A method and system for lossless transmission of data over coaxial cable

Abstract

The application discloses a coaxial cable-based lossless data transmission method and system. The method comprises the following steps: an original data is differentially encoded into a code word sequence with a preset difference degree by a sending end, the code word is mapped into a luminance pixel value, and a synchronization header containing a square wave sequence is added; a training video frame is sent before formal transmission, and a decoding mapping relationship is established according to a local pre-stored original digital sequence and an actually received luminance pixel value by a receiving end; during formal transmission, the receiving end matches the synchronization header with the local pre-stored square wave sequence to determine a sampling starting point, and restores the original data from the luminance pixel value through the mapping relationship after the luminance pixel value is extracted. The application solves the video attenuation problem of analog high-definition technology in the coaxial transmission process, and realizes the consistency of long and short line effects.

Description

Technical Field

[0001] This invention belongs to the field of analog high-definition video transmission technology, specifically relating to a method and system for lossless data transmission based on coaxial cable, so as to realize lossless transmission of video information on coaxial cable. Background Technology

[0002] Currently, when transmitting video signals via coaxial cables, whether using CVBS or analog high-definition solutions like TVI / CVI / AHD, data distortion inevitably occurs due to analog-to-digital conversion at the back end after transmission through the coaxial cable. Generally, the longer the coaxial cable, the more severe the distortion.

[0003] Traditional analog high-definition solutions transmit raw data by superimposing luminance and chrominance. This approach has several drawbacks: First, the quality of the video signal cannot be guaranteed, with varying effects for different lengths of cable. Second, the superimposed transmission of luminance and chrominance information can easily cause mutual interference between luminance and chrominance during backend parsing, resulting in image noise.

[0004] With the development of analog high-definition equipment based on coaxial cables in industries such as security, automotive, and drones, there is an urgent need for a technology that can achieve lossless video transmission to meet market demands.

[0005] In existing technologies, analog high-definition technology, as a transmission scheme for coaxial cables, suffers from information loss. Therefore, providing a method and system for lossless data transmission over coaxial cables to solve the above problems and achieve lossless transmission of video information is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a method and system for lossless data transmission based on coaxial cables, overcoming the technical defects in the prior art such as unreliable video signal quality, inconsistent effects between long and short cables, and mutual interference between brightness and color to form image noise.

[0007] This invention achieves lossless transmission of video information over coaxial cables by constructing a core technical solution of "differential coding-luminance mapping-synchronization header-training to learn channel characteristics-statistical mapping decoding".

[0008] Specifically, the front-end camera of this invention packages video data into a unified bitstream, processes it using an encoding algorithm, and then segments it into data frames. These frames are transmitted to the back-end as brightness information via a video frame. Before sending the actual data, a pre-trained image based on the encoding algorithm is sent to the back-end. The back-end demodulates the data and compares it with the original data to establish a quantization mapping table. The back-end sends an acknowledgment signal to the front-end camera. Upon receiving the signal, the front-end camera switches to the actual video signal transmission mode. The back-end then parses the brightness data and queries the quantization mapping table to reconstruct the video data.

[0009] Therefore, this invention solves the video attenuation problem caused by analog high-definition technology during coaxial transmission, and ensures consistent performance across long and short lines, thus improving the user experience.

[0010] According to one aspect of the present invention, a method for lossless data transmission based on coaxial cable is provided, comprising the following steps: The sending end converts the raw data to be transmitted into a codeword sequence according to a preset encoding rule, wherein the codeword sequences corresponding to different raw data have a preset degree of difference. The transmitting end maps each codeword in the codeword sequence to a luminance pixel value, and all the luminance pixel values ​​obtained by mapping constitute a luminance pixel sequence; The transmitting end adds a leading pixel sequence at the beginning of the brightness pixel sequence and a trailing pixel sequence at the end of the brightness pixel sequence. The leading pixel sequence and the trailing pixel sequence constitute a synchronization header. Before the actual data is transmitted, the sending end first sends a pre-generated training video frame to the receiving end. The training video frame is generated in the same way as the aforementioned steps. After receiving the training video frame, the receiving end obtains the locally pre-stored original digital sequence corresponding to the training video frame; The receiving end converts the original digital sequence into expected codewords according to the preset encoding rules, and then statistically analyzes the expected codewords with the actual received brightness pixel values ​​at the corresponding positions to establish a statistical decoding mapping relationship; During actual transmission, the sending end repeats the steps of conversion, mapping, and adding synchronization headers to generate service video frames and send them. After receiving the service video frame, the receiving end performs a matching calculation between the synchronization header in the service video frame and the synchronization header template stored locally. Based on the matching result, it determines the sampling start point of the luminance pixels in each row after removing the synchronization header, and extracts each luminance pixel starting from the sampling start point. The receiving end restores each extracted brightness pixel to its corresponding codeword according to the statistical decoding mapping relationship, and then combines multiple consecutive codewords to restore the original data.

[0011] In another aspect, the present invention provides a system for lossless data transmission based on coaxial cable, which includes a transmitter and a receiver; The sending end is used for: The raw data to be transmitted is converted into codeword sequences according to preset encoding rules, wherein the codeword sequences corresponding to different raw data have a preset degree of difference. Each codeword in the codeword sequence is mapped to a luminance pixel value to form a luminance pixel sequence; A leading pixel sequence is added at the beginning of the brightness pixel sequence, and a trailing pixel sequence is added at the end of the brightness pixel sequence. The leading pixel sequence and the trailing pixel sequence constitute a synchronization header. Before transmitting the actual data, pre-generated training video frames are sent first. These training video frames are generated in the same way as the steps described above. After receiving the confirmation signal returned by the receiving end, switch to the formal transmission mode and repeat the steps of converting the original data to be transmitted into a codeword sequence, mapping the codewords to luminance pixel values, and adding the leading pixel sequence and the trailing pixel sequence to generate a service video frame and send it. The receiving end is used for: After receiving the training video frame, a locally pre-stored original digital sequence is obtained, and the original digital sequence is the same as the original data carried by the training video frame. The original digital sequence is converted into expected codewords according to the preset encoding rules. Then, the expected codewords are statistically analyzed with the actual received brightness pixel values ​​at the corresponding positions to establish a statistical decoding mapping relationship. After receiving the service video frame, the synchronization header in the service video frame is matched and calculated with the synchronization header template stored locally. Based on the matching result, the sampling start point of the luminance pixels after removing the synchronization header in each row is determined, and each luminance pixel is extracted from the sampling start point. Based on the statistical decoding mapping relationship, each extracted brightness pixel is restored to its corresponding codeword, and then multiple consecutive codewords are combined to restore the original data. The receiving end is also used to return an acknowledgment signal to the sending end after establishing the statistical decoding mapping relationship.

[0012] Compared with the prior art, the present invention has the following beneficial effects: This invention solves the problem of video attenuation caused by analog high-definition technology during coaxial transmission and ensures consistent performance across long and short cables, greatly improving the user experience. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall architecture of the system for lossless data transmission based on coaxial cable provided in an embodiment of the present invention. Figure 2 This is a flowchart of a method for lossless data transmission based on coaxial cable provided in an embodiment of the present invention.

[0015] Terminology Explanation To facilitate understanding of the technical solution of this invention, some technical terms appearing in the specification are explained as follows: Analog HD: refers to high-definition video transmission technology based on coaxial cable to transmit analog video signals, including mainstream solutions such as TVI, CVI, and AHD.

[0016] TVI: an abbreviation for Transport Video Interface, is a high-definition analog video transmission standard based on coaxial cable, supporting the transmission of video signals with high-definition resolutions such as 1080P.

[0017] CVBS: Abbreviation for Composite Video Broadcast Signal, is a traditional analog video transmission standard.

[0018] Codeword: refers to the basic data unit obtained after converting the original data according to preset encoding rules.

[0019] Luminance pixel value: refers to the numerical value representing the luminance component of an image in a video signal, with a value range of 0 to 255.

[0020] Synchronization header: This refers to the preceding pixel sequence added at the beginning of the luminance pixel sequence and the following pixel sequence added at the end. The preceding and following pixel sequences constitute the synchronization header, which is used by the receiving end to determine the sampling start point of valid data. The preceding pixel sequence contains a preset square wave pattern, which is used by the backend to perform waveform matching calculations for the parsing start point.

[0021] Leading pixels: These are specific pixel sequences located at the beginning of each row of brightness pixel sequences. They contain a preset square wave pattern and are used to solve the sampling start point deviation problem that exists during the analog-to-digital conversion at the back end.

[0022] Training video frames: These are pre-generated video frames that are sent before actual data transmission and are used by the receiver to learn the channel transmission characteristics.

[0023] Statistical decoding mapping relationship: refers to the mapping relationship established by the receiver based on the channel distortion rules statistically analyzed during the training phase, used to restore the received luminance pixel values ​​to the original codewords.

[0024] Business video frame: refers to the video frame that carries the actual data to be transmitted.

[0025] Hamming distance: refers to the number of different symbols in corresponding positions between two codewords of equal length, and is used to measure the degree of difference between codewords.

[0026] Manhattan distance: refers to the sum of the absolute values ​​of the numerical differences between corresponding positions of two codewords, and is used to measure the degree of difference between codewords.

[0027] CodeTab: refers to the encoding table, which is used to encode the original byte into multiple 3-bit codewords. In this embodiment, CodeTab

[256] [4] encodes each byte into 4 3-bit codewords.

[0028] QTab: refers to the quantization mapping table, which is used to look up the table to obtain the decoded 3-bit codeword corresponding to the current pixel based on the high 5 bits of the brightness value of the previous pixel and the current actual sampled brightness value.

[0029] DTab: refers to the inverse mapping table, used to quickly restore a 12-bit index consisting of four consecutive 3-bit codewords to the original 0 to 255 bytes of data. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The embodiments of this invention are written in a progressive manner.

[0032] Example 1: System Architecture

[0033] like Figure 1 As shown, this invention provides a system for lossless data transmission based on coaxial cable. Its core lies in the technical solution of "differential coding - luminance mapping - synchronization header - training to learn channel characteristics - statistical mapping decoding" to achieve lossless transmission of video information on coaxial cable.

[0034] The system includes a transmitter and a receiver, which are connected by a coaxial cable. Each transmitter and receiver contains multiple functional modules, which work together to form a complete closed-loop system.

[0035] (I) Sending end functional module The differential coding module is used to convert the raw data to be transmitted into a codeword sequence according to a preset coding rule. The codeword sequences corresponding to different raw data have a preset difference degree. The preset difference degree includes the minimum Hamming distance or the minimum Manhattan distance. The coding rule is implemented through the CodeTab table. Each element in the CodeTab

[256] [4] table occupies 3 bits, which is equivalent to encoding 8 bits of information into 12 bits of codeword. The generation method of CodeTab is based on the traversal search principle to find the combination with the largest difference from the existing items in the current CodeTab. It requires that the minimum Hamming distance is at least 2 and the minimum Manhattan distance is the largest.

[0036] The luminance mapping module maps each codeword in the codeword sequence to a luminance pixel value, forming a luminance pixel sequence. Specifically, each codeword is mapped to N luminance pixel values, where N is an integer greater than 1, representing the number of luminance pixel values ​​obtained from each codeword mapping. Each luminance pixel value is horizontally copied and stretched by a factor of M, resulting in M ​​stretched luminance pixel values, where M is an integer greater than 1, representing the horizontal copying and stretching factor. All stretched luminance pixel values ​​constitute the luminance pixel sequence. In this embodiment, N is 4 and M is 5.

[0037] The synchronization header adding module is used to add a leading pixel sequence at the beginning of the luminance pixel sequence and a trailing pixel sequence at the end of the luminance pixel sequence. The leading and trailing pixel sequences constitute the synchronization header. In this embodiment, the leading pixel sequence is a square wave sequence. Each row has a total of 1920 pixels, of which the effective data in each row is encoded and mapped to obtain 92×4=368 pixel values. Each pixel value is horizontally stretched by 5 times to obtain 368×5=1840 pixel values. The remaining 80 pixel values ​​in each row are used as leading and trailing pixels. The leading pixels are set as follows: the first 50 pixels in each row are used as leading pixels, of which the first 10 pixels are all transmitted with the middle value 3, and the last 40 pixels are grouped into groups of 5 with the values ​​7, 0, 7, 0, 7, 0, 7, 0, which manifest as 8 square waves of varying heights at the waveform level. The trailing pixels are the last 30 pixels, which are not specially processed.

[0038] The training sending module is used to send pre-generated training video frames to the receiving end before the actual data is transmitted. The training video frames are generated in the same way as the aforementioned modules. A training array trainBuf

[99360] is randomly generated in the training video frames, and the training data is generated after being encoded by CodeTab.

[0039] The digital-to-analog converter module is used to convert digital luminance pixel sequences into analog video signals for transmission via coaxial cable. Before transmitting the actual data, digital-to-analog conversion is required to map the code values ​​to the range of 0 to 255; that is, the value before actual digital-to-analog conversion is codeTab × 36 + 2.

[0040] The service transmission module is used to repeatedly perform differential encoding, luminance mapping, and synchronization header addition operations during actual transmission to generate service video frames and send them.

[0041] (II) Receiver Functional Module The synchronization header matching module receives service video frames and performs matching calculations between the synchronization header in the service video frames and a locally pre-stored synchronization header template. Based on the matching results, it determines the sampling start point for the luminance pixels in each row after removing the synchronization header. Specifically, it uses a built-in matching matrix of size 40 to perform sliding matching calculations with pixels 8 to 55 of each row, calculates the correlation value at each sliding position, and uses the sliding position with the highest correlation value as the sampling start point for the luminance pixels in each row after removing the synchronization header.

[0042] The luminance pixel extraction module is used to extract each valid luminance pixel value in each row, starting from the sampling start point. Once the sampling start point is determined, luminance pixel values ​​are extracted every 5 pixels from that start point, for a total of 368 valid luminance pixel values ​​per row.

[0043] The training receiving module receives training video frames and then retrieves the locally pre-stored raw digital sequence corresponding to those training video frames. The locally pre-stored raw digital sequence is identical to the raw data carried in the training video frames sent by the transmitting end.

[0044] The statistical mapping establishment module is used to convert the original digital sequence into expected codewords according to the same preset encoding rules as the sending end, and then statistically analyze the expected codewords and the actual received brightness pixel values ​​at the corresponding positions to establish a statistical decoding mapping relationship. Specifically, the number of times the combination of the high K bits of the previous brightness pixel, the expected codeword corresponding to the current brightness pixel, and the actual received brightness pixel value of the current brightness pixel is counted, where K is a positive integer and K represents the number of high bits of the previous brightness pixel value (K is 5 in this embodiment). The starting value and ending value of the effective mapping are determined according to the cumulative distribution of the occurrence of each combination, the average value of the starting value and the ending value is calculated, and the mapping relationship from the high K bits of the actual received brightness pixel value and its previous brightness pixel value to the codeword is established based on the average value, i.e., QTab

[32]

[256] .

[0045] The inverse mapping table generation module is used to pre-generate the inverse mapping table DTab. Based on the 256 codewords in CodeTab, each codeword corresponds to 4 3-bit bins, forming a 12-bit value. Iterates through all 4096 possible 12-bit combinations, calculates the Manhattan distance between each combination and the 256 codewords in CodeTab, selects the original data byte corresponding to the codeword with the smallest distance as the query result of that combination, and fills it into DTab

[4096] .

[0046] The statistical decoding module is used to restore each extracted luminance pixel to its corresponding codeword according to the statistical decoding mapping relationship, and then combine multiple consecutive codewords to restore the original data. Specifically, the R L-bit codewords restored from R consecutive luminance pixels are combined into an index, where R is an integer greater than 1, representing the number of consecutive luminance pixel values, and L is a positive integer, representing the number of bits in each codeword (in this embodiment, R is 4 and L is 3, that is, 4 consecutive luminance pixels restore 4 3-bit codewords, which are combined into a 12-bit index). The original data byte corresponding to the index is queried using DTAb.

[0047] The local storage module is used to store the synchronization header template, the original digital sequence, the QTab mapping table, and the DTab inverse mapping table; wherein, the synchronization header template corresponds to the synchronization header composed of the leading pixel sequence and the trailing pixel sequence added by the transmitting end.

[0048] (III) Module Collaboration Workflow The above functional modules work together to form a complete closed-loop system: Training phase: The training sending module generates and sends training video frames; the training receiving module receives the training video frames and obtains the locally pre-stored raw digital sequence; the statistical mapping establishment module statistically establishes the QTab mapping relationship; the inverse mapping table generation module pre-generates the DTab inverse mapping table; and the local storage module stores the established mapping table.

[0049] In the formal transmission phase: the differential encoding module at the transmitting end converts the raw data into a codeword sequence, the luminance mapping module maps the codewords to luminance pixel values, the synchronization header addition module adds a synchronization header, and the data is transmitted through a coaxial cable via the digital-to-analog converter module; at the receiving end, the synchronization header matching module performs matching calculations to determine the sampling start point, the luminance pixel extraction module extracts the valid luminance pixel values, and the statistical decoding module restores the luminance pixel values ​​to the raw data based on QTab and DTab.

[0050] Example 2: General Process

[0051] like Figure 2 As shown, the present invention provides a method for lossless data transmission based on coaxial cable, comprising the following steps: Step S1: Differential coding and luminance mapping The transmitting end converts the raw data to be transmitted into a codeword sequence according to a preset encoding rule, wherein the codeword sequences corresponding to different raw data have a preset degree of difference. The transmitting end maps each codeword in the codeword sequence to a luminance pixel value, forming a luminance pixel sequence.

[0052] Step S2: Add synchronization header The transmitting end adds a leading pixel sequence at the beginning of the luminance pixel sequence and a trailing pixel sequence at the end of the luminance pixel sequence. The leading and trailing pixel sequences constitute a synchronization header. The synchronization header contains leading pixels, which contain a square wave sequence, used by the receiving end to perform matching calculations for the sampling start point.

[0053] Step S3: Pre-training and Establishment of Statistical Mapping Before transmitting the actual data, the sending end first sends pre-generated training video frames to the receiving end. The training video frames are generated in the same way as the steps described above. After receiving the training video frames, the receiving end obtains the locally stored original digital sequence corresponding to the training video frames. The receiving end converts the original digital sequence into expected codewords according to preset encoding rules, and then statistically analyzes the expected codewords with the actual received brightness pixel values ​​at the corresponding positions to establish a statistical decoding mapping relationship.

[0054] Step S4: Formal Transmission and Decoding During actual transmission, the sending end repeats steps S1 to S2 to generate and send service video frames. After receiving the service video frames, the receiving end matches the synchronization header in the service video frames with a locally stored synchronization header template. It then uses a sliding match based on the square wave sequence in the leading pixels to determine the sampling start point for the luminance pixels in each row (excluding the synchronization header), and extracts each luminance pixel starting from that sampling start point. Based on the statistical decoding mapping relationship, the receiving end restores each extracted luminance pixel to its corresponding codeword, and then combines multiple consecutive codewords to restore the original data.

[0055] Example 3: Specific Applications under the TVI1080P30 Framework In this embodiment, the TVI1080P30 video frame is used as an example to illustrate the implementation of the present invention under specific parameters.

[0056] In TVI1080P30 format, there are 1920 pixels per line, for a total of 1080 lines. The transmitting end transmits valid information based solely on luminance data, sending 92 valid data bytes per line, with each byte having a value ranging from 0 to 255.

[0057] The sending end encodes each valid data byte into four 3-bit codewords using the CodeTab

[256] [4] table. The CodeTab generation method is based on a traversal search principle, finding the combination with the largest difference from the existing items in the current CodeTab, requiring a minimum Hamming distance of at least 2 and a maximum minimum Manhattan distance. The actual range of 3 bits is 0 to 7, which is equivalent to dividing the waveform into 8 parts. In the actual coaxial waveform, the waveform height corresponding to 0 is assumed to be 200mV, the waveform height corresponding to 7 is assumed to be 900mV, the height corresponding to 1 is 300mV, the height corresponding to 2 is 400mV, and so on.

[0058] The sending end maps each codeword to a corresponding luminance pixel value. For each value, the mapped pixel value is planned in advance; for example, 0 corresponds to the four Y pixel values ​​0, 0, 0, 0, and 1 corresponds to the four Y pixel values ​​250, 250, 250, 250, resulting in 256 mapping relationships. Each line contains 92 valid data bytes, which, after encoding, yields 92 × 4 = 368 pixel values. Each pixel value is then horizontally copied and stretched by a factor of 5 before transmission, ultimately resulting in 368 × 5 = 1840 pixel values.

[0059] The sending end needs to perform digital-to-analog conversion before sending the actual data, mapping the code value to the range of 0 to 255, that is, the actual value before digital-to-analog conversion is codeTab×36+2.

[0060] Each row contains 1920 pixels, with 1840 pixels being effective content. The remaining 80 pixels are used as leading and trailing pixels. The leading pixels are set as follows: the first 50 pixels of each row are used as leading pixels, with the first 10 pixels all having a median value of 3. The remaining 40 pixels are grouped into sets of 5: 7, 0, 7, 0, 7, 0, 7, 0, resulting in eight square waves of varying heights. The trailing pixels, the last 30 pixels, are not specially processed.

[0061] After the receiving end receives the raw data array rawBuf

[1080]

[1920] , it uses the built-in matching matrix to multiply the 8th to 48th, 9th to 49th, 10th to 50th, 11th to 51st, 12th to 52nd, 13th to 53rd, 14th to 54th, and 15th to 55th pixels of each row, and then accumulates the results to obtain 8 sets of data. The pixel offset with the highest correlation value is found from these data sets. This value, plus the leading part 40 in the leading pixels, is the sampling starting point of the 1840 pixels that will ultimately transmit the effective content.

[0062] Once the starting point of the valid content is determined, let's say it's 52, then the value of the first valid content in the first row is rawBuf

[1080]

[52] . Because the original pixel is stretched by 5 times, the second valid pixel value is rawBuf

[1080]

[57] , and so on, a total of 368 valid pixels can be extracted.

[0063] The receiving end establishes a statistical decoding mapping relationship. For each row of valid pixels, the high 5 bits of the previous pixel value, the actual bin corresponding to the current pixel, and the actual back-end sampled value are counted and filled into the QTabStat_hist

[32] [8]

[256] array. After the statistics are completed, the accumulation calculation is performed from the left and right boundaries respectively. When the accumulation exceeds 32 times, the start point and end point of the boundary are determined, resulting in QTabStat_hist_S

[32] [8] and QTabStat_hist_E

[32] [8]. The start value and end value are added together and divided by 2 to obtain QTabStat_acc

[32] [8], which stores the middle value of the left and right boundaries of the most likely Y value. By traversing the left value and the actual sampled Y value, the bin corresponding to the closest Y value in QTabStat_acc is found, and the QTab

[32]

[256] array is constructed.

[0064] The receiving end establishes an inverse mapping table DTab. Based on the 256 codewords in CodeTab, each codeword corresponds to 4 3-bit bins, forming a 12-bit value. The receiving end traverses all 4096 possible 12-bit combinations, calculates the Manhattan distance between each combination and the 256 codewords in CodeTab, selects the original data byte corresponding to the codeword with the smallest distance as the query result of that combination, and fills it into DTab

[4096] .

[0065] During actual transmission, the receiving end uses QTab to query the corresponding bin for each valid brightness pixel, combining the high 5 bits of the previous pixel. It then combines four consecutive bins into a 12-bit index and uses DTab to query and restore the original data bytes.

[0066] This embodiment achieves a data transmission rate of 92 bytes of valid data per line, 99,360 bytes per frame, and 2,980,800 bytes per second under the TVI1080P30 framework, meeting the usage requirements of the security monitoring industry.

[0067] The foregoing has provided a detailed description of a method and system for lossless data transmission based on coaxial cables, as provided by the present invention. The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lossless data transmission method based on coaxial cable, characterized in that, Includes the following steps: The raw data to be transmitted is converted into codeword sequences according to preset encoding rules, wherein the codeword sequences corresponding to different raw data have a preset degree of difference. Each codeword in the codeword sequence is mapped to a luminance pixel value, and all the luminance pixel values ​​obtained by mapping constitute a luminance pixel sequence. A leading pixel sequence is added at the beginning of the brightness pixel sequence, and a trailing pixel sequence is added at the end of the brightness pixel sequence. The leading pixel sequence and the trailing pixel sequence constitute a synchronization header. Before transmitting the actual data, pre-generated training video frames are sent first. These training video frames are generated in the same way as the steps described above. After receiving the training video frame, a locally pre-stored original digital sequence is obtained, and the original digital sequence is the same as the original data carried by the training video frame. The original digital sequence is converted into expected codewords according to the preset encoding rules. Then, the expected codewords are statistically analyzed with the actual received brightness pixel values ​​at the corresponding positions to establish a statistical decoding mapping relationship. During actual transmission, the steps of converting the raw data to be transmitted into the codeword sequence, mapping the codeword to the brightness pixel value, and adding the leading pixel sequence and the trailing pixel sequence are repeatedly executed to generate service video frames and send them. After receiving the service video frame, the synchronization header in the service video frame is matched and calculated with the synchronization header template stored locally. Based on the matching result, the sampling start point of the brightness pixel value after removing the synchronization header in each line is determined, and each brightness pixel value is extracted from the sampling start point. Based on the statistical decoding mapping relationship, each extracted brightness pixel value is restored to the corresponding codeword, and then multiple consecutive codewords are combined to restore the original data.

2. The lossless data transmission method based on coaxial cable according to claim 1, characterized in that, The preset difference is the minimum Hamming distance or the minimum Manhattan distance.

3. The lossless data transmission method based on coaxial cable according to claim 1, characterized in that, The step of matching the synchronization header in the service video frame with the locally pre-stored synchronization header template, and determining the sampling start point of the brightness pixel value after removing the synchronization header in each row based on the matching result, includes the following steps: Perform a sliding match calculation between the received synchronization header and the locally pre-stored synchronization header template; Calculate the correlation value for each sliding position; The sliding position with the highest correlation value is used as the sampling starting point for the brightness pixel value after removing the synchronization header in each row.

4. The lossless data transmission method based on coaxial cable according to claim 1, characterized in that, The step of mapping each codeword in the codeword sequence to a luminance pixel value, and forming the luminance pixel sequence from all the mapped luminance pixel values, includes the following steps: Each codeword is mapped to N luminance pixel values, where N is an integer greater than 1; Each brightness pixel value is copied and stretched M times in the horizontal direction to obtain M stretched brightness pixel values, where M is an integer greater than 1; The luminance pixel sequence is composed of all the stretched luminance pixel values.

5. The lossless data transmission method based on coaxial cable according to claim 1, characterized in that, The step of statistically analyzing the expected codeword and the actual received brightness pixel value at the corresponding position to establish the statistical decoding mapping relationship includes the following steps: The number of times the combination of the high K bits of the previous brightness pixel value, the expected codeword corresponding to the current brightness pixel value, and the actual brightness pixel value received by the current brightness pixel value is counted, where K is a positive integer; The starting and ending values ​​of the effective mapping are determined based on the cumulative distribution of the frequency of each combination. Calculate the average of the starting value and the ending value; The mapping relationship from the actual received luminance pixel value and the high K bits of the previous luminance pixel value to the codeword is established based on the average value.

6. The lossless data transmission method based on coaxial cable according to claim 1, characterized in that, The step of restoring each extracted brightness pixel value to its corresponding codeword, and then combining multiple consecutive codewords to restore the original data, includes the following steps: The R L bits of codewords recovered from the R consecutive brightness pixel values ​​are combined into an index, where R is an integer greater than 1 and L is a positive integer; The original data bytes corresponding to the index are retrieved by querying the pre-generated inverse mapping table.

7. The lossless data transmission method based on coaxial cable according to claim 6, characterized in that, The method of pre-generating the inverse mapping table includes the following steps: Iterate through the entire range of values ​​for the index; Calculate the difference between each index and the encoding corresponding to each codeword sequence in the preset encoding rule; The original data byte corresponding to the codeword sequence with the smallest difference is selected as the query result of the index.

8. The lossless data transmission method based on coaxial cable according to claim 1, characterized in that, The training video frames and the service video frames are transmitted using a coaxial video transmission format.

9. The lossless data transmission method based on coaxial cable according to claim 4, characterized in that, Each line of the service video frame contains P valid data bytes. Each valid data byte is encoded into N codewords. Each codeword is mapped to N luminance pixel values. Each line is mapped to P × N luminance pixel values. Each luminance pixel value is horizontally stretched by M times to obtain M stretched luminance pixel values. Each line has a total of P × N × M stretched luminance pixel values. All the stretched luminance pixel values ​​constitute the luminance pixel sequence of each line. In each line, except for the pixel positions occupied by the luminance pixel sequence, the remaining pixel positions are used to place the synchronization header, where P, N, and M are all integers greater than 1.

10. A lossless data transmission system based on coaxial cable, characterized in that, Includes the sending end and the receiving end; The sending end is used for: The raw data to be transmitted is converted into codeword sequences according to preset encoding rules, wherein the codeword sequences corresponding to different raw data have a preset degree of difference. Each codeword in the codeword sequence is mapped to a luminance pixel value, and all the luminance pixel values ​​obtained by mapping constitute a luminance pixel sequence. A leading pixel sequence is added at the beginning of the brightness pixel sequence, and a trailing pixel sequence is added at the end of the brightness pixel sequence. The leading pixel sequence and the trailing pixel sequence constitute a synchronization header. Before transmitting the actual data, pre-generated training video frames are sent first. These training video frames are generated in the same way as the steps described above. After receiving the confirmation signal returned by the receiving end, switch to the formal transmission mode and repeat the steps of converting the original data to be transmitted into the codeword sequence, mapping the codeword to the brightness pixel value, and adding the leading pixel sequence and the trailing pixel sequence to generate the service video frame and send it. The receiving end is used for: After receiving the training video frame, a locally pre-stored original digital sequence is obtained, and the original digital sequence is the same as the original data carried by the training video frame. The original digital sequence is converted into expected codewords according to the preset encoding rules. Then, the expected codewords are statistically analyzed with the actual received brightness pixel values ​​at the corresponding positions to establish a statistical decoding mapping relationship. After receiving the service video frame, the synchronization header in the service video frame is matched and calculated with the synchronization header template stored locally. Based on the matching result, the sampling start point of the brightness pixel value after removing the synchronization header in each line is determined, and each brightness pixel value is extracted from the sampling start point. Based on the statistical decoding mapping relationship, each extracted brightness pixel value is restored to the corresponding codeword, and then multiple consecutive codewords are combined to restore the original data. The receiving end is also used to return an acknowledgment signal to the sending end after establishing the statistical decoding mapping relationship.

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