are used to ensure the transmission driving capability and reduce signal attenuation according to the transmission distance. The H-bridge performs voltage stabilization on the power input of the serial data, the Charge PUMP performs constant current processing on the current of the serial data signal, current control is performed through voltage pulse width adjustment, and overcurrent and low-current protection are performed through the current threshold.

[0065] Step 6: Figure 5The figure shows the data processing process after the receiving end of the vehicle audio and video equipment receives the serial data. After the receiving end of the vehicle audio and video equipment receives the serial data, it first converts the serial data into three parallel data paths: high-frequency data, medium-frequency data, and low-frequency data using a serial-to-parallel conversion method. The process is as follows:

[0066] First, the serial data and transmission clock information are received at the receiving end of the in-vehicle audio and video equipment, and the serial data is checked by CRC to confirm the integrity of the data transmission and that there are no code loss or errors in the received data.

[0067] In addition, the serial data sent by the audio and video data source transmitter is processed by a voltage equalizer to remove power ripple in the serial data and stabilize the voltage, so that the high and low levels of the input differential signal reach a minimum voltage of 0.75mV and the high voltage reaches 1.1V, thereby filtering out low-voltage and high-voltage ripples.

[0068] The serial data is then converted to parallel data to obtain three parallel data paths: high-frequency data, intermediate-frequency data, and low-frequency data. Specifically, the serial data is converted to three parallel data paths based on the reverse process of the 12-bit in-phase frequency multiplication in step 4.

[0069] When the receiving end of the vehicle audio and video device receives the transmission clock information sent by the sending end of the audio and video data source, it uses the quadruple frequency method opposite to the four-frequency division in step 4 and uses the main phase-locked loop MPLL to recover the clock required for actual data processing.

[0070] In addition, the receiving end of the on-board audio and video equipment self-tests the clock when receiving serial data, parses the corresponding transmission clock information (including the frequency, period, phase, duty cycle, etc. of the transmission clock), and compares it with the transmission clock information sent by the sending end of the audio and video data source to obtain the parameters included in the correct transmission clock information.

[0071] Because the three channels of data have different delays during transmission and data recovery, in order to achieve true synchronization, this step 6 synchronizes the three channels of parallel data, using the same small storage buffer as step 4 for processing, and using the recovered clock signal to achieve true data synchronization and data phase alignment, thereby obtaining synchronized three channels of parallel data.

[0072] Step 7: At the receiving end of the vehicle-mounted audio and video equipment, three data inverse processing channels are used to process the three parallel data channels respectively to obtain three transmission coded data channels.

[0073] like Figure 6 As shown in FIG, the processing process of the three-way data inverse processing channel is the reverse process of step 3, specifically:

[0074] The first data inverse processing channel includes an escape compensation reverse circuit, a high-frequency protection reverse circuit, and a high-pass filter. The high-frequency data is sequentially de-compensated by the escape compensation reverse circuit, de-aliased by the high-frequency protection reverse circuit, and filtered by the high-pass filter to obtain the high-frequency part of the transmission coded data.

[0075] The second data inverse processing channel includes an escape compensation reverse circuit, a synchronous delay circuit, and a bandpass filter. The intermediate frequency data is sequentially decompensated by the escape compensation reverse circuit, synchronized with the high-frequency part of the transmission coded data by the synchronous delay circuit, and filtered by the bandpass filter to obtain the intermediate frequency part of the transmission coded data.

[0076] The third data inverse processing channel includes an escape compensation reverse circuit, a synchronous delay circuit, and a low-pass filter. The low-frequency data is sequentially decompensated by the escape compensation reverse circuit, synchronized with the high-frequency part of the transmitted coded data by the synchronous delay circuit, and filtered by the low-pass filter to obtain the low-frequency part of the transmitted coded data.

[0077] Step 8: Integrate the high-frequency portion of the transmission coded data, the intermediate-frequency portion of the transmission coded data, and the low-frequency portion of the transmission coded data obtained in step 7.

[0078] Specifically, the integrated data calculated using the formula Q= A*X + B*Y+ C*Z is the transmission coded data, where: A, B, and C are the gain constants of the high-frequency part, the intermediate-frequency part, and the low-frequency part, respectively; X, Y, and Z are the high-frequency part, the intermediate-frequency part, and the low-frequency part of the transmission coded data, respectively; and Q is the final integrated single-channel transmission coded data.

[0079] Step 9: Perform the reverse processing of step 3, i.e., Gray decoding, on the integrated transmission coded data obtained in step 8 to obtain compressed coded data, timing information of each frame of audio and video data, and clock information.

[0080] Step 10: Perform the reverse processing of step 2 on the compressed coded data obtained in step 9, i.e., descramble the data and remove the anti-interference factor, and then perform the reverse processing of step 1, i.e., decode and decompress the data to obtain each frame of audio and video data. Then, based on the timing information and clock information of each frame of audio and video data, assemble each frame of audio and video data into complete audio and video data.

[0081] The embodiments described in the present invention are merely descriptions of the preferred implementation methods of the present invention and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should fall within the scope of protection of the present invention. The technical contents for which protection is sought in the present invention have all been recorded in the claims.

Claims

1. A method for transmitting and processing vehicle-mounted audio and video data, characterized in that: The following steps are involved: Step 1: At the transmitting end of the audio and video data source, obtain each frame of audio and video data, clock information and timing information of each frame of audio and video data, and compress and encode each frame of audio and video data to obtain compressed encoded data; Step 2: At the transmitting end of the audio and video data source, the compressed coded data obtained in step 1 is scrambled after adding an anti-interference factor. The scrambled data is then encoded together with the timing information and clock information obtained in step 1 to obtain transmission coded data. Step 3: At the transmitting end of the audio and video data source, the transmission coded data obtained in step 2 is sent to three data processing channels for processing, and three data channels, namely high-frequency data, medium-frequency data, and low-frequency data, are obtained, where: The first data processing channel includes a high-pass filter, a high-frequency protection circuit, and an escape compensation circuit. The transmission coded data is filtered by the high-pass filter, subjected to aliasing gain processing by the high-frequency protection circuit, and subjected to bit compensation by the escape compensation circuit in sequence to obtain high-frequency data. The second data processing channel includes a bandpass filter, a synchronous delay circuit, and an escape compensation circuit. The transmission coded data is filtered by the bandpass filter, synchronized with the high-frequency data by the synchronous delay circuit, and bit-compensated by the escape compensation circuit to obtain intermediate frequency data. The third data processing channel includes a low-pass filter, a synchronous delay circuit, and an escape compensation circuit. The transmission coded data is filtered by the low-pass filter, synchronized with the high-frequency data by the synchronous delay circuit, and bit-compensated by the escape compensation circuit to obtain low-frequency data. Step 4: At the transmitting end of the audio and video data source, synchronize the high-frequency data, intermediate-frequency data, and low-frequency data obtained in step 3. Then, convert the synchronized three-way data into serial data using a parallel-to-serial conversion method. This conversion is achieved using a 12-bit deep in-phase frequency multiplication method. Step 5: The audio and video data source transmitting end transmits the serial data obtained in step 4 to the vehicle-mounted audio and video device receiving end; Step 6: Receive the serial data at the receiving end of the vehicle-mounted audio and video device, and convert the serial data into three parallel data paths, namely, high-frequency data, medium-frequency data, and low-frequency data, by using a serial-to-parallel conversion method; Step 7: At the receiving end of the vehicle-mounted audio and video equipment, three data inverse processing channels are used to process the three parallel data obtained in step 6 respectively, where: The first data inverse processing channel includes an escape compensation reverse circuit, a high-frequency protection reverse circuit, and a high-pass filter. The high-frequency data is sequentially decompensated by the escape compensation reverse circuit, de-aliased by the high-frequency protection reverse circuit, and filtered by the high-pass filter to obtain the high-frequency part of the transmission coded data; The second data inverse processing channel includes an escape compensation inverse circuit, a synchronous delay circuit, and a bandpass filter. The intermediate frequency data is sequentially decompensated by the escape compensation inverse circuit, synchronized with the high frequency part of the transmission coded data by the synchronous delay circuit, and filtered by the bandpass filter to obtain the intermediate frequency part of the transmission coded data; The third data inverse processing channel includes an escape compensation inverse circuit, a synchronization delay circuit, and a low-pass filter. The low-frequency data is sequentially decompensated by the escape compensation inverse circuit, synchronized with the high-frequency portion of the transmission coded data by the synchronization delay circuit, and filtered by the low-pass filter to obtain the low-frequency portion of the transmission coded data. Step 8: Integrate the high-frequency part, the intermediate-frequency part, and the low-frequency part of the transmission coded data obtained in step 7, and calculate the integrated data using the formula Q = A*X + B*Y + C*Z, which is the transmission coded data, wherein: A, B, and C are the gain constants of the high-frequency part, the intermediate-frequency part, and the low-frequency part, respectively; X, Y, and Z are the high-frequency part, the intermediate-frequency part, and the low-frequency part of the transmission coded data, respectively; and Q is the final single-channel data after integration; Step 9: Decode the transmission coded data obtained in step 8 to obtain the compressed coded data, timing information of each frame of audio and video data, and clock information; Step 10: Descramble and remove the anti-interference factor of the compressed coded data obtained in step 9, and then decode and decompress it to obtain each frame of audio and video data. Then, based on the timing information and clock information of each frame of audio and video data, assemble each frame of audio and video data into complete audio and video data.

2. The method for transmitting and processing vehicle-mounted audio and video data according to claim 1, characterized in that: The compression encoding in step 1 is lossless compression encoding.

3. The method for transmitting and processing vehicle-mounted audio and video data according to claim 1, wherein: In step 4, a data buffer is used to synchronize the high-frequency data, medium-frequency data, and low-frequency data obtained in step 3.

4. The method for transmitting and processing vehicle-mounted audio and video data according to claim 1, wherein: In step 5, the audio and video data source sending end also sends transmission clock information to the vehicle-mounted audio and video device receiving end; in step 6, the vehicle-mounted audio and video device receiving end also receives the transmission clock information, and the vehicle-mounted audio and video device receiving end self-tests the transmission clock information of the serial data and compares it with the received transmission clock information to obtain the correct transmission clock information.

5. The method for transmitting and processing vehicle-mounted audio and video data according to claim 4, characterized in that: In step 5, the audio and video data source transmitting end uses a frequency division method to send the transmission clock information; in step 6, the vehicle-mounted audio and video equipment receiving end uses a frequency multiplication method to restore the transmission clock information.

6. The method for transmitting and processing vehicle-mounted audio and video data according to claim 1, characterized in that: In step 6, the serial data is passed through a voltage equalizer to remove power ripple and stabilize the voltage before being converted from serial to parallel.

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