MTL - The Science Fiction World of Xueba-Chapter 436 Prototype

"Brother Pang, Brother Pang, what's wrong with you?"

Seeing Pang Xuelin lost in thought, Liu Fatzi curiously.

Pang Xuelin shook his head and smiled: "It's all right, Brother Liu, when are we going to Shencheng?"

It is May 20th. There is still more than three months before Wan Yan launched the VCD player in September, and he has to get the patent of the VCD player within three months.

In addition, the first start-up capital needed to open the factory has to be earned.

As for how the money came, it depends on the next trip to the deep city.

Liu Qi said: "I'll arrange it for you first. Without a border card, I can only find a snakehead to cross the second line. I have to find a reliable one. It takes at least two or three days."

Pang Xuelin laughed: "Brother Liu, please trouble you!"

At noon, the nanny made a Cantonese-style morning tea for everyone. Pang Xuelin had tasted Cantonese food in the afterlife, but didn't find it special.

It is Mu Donglai and Mu Qingqing, who have been living in the northwest, and they are very strange to this pure Cantonese cuisine.

Crystal shrimp dumplings, chicken feet, pork ribs, pork belly, fish fillet, intestines, etc., both of them praised.

After lunch, in the afternoon, everyone looked at the LD player in the living room.

Various old-fashioned Xiangjiang films, "The True Colors of Heroes", "The Story of Alang" and so on, have made Pang Xuelin experience the feelings of Hong Kong films after the 1980s.

Mu Qingqing, Mu Donglai, and Liu Fatty all looked with great interest. Pang Xuelin was not interested.

After he was ninety-five years old, he remembered that Hong Kong films had already faded. In addition, the later era of the mobile Internet has greatly improved the aesthetics. Although these films are classic, they are no longer in line with Pang Xuelin's taste.

Early the next morning, Liu Fat and Mu Dong went out.

Fat Liu said he would go to a friend and arrange for Pang Xuelin to pass.

As for Mu Dong, he went out to visit friends from Sun Yat-sen University.

"Big brother, we are fine today. Would you like to hang out?"

Mu Qingqing changed into a chiffon short-sleeved dress and stepped on small leather boots. The black hair was tied into two beautiful tresses, which extended from the foreheads on both sides to the back of the head, looking clean and beautiful.

This girl also belongs to Bai Fumei in this era. She came from a family in Kochi. She was a strict tutor since she was a child. She has a simple personality and has not experienced any twists and turns. She is also a typical life winner.

Pang Xuelin was very clear about Mu Qingqing's mind, but he didn't care too much.

He is very clear that he will leave the earth sooner or later, so in this world, Pang Xuelin did not fall in love with the idea of ​​forming a family.

As for Mu Qingqing's feelings, in his opinion, it was more because of the psychological shock that suddenly appeared in front of her that night at her most desperate moment, thus creating some attachment emotions to herself.

Anyway, she will go to Xiangjiang to go to college next time, and over time, such feelings will gradually fade.

Looking at Mu Qingqing's expectant eyes, Pang Xuelin laughed and said, "Okay, where do you want to go?"

Mu Qingqing said with a smile: "Big brother, I will go wherever you go."

Pang Xuelin thought for a while, and laughed, "OK, let's go to Yangcheng Computer City today."

"Yangcheng Computer City?"

Mu Qingqing's eyes lit up.

In this era, digital products have just begun to show their light in the country. Regarding boys and girls, they are very interested in computers and the like. Naturally, there will not be a scene in which many girls in future generations do not feel digital products.

Not to mention, Mu Qingqing himself is a science bully.

The two went downstairs together, and Huang Mao, who was standing in the store, greeted him and nodded and said, "Lin brother, sister Qingqing, where are you going? I will send you over."

Pang Xuelin said with a smile: "Huangmao, do you know where Yangcheng Computer City is?"

Huang Mao froze slightly and said, "I know, Yangcheng Computer City is not far from here. Cross this road forward two intersections, turn right on Tianhe East Road and walk for ten minutes."

Mu Qingqing said: "Big brother, since it's so close, let's walk over and don't have to send it."

Pang Xuelin laughed: "That's OK, Huang Mao. If Professor Mu or Old Liu come back, you tell them that Qingqing and I have gone to Computer City."

"Okay! Brother, then you can walk slowly!"

Huang Mao looked envious at the back of Pang Xuelin and Mu Qingqing.

At this moment, behind him, another employee in Liu Qi's shop took the front road: "Brother Huang Mao, that's what you said, Qing Qing sister? Really pretty, that pretty boy is really blessed ..."

Huang Mao patted his head and said, "Smelly boy, don't think about it, do you know who Liangzi is?"

"who is it?"

Huang Maodao: "Have you read the news over Xiangnan over the past two days? It said that the police destroyed a group of railway car bandits and seized a lot of guns and axes."

The young man curiously said, "Brother Huang Mao, what's wrong with this? Is it related to that pretty boy?"

"Do n’t scream at Liangzai. When you saw him calling Lin, the robbers were the ones who packed them up. I heard that there were more than a dozen people when they robbed on the train. Brother Lin was killed alone. "

"real or fake?"

"Then there can still be fakes, all of which the boss sees with blue eyes, otherwise why would the boss stagnate others."

"Hey, you're right!"

...

Pang Xuelin naturally did not know that he had become the object of Huang Mao's gossip.

He and Mu Qingqing strolled on the streets of Yangcheng. Mu Qingqing jumped up and down, happily like a lark.

Many people passing by have set their sights on the boys and girls.

Although Mu Qingqing is the focus of attention, Pang Xuelin, wearing a simple T-shirt jeans, is not inferior.

Pang Xuelin was not bad at all. Coupled with the experience of many worlds, the whole person has a touch of scholarly temperament and a wild charm.

Otherwise Mu Qingqing would not fall in love with him at first sight.

After all, love at first sight in any form is nothing but gratification.

If Pang Xuelin grows up like Liu Fatman, Mu Qingqing is most grateful to him, instead of the whole person's tendency to fall into it.

In front of the Computer City, Pang Xuelin did not see the crowded and crowded scene of the Digital City before the rise of e-commerce in the future, but it seemed a bit deserted.

Yangcheng Computer City was established not long ago. It is the pioneer of the digital professional market in South China. It contains the maintenance department of various digital product brands and various compatible machines, electronic spare parts, genuine software, consumables and so on.

After the two went in, Pang Xuelin did not go straight to the brand stores set up by computer brand manufacturers, but instead walked around in it, then stopped in front of a relatively small electronics consumables store.

"Big brother, are you buying a computer?"

Mu Qingqing was curious.

Pang Xuelin smiled and shook her head, saying, "I'll buy some parts."

Then, he stepped forward and said to the owner of the supplies store who was sitting idle at the counter: "Boss, do you have a CD-ROM drive?"

The boss froze slightly, wondering, "Boy, what do you want that thing for?"

Pang Xuelin laughed: "My computer's CD-ROM drive is broken, I'm going to replace it myself."

The boss groaned for a moment and said, "Yes, yes, but the price is not cheap, it is more than five hundred. If you change it yourself, if it is not successful, I will not return it."

Pang Xuelin said with a smile: "Relax, I will install it myself. In addition, if you have pen and paper, I still have a list of parts, including DSP chips, diodes, transistors, resistors, capacitors, power transformers, and some small ones. Servos, etc ... "

The boss froze, found a pen and paper and handed it to Pang Xuelin, curiously, "Boy, what do you want these things to do?"

Pang Xuelin said with a smile: "Do a small experiment."

Next, Pang Xuelin didn't say much. He wrote a series of dense lists on the paper and gave them to the owner of the supplies store.

The owner of the supplies store is a bit surprised. Many of the above things are only known by more professional electronic engineers. Some of them are not very familiar with himself. Who is this teenager who looks like a high school student?

Seems to see the curiosity of the owner of the supplies store, Pang Xuelin said with a smile: "I am a graduate student in electronic information engineering at Sun Yat-sen University, and by the way help my mentor buy something."

"It turned out to be a talented student of Zhongda University."

The owner of the supplies shop was immediately relieved and said with a smile: "Jiangzi, the parts you listed are about 1,200 yuan in total. I do n’t necessarily have some parts here. So, you pay 500 yuan first. Deposit, pick it up tomorrow, can I help you get it all together today? "

"no problem!"

Pang Xuelin laughed and quickly took out five hundred dollars to the boss. The boss wrote a receipt and a bill of return to Pang Xuelin.

Twenty minutes later, Pang Xuelin and Mu Qingqing came out of Computer City, and Mu Qingqing was still a little dazed.

"Big brother, what do you buy these things for?"

Like the boss, Mu Qingqing couldn't understand Pang Xuelin's purpose.

Pang Xuelin laughed and said, "Make a small toy, I can't say clearly for a while and a half, you will know it in two days anyway."

"Oh!"

Mu Qingqing nodded, seemingly understand.

Pang Xuelin felt mysterious to her.

An orphan who was born with a strong fighting force, handsome and extraordinary, and all kinds of insights are scary, even his father, a university professor, was amazed at him.

Therefore, for Pang Xuelin's knowledge of so much electronics, Mu Qingqing, although he did not want to understand, was relieved soon.

Anyway, Pang Xuelin has omnipotent existence in her mind. Is it strange to add a few new skills?

Pang Xuelin naturally did not know what Mu Qingqing was thinking, and he was going to make a VCD prototype.

In fact, after the emergence of MPEG technology, VCD technology has become fully mature.

The so-called MPEG refers to image compression technology.

Before the emergence of MPEG technology, the amount of digitized video image data was very amazing. If the original video image data is not compressed, it can only store 20 seconds of medium-resolution color digital data on a 650 megabyte 12 cm disc Video image.

The MPEG technology can compress and encode 30 or 25 frames per second of moving video images and its stereo audio signals into a CD, making a VCD with the same size as an ordinary CD. It can continuously play a video program of 74 minutes. Its image quality is much better than that of VHS video recorder, and the sound quality can reach the effect of CD laser sound.

The reason why MPEG image compression can be achieved is because the original image has a large degree of information redundancy, such as television images. There is a large spatial correlation between adjacent pixels of such images, and there is also a very high Great time correlation.

The MPEG compression algorithm first preprocesses the video image with a resolution of 704 × 408 or 704 × 576 as recommended in the CCIR601 standard. The compression is to reduce the horizontal and vertical pixels by half and become a SIM of 352 × 240 or 352 × 288. Image format.

Subsequently, the two main techniques of discrete cosine transform and motion compensation are used for further compression.

The discrete cosine transform technique based on 8 × 8 sub-blocks can reduce spatial redundancy, and the 16 × 16 fast motion compensation technology can reduce temporal redundancy.

Discrete cosine transform for the inter prediction error can achieve the purpose of further compressing the data.

At the same time, the MPEG compression standard also takes advantage of the physiological characteristics that the human eye is sensitive to image brightness information and not sensitive to color information. A double brightness sampling scheme is adopted, which means that for every four-bit brightness value, only two-bit chroma values ​​are generated. .

In the end, this algorithm can obtain a data compression ratio of one-fifth to two-hundredths.

In addition, this algorithm also uses the basic principle of acoustic psychology, that is, the audio of some frequencies cannot be heard when the audio of other frequencies appears, which is the shielding function of the human ear.

In this way, the MPEG audio compression system can remove those redundant audio signals that are completely or substantially inaudible to those people.

It can make the compression ratio of the audio signal with a sampling frequency of 44.1k Hz reach 1/8, and there is no obvious distortion of the sound quality. It is difficult for ordinary users to distinguish the difference between the sound quality of the MPEG system and the standard CD.

At present, the international MPEG compression technology has been fully mature, and the rest is how to write video information into a CD disc and decode it again to convert it into a video signal for broadcast on TV.

The two core technologies needed here ~ www.novelbuddy.com ~ one is the laser reading probe technology commonly used on CDs, and the other is the video decoding chip technology.

At present, the laser reading probe technology is mainly in the hands of two giants, Philips and Sony. This is why Pang Xuelin bought a CD-ROM drive because it has a laser reading probe on it.

In future generations, there are many DIY fans on the Internet who have converted CD-ROM drives into VCD players.

The principle is that the signal picked up from the VCD by the laser head assembly on the optical drive is processed by the digital signal processing chip DSP, and then the RF signal is output from its RF RF pin. , Output video and audio signals.

The only trouble is that there is no dedicated video decoding chip for VCD.

Pang Xuelin can only use a variety of small integrated circuits to temporarily design a video decoding chip to output video signals.

That's why he bought so many small electronic components.

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