A method and apparatus for evaluating the quality of a cable for a television serial data interface

Abstract

The application discloses a kind of cable quality evaluation method and device for television serial data interface, it is related to communication data processing technical field, the present application generates pseudo-random binary sequence and ill-conditioned code by linear feedback shift register, after being selected by gating switch, it is converted into serial data by serializer.The amplitude of serial data is adjusted by adjustable attenuator, input target cable transmission, after transmission, signal is processed by rate adaptive equalizer, and is parsed into parallel data by deserializer.Pseudo-random code and ill-conditioned code checker are used for error rate analysis, from HD-SDI gradually upgrade to 3G-SDI, UHD-SDI, whether cable meets corresponding rate requirement is judged by double detection logic.Record the initial attenuation value of error rate under different rates, construct model based on attenuation formula, calculate β and γ to judge the theoretical feasibility of 3G-SDI, UHD-SDI, if feasible, then measured, if not feasible, then calculate the maximum transmission distance, finally generate evaluation information containing applicable rate etc..

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication data processing, in particular to a method and device for evaluating the quality of a cable for a television serial data interface. BACKGROUND

[0002] The television serial data interface (SDI) is a serial digital component interface managed by the National Radio, Film and Television Standardization Technical Committee, covering standard definition to ultra-high definition specifications, capable of carrying auxiliary data, with the advantages of high definition, small transmission delay, compatibility with existing analog video cables, and has been widely used in the fields of broadcast television, film production, professional monitoring, security, etc. The current mainstream SDI standards include HD-SDI (1.485Gbps), 3G-SDI (2.97Gbps) and UHD-SDI (11.88Gbps), and the data rate increases significantly with the increase of definition (the ultra-high definition rate is 8 times that of high definition).

[0003] The prior art has the following defects, specifically, the high-rate signal attenuation is aggravated: the ultra-high definition (UHD-SDI) data rate is much higher than that of high definition (HD-SDI), the signal attenuates faster in the transmission cable, the requirement for cable quality is significantly improved, and the traditional cable may not meet the high-rate transmission requirement.

[0004] Low cable evaluation efficiency: in the prior art, there is a lack of fast and accurate evaluation method for the already laid or newly erected cable, it is difficult to determine whether it supports higher rate (such as 3G-SDI, UHD-SDI) transmission, and it is also impossible to efficiently predict the maximum transmission distance, resulting in the frequent occurrence of cable inapplicability during scene erection, causing waste of manpower and material resources.

[0005] The evaluation method lacks systematicness: the existing test is mainly for single rate or single signal type (such as only using pseudo-random code), without forming a step-by-step evaluation logic from low rate to high rate, and without combining the dual verification of "basic signal + limit signal", it is difficult to fully reflect the transmission performance of the cable in complex scenarios. SUMMARY

[0006] To solve the above technical problems, the present application provides the following technical solutions:

[0007] A cable quality evaluation method for a television serial data interface, comprising: generating a pseudo-random binary sequence based on a linear feedback shift register and a pathological code for limit performance testing of the television serial data interface, and converting the serial data into serial data through a serial converter after selection by a gating switch; inputting the serial data into a target test cable for transmission after adjusting the amplitude of the signal source by an adjustable attenuator, processing the transmitted signal by a rate adaptive equalizer, and analyzing the parallel data by a deserializer; performing bit error rate analysis on the parallel data by using a pseudo-random code checker and a pathological code checker, starting from HD-SDI, gradually upgrading to 3G-SDI and UHD-SDI, and judging whether the cable meets the corresponding rate transmission requirement through the double detection logic of the pseudo-random code basic verification to the pathological code limit verification; recording the attenuation value when the error starts to appear under different rates, and constructing a cable attenuation model based on the attenuation formula, wherein the attenuation formula is ; calculating and to determine the theoretical feasibility of 3G-SDI and UHD-SDI respectively, if the prediction is feasible, performing actual measurement verification, if not, calculating the maximum transmission distance by / β or / γ, wherein and are specific values of f; based on the test results of different television serial data interface standards, generating cable quality evaluation information containing applicable rate level, limit transmission performance and theoretical maximum distance, wherein the different television serial data interface standards include HD-SDI, 3G-SDI and UHD-SDI interface standards.

[0008] A cable quality evaluation device for a television serial data interface, comprising: a signal generation module for generating a pseudo-random binary sequence based on a linear feedback shift register and a pathological code for limit performance testing of the television serial data interface, and converting the serial data into serial data through a serial converter after selection by a gating switch; a signal conditioning and transmission module for inputting the serial data into a target test cable for transmission after adjusting the amplitude of the signal source by an adjustable attenuator, processing the transmitted signal by a rate adaptive equalizer, and analyzing the parallel data by a deserializer; an error detection module for performing bit error rate analysis on the parallel data by using a pseudo-random code checker and a pathological code checker, starting from HD-SDI, gradually upgrading to 3G-SDI and UHD-SDI, and judging whether the cable meets the corresponding rate transmission requirement through the double detection logic of the pseudo-random code basic verification to the pathological code limit verification; a model calculation module for recording the attenuation value when the error starts to appear under different rates, and constructing a cable attenuation model based on the attenuation formula, wherein the attenuation formula is ; calculating and The theoretical feasibility of 3G-SDI and UHD-SDI is judged respectively, if the prediction is feasible, the actual measurement is verified, if it is not feasible, the maximum transmission distance is calculated through / β or / γ, wherein, and are specific values of f; and a result output module, configured to generate cable quality evaluation information containing applicable rate level, limit transmission performance and theoretical maximum distance based on test results of different television serial data interface standards, wherein the different television serial data interface standards include HD-SDI, 3G-SDI and UHD-SD interface standards.

[0009] The beneficial effects are that the application provides a cable quality evaluation method and device for television serial data interface, gradually tests from low rate to high rate, combines double verification of pseudo-random code and ill-conditioned code, and evaluates the performance based on the attenuation model, so as to solve the core defects of inaccurate and low efficiency of cable quality evaluation in the prior art, and meet the demand of cable performance verification for the upgrading of ultra-high definition industry. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 A flow chart of the television serial data interface cable quality evaluation method provided by the embodiment of the application when applied to an edge device is shown in the figure;

[0011] Figure 2 A module schematic diagram of the television serial data interface cable quality evaluation device provided by the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0012] The preferred embodiments of the application are described below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the application, and are not used to limit the application. The television serial data interface cable quality evaluation method according to the exemplary embodiments of the application is described below with reference to the accompanying drawings. Figure 1 As shown in the figure: Figure 1

[0013] In the embodiment of the application, a television serial data interface cable quality evaluation method is shown in the figure: Figure 1

[0014] S101, generate a pseudo-random binary sequence based on a linear feedback shift register and an ill-conditioned code for television serial data interface limit performance test, and select through a gate switch, and then convert into serial data through a serializer.

[0015] ​​In one embodiment, a pseudo-random binary sequence based on a linear feedback shift register and a pathological code for limit performance test of a television serial data interface are generated to form original test data, wherein the pseudo-random binary sequence includes PRBS7, PRBS15, PRBS20, and PRBS31. Different types of pseudo-random binary sequences, such as PRBS7, PRBS15, PRBS20, and PRBS31, are generated by using a linear feedback shift register (LFSR). At the same time, a pathological code is generated according to the requirement of limit performance test of the television serial data interface. These code types constitute the original test data. Taking PRBS7 as an example, its primitive polynomial is When the initial value of the LFSR is set as 0000001, a pseudo-random sequence of 127 bits in length can be generated by continuously shifting the register and performing XOR operation on the 6th and 7th bits of the register and inputting the result to the 1st bit of the register. In this sequence, the number of 1s is 64, the number of 0s is 63, the number of the longest consecutive 1s is 7, and the number of the longest consecutive 0s is 6. The pathological code can be designed as an extreme code type containing a plurality of consecutive 0s or 1s, such as a sequence of 19 consecutive 1s, for testing the transmission limit of a cable under complex signals.

[0016] The pseudo-random binary sequence and the pathological code are selected by a gate switch to generate the type of signal currently used for testing. The pseudo-random binary sequence and the pathological code are selected by a gate switch to determine the type of signal currently used for testing. The gate switch is similar to a multiplexer, which determines which signal to output according to a control signal. If the current test requirement is a regular error code test, the control signal causes the gate switch to be connected to the output end of the pseudo-random binary sequence. Assuming that the PRBS15 sequence is selected, the parallel data of the PRBS15 sequence is output by the gate switch. If a limit performance test is to be performed, the control signal is switched, and the gate switch is connected to the output end of the pathological code. The parallel data of the pathological code of 10 consecutive 1s designed above is output.

[0017] The parallel pseudo-random binary sequence or the pathological code selected by the gate switch is input to a serializer. The serializer converts the parallel data into serial data according to a serial ratio of 20:1, and completes the serialization of the test signal. The parallel pseudo-random binary sequence or the pathological code selected by the gate switch is input to the serializer. The serializer converts the parallel data into serial data according to a serial ratio of 20:1, and completes the serialization of the test signal to adapt to the transmission format of the television serial data interface.

[0018] ​If the gating switch outputs parallel PRBS15 data, when the serializer works at a 20:1 serial ratio, the parallel PRBS15 data is transmitted to the serializer at a rate of 20 bits per clock cycle after being aligned by shifting, and the serializer converts the 20 bits of data into high-priority serial data output. After being transmitted through the 2 15 -1 PRBS15 data generation clock, a complete conversion of a set of PRBS15 data is completed. For ill-conditioned code parallel data, the data is fixed at 20 bits, and the sequence code is divided into two code types: 19 consecutive 1s plus 1 bit of 0 and 19 consecutive 0s plus 1 bit of 1. Each code type is repeated 65536 times before being replaced by the other code type, and the cycle is repeated.

[0019] In S102, the serial data is input into the target test cable after being adjusted in amplitude by the adjustable attenuator, and the transmitted signal is processed by the rate adaptive equalizer and parsed into parallel data by the deserializer.

[0020] In one embodiment, the serial data is input into the adjustable attenuator, the amplitude of the signal source is changed by adjusting the attenuation value of the attenuator, and the serial test signal with adjustable amplitude is generated, wherein the attenuation value is initially set to 0 dB. The serialized test signal is input into the adjustable attenuator. The adjustable attenuator adjusts the attenuation value of the signal by changing the internal circuit parameters, thereby changing the amplitude of the signal source and generating a serial test signal with controllable amplitude. In the initial state, the attenuation value is set to 0 dB, i.e. no attenuation is performed on the signal to ensure that the signal enters the subsequent link at the original amplitude. The amplitude of the serial test signal input into the adjustable attenuator is 500 mV, and the frequency is 1.485 GHz (corresponding to the HD-SDI rate). When the attenuator is set to 0 dB, the output signal amplitude is still 500 mV. If the subsequent test needs to simulate the attenuation of the signal after long-distance transmission, the attenuator can be adjusted to 5 dB, at which time the output signal amplitude will be about 316.23 mV. According to the attenuation formula , .

[0021] The serial test signal adjusted by the adjustable attenuator is input into the target test cable, the signal transmission is completed through the cable, and the transmitted serial signal is obtained. The serial test signal with adjusted amplitude is connected to the target test cable. Due to its own resistance, capacitance, inductance and other characteristics, the signal will be attenuated and distorted during transmission. The amplitude of the transmitted signal will be reduced, and the waveform may be distorted. The transmitted serial signal is obtained for subsequent processing.

[0022] The transmitted serial signal is input into a rate adaptive equalizer, which processes the signal to compensate for attenuation and distortion in the transmission process. The transmitted serial signal is input into a rate adaptive equalizer. The equalizer automatically adjusts the internal compensation parameters according to the input signal rate, compensates for the attenuation and distortion of the signal in the transmission process. By boosting high-frequency components, adjusting the phase, etc., the signal is restored as close to the original state as possible to meet the signal quality requirements of the subsequent deserializer.

[0023] If the signal rate input into the equalizer is 2.97Gbps (corresponding to 3G-SDI rate), the signal will experience severe high-frequency attenuation and waveform distortion due to cable transmission. After the equalizer detects this rate, it automatically adjusts its internal filter parameters to compensate for the gain of the high-frequency part. The original high-frequency part is attenuated by 10dB, and the equalizer adjusts the high-frequency gain by about 10dB, making the signal spectrum more uniform and the rising and falling edges of the waveform more steep, closer to the characteristics of the original transmitted signal, thereby improving the signal quality.

[0024] The serial signal processed by the equalizer is input into the deserializer, which parses the serial data into parallel data to provide a processable parallel signal format for subsequent bit error rate analysis. The serial signal processed by the equalizer is input into the deserializer. The deserializer converts the serial data into parallel data according to the preset deserialization rule (corresponding to the 20:1 serial ratio of the serializer described above). The converted parallel data meets the processing requirements of the subsequent bit error rate analysis module, facilitating efficient bit error detection and analysis.

[0025] If the input into the deserializer is a serial signal with a rate of 11.88Gbps (corresponding to UHD-SDI rate) and the signal has been processed by the equalizer to an acceptable quality. The deserializer works with a deserialization ratio of 20:1 to convert the serial data into parallel data. For example, every 20 clock cycles, the deserializer converts the received serial data into 8-bit parallel data output. If the serial data is "10110101011100101100...", after processing by the deserializer, the parallel data groups may be output as "10110101" "01110010" "1100...", providing a parallel signal format for bit error rate analysis.

[0026] S103, using a pseudo-random code checker and a pathological code checker to analyze the bit error rate of the parallel data, starting from HD-SDI, gradually upgrading to 3G-SDI and UHD-SDI, through the dual detection logic of pseudo-random code basic verification to pathological code limit verification, to determine whether the cable meets the corresponding rate transmission requirements.

[0027] In one embodiment, a specially designed pseudo-random code checker and ill-conditioned code checker are used, which are the core tools for bit error rate analysis. The pseudo-random code checker is used to detect bit errors in the transmission of a regular pseudo-random code sequence, and the ill-conditioned code checker is used to detect bit errors in the transmission of an ill-conditioned code, which is an extreme test code. The pseudo-random code checker can be internally constructed based on an XOR gate circuit. For example, for input parallel pseudo-random code data and locally generated pseudo-random code data of the same type and phase, a bitwise XOR operation is performed. If the result is "1", it indicates that a bit error has occurred. The ill-conditioned code checker is designed to detect the special structure of the ill-conditioned code, such as a code pattern of consecutive multiple "1"s or "0"s. For example, by judging whether the length of consecutive identical code elements meets the expected value, the ill-conditioned code checker can identify bit errors.

[0028] The bit error rate test starts from the HD-SDI (1.485 Gbps) rate and then gradually upgrades to the 3G-SDI (2.97 Gbps) and UHD-SDI (11.88 Gbps) rates. Each time the rate is increased, the pseudo-random code checker and the ill-conditioned code checker are used to analyze the bit errors of the parallel data, respectively. At the HD-SDI rate, the parallel pseudo-random code data output by the deserializer is first input into the pseudo-random code checker. Assuming that the transmitted pseudo-random code sequence is PRBS15, the checker counts the number of detected bit errors within a certain period of time (e.g., 1 second). Then, the parallel ill-conditioned code data is input into the ill-conditioned code checker to count the bit errors in the ill-conditioned code. After completing the HD-SDI rate test, the rate of the test equipment is switched to 3G-SDI, and the above-mentioned bit error detection process for the pseudo-random code and the ill-conditioned code is repeated.

[0029] The dual detection logic of the pseudo-random code basic verification and the ill-conditioned code limit verification is used to determine whether the cable meets the transmission requirements of the corresponding rate. The pseudo-random code basic verification mainly reflects the reliability of the cable in the transmission of regular signals, and the ill-conditioned code limit verification evaluates the transmission capability of the cable in the transmission of complex signals. Only when the bit error rates of the pseudo-random code and the ill-conditioned code are both within the acceptable range, it is determined that the cable meets the transmission requirements of the rate.

[0030] At the UHD-SDI rate, the pre-set acceptable bit error rate standards are: the pseudo-random code bit error rate does not exceed 1E-11, and the ill-conditioned code bit error rate does not exceed 1E-9. When the pseudo-random code checker detects a bit error rate of 2E-13 and the ill-conditioned code checker detects a bit error rate of 4E-11, neither of which exceeds the standard, it is determined that the cable meets the transmission requirements of the UHD-SDI rate. If the pseudo-random code bit error rate meets the standard, but the ill-conditioned code bit error rate is 1E-7, which exceeds the standard, it is determined that the cable has problems in the transmission of complex signals at the UHD-SDI rate and does not meet the overall transmission requirements at the rate.

[0031] S104, record the attenuation value at which the error code starts to appear at different rates, and construct a cable attenuation model based on the attenuation formula.

[0032] In an embodiment, at different data rates, the error rate of the pseudo-random code checker is monitored by gradually increasing the attenuation value of the adjustable attenuator, the attenuation value at which the error code starts to appear is recorded, and attenuation value record data is generated, wherein the attenuation values are respectively recorded as 、 、 When constructing the cable attenuation model, the cable at different rates is first tested to obtain key data. Taking three common television serial data interface rates, HD-SDI, 3G-SDI, and UHD-SDI, as examples, when starting the test, the attenuation value of the adjustable attenuator is set to 0 dB, at which time the signal is input to the target cable at the original intensity. As the test progresses, the attenuation value of the attenuator is gradually increased, and the error code is continuously monitored at the HD-SDI rate until the first error code appears. At this time, the attenuation value recorded represents the attenuation degree at which the cable starts to have transmission problems at the HD-SDI rate, for example, an attenuation value of 8 dB can be obtained, which is recorded as .

[0033] Next, switch to the 0.75 times rate of HD-SDI and perform the same operation, and continuously adjust the attenuator. When the first error code appears at this rate, the corresponding attenuation value is recorded, which is assumed to be 10 dB, and is recorded as . Then, the above steps are repeated for the 0.5 times rate of HD-SDI, and a new attenuation value of, for example, 13 dB is obtained, which is recorded as .

[0034] Based on the attenuation formula , an initial framework of the cable attenuation model is constructed, wherein, is the attenuation amount of the test cable at a transmission rate of f, is a fixed attenuation constant, is a conductor loss coefficient, is a dielectric loss coefficient, and are determined by the cable material and size, is the transmission data rate. With these error code starting attenuation values at different rates, the cable attenuation model can be constructed according to the attenuation formula. In the formula, represents a fixed attenuation constant, which is determined by some inherent factors of the cable, such as cable joints, connectors, and other frequency-independent losses. In actual scenarios, for a certain type of cable, through some basic tests or experience data in the early stage, The value is a fixed attenuation constant, related to factors such as the wire connector and non-uniformity. For example, in the case of a 75Ω coaxial cable, the value is set based on its physical characteristics and prior testing. The value is 0.1 dB, and the actual evaluation process does not require further analysis. Perform the solution calculation. This is the conductor loss factor, which is closely related to factors such as the conductor's material and wire diameter. These factors affect the skin effect, thus influencing high-frequency loss. For example, different conductor materials have different conductivities, resulting in varying degrees of signal loss. These factors need to be considered at the time. The dielectric loss coefficient is related to the dielectric constant and loss tangent of the insulating medium. These parameters determine the impact of dielectric polarization on signal loss. For example, polyethylene insulating media has different dielectric constants and loss tangents compared to other types of insulating media, leading to... The value will also be different.

[0035] Substituting the above parameters into the attenuation formula, we obtain the system of equations. and Solving the system of equations yields and The specific values ​​are used to generate a cable attenuation model. The attenuation values ​​obtained earlier at different rates ( , , ) and the corresponding rate (HD-SDI corresponding to 3G-SDI corresponding UHD-SDI corresponding Substituting these values ​​into the attenuation formula creates a system of equations. By solving this system of equations, the result can be calculated. and The specific values ​​are obtained to complete the construction of the cable attenuation model. This model can then be used to predict the attenuation of cables at different speeds and to analyze the transmission performance of cables in different application scenarios.

[0036] S105, calculated using the attenuation model and Determine the theoretical feasibility of 3G-SDI and UHD-SDI respectively. If the prediction is feasible, conduct field tests to verify it; otherwise, proceed with further investigation. / β or / γ calculates the maximum transmission distance.

[0037] In one implementation, an attenuation model is used to calculate... and Generate theoretical feasibility assessment data, among which, Corresponding to a 3G-SDI data rate of 2.97Gbps, corresponding to the 11.88 Gbps data rate of UHD-SDI, corresponding to the initial test rate of 1.485 Gbps. With the cable attenuation model built, two parameters β and γ are calculated respectively to evaluate the transmission feasibility of 3G-SDI and UHD-SDI. , wherein corresponding to the 2.97 Gbps of 3G-SDI, corresponding to the initial test rate of 1.485 Gbps (HD-SDI); , wherein corresponding to the 11.88 Gbps of UHD-SDI. The attenuation model is (unit: dB).

[0038] then ≈2.75 dB;

[0039] =0.1+1.2 +0.8×2.97≈4.2 dB, so β=4.2-2.75=1.45 dB;

[0040] =0.1+1.2 +0.8×11.88≈11.5 dB, so γ=11.5-2.75=8.75 dB.

[0041] Based on and , and comparison results of 3G-SDI and UHD-SDI theoretical feasibility, if β then 3G-SDI is theoretically feasible, if γ then UHD-SDI is theoretically feasible, the feasibility judgment result is generated, wherein, is the attenuation value of the adjustable attenuator when the error code appears for the first time at the rate of 1.485 Gbps. By comparing and , and , it is determined whether the cable supports higher rate transmission. The judgment rules are as follows, if β then 3G-SDI is theoretically feasible; if γ then UHD-SDI is theoretically feasible. is the attenuation value when the error code appears for the first time at the rate of 1.485 Gbps, reflecting the limit carrying capacity of the cable at the reference rate).

[0042] Specifically, if the HD-SDI test records =8dB (i.e. the cable can withstand 8dB attenuation at 1.485Gbps at maximum): since β=1.45dB<8dB, 3G-SDI is theoretically feasible; since γ=8.75dB>8dB, UHD-SDI is theoretically infeasible.

[0043] If 3G-SDI or UHD-SDI is theoretically feasible, configure the programmable clock generator of the corresponding rate, select the pseudo-random code generator as the test data signal, configure the minimum attenuation value of the adjustable attenuator, and perform actual measurement verification, wherein the 3G-SDI is 148.5MHz and the UHD-SDI is 594MHz.

[0044] Configure the programmable clock of the corresponding rate (3G-SDI is 148.5MHz and UHD-SDI is 594MHz); select the pseudo-random code generator, set the attenuator to the minimum attenuation value, and detect the error code through the checker. For 3G-SDI (theoretically feasible), set the clock to 148.5MHz, adjust the attenuator to 0dB, and the pseudo-random code checker detects no error code, then continue the pathological code test; if there is an error code, directly determine that "3G-SDI is theoretically feasible, but not practically feasible".

[0045] If not feasible, calculate the predicted maximum distance of 3G-SDI data transmission through / β, calculate the predicted maximum distance of UHD-SDI data transmission through / γ, and generate an actual measurement verification plan or maximum transmission distance data. For rates that are not theoretically feasible, calculate the maximum transmission distance through the attenuation relationship. The calculation formula is 3G-SDI maximum distance= / β; UHD-SDI maximum distance= / γ. For UHD-SDI (theoretically infeasible): given =8dB, γ=8.75dB, so the maximum distance=8 / 8.75≈0.91, and the calculation result is the relative length, i.e. 0.91 times. For example, if the current test cable length is 100 meters, then 0.91 represents that at the target rate, the cable can be transmitted at the UHD-SDI rate for a maximum of 91 meters.

[0046] In the actual measurement verification process, the pseudo-random code checker and the ill-conditioned code checker are used to analyze the error rate of parallel data, the actual transmission performance of the cable at the corresponding rate is judged according to the error condition, the cable quality evaluation information containing the application situation and performance of 3G-SDI and UHD-SDI is generated combined with the theoretical feasibility judgment result and the maximum transmission distance data. For the theoretically feasible 3G-SDI or UHD-SDI rate, the test environment is configured and the error rate is detected, 3G-SDI: programmable clock is set to 148.5MHz, strobe pseudo-random code generator, adjustable attenuator is set to minimum attenuation value (0dB); UHD-SDI: programmable clock is set to 594MHz, other configurations are the same as above.

[0047] First, the pseudo-random code checker detects the error rate of parallel data, if there is no error, switch to the ill-conditioned code generator, and then detect it through the ill-conditioned code checker; if there is any error in any link, record the error rate and type. For the theoretically feasible 3G-SDI rate, the pseudo-random code checker (PRBS31 sequence) detects for 10 minutes, the error rate is 0, and it is determined that the pseudo-random code transmission is normal; switch to the ill-conditioned code (19 consecutive 1 plus 1 0 and 19 consecutive 0 plus 1 1), the checker detects 3 errors, and the error rate is .

[0048] According to the error detection result, the actual carrying capacity of the cable at the corresponding rate is evaluated: the judgment standard is that there is no error in the pseudo-random code and the ill-conditioned code: the cable completely meets the transmission requirements of the rate; there is no error in the pseudo-random code but there is error in the ill-conditioned code: the cable can support basic transmission, but the limit performance is insufficient; there is error in the pseudo-random code: the cable cannot meet the transmission of the rate. In the 3G-SDI test, there is no error in the pseudo-random code but the error rate of the ill-conditioned code is 1E-8 (higher than the preset threshold 1E-9), which is determined as "can be applied to 3G-SDI transmission, but the limit performance is insufficient.

[0049] Integrate the theoretical feasibility conclusion, the maximum transmission distance and the actual measurement result to generate a comprehensive evaluation report, the report contains the following elements, specifically, the applicable rate level (such as "supporting HD-SDI and 3G-SDI, not supporting UHD-SDI"); the maximum distance (such as "UHD-SDI transmission is theoretically feasible, but not practically feasible"). The final evaluation information is "the target cable can be applied to HD-SDI and 3G-SDI transmission. Among them, the 3G-SDI data transmission test is passed, which can be used normally; UHD-SDI data transmission is theoretically feasible, but the limit performance is insufficient, which cannot meet the transmission requirements.

[0050] S106, based on the test results of different television serial data interface standards, generate cable quality evaluation information containing applicable rate level, limit transmission performance and theoretical maximum distance.

[0051] In one implementation, test data for three interface standards—HD-SDI, 3G-SDI, and UHD-SDI—are collected, including core information such as theoretical feasibility assessment, measured bit error rate, and maximum transmission distance: For HD-SDI, the bit error rate of pseudo-random codes and pathological codes is recorded as meeting the standard (e.g., "no bit error rate for pseudo-random codes, 0% bit error rate for pathological codes"); for 3G-SDI, theoretical feasibility conclusions are integrated (e.g., "β < (Theoretically feasible), measured bit error rate (e.g., "pseudo-random codes have no errors, while ill-conditioned codes have a bit error rate of 1E-10") and maximum predicted distance (e.g., "if not feasible, ...) / β=0.91”); UHD-SDI, similarly integrating theoretical feasibility (such as “γ> (Theoretical infeasibility), experimental results (such as "pseudo-random code error rate exceeds standard") and predicted maximum distance (such as "theoretical infeasibility") / γ=0.8, 0.8 times the distance of the current test cable).

[0052] The test results for a certain cable are as follows: HD-SDI: no errors in both pseudo-random code and pathological code; 3G-SDI: theoretically feasible, with no errors in pseudo-random code in actual testing, but the error rate of pathological code is [not specified]. UHD-SDI: Theoretically infeasible, predicted maximum distance is 0.8 times, actual measured pseudo-random code error rate is 0.01% (exceeding the standard).

[0053] Based on the test results, the highest interface standard supported by the cable was determined, resulting in a grade classification: If the HD-SDI test is passed, but both 3G-SDI and UHD-SDI tests are failed: the grade is "HD-SDI only"; if HD-SDI and 3G-SDI tests are passed, but UHD-SDI tests are failed: the grade is "HD-SDI and 3G-SDI supported"; if all three are passed: the grade is "Full rate support". Based on the test results above, the applicable rate grade for this cable is "HD-SDI and 3G-SDI supported".

[0054] For speeds that are theoretically infeasible or fail practical testing, a predicted maximum distance based on an attenuation model is added: 3G-SDI theoretical maximum distance = / β ( (Error start attenuation value at 1.485Gbps); UHD-SDI theoretical maximum distance = / γ. The theoretical maximum distance for UHD-SDI of this cable is 0.8 times the distance, and it is marked as "The theoretical maximum transmission distance for UHD-SDI is 0.8 times the distance, which is not feasible in actual testing".

[0055] The integrated suitable rate level, limit transmission performance and theoretical maximum distance form a complete cable quality evaluation report. The report needs to clearly correspond to the test conclusion of HD-SDI, 3G-SDI and UHD-SDI interface standards. Specifically, the target cable quality evaluation information is as follows: suitable rate level, support HD-SDI (1.485 Gbps): no error code in pseudo-random code and ill-conditioned code test, meet the transmission requirements; support 3G-SDI (2.97 Gbps): theoretically feasible, no error code in pseudo-random code test, error code rate of ill-conditioned code is 1E-12 (lower than threshold 1E-9); not support UHD-SDI (11.88 Gbps): theoretically infeasible, error code rate of pseudo-random code is 0.01% (higher than threshold 1E-11).

[0056] In an embodiment, as shown in Figure 2 , the application also provides a cable quality evaluation device for television serial data interface, comprising:

[0057] The signal generation module 201 is configured to generate a pseudo-random binary sequence based on a linear feedback shift register and an ill-conditioned code for television serial data interface limit performance test. After selection by the gating switch, the serial data is converted into serial data by the serializer;

[0058] The signal conditioning and transmission module 202 is configured to input the serial data into the target test cable after adjusting the signal source amplitude by the adjustable attenuator, and process the transmitted signal by the rate adaptive equalizer, and parse the parallel data by the deserializer;

[0059] The error code detection module 203 is configured to analyze the error code rate of the parallel data by the pseudo-random code checker and the ill-conditioned code checker, and gradually upgrade from HD-SDI to 3G-SDI and UHD-SDI. Through the double detection logic of pseudo-random code basic verification to ill-conditioned code limit verification, it is judged whether the cable meets the corresponding rate transmission requirements;

[0060] The model calculation module 204 is configured to record the attenuation value when the error code appears at different rates, and construct a cable attenuation model based on the attenuation formula, wherein the attenuation formula is ; and the attenuation model is used to calculate and to judge the theoretical feasibility of 3G-SDI and UHD-SDI respectively. If it is predicted to be feasible, the actual measurement is verified. If it is not feasible, the maximum transmission distance is calculated by / β or / γ, wherein and are specific values of f;

[0061] The result output module 205 is configured to generate cable quality evaluation information including applicable rate level, limit transmission performance and theoretical maximum distance based on test results of different television serial data interface standards, wherein the different television serial data interface standards include HD-SDI, 3G-SDI and UHD-SD interface standards.

[0062] An electronic device includes a first processor; and a memory configured to store executable instructions of the first processor; wherein the first processor is configured to execute any of the cable quality evaluation methods for television serial data interface via executing the executable instructions.

[0063] A computing device includes a memory configured to store computer program instructions and a processor configured to execute the computer program instructions, wherein the computer program instructions, when executed by the processor, trigger the device to execute any of the cable quality evaluation methods for television serial data interface.

[0064] The methods and / or embodiments in the present application can be implemented as a computer software program. For example, the embodiments of the present disclosure include a computer program product comprising a computer program that is carried on a computer readable medium, the computer program comprising program code for executing the methods shown in the flowcharts. When the computer program is executed by a processing unit, the above-mentioned functions defined in the methods of the present application are performed.

[0065] It should be noted that the computer readable medium in the present application can be a computer readable signal medium or a computer readable storage medium or any combination of the two. More specific examples of the computer readable storage medium can include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, the computer readable medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device or apparatus.

[0066] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0067] It will be apparent to those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A method of cable quality assessment for a television serial data interface, characterized by, include: A pseudo-random binary sequence based on a linear feedback shift register and a pathological code for extreme performance testing of a television serial data interface are generated. After being selected by a gating switch, the sequence is converted into serial data by a serializer. After the serial data is adjusted by an adjustable attenuator to adjust the signal source amplitude, it is input into the target test cable for transmission. The transmitted signal is processed by a rate adaptive equalizer and then parsed into parallel data by a deserializer. The pseudo-random code checker and the pathological code checker are used to perform bit error rate analysis on parallel data. Starting from HD-SDI, it is gradually upgraded to 3G-SDI and UHD-SDI. Through the dual detection logic from pseudo-random code basic verification to pathological code limit verification, it is determined whether the cable meets the corresponding rate transmission requirements. The attenuation values at which the error codes start to appear at different rates are recorded, and a cable attenuation model is constructed based on the attenuation formula, which includes: at different data rates, by gradually increasing the attenuation value of the adjustable attenuator, monitoring the error rate of the pseudo-random code checker, recording the attenuation value at which the error code starts to appear, and generating attenuation value record data, wherein the attenuation values are respectively recorded as 、 、 ; based on the attenuation formula , an initial framework of the cable attenuation model is constructed, wherein, is the attenuation per unit length, is a fixed attenuation constant, is a conductor loss coefficient, is a dielectric loss coefficient, and are determined by the cable material and size, is the transmission data rate; and 、 、 and the corresponding rate 、 、 are substituted into the attenuation formula to obtain the equation group and , and the specific values of and are obtained by solving the equation group to generate the cable attenuation model; Using the attenuation model to calculate and respectively determine the theoretical feasibility of 3G-SDI and UHD-SDI, if the predicted feasibility is measured, if not, the maximum transmission distance is calculated by / β or / γ, wherein, and are specific values of f; Based on test results from different TV serial data interface standards, cable quality assessment information is generated, including applicable rate levels, extreme transmission performance, and theoretical maximum distance. The different TV serial data interface standards include those for HD-SDI, 3G-SDI, and UHD-SD interfaces.

2. The method of claim 1, wherein, A pseudo-random binary sequence based on a linear feedback shift register and a pathological code for extreme performance testing of a television serial data interface are generated. After selection by a gating switch, the sequence is converted into serial data by a serializer, including: A pseudo-random binary sequence based on a linear feedback shift register and a pathological code for extreme performance testing of a television serial data interface are generated to form the original test data. The pseudo-random binary sequence includes PRBS7, PRBS15, PRBS20, and PRBS31. By using a gating switch to select between pseudo-random binary sequences and pathological codes, the current signal type used for testing is generated; The parallel pseudo-random binary sequence or pathological code selected by the gating switch is input into the serializer, which converts the parallel data into serial data at a serial ratio of 20:1, thus completing the serialization process of the test signal.

3. The method of claim 2, wherein, After the serial data is adjusted by an adjustable attenuator to adjust the signal source amplitude, it is input into the target test cable for transmission. The transmitted signal is processed by a rate adaptive equalizer and then parsed into parallel data by a deserializer, including: Serial data is input into an adjustable attenuator. The amplitude of the signal source is changed by adjusting the attenuation value of the attenuator, thereby generating an adjustable serial test signal. The initial attenuation value is set to 0dB. The serial test signal, adjusted by the adjustable attenuator, is input into the target test cable, and the signal is transmitted through the cable to obtain the transmitted serial signal. The transmitted serial signal is input into a rate adaptive equalizer, which processes the signal to compensate for attenuation and distortion during transmission. The serial signal processed by the equalizer is input into the deserializer, which parses the serial data into parallel data, providing a processable parallel signal format for subsequent bit error rate analysis.

4. The method of claim 1, wherein, Using the attenuation model to calculate and respectively determine the theoretical feasibility of 3G-SDI and UHD-SDI, if the predicted feasibility is measured, if it is not feasible, the maximum transmission distance is calculated by / β or / γ, wherein, and are specific values of f, including: Using a decay model calculation and generate theoretical feasibility assessment data, wherein, corresponding to a 2.97 Gbps data rate for 3G-SDI, corresponding to an 11.88 Gbps data rate for UHD-SDI, corresponding to a starting test rate of 1.485 Gbps; Based on With , With The theoretical feasibility of 3G-SDI and UHD-SDI is determined by comparing the results, if β 3G-SDI is theoretically feasible, if γ UHD-SDI is theoretically feasible, and the feasibility determination result is generated, wherein, The attenuation value of the adjustable attenuator when the error code starts to appear at a rate of 1.485Gbps; If 3G-SDI or UHD-SDI is theoretically feasible, then a programmable clock generator with the corresponding rate is configured, a pseudo-random code generator is selected as the test data signal, and the attenuation value of the adjustable attenuator is configured to be minimized for actual measurement and verification. Among them, 3G-SDI is 148.5MHz and UHD-SDI is 594MHz. If not, then by / β calculating the predicted maximum distance for 3G-SDI data transmission, by / γ calculating the predicted maximum distance for UHD-SDI data transmission, generating measured validation plan or maximum transmission distance data; In the actual measurement verification process, the pseudo-random code verifier and the ill-conditioned code verifier are used to analyze the bit error rate of the parallel data, the actual transmission performance of the cable at the corresponding rate is judged according to the bit error condition, the cable quality evaluation information containing the application and performance of 3G-SDI and UHD-SDI is generated by combining the theoretical feasibility judgment result and the maximum transmission distance data.

5. A cable quality assessment device for a television serial data interface, characterized by The apparatus for implementing the method of claim 1 comprises: A signal generation module for generating a pseudo-random binary sequence based on a linear feedback shift register and an ill-conditioned code for limit performance testing of a television serial data interface, and after selection by a gating switch, converting the serial data into serial data through a serializer; A signal conditioning and transmission module for inputting the serial data into the target test cable after adjusting the amplitude of the signal source by an adjustable attenuator, processing the transmitted signal by a rate adaptive equalizer, and parsing the parallel data by a deserializer; An error detection module for analyzing the bit error rate of the parallel data by using the pseudo-random code verifier and the ill-conditioned code verifier, starting from HD-SDI, gradually upgrading to 3G-SDI and UHD-SDI, and judging whether the cable meets the transmission requirements of the corresponding rate through the double detection logic of the pseudo-random code basic verification to the ill-conditioned code limit verification; The model calculation module is configured to record the attenuation values at which the error codes start to appear at different rates, and to construct a cable attenuation model based on an attenuation formula, wherein the attenuation formula is ; the attenuation model is used to calculate and to determine the theoretical feasibility of 3G-SDI and UHD-SDI respectively, if the prediction is feasible, the actual measurement is verified, if it is not feasible, the maximum transmission distance is calculated by / β or / γ, wherein and are specific values of f. A result output module for generating cable quality evaluation information containing applicable rate level, limit transmission performance and theoretical maximum distance based on the test results of different television serial data interface standards, wherein the different television serial data interface standards include HD-SDI, 3G-SDI, UHD-SD interface standards.

6. An electronic device, comprising: Comprise: A first processor; And a memory for storing executable instructions of the processor; wherein the processor is configured to execute the method of any one of claims 1 to 4 by executing the executable instructions.

7. A computing device, the device comprising a memory for storing computer program instructions and a second processor for executing the computer program instructions, wherein, When the computer program instructions are executed by the second processor, the device is triggered to execute the method of any one of claims 1 to 4.

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