The system of the surveillance camera-the existence of the inverse day

Then the previous record, followed by the exploration of the camera's pigtail, but later found that the pigtail is really not catch!

The previous article also said, I guess directly the output of the camera to the TV interface to go, is the data can be displayed. Here to apologize to the reader, because there are readers to my reflection-Lou Zhu, you come, see I do not kill you, my home TV behind so many interfaces, you tell me exactly Which??? When he sent a picture to me .... I cried ~

A few, perhaps this reader's TV set is relatively high, the interface will be more, but I think about it, my home TV interface, it seems a lot ah!

　　　　　　　　　　　　　　　　　　　　　　　　　　　　

At least these four, I'll be a circle. So, I decided, or give a good introduction to some of the parents of the baby, want to bubble people, parental clearance is necessary. Netizens Home TV, I do not dare to move, they are nobles, I will introduce my home TV several interfaces behind.

See is four interfaces, they belong to two types of interface: AV terminal and S-terminal. AV terminal is that three have color, as to what color stands for, said later. The S-terminal is the one with the black non-trash. Long like this: (I stole the picture)

　　　　　　　　　　　　　　　　　　　　　　　　　　　　

First of all, AV terminal. This thing, we will encounter in childhood with DVD playing CD-ROM, and then the DVD and TV connection is through a few colorful lines to connect, specifically a few root it? Mine (I know, there must be another reader to ask me to stand out, so that they kill me, because some of the advanced points of the device is several ~)! These three lines are the first type of connector to be introduced today, and the protagonist of today. To the last picture, remind the reader of the memory of the Sleeping years:

　　　　　　　　　　　　　　　　　　　　　　　　　　　　

Well, that's it, are you familiar with it? When I was a child, my father would not let me take the DVD playing games, will pull the line, thought I will not pick up, but that year on the "Talent smart" I am still very smooth connection success-I was the color, unified opinion, the yellow wiring behind the DVD yellow, the Yellow line of the TV yellow ............... Yes, it's all the same color that's connected together. I did not know why, until many years later (that is, a while ago), I did not know the secret of the color-red is the left channel, White is the right channel, yellow is the video interface!

The reader may be difficult for me-Lou Zhu Ah, do not care too much about how the line is connected, you tell me, this signal is in what form in this line transmission.

These three lines, two is the transmission of audio (audio has not been studied, so not to mislead the audience here), one is the transmission of video. In the previous article, I said that this video transmission line is an inverse of the existence of the day! The data running on this line follows a certain protocol, in the current world, using a very wide range of three "big giants", that is, three kinds of protocols: Ntsc,pal,secam. In a moment another reader asked, what the hell are these three? I told you, it's a TV data transfer protocol that can be understood by analogy when you don't know what kind of ghost he is-serial transfer protocol you understand? One starting bit, eight bits data bit, one check bit, one stop bit. So this video transmission protocol You can also like this analogy ah, there is the beginning of the place, there is a place for data, there is the end of the place! Yes, that's what understanding is, the so-called protocol! The so-called agreement is everyone agreed to, we follow such a kind of hair, and then I so kind of collect, it must be correct.

Well, it's far away. To the last figure, explain what the deal is all about, I'm transmitting a relatively wide range of Pal,pal and NTSC in the celestial world is similar.

　　　　　　　　　　　　　　　　　　　　

Oh, no!. Landlord, you put this what things!!! This thing, I look at the beginning of the time is also want to cry no tears, completely do not understand this exactly want to express what things!!! This is where he is the inverse of heaven. We knew from a young age that the display of the TV is by the electron beam line on the display, the corresponding place to illuminate the image, the back of the development to the LCD, without electron beam, but still not run off a line to show the life! This thing, in the back of the introduction of the VGA will be in detail to say. The display of a CRT display is a line to display, and there is a hidden action between each row, why should it be hidden?

　　　　　　　　　　　　　　　　　　　　　

The electron beam from left to right hit, hit to the far right when it to go back to the left, in order to let it return to the time not to make a point, so let it stop work, this time is called line blanking, the same, each full screen display, to return to the top left corner, in the return of this time, called field blanking. Well, this is the reason why the field is hidden.

Back to that heavenly book the same figure, the main is that there are three places is confusing, the first is that suddenly become very low that level, one is that color synchronization signal is what thing, there is one of those a square bar, these square, in these drawings said is the color: white, yellow, cyan, green ....

　　　　　　　　　　　　　　　　　　　　　　　　

How do these things really come to be understood? The synchronization level, also known as the digital synchronization level, his level has become very low, and all other places of the level are not the same, this is to inform the receiver: Ah, hurry up, then wait for me to get higher level of the time (blanking level) into the official line of transmission, next, and so my level back to the blanking level of the time , you will detect a 3.58MHZ sine wave signal, probably lasts 8-10 cycles that way, that is to tell you again, chromatic aberration signal ready to transmit, ready. This way, the receiver is notified, do two preparation, one is the level of signal reception preparation, one is the reception preparation of chromatic aberration signal. OK, then the receiving side of the two reception workshop started-a workshop detection level signal, a workshop to detect chromatic aberration signal.

The problem comes, the level signal represents what, chromatic aberration signal and how to detect! Don't be a jerk! Wait for me to speak slowly.

The signal transmitted by the PAL or NTSC format via the video terminal of the AV terminal line is the transmission of the luminance signal, the tone signal and the color saturation signal. We see the heavenly Book of the same signal map Ah, in fact, is a synthetic signal, he is composed of luminance signal and chromatic aberration signal synthesis.

　　　　　　　　　　　　　　　　　　　　　　　　　

We look at this diagram first, this picture is not just so gorgeous and colorful, he is simply the luminance signal, that is, black and white signal. Readers want to quarrel, obviously wrote Yellow Green, you tell me this is black and white!!?? Is this, we know that RGB three primary colors, three primary colors mixed to get color, color, through the corresponding formula, can be converted into black and white, that is, gray value, this is how to convert, perhaps now the author is also a comparative dish, say, haha, is later, to the image processing part of the time to say. Now just know the color is corresponding to have black and white on it. This is the level of the luminance information, that is, the one responsible for the detection level of the workshop, you can detect the grayscale information-here you have ideas? If you are making black and white, then as long as there is a level workshop can be, the gray information to grasp out, it can be displayed.

　　　　　　　　　　　　　　　　　　

This is the color difference signal, the color difference signal is the essence of the television format inside, anyway, I think so. Simply look at this picture, some black small note, it is not interesting, good, in order to save some lazy eggs back to look at the need, I in the last picture:

　　　　　　　　　　　　　　　　　　　

In combination with the above two graphs, I'll explain the chromatic aberration signal. What is called chromatic aberration signal???? Well, now inconvenient to say (an essay on all the things, I can eat!) ）。 As long as the signal is known by the color signal of the product, it represents a color signal can be.

We see that the gray strips are amplified and then a sine wave--well, speaking of sine waves, we're going to remember three elements of sine wave: amplitude, frequency plus phase. In the format of the rules, ah, the frequency has been stipulated, can not be changed. The rest of the phase and amplitude can be somewhat interesting-in this inverse-day transmission protocol, the amplitude of the chromatic aberration is given the meaning of saturation, while the phase is given the meaning of the hue.

Don't know about here, spectators see clearly no, in the video of the sender, respectively, create a bright signal (level) and chromatic aberration signal (sine wave), and then said they are superimposed on the two signals to get the same heavenly signal, and finally through a video cable in the form of analog signal sent out. At the receiving end, there are two workshops, one workshop is responsible for decoding the level to get the luminance information, a workshop is responsible for decoding the sine signal, to obtain the hue and saturation information.

This is the PAL format in the AV line transmission, in a line inside the transmission of luminance signals and chromatic aberration signals. In the reception, if you are black and white, it is easy to decode the brightness information directly, if you are color TV, bad idea, you have to add a cost to open a workshop to decode the chromatic aberration signal.

OK, the AV terminal is finished. Next, take the S-terminal.

S-terminal is an upgraded version of AV terminal, both raw Yoga Sheng also???? Is AV terminal bad? Really bad, we look at is also the egg, you transmit the time to put all the signals together, I decode the time also have to take this pair of mess untie, the middle caused the misunderstanding do not know how many!!! If we can separate the luminance information from the chromatic aberration, how good is that feeling? Well, I'll transfer them to you separately. The--s terminal is born, the luminance information and the chromatic aberration information transmits separately. But the S-terminal so many pins, specifically which pin transmits the brightness information, which pin transmits the color difference information? This, landlord now do not understand, because, now use the S terminal machine and very less. However, in the later article, the S terminal will appear, he will be the protagonist of another world, but in the camera series inside, he is not the protagonist, in the later display series inside, there will be a topic, in you can not buy s terminal or the S terminal is too expensive, How to manually create an interface that converts the S-terminal into an AV line!!!! There, the S-terminal will be the protagonist in the main character.

Speaking for a long while, I do not know if you have already know how to put the camera to the TV? Give me a definite answer--tell me, you already know very well how to answer! But in order to reduce the number of complaints, I would like to say again how to answer: The video signal of the camera to the end of a yellow TV festival (normal is this way, but if your home TV is fully customized, then we also do not talk), the edge will be labeled video words of the cut, put them up!!!! Into!!! OK, then give the camera and TV power!!! Ok!!! Your 50 ocean-made video surveillance system is ready-but I'm sorry, this shoddy surveillance system is a lot more expensive than a TV.

The purpose of this is to talk about how the inverse of the transmission protocol is in a line inside the huge video of the transmission out, the speech is still vague, it is estimated that you can be blindfolded.

If not, please look forward to the next update-hand-held camera: I know what you say

The system of the surveillance camera-the existence of the inverse day