CN106303299B - Video data distribution unit, device and system - Google Patents
Video data distribution unit, device and system Download PDFInfo
- Publication number
- CN106303299B CN106303299B CN201510292010.1A CN201510292010A CN106303299B CN 106303299 B CN106303299 B CN 106303299B CN 201510292010 A CN201510292010 A CN 201510292010A CN 106303299 B CN106303299 B CN 106303299B
- Authority
- CN
- China
- Prior art keywords
- video data
- node
- video
- control signal
- reverse control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Picture Signal Circuits (AREA)
- Studio Devices (AREA)
Abstract
The invention discloses a video data distribution unit, equipment and a system, which mainly comprise the following contents: the video driving module receives video data and transmits the video data to the video data receiving equipment in a forward direction through the first matching resistor, the video control module obtains the voltage of a first node positioned at a video data output end in the first matching resistor and the voltage of a second node positioned at a video data input end, extracts a reverse control signal positioned in a blanking area when the voltage of the first node is higher than that of the second node, transmits the extracted reverse control signal to the video data acquisition equipment, and triggers the video interference elimination module to control the voltages of the two nodes of the first matching resistor by utilizing the reverse control signal, so that the extracted reverse control signal is not transmitted back, and the correct continuous extraction and forward transmission of the reverse control signal are ensured. In addition, digital-to-analog conversion is not needed, and the problems of quantization distortion and processing delay caused by digital processing are avoided.
Description
Technical Field
The present invention relates to the field of communications technologies, and in particular, to a video data distribution unit, a device, and a system.
Background
At present, the industry has many analog video interfaces with coaxial counter-control function, such as: HDCVI, HDTVI, AHD, etc., and the principle of the analog video interface is that the blanking area of video data is used for transmitting a reverse control signal, thereby realizing the coaxial inverse control function.
Based on the principle of coaxial inverse control, for such distributors (also referred to as distribution devices) of analog video interfaces, conventional solutions all use digital processing, and since the inverse control signal is in the blanking region, a processor is required to parse the current video and find the blanking region to extract the inverse control signal.
As shown in fig. 1(a), a schematic diagram of a structure of a conventional video distribution system, in which an analog camera 101, a distributor 102, and a plurality of analog terminal devices 103 are mainly included. During forward control (i.e., forward video data transmission), the distributor 102 first uses an Analog-to-digital converter (ADC) to complete Analog-to-digital conversion of input video data, then the processor copies the input digital signal and distributes the copied signal to a plurality of output ports, and finally each output port restores the input video data through the ADC and sends the restored input video data to a corresponding Analog terminal device. In the reverse control, as shown in fig. 1(b), the structure of the conventional distributor is schematically illustrated, and the distributor includes an ADC1021, a DAC1022, a processor 1023, a comparator 1024, and a matching resistor R1. The processor 1023 first finds the video blanking area by parsing the forward video data, and extracts the reverse control signal through the comparator 1024 when the video data is found to be transmitting the blanking area. Specifically, the principle is based on: the reverse control signals are all sent in a larger amplitude, and the forward video data in the blanking area are all in a smaller amplitude, so that the reverse control signals with larger amplitude can be extracted by comparing the analog signal output with a fixed level VREF by using a comparator, and then the extracted reverse control signals are superposed on the blanking area of the video signals transmitted forwards in the blanking area time period by the same principle and are sent to the camera, thereby realizing the reverse control function of the distributor.
However, since the extraction of the reverse control signal is compared to a fixed level in the conventional video distribution scheme, and the magnitude of the forward video active area level is related to the actual brightness of the image, it is also possible to have a signal higher than the fixed level (in other words, the forward video active area triggers the extraction of the reverse control signal). In the prior art, in order to avoid that a reverse control signal triggered by a forward video in an effective area affects the operation of a camera, a processor is needed to identify whether the current video transmission is in a blanking area, and if the current video transmission is not in the blanking area, all the reverse control signals are ignored, so that the processes of digital quantization and digital processing are undoubtedly increased, and quantization distortion and processing delay of signals are caused.
Disclosure of Invention
Embodiments of the present invention provide a video distribution unit, a device, and a system, so as to solve the problems of quantization distortion and processing delay in the prior art.
The embodiment of the invention adopts the following technical scheme:
a video data distribution unit comprising: a video driving module, a first matching resistor, a video control module and a video interference elimination module, wherein,
the video driving module is used for receiving video data transmitted by the video data acquisition equipment and transmitting the video data to the video data receiving equipment in a forward direction through the first matching resistor;
the video control module is used for acquiring the voltage of a first node positioned at a video data output end in the first matching resistor, acquiring the voltage of a second node positioned at a video data input end in the first matching resistor, extracting a reverse control signal positioned in a blanking area of video data when the acquired voltage of the first node is determined to be higher than the voltage of the second node, transmitting the extracted reverse control signal to the video data acquisition equipment, and triggering the video descrambling module to control the voltages of the two nodes of the first matching resistor by using the reverse control signal;
and the video interference elimination module is used for controlling the voltages of the two nodes of the first matching resistor when triggered by the reverse control signal extracted by the video control module so as to prevent the extracted reverse control signal from returning.
Preferably, the video control module specifically includes:
the positive electrode of the comparator is connected with the first node of the first matching resistor, and the negative electrode of the comparator is connected with the second node of the first matching resistor;
the grid electrode of the first N-type transistor is connected with the output port of the comparator through a third node, the drain electrode of the first N-type transistor is connected with a first voltage, and the source electrode of the first N-type transistor is connected with the video data acquisition equipment through a fourth node;
if the reverse control signal is driven to be at a high level, the voltage of the first node of the first matching resistor is higher than the voltage of the second node, an output port of the comparator outputs a high-level signal, the high-level signal triggers the first N-type transistor to be turned on, so that the fourth node becomes at a high level, and the high-level signal of the reverse control signal is transmitted to the video data acquisition device;
if the reverse control signal is driven to be at a low level, the voltage of the first node of the first matching resistor is not higher than the voltage of the second node, the comparator outputs a low level signal, the first N-type transistor is turned off, the fourth node keeps at a low level, and the low level signal of the reverse control signal is transmitted to the video data acquisition device.
In the embodiment of the invention, the voltage of the node connected with the anode and the cathode of the comparator is compared in real time through the arranged comparator so as to correctly extract the reverse control signal; and when the comparator outputs high voltage, the first N-type transistor is turned on, and a reverse control signal is sent to the video data acquisition equipment.
Preferably, the video descrambling module specifically includes:
a second N-type transistor, wherein the grid is connected with the third node, the drain is connected with the second node, and the source is grounded;
if the comparator outputs a high-level signal, the second N-type transistor is turned on, the second node is always kept at a low level, and the level of the second node is not higher than that of the first node, so that the comparator can continuously extract the reverse control signal and control the extracted reverse control signal not to return;
if the comparator outputs a low level signal, the second N-type transistor is turned off, the fourth node is at a low level, the second node is also at a low level, and the level of the second node is not less than that of the first node, so that the comparator can continuously extract the reverse control signal and control the extracted reverse control signal not to return.
Preferably, the video driving module specifically includes: an analog driver and a second matching resistor;
the input port of the analog driver is connected with the fourth node, the output port of the analog driver is connected with the second node through the second matching resistor, and the analog driver is used for driving and amplifying the analog signal of the received video data.
Preferably, the transistor is a MOS transistor.
A video data distribution apparatus comprising said at least one video data distribution unit.
A video data distribution system comprises video data acquisition equipment, video data receiving equipment, the video data distribution equipment and a third matching resistor;
the video data distribution equipment is used for receiving video data, transmitting the video data to the video data receiving equipment in a forward direction, receiving a reverse control signal sent by the video data receiving equipment in a blanking area of the video data, extracting the reverse control signal, and controlling the voltages of two nodes of a first matching resistor contained in the video data distribution equipment so as to prevent the extracted reverse control signal from returning.
One node of the third matching resistor is grounded, and the other node is connected to a fourth node of the video data distribution apparatus.
The video distribution unit comprises a video drive module, a first matching resistor, a video control module and a video interference elimination module, wherein the video drive module is used for receiving video data transmitted by video data acquisition equipment and transmitting the video data to video data receiving equipment in a forward direction through the first matching resistor; the video control module is used for acquiring the voltage of a first node positioned at a video data output end in the first matching resistor, acquiring the voltage of a second node positioned at a video data input end in the first matching resistor, extracting a reverse control signal positioned in a blanking area of video data when the acquired voltage of the first node is determined to be higher than the voltage of the second node, transmitting the extracted reverse control signal to the video data acquisition equipment, and triggering the video interference elimination module by using the reverse control signal to control the voltages of the two nodes of the first matching resistor, so that the effective area of forward-transmitted video data can not trigger the extraction and forward transmission of the reverse control signal; the video interference elimination module is used for controlling the voltages of the two nodes of the first matching resistor when triggered by the reverse control signal extracted by the video control module, so that the extracted reverse control signal is not transmitted back, meanwhile, the extracted reverse control signal is used for inhibiting the reverse control signal from being re-driven to form a loop, and the transmission of the normal reverse control signal is interrupted due to the fact that the reverse control signal is re-driven, and the correct continuous extraction and forward transmission of the reverse control signal are guaranteed. In addition, the scheme of the invention does not involve a processor, so that digital-to-analog conversion is not needed, and the problems of quantization distortion and processing delay caused by digital processing are avoided.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
FIG. 1(a) is a schematic diagram of a conventional video distribution system;
FIG. 1(b) is a schematic structural diagram of a conventional dispenser;
fig. 2 is a schematic structural diagram of a video data distribution unit according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a video data distribution apparatus according to a second embodiment of the present invention;
fig. 4 is a schematic structural diagram of a video data distribution system according to a third embodiment of the present invention;
fig. 5 is a circuit diagram of a video data distribution system according to a fourth embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Since the existing extraction of the reverse control signal is compared with a fixed level, and the level amplitude of the forward video data valid area is related to the actual brightness of the image, it is also possible to have a signal higher than the fixed level (in other words, the forward video data valid area also triggers the extraction of the reverse control signal). In order to avoid that the extraction operation of the reverse control signal triggered by the active area of the forward video data affects the normal operation of the video data acquisition equipment, a processor is needed to identify whether the currently transmitted video data is in a blanking area, and if the currently transmitted video data is not in the blanking area, all the reverse control signals are ignored, so that the processes of digital quantization and digital processing are undoubtedly increased, and the quantization distortion and the processing delay of the signals are caused.
Therefore, the video distribution unit adopts a pure hardware circuit to realize the transparent transmission of the distribution drive and the reverse control signals, and specifically comprises a video drive module, a video control module and a video interference elimination module, wherein the video drive module is used for receiving video data transmitted by video data acquisition equipment and transmitting the video data to video data receiving equipment in a forward direction through a first matching resistor; the video control module is connected with two nodes of a first matching resistor of the video driving module and used for acquiring the voltage of a first node positioned at a video data output end in the first matching resistor, acquiring the voltage of a second node positioned at a video data input end in the first matching resistor, extracting a reverse control signal positioned in a blanking area of video data when the acquired voltage of the first node is higher than the voltage of the second node, transmitting the extracted reverse control signal to the video data acquisition equipment, and triggering the video interference elimination module by using the reverse control signal to control the voltages of the two nodes of the first matching resistor, so that the effective area of the forward transmitted video data can not trigger the extraction and forward transmission of the reverse control signal; the video interference elimination module is used for controlling the voltages of the two nodes of the first matching resistor when triggered by the reverse control signal extracted by the video control module so as to control the extracted reverse control signal not to return, and meanwhile, the extracted reverse control signal is used for inhibiting the reverse control signal from being driven again to form a loop, so that the reverse control signal is correctly and continuously extracted and transmitted forwards. In addition, the scheme of the invention does not involve a processor, so that digital-to-analog conversion is not needed, and the problems of quantization distortion and processing delay caused by digital processing are avoided.
The invention will now be described in detail by way of specific examples, which include, but are not limited to the following examples.
The first embodiment is as follows:
in the embodiment of the present invention, a video data distribution unit 2 is introduced first, and as shown in fig. 2, the video data distribution unit 2 includes a video driving module 201, a first matching resistor 202, a video control module 203, and a video descrambling module 204:
the video driving module 201 is configured to receive video data transmitted by the video data acquisition device, and forward transmit the video data to the video data receiving device through the first matching resistor 202.
The video control module 203 is configured to obtain a voltage of a first node of the first matching resistor 202 located at a video data output end, obtain a voltage of a second node of the first matching resistor 202 located at the video data input end, extract a reverse control signal located in a blanking region of video data when it is determined that the obtained voltage of the first node is higher than the voltage of the second node, transmit the extracted reverse control signal to the video data acquisition device, and trigger the video descrambling module 204 to control the voltages of the two nodes of the first matching resistor 202 by using the reverse control signal.
The video descrambling module 204 is configured to control voltages of two nodes of the first matching resistor 202 when triggered by the reverse control signal extracted by the video control module 203, so that the extracted reverse control signal is not transmitted back.
Therefore, the extracted reverse control signal is transmitted to the video data acquisition equipment, and the control signal is prevented from being transmitted back to influence the normal transmission of the reverse control signal.
Preferably, in an embodiment of the present invention, the video control module specifically includes:
the positive electrode of the comparator is connected with the first node of the first matching resistor, and the negative electrode of the comparator is connected with the second node of the first matching resistor;
the grid electrode of the first N-type transistor is connected with the output port of the comparator through a third node, the drain electrode of the first N-type transistor is connected with a first voltage, and the source electrode of the first N-type transistor is connected with the video data acquisition equipment through a fourth node;
if the reverse control signal is driven to be at a high level, the voltage of the first node of the first matching resistor is higher than the voltage of the second node, an output port of the comparator outputs a high-level signal, the high-level signal triggers the first N-type transistor to be turned on, so that the fourth node becomes at a high level, and the high-level signal of the reverse control signal is transmitted to the video data acquisition device;
if the reverse control signal is driven to be at a low level, the voltage of the first node of the first matching resistor is not higher than the voltage of the second node, the comparator outputs a low level signal, the first N-type transistor is turned off, the fourth node keeps at a low level, and the low level signal of the reverse control signal is transmitted to the video data acquisition device.
Preferably, the video descrambling module specifically includes:
the grid electrode of the second N-type transistor is connected with the third node, the drain electrode of the second N-type transistor is connected with the second node, and the source electrode of the second N-type transistor is grounded;
if the comparator outputs a high-level signal, the second N-type transistor is turned on, the second node is always kept at a low level, and the level of the second node is not higher than that of the first node, so that the comparator can continuously extract the reverse control signal and control the extracted reverse control signal not to return;
if the comparator outputs a low level signal, the second N-type transistor is turned off, the fourth node is at a low level, the second node is also at a low level, and the level of the second node is not less than that of the first node, so that the comparator can continuously extract the reverse control signal and control the extracted reverse control signal not to return.
Preferably, the video driving module specifically includes: an analog driver and a second matching resistor;
the input port of the analog driver is connected with the fourth node, the output port of the analog driver is connected with the second node through the second matching resistor, and the analog driver is used for driving and amplifying the analog signal of the received video data.
Preferably, in the embodiment of the present invention, the N-type transistor may be an N-type MOS transistor.
Example two:
as shown in fig. 3, a video data distribution apparatus 3 according to a second embodiment of the present invention includes at least one video data distribution unit 2, and the connection relationship of the video data distribution apparatus 3 is similar to that of the prior art, except that the video data distribution unit 2 is different from that of the prior art, which has already been described above and is not described herein again.
Example three:
as shown in fig. 4, a video data distribution system 4 provided by an embodiment of the present invention includes: a video data acquisition device 401, a video data reception device 402, a video data distribution device 403, and a third matching resistor R3.
The video data distribution device 403 is configured to receive video data and forward transmit the video data to a video data receiving device, and receive a reverse control signal sent by the video data receiving device 402 in a blanking area of the video data, extract the reverse control signal, and control voltages of two nodes of a first matching resistor included in the device to control the extracted reverse control signal not to be returned. Thereby, the extracted reverse control signal is caused to be transmitted to the video data capture apparatus 401.
One node of the third matching resistor R3 is grounded, and the other node is connected to the fourth node of the video data distribution apparatus 403.
Preferably, the video data acquisition device 401 according to the present invention may be an acquisition device such as a video camera, and the video data reception device 402 may be a terminal device such as an analog reception terminal.
Example four:
for a more detailed description of the video data distribution unit, the apparatus and the system, the following description is provided with specific signaling rules.
As shown in fig. 5, a circuit diagram of a video data distribution system according to a fourth embodiment of the present invention is provided, in which a video data acquisition device 501 is connected to a video data distribution device 502 as a video data acquisition device (in the present invention, only one video data distribution device is connected as an example, the video data acquisition device 501 may also be connected to a plurality of video data distribution devices 502), where the video data distribution device 502 includes a video data distribution unit. The video data distribution apparatus 502 is connected to a video data reception apparatus 503.
Also as shown in fig. 5, in the circuit diagram of the distribution system, the video data capture device 501 is connected to the video data distribution device 502 through a fourth node a4, and one end of a third matching resistor R3 is connected between the video data capture device 501 and the fourth node a4, and the other end of the third matching resistor R3 is grounded. Here, the third matching resistor R3 may be set to 75 Ω generally, and is present for the purpose of impedance matching between the video data distribution apparatus 502 and the video data capture apparatus 501, and only one third matching resistor is set regardless of how many paths of the video data distribution apparatus 502 are connected to the video data capture apparatus 501.
The video data distribution apparatus 502 includes a video driving module 5021, a video control module 5022, and a video descrambling module 5023. An input port of the analog driver U1 in the video driving module 5021 is connected to a fourth node a4 as an input port of the video driving module 5021, the analog driver U1 is connected to one end of a second matching resistor R2, the other end of the second matching resistor R2 is connected to one end of a first matching resistor R1 through a second node a2, and the other end of the first matching resistor R1 is connected to the video data receiving device 503 as an output port of the video driving module 5021 through a first node a 1. The video driving module 5021 is used to drive and output the received video data, and usually, the analog driver U1 is needed to amplify the video data signal, but the present invention is not limited to the amplification scheme, and in the case of low requirement on transmission distance, the received video data may be directly transmitted without the analog driver U1. Further, the present invention also includes an example of narrowing down the received signal of the video data without considering the limitation of the condition of the transmission distance or the like.
It should be noted that, in conjunction with the video data driving module 5021, the first matching resistor R1 is necessary to support the function of the subsequent comparator to implement the proposed solution of the present invention. The second matching resistor R2 may be present as a preferred solution to limit the current and ensure that the U1 can be used normally.
In addition, the video control module 5022 includes a comparator U2 and an NMOS transistor Q1, the positive pole of the comparator U2 is connected to the first node a1, the negative pole of the comparator U2 is connected to the second node a2, that is, the positive pole and the negative pole of the comparator are respectively connected to two ends of the first matching resistor R1, so that when the video data is transmitted in the forward direction and the reverse control signal is transmitted in the reverse direction, the level of the output port output of the comparator is determined by the levels of the first node a1 and the second node a2, for example: when the level of the first node A1 is higher than the level of the second node A2, the signal of the positive input voltage of the comparator U2 is higher than that of the negative input voltage, and the output port of the comparator U2 outputs a high level; otherwise, a low level is output, thereby realizing the function of the comparator U2 of extracting the inverted control signal. The gate of the NMOS transistor Q1 is connected to the output port of the comparator U2 through a third node A3, the drain is connected to the first voltage V1, and the source is connected to the video data acquisition device 501 through a fourth node a4, so that the on and off of the NMOS transistor Q1D depends on the level of the output port of the comparator U2, and if the output port of the comparator U2 outputs a high level, the NMOS transistor Q1 is turned on, and if the output port of the comparator U2 outputs a high level, the output is turned off.
In addition, in order to avoid that the reverse control signal extracted by the video control module 5022 is transmitted back to the video driving module 5021 and is extracted by the video control module 5022 again, the video data distribution device 502 in the embodiment of the present invention further includes a video descrambling module 5023, specifically, the video descrambling module 5023 includes an NMOS transistor Q2, a gate of the NMOS transistor Q2 is connected to the third node A3, a drain of the NMOS transistor Q2 is connected to the second node a2, and a source of the NMOS transistor Q1 is grounded.
While the circuit diagram of a video data distribution system is described in detail above with reference to fig. 5, it is necessary to describe the system in conjunction with a specific overall workflow because the correlation between the various structures is not described by a single structure. The operation of each of the above-described modules is explained below by two specific examples, with reference to the circuit diagram shown in fig. 5.
Example 1: forward transmission of video data
When the video data acquisition device 501 sends forward-transmission video data to the node a6, the video data is sent to the analog driver U1 through the fourth node a4 to perform signal amplification operation, then is transmitted to the second node a2 through the second matching resistor R2, then is sent to the first node a1 through the first matching resistor R1, and finally is output to the video data receiving device 503. In this transmission process, since the video data is driven from the second node a2 to the first node a1, the level of the second node a2 is higher than that of the first node a1, i.e. the negative electrode of the comparator U2 is higher than the positive electrode, so the output port of the comparator outputs a low level, and further the third node A3 is a low level, then the NMOS transistor Q2 and the NMOS transistor Q1 are both in an off state, i.e.: the video control module and the video interference eliminating module do not influence the forward transmission video data. If the video data acquisition device 501 is connected to multiple paths of video data distribution devices and video data receiving devices in this example 1, two adjacent paths of distribution and output operations are performed independently, and two non-interfering and identical forward video signals are formed respectively.
Example 2: reverse transmission of reverse control signals
Since the principle of the coaxial inversion control is generated in the blanking region of the video data, that is, when the video data is at an inactive low level, the coaxial inversion control is initiated by the video data receiving apparatus 503, which outputs an inversion control signal (for example, an inversion 485 signal) to the first node a 1.
When the reverse 485 signal is at a high level, the level of the first node a1 is higher than the level of the second node a2, which causes the output port of the comparator U2 to output a high level, and the NMOS transistor Q2 and the NMOS transistor Q1 are both turned on. Since the NMOS transistor Q1 is turned on, the fourth node a4 is short-circuited to the first voltage, which may be 3.3V (the first voltage may be set according to actual circuit requirements, but the present invention is not limited thereto) through the NMOS transistor Q1, and the fourth node a4 becomes a high level, so that the high level of the inverse 485 signal is transmitted to the video data capture device 501.
However, since there are two transmission branches at the position of the fourth node a4, the two transmission branches can be transmitted to the video data acquisition device 501 and also to the video driving module, and further can be re-extracted by the comparator U2, thereby infinitely looping. Therefore, in order to ensure that the extracted high level of the reverse 485 signal is accurately transmitted to the video data acquisition device 501, a video descrambling module 5023 may be provided between the video control module 5022 and the video driving module 5021, and the video descrambling module may specifically be an NMOS transistor. At this time, since the NMOS transistor Q2 is turned on, the second node a2 is short-circuited and grounded by the NMOS transistor Q2, and even if the high level of the previously extracted reverse 485 signal is transmitted to the analog driver U1, no matter the analog driver U1 outputs the high level or the low level, the second node a2 is kept at the low level (short-circuited and grounded), so that the high level of the fourth node a4 is prevented from being transmitted to the second node a2 after being driven by the analog driver U1, and the level of the second node a2 is greater than or equal to the level of the first node a1, which results in the output of the low level at the output port of the comparator U2 and affects the continuous transmission of the high level of the reverse 485 signal.
When the reverse 485 signal is at a low level, the level of the first node a1 is less than or equal to that of the second node a2, the comparator U2 outputs a low level, the NMOS transistor Q2 and the NMOS transistor Q1 are turned off, the first node a1 is kept at the low level of the blanking region all the time, that is, the low level of the reverse 485 signal is transmitted to the video camera, and because the NMOS transistor Q2 is turned off, the level of the second node a2 is kept at the low level of the original blanking region, that is, the condition that the level of the second node a2 is greater than or equal to that of the first node a1 is kept, so that the low level of the reverse 485 signal is completely transmitted. In conclusion, the correct forward transmission of the reverse 485 signal is achieved.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (6)
1. A video data distribution unit, comprising: a video driving module, a first matching resistor, a video control module and a video interference elimination module, wherein,
the video driving module is used for receiving video data transmitted by the video data acquisition equipment and transmitting the video data to the video data receiving equipment in a forward direction through the first matching resistor;
the video control module is used for acquiring the voltage of a first node positioned at a video data output end in the first matching resistor, acquiring the voltage of a second node positioned at a video data input end in the first matching resistor, extracting a reverse control signal positioned in a blanking area of video data when the acquired voltage of the first node is determined to be higher than the voltage of the second node, transmitting the extracted reverse control signal to the video data acquisition equipment, and triggering the video descrambling module to control the voltages of the two nodes of the first matching resistor by using the reverse control signal;
the video interference elimination module is used for controlling the voltages of the two nodes of the first matching resistor when triggered by the reverse control signal extracted by the video control module so as to prevent the extracted reverse control signal from returning back;
wherein, the video control module specifically includes:
the positive electrode of the comparator is connected with the first node of the first matching resistor, and the negative electrode of the comparator is connected with the second node of the first matching resistor;
the grid electrode of the first N-type transistor is connected with the output port of the comparator through a third node, the drain electrode of the first N-type transistor is connected with a first voltage, and the source electrode of the first N-type transistor is connected with the video data acquisition equipment through a fourth node;
if the reverse control signal is driven to be at a high level, the voltage of the first node of the first matching resistor is higher than the voltage of the second node, an output port of the comparator outputs a high-level signal, the high-level signal triggers the first N-type transistor to be turned on, so that the fourth node becomes at a high level, and the high-level signal of the reverse control signal is transmitted to the video data acquisition device;
if the reverse control signal is driven to be at a low level, the voltage of the first node of the first matching resistor is not higher than the voltage of the second node, the comparator outputs a low level signal, the first N-type transistor is turned off, the fourth node keeps at a low level, and the low level signal of the reverse control signal is transmitted to the video data acquisition device.
2. The video data distribution unit of claim 1, wherein the video descrambling module specifically comprises:
a second N-type transistor, wherein the grid is connected with the third node, the drain is connected with the second node, and the source is grounded;
if the comparator outputs a high-level signal, the second N-type transistor is turned on, the second node is always kept at a low level, and the level of the second node is not higher than that of the first node, so that the comparator can continuously extract the reverse control signal and control the extracted reverse control signal not to return;
if the comparator outputs a low level signal, the second N-type transistor is turned off, the fourth node is at a low level, the second node is also at a low level, and the level of the second node is not less than that of the first node, so that the comparator can continuously extract the reverse control signal and control the extracted reverse control signal not to return.
3. The video data distribution unit according to claim 1 or 2, wherein the video driver module specifically comprises: an analog driver and a second matching resistor;
the input port of the analog driver is connected with the fourth node, the output port of the analog driver is connected with the second node through the second matching resistor, and the analog driver is used for driving and amplifying the analog signal of the received video data.
4. The video data distribution unit according to claim 1 or 2, wherein the transistor is a MOS transistor.
5. Video data distribution apparatus comprising at least one video data distribution unit according to any of claims 1 to 4.
6. A video data distribution system comprising a video data acquisition device, a video data receiving device, and the video data distribution device of claim 5, a third matching resistor;
the video data distribution equipment is used for receiving video data, transmitting the video data to the video data receiving equipment in a forward direction, receiving a reverse control signal sent by the video data receiving equipment in a blanking area of the video data, extracting the reverse control signal, and controlling the voltages of two nodes of a first matching resistor contained in the video data distribution equipment so as to prevent the extracted reverse control signal from returning;
one node of the third matching resistor is grounded, and the other node is connected to a fourth node of the video data distribution apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510292010.1A CN106303299B (en) | 2015-05-29 | 2015-05-29 | Video data distribution unit, device and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510292010.1A CN106303299B (en) | 2015-05-29 | 2015-05-29 | Video data distribution unit, device and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106303299A CN106303299A (en) | 2017-01-04 |
| CN106303299B true CN106303299B (en) | 2020-04-03 |
Family
ID=57655397
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510292010.1A Active CN106303299B (en) | 2015-05-29 | 2015-05-29 | Video data distribution unit, device and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106303299B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106657860B (en) * | 2016-12-23 | 2019-09-17 | 浙江大华技术股份有限公司 | A kind of video extender, its control method and coaxial view control transmitting device |
| CN107483847B (en) | 2017-07-24 | 2019-12-20 | 浙江大华技术股份有限公司 | Video distributor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1564591A (en) * | 2004-04-09 | 2005-01-12 | 南京大学 | Method and appts. for duplex transmitting video signal and controlling data |
| US7256837B2 (en) * | 2001-06-25 | 2007-08-14 | Matsushita Electric Industrial Co., Ltd. | Baseband video transmission system |
| CN102387302A (en) * | 2010-08-27 | 2012-03-21 | 索尼公司 | Camera device, camera system and camera control method |
| CN104601941A (en) * | 2014-01-26 | 2015-05-06 | 杭州海康威视数字技术股份有限公司 | Ball machine pan-tilt control system |
-
2015
- 2015-05-29 CN CN201510292010.1A patent/CN106303299B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7256837B2 (en) * | 2001-06-25 | 2007-08-14 | Matsushita Electric Industrial Co., Ltd. | Baseband video transmission system |
| CN1564591A (en) * | 2004-04-09 | 2005-01-12 | 南京大学 | Method and appts. for duplex transmitting video signal and controlling data |
| CN102387302A (en) * | 2010-08-27 | 2012-03-21 | 索尼公司 | Camera device, camera system and camera control method |
| CN104601941A (en) * | 2014-01-26 | 2015-05-06 | 杭州海康威视数字技术股份有限公司 | Ball machine pan-tilt control system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106303299A (en) | 2017-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102237026B1 (en) | Display device | |
| US9799295B2 (en) | Scan driving circuit and liquid crystal display device having the circuit | |
| US10841478B2 (en) | Image sensor and control system | |
| KR102345861B1 (en) | Latch and its driving method, source driving circuit and display device | |
| RU2013104449A (en) | SOLID IMAGE READER | |
| CN106303299B (en) | Video data distribution unit, device and system | |
| JP2015228554A5 (en) | ||
| US9613555B2 (en) | Pixel driving circuit including signal splitting circuits, driving method, display panel, and display device | |
| US20140077603A1 (en) | Power supply apparatus with power backup mechanism | |
| US20150286599A1 (en) | Chassis identification method using modulation | |
| US9030609B1 (en) | Segmented video data processing | |
| EP3579549A3 (en) | Imaging apparatus, imaging system, moving body, and semiconductor substrate for lamination | |
| CN107493486B (en) | Method, system and terminal equipment for video playing termination | |
| US10636346B2 (en) | Electronic device for driving display panel and operation method thereof | |
| US20180196679A1 (en) | Initialization method for use in i2c system and master device | |
| US20170199602A1 (en) | Touch display driving method and device, display device and application processor | |
| US20210174717A1 (en) | Gate driving circuit, driving method thereof, gate driver, display panel and display apparatus | |
| US20180288344A1 (en) | Systems and methods for dynamic voltage scaling of an image signal processor | |
| EP3203729B1 (en) | Method, device and video conference system for detecting video signals in same standard | |
| US10564631B2 (en) | Servo movement control method, device, and terminal device | |
| EP3542527B1 (en) | Video extenders, control methods therefor and coaxial video-controlling transmission devices | |
| CN107483847B (en) | Video distributor | |
| CN106847155B (en) | GOA circuit, array substrate and display device | |
| US20180335879A1 (en) | In-cell touch and display apparatus, common voltage provider, and providing method thereof | |
| JP2016080958A (en) | Signal input changeover circuit, control method for signal input changeover circuit and display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |