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CN-121984808-A - Method and system for transmitting audio and video signals through single-wire network cable

CN121984808ACN 121984808 ACN121984808 ACN 121984808ACN-121984808-A

Abstract

The application relates to the technical field of audio and video signal data transmission, and discloses a method and a system for transmitting audio and video signals by a single-wire network cable, wherein the method comprises the steps of acquiring composite link parameters and executing self-calibration frequency spectrum division; the method comprises the steps of performing self-adaptive impedance matching adjustment, performing differential coding and baseline drift compensation processing on audio and video modulation signals, recovering audio and video receiving signals resisting ripple interference, and performing closed-loop optimization updating on spectrum isolation boundaries. Compared with the scheme of realizing power supply and data multiplexing in the prior art by relying on a fixed filter circuit or a fixed impedance matching mode, the method has the technical problem that stability of audio and video frames is difficult to maintain especially in the scene that a single network cable simultaneously carries direct current power supply and audio and video signals and power supply load changes dynamically. The application improves the audio signal-to-noise ratio and the video frame stability under the single-line transmission condition by the combined mechanism of frequency spectrum self-calibration, impedance network synthesis and differential direct current balance coding.

Inventors

  • REN GUOBIN

Assignees

  • 凯新创达（深圳）科技发展有限公司

Dates

Publication Date
20260505
Application Date
20260203

Claims (10)

  1. 1. A method for transmitting an audio/video signal over a single wire network, the method comprising: Step S10, acquiring a composite link parameter set A of a single network cable transmission link, executing a spectrum isolation boundary generation task by adopting a self-calibration spectrum division mechanism based on the composite link parameter set A, and outputting a spectrum isolation control parameter set O; Step S20, based on the frequency spectrum isolation control parameter set O, adopting a joint mechanism based on positive real function approximation and impedance network coupling to execute decoupling injection control tasks of power supply and audio/video signals on a single network cable and output a composite transmission signal ; Step S30, based on the composite transmission signal A dynamic impedance matching adjustment mechanism based on power state sensing is adopted to execute a power disturbance rejection adjustment task, and an audio and video modulation signal after dynamic impedance matching is output ; Step S40, modulating the signal based on the audio and video An anti-baseline drift suppression mechanism based on direct current balance coding and sliding mean value baseline correction is adopted to execute an audio-video differential coding task, and an audio-video receiving signal set for anti-ripple recovery is output Audio-video receiving signal set Comprising a sequence of audio samples and a sequence of video frames; Step S50, executing transmission link parameter closed-loop optimization updating task based on the audio sampling sequence and the video frame sequence, and outputting the cut-off frequency of the updating interval 。
  2. 2. The method for transmitting an audio/video signal by a single-wire network cable according to claim 1, wherein in step S10, a composite link parameter set a of a single-wire network cable transmission link is obtained, a spectrum isolation boundary generating task is executed by a self-calibrated spectrum division mechanism based on the composite link parameter set a, and a spectrum isolation control parameter set O is output, which specifically includes: Step S101, obtaining a composite link parameter set A of a single network transmission link, wherein the composite link parameter set A comprises direct current voltage, ripple amplitude and frequency ripple main frequency Characteristic impedance And a bandwidth efficient zone; step S102, dividing a single-wire transmission frequency spectrum into a power supply leading section and an audio/video safety section based on a frequency ripple main frequency by adopting a frequency spectrum dividing method based on weighted power spectral density estimation, and outputting a section cut-off frequency ; Step S103, according to the composite link parameter set A and the interval cut-off frequency And outputting a frequency spectrum isolation control parameter set O.
  3. 3. The method for transmitting audio and video signals through single-wire network cable according to claim 2, wherein in step S20, a combination mechanism based on positive real function approximation and impedance network coupling is adopted based on the spectrum isolation control parameter set O, a decoupling injection control task of power supply and audio and video signals is performed on a single wire cable, and a composite transmission signal is output Specifically comprises the following steps: step S201, according to the interval cut-off frequency Construction of an ideal impedance objective function ; Step S202, aiming at ideal impedance objective function Performing positive real function approximation by adopting rational function approximation, and outputting an impedance function meeting a positive real condition; Step S203, combining the preset impedance function according to the positive reality condition And the Cauer network performs network synthesis by adopting a normalized low-pass frequency mapping transformation method, outputs actual inductance capacitance network parameters, and finally outputs a composite transmission signal based on the actual inductance capacitance network parameters and a preset decoupling injection network topology template 。
  4. 4. A method for transmitting an audio/video signal over a single wire network as defined in claim 3, wherein, in step S20, Wherein, the method comprises the steps of, Is a frequency variable; as frequency variable Lower corresponding equivalent input impedance; as frequency variable Lower corresponding characteristic impedance, ideal impedance objective function For describing the optimum transmission impedance trajectory of the supply current and the audio-visual signal in the frequency domain.
  5. 5. The method for transmitting audio/video signals over a single wire network as claimed in claim 1, wherein in step S30, the method is based on the composite transmission signal A dynamic impedance matching adjustment mechanism based on power state sensing is adopted to execute a power disturbance rejection adjustment task, and an audio and video modulation signal after dynamic impedance matching is output Specifically comprises the following steps: Step S301, composite transmission signal based on time t Current variation to power supply port by high frequency sampling And the amount of voltage fluctuation Real-time monitoring is carried out, and power disturbance parameters are extracted , ; Step S302, according to the power disturbance parameters Characteristic impedance for transmitting audio and video data by adopting proportional mapping mode Adjusting and outputting an impedance adjustment result; step S303, optimizing and adjusting the decoupling injection network of the audio and video signals in a parameter recalibration mode by applying the impedance adjustment result, and outputting the final audio and video modulation signals 。
  6. 6. The method for transmitting audio/video signals over a single wire network as claimed in claim 1, wherein in step S40, the audio/video modulation signal is based on An anti-baseline drift suppression mechanism based on direct current balance coding and sliding mean value baseline correction is adopted to execute an audio-video differential coding task, and an audio-video receiving signal set for anti-ripple recovery is output Audio-video receiving signal set The method comprises the steps of an audio sampling sequence and a video frame sequence, and specifically comprises the following steps: Step S401, modulating the audio/video signals by adopting the differential signal transmission principle Performing differential driving coding to obtain differential mode coded signals Differential mode encoded signal Comprising first drive waveforms transmitted simultaneously on twisted pairs in opposite phase with each other And a second driving waveform , ; Step S402 of encoding the differential mode signal Applying a DC balance constraint to make a differential mode encoded signal The integral average value of a sliding time window in a preset time window is zero, and a direct current balance differential mode signal is output; Step S403, performing DC component inhibition on the differential mode encoded signal by adopting a discrete first-order differential operator mode based on the DC balance differential mode signal to obtain a baseline drift amount, and performing differential mode encoding on the differential mode encoded signal according to the baseline drift amount Performing baseline drift compensation processing, outputting a baseline drift resisting recovery signal, and constructing and outputting an audio/video receiving signal set according to the baseline drift resisting recovery signal Then, based on preset audio-video analysis rules, the audio-video receiving signals are assembled And separating to obtain an audio sampling sequence and a video frame sequence.
  7. 7. The method for transmitting audio/video signals over a single wire network as claimed in claim 1, wherein in step S50, a transmission link parameter closed-loop optimization update task is performed based on the audio sampling sequence and the video frame sequence, and an update interval cut-off frequency is outputted Specifically comprises the following steps: step S501, in the performance function construction stage, an audio signal-to-noise ratio is extracted by adopting a time domain statistical analysis method based on an audio sampling sequence and a video frame sequence Jitter index with video frames And is based on the audio signal-to-noise ratio Jitter index with video frames A comprehensive transmission performance function T is constructed, , wherein, The sensitivity of the current application scene to the audio stability is reflected for the audio quality weight coefficient, The sensitivity degree of the current application scene to video jitter is reflected by the video stability weight coefficient; Step S502, obtaining the current interval cut-off frequency According to the comprehensive transmission performance function T and the interval cut-off frequency Gradient estimation of interval cut-off frequency change trend is carried out, and a sensitivity function is output Sensitivity function The method is used for describing the influence direction of the cut-off frequency change on the audio/video transmission quality; Step S503, according to the sensitivity function Cut-off frequency for interval Performing gradient descent update, outputting update interval cutoff frequency 。
  8. 8. A system for transmitting audio and video signals through a single-wire network line, which is applied to a method for transmitting audio and video signals through a single-wire network line according to any one of claims 1to 7, and is characterized in that the system for transmitting audio and video signals through the single-wire network line comprises: The spectrum self-calibration analysis module is used for acquiring a composite link parameter set A of a single network cable transmission link, executing a spectrum isolation boundary generation task by adopting a self-calibration spectrum division mechanism based on the composite link parameter set A, and outputting a spectrum isolation control parameter set O; The impedance network synthesis and decoupling injection module is used for performing power supply and audio/video signal decoupling injection control tasks on a single network cable based on a spectrum isolation control parameter set O by adopting a joint mechanism based on positive real function approximation and impedance network coupling, and outputting a composite transmission signal ; The power supply perception self-adaptive impedance adjusting module is used for being based on composite transmission signals A dynamic impedance matching adjustment mechanism based on power state sensing is adopted to execute a power disturbance rejection adjustment task, and an audio and video modulation signal after dynamic impedance matching is output ; Differential coding and baseline drift suppression module for modulating signals based on audio and video An anti-baseline drift suppression mechanism based on direct current balance coding and sliding mean value baseline correction is adopted to execute an audio-video differential coding task, and an audio-video receiving signal set for anti-ripple recovery is output Audio-video receiving signal set Comprising a sequence of audio samples and a sequence of video frames; the performance feedback driven frequency spectrum parameter optimization module is used for executing a transmission link parameter closed-loop optimization updating task based on the audio sampling sequence and the video frame sequence and outputting an updating interval cut-off frequency 。
  9. 9. An apparatus for transmitting audio and video signals over a single wire network, wherein the apparatus for transmitting audio and video signals over a single wire network comprises a memory, a processor, and a program for transmitting audio and video signals over a single wire network stored in the memory and operable on the processor, and wherein the program for transmitting audio and video signals over a single wire network, when executed by the processor, implements a method for transmitting audio and video signals over a single wire network according to any one of claims 1 to 7.
  10. 10. A computer program product, characterized in that the computer program product comprises a program for single-wire network transmission of audio-video signals, which program, when being executed by a processor, implements a method for single-wire network transmission of audio-video signals according to any one of claims 1 to 7.

Description

Method and system for transmitting audio and video signals through single-wire network cable Technical Field The invention relates to the technical field of audio and video signal data transmission, in particular to a method and a system for transmitting audio and video signals through a single-wire network cable. Background At present, in embedded equipment such as security cameras and industrial control terminals, network cables are often adopted as multiplexing carriers of audio and video signals and power supply lines, so that wiring cost is reduced, and deployment convenience is improved. The existing scheme refers to multiplexing thought of power over Ethernet (PoE) or HDBaseT-like, and superposition transmission of power and data signals on the same transmission medium is realized through inductance and capacitance filtering and a fixed impedance matching circuit. However, such schemes are generally established under the precondition of standard ethernet physical layer protocol, stable load model and fixed spectrum division, and are difficult to be directly applied to embedded audio/video transmission scenes of low-cost and nonstandard ethernet architecture. For example, in the case where a single network cable carries both dc power and audio and video signals, ripple on the power supply side, power switching noise, and load dynamics can couple into the audio and video signal path through parasitic capacitance, parasitic inductance, and impedance mismatch, resulting in low frequency noise in the audio signal, and inter-frame brightness fluctuation and transient jitter in the video picture. The prior art generally only inhibits by adding a filter circuit or fixing a cut-off frequency, but when power supply load changes, cable length changes or environmental interference is enhanced, the filtering and impedance matching means of fixed parameters are difficult to keep stable effects, and the prior art cannot fully meet the requirement of stable transmission of audio and video signals under complex working conditions. Therefore, a transmission method for effectively decoupling a power supply path and an audio/video path and suppressing the influence of power supply disturbance under the condition that a single network cable carries both direct current power supply and audio/video signals is still needed, so as to improve the stability and reliability of audio/video signal transmission under a single-wire condition. Disclosure of Invention Aiming at the technical defects, the invention aims to provide a method for transmitting audio and video signals by a single-wire network cable, and aims to solve the technical problems that in the prior art, a scheme of realizing power supply and data multiplexing in a fixed filter circuit or a fixed impedance matching mode is dependent, and particularly, the stability of audio and video frames is difficult to maintain under the condition that a single network cable simultaneously carries direct current power supply and audio and video signals and power supply load dynamically changes. In order to solve the technical problems, the invention adopts the following technical scheme that the invention provides a method for transmitting audio and video signals by a single-wire network cable. The method for transmitting the audio and video signals through the single-wire network cable comprises the following steps: Step S10, acquiring a composite link parameter set A of a single network cable transmission link, executing a spectrum isolation boundary generation task by adopting a self-calibration spectrum division mechanism based on the composite link parameter set A, and outputting a spectrum isolation control parameter set O; Step S20, based on the frequency spectrum isolation control parameter set O, adopting a joint mechanism based on positive real function approximation and impedance network coupling to execute decoupling injection control tasks of power supply and audio/video signals on a single network cable and output a composite transmission signal ; Step S30, based on the composite transmission signalA dynamic impedance matching adjustment mechanism based on power state sensing is adopted to execute a power disturbance rejection adjustment task, and an audio and video modulation signal after dynamic impedance matching is output; Step S40, modulating the signal based on the audio and videoAn anti-baseline drift suppression mechanism based on direct current balance coding and sliding mean value baseline correction is adopted to execute an audio-video differential coding task, and an audio-video receiving signal set for anti-ripple recovery is outputAudio-video receiving signal setComprising a sequence of audio samples and a sequence of video frames; Step S50, executing transmission link parameter closed-loop optimization updating task based on the audio sampling sequence and the video frame sequence, and outputting the cut-off frequency of the updating interval 。 Pref