Technical/process specifications
VCD is a video standard for full motion and full screen playback. Its format can be divided into:
The resolution is 352x240 pixels, with 29.97 pictures per second (suitable for NTSC TV);
The resolution is 352x240 pixels, with 23.976 pictures per second;
The resolution is 352x288 pixels, with 25 pictures per second (suitable for PAL TV).
Overall, the resolution is about a quarter of that of the corresponding TV system. The video of VCD adopts MPEG- 1 compression coding, and the audio adopts MPEG- 1/2Layer 2 (MP2) coding. The bit rate of video is 1 150kbit/s, and the bit rate of audio is 224kbit/s. The whole video quality is equivalent to VHS video tape.
Because the bit rate of VCD is comparable to that of ordinary music CDs, a standard 74-minute CD can store about 74 minutes of video in VCD format.
VCD standard
There are three formal standards for VCD: 1.0, 1. 1 and 2.0:
1.0: original version.
1. 1: revised version.
2.0: Playback menu function (PBC), clear still picture playing function (704x480 or 704x576 pixels) and support for 352x288/25fps format have been added.
(3.0: Many people say that there is version 3.0, but the finished product has not yet been produced. )
VCD application
VCD is widely used in Asia. In Hong Kong, VCD and DVD have completely replaced video tapes and laser discs in the distribution market.
VCD is thought to be replaced by DVD, but it will remain in the market for some time due to its characteristics.
VCD doesn't have area code restrictions like DVD, which means it can be watched on any compatible machine.
Because of the cost, some programs will not produce DVD or VHS video version, and buyers can only buy VCD version.
VCD is cheaper than DVD, and the production cost is lower. Of course, VCD lacks many extra functions provided by DVD, such as subtitles, powerful menu functions (for making tidbits) and so on.
[Edit this paragraph ]SVCD
SVCD is an improved standard of VCD, which adopts MPEG-2 compression and variable compression rate to obtain better video quality.
It is as big as an ordinary CD, and there is no difference in structure, except that it stores movies and TV programs, so it is commonly called "DVD" or "mini DVD" because it is smaller than the LD DVD used in CD players. Its audio and video playback quality is better than that of video tape, but slightly worse than that of large DVD. VCD discs can be played directly on VCD machines or on computers with CD-ROM drives.
[Edit this paragraph ]VCD file format
VCD format is usually MPG or DAT.
MPG is a format that the computer uses to save after editing.
DAT is a format after burning into a CD.
What is a VCD?
There may still be many people who don't know what VCD is. VCD is actually the abbreviation of video disc, which is a compressed image format. It uses MPEG- 1 compression method to compress images, and the resolution reaches 352 * 240(NTSC) or 352 * 288 (PAL)1.15mb/s video bit rate, and the sound format adopts 44. 1KHz sampling frequency and/kloc-0. ) mpeg-1layer2,224 kb/s audio bit rate compression method. With this compression method, even the professionally trained audition can't tell the difference between the sound quality after being restored to the music CD format and the original CD. In other words, this compression method is non-destructive compression.
Is the audio format of VCD MP3?
The correct name of MP3 is MPEG- 1 Layer 3. In the audio part of VCD format, although it is a compressed audio format, it is not the well-known MP3 music format, but the format of MPEG- 1 layer 2. So it can't be transcribed into music CD format. (Because most burning software only supports the function of converting WAV files and MP3 files into CDs. If it is really necessary to make the sound part of VCD into a music CD, you only need to use a sound card with a recording program to record it into a WAV file, and then use a recording software to burn the WAV file into a CD format, without an image acquisition card. (Windows's built-in recording program has a 60-second limit and cannot be used, so you need to use the public program attached to the sound card to record. ) MPEG- 1 Layer 1 and Layer 2 are compression processing methods specially designed for processing the audio format of VCD, and Layer 3 is the well-known MP3 music format. The compression mode of MP3 is audio bit rate 192Kb/s, and the rest is the same as the second layer. However, after being restored to the music CD format, if you listen carefully and compare it, you can hear that it has a slight distortion of the sound quality of the original CD. In other words, MP3 is actually a destructive compression method, so if you have a high demand for sound quality, MP3 is not your good choice. But relatively speaking, the file size of MP3 is only110 of WAV file with general CD sound quality!
Please pay attention to the size of the image file.
As far as a blank CD is concerned, the capacity is about 650MB-680MB, and the recorded music CD format can be put in 74 minutes, while the recorded VCD image can be put down for about 50-60 minutes. Therefore, if the length of your image exceeds 1 hour, please intercept it in segments to avoid burning to a blank CD beyond its maximum capacity. Most importantly, when shooting an image, you must pay attention to whether the image shooting format parameters you set are in full compliance with the VCD standard. As long as any one of them doesn't meet the requirements, the burned CD can't be played, so it is considered a failure.
Of course, the recent blank CDs are advertised as "super-long", with a capacity of 700MB, which is about 79 minutes when converted into a music CD format, while VCD images can be squeezed for nearly 70 minutes. However, in order to keep the image for a long time, the author still suggests that users should try not to burn it so full and leave some space in the outer ring, because the track of the outer ring of a CD-R blank disc is usually unevenly coated with dye (that is, the part that can be burned), and it is easy for you to touch the outer ring when you pick it up and put it, resulting in scratches or blurred surface, which will easily lead to unreadability after a long time.
Why can't the recorded VCD be played?
I believe this is a headache that many people will encounter: why can the images I made be played on the computer after being burned into a CD, but not on the VCD? In fact, most of the problems are in the "VCD compatibility parameters" option mentioned above. Because VCD has its strict format, and if the image format you make does not meet the standard of VCD, the VCD machine will not recognize the CD you burned, and of course there is no way to play it. From this, you can know that not all MPEG- 1 files can be burned into VCD! In addition, it is also possible that your VCD player "picked the disk"!
So complicated? ! How can I possibly remember so many parameters? !
Maybe you feel that paying attention to a lot of standard parameters makes you dizzy, but the author can't help but remind you. Don't say goodbye and make a fool of yourself. You can rest assured that most MPEG- 1 image acquisition cards have a considerate design: you only need to check the empty VCD box in the options before you start intercepting, and the system will automatically lock the relevant parameter options and forbid you to change them. With a mirror that meets the VCD standard, you can burn it into a VCD mirror CD. Isn't it convenient?
How to check whether the disc I burned is correct?
Here is a simple check secret to ensure that the burned VCD disc can be played on the VCD player. All you have to do is press the right mouse button to bring up the function menu, select "File Properties" and confirm that each data track is "Yes" in the "Compliance with Standards" item.
If your VCD player still can't read the CD after you confirm that it is "up to standard", but it can be played normally on a computer or other VCD players, then your VCD player will "pick the disk". You can try other brands of CD-R blank discs, or clean the VCD player with clean discs and try again.
What recording software should I choose?
You can burn with any recording program, as long as there is a standard template that supports VCD. Well-known burning software includes CD Maker, Nero, Win On CD, EZ CD Creator, Easy CD Pro… and so on. When choosing a burning software, you must also consider whether this burning software can "know" your burner (you can find the answer on the original website of each burning software. ) and most importantly, whether it can support the recording of standard VCD format. For example, burning a clone CD that players like can only be used for CD reproduction, and VCD burning is not supported! So even if you have this burning software, you can't burn VCD.
MPEG- 1 = VCD？ MPEG-2 = DVD？
Many people intuitively equate VCD with MPEG- 1 and DVD with MPEG-2, and think that the picture quality of MPEG-2 must be better than MPEG- 1, which is incorrect. Correctly speaking, VCD is only an image file generated by the compression method of MPEG- 1. Not all MPEG- 1 files can be made into VCD. Similarly, DVD is only an image file produced by MPEG-2 compression, and it cannot be said that DVD is equal to MPEG-2.
MPEG- 1 doesn't have to be made into a VCD, but it can also be played on a computer. MPEG-2 doesn't have to be made into a DVD, but it can also be played in a computer. Only in this way, because it is not the standard format of VCD or DVD, your VCD or DVD player will not know it, so it cannot be played. In fact, the reason why the quality of VCD is not good is that its video bit rate (video stream) is limited to 1. 15Mb per second when formulating standards, and it is not accepted to be higher or lower than this value, not because it adopts MPEG- 1 compression method.
Can the quality of VCD be improved?
Many people always think that DVD is of good quality. In fact, apart from commercial use, it is not the best choice to spend so much money only for personal interests. In contrast, although the prices of DVD burners and DVD discs are approachable now, DVD is far less popular than VCD. However, according to the standard of VCD, because it has been limited to the video bit rate of 1. 15Mb/s per second, the image quality can't be improved much no matter how hard you try. But if you don't have to make a VCD, MPEG- 1 files can also achieve good image quality, and you don't have to use MPEG-2 compression to get good image quality.
What are the advantages and disadvantages of doing so? The advantage is that the image quality is greatly improved, and the CD can be stored for a long time, so it is not necessary to stuff all files into the hard disk to occupy space. The disadvantage is that it can't be played on a VCD player, and the image length that a CD-R blank disk can hold will be greatly shortened (because the bit rate increases, the file will also become larger! Therefore, this method is very suitable for users who require high image quality but short image length, such as advertisers.
If you don't need to play it on a VCD player, you just need to play it on a computer, then why do you insist on the VCD format? Improving video streaming can greatly improve your image quality, and now the price of hard disk is also cheaper. The storage cost of the same video is much lower than that of the disc. Why not?
[Edit this paragraph ]VCD DVD player
In the early 1990s, the formulation and release of the standard algorithm of the International Organization for Standardization formed the starting point for the rapid transformation of data compression technology into new products in various industries, which triggered a revolution in film and television technology and brought modern household appliances into a new world of digital technology. The first VCD player in China was first introduced by Hefei Meiling Wanyan Electronics Co., Ltd. on 1993. VCD video player is a digital audio-visual product integrating optical, electrical and mechanical technologies. It is a combination of MPEG digital compression technology and CD technology. It is recognized by people for its low price, high cost performance and rich software programs. Although it is not as good as LD and DVD in image clarity and timbre, it has not affected its entry into ordinary families, but has become a hot spot in household appliances consumption.
VCD player is a new type of CD player developed after LD player and CD player. This is a digital audio and video signal player. The movement, laser head, servo circuit and digital signal processing circuit of VCD player are the same as those of CD player, but a set of MPEG decoding circuit and video D/A conversion coding circuit are added on the basis of CD player. Therefore, VCD players can play CDs and VCD discs. The picture quality played by VCD video player has a horizontal definition of 250 lines, which is equivalent to the picture quality level of VHS playback. In fact, because VCD video players use laser beams to read information, the optical disc and laser head are not worn, and the image quality will not deteriorate due to long-term use, so the image quality of VCD video players is better than that of home video recorders.
[Edit this paragraph] Maintenance and maintenance of ]VCD DVD player
First, shockproof. Although some brands of VCD machines have good shockproof performance, most VCD machines are not suitable for use in places with vibration, otherwise it will affect the laser scanning accuracy and seriously affect the sound and picture quality. Therefore, when using the VCD player, it is not advisable to move it frequently, let alone collide and impact it. Even when handling, handle it carefully to avoid affecting internal components.
The second is dustproof. The accuracy of VCD machine parts is improved. If dust enters the machine, it will make its parts work abnormally and even cause serious failures such as damage. Therefore, VCD players should be placed in a clean environment, and corresponding dust-proof measures should be taken. Dust removal should be carried out by means of hair dryer cold blowing or vacuum cleaner suction when the machine is stopped. Don't disassemble the machine frequently for dust removal.
The third is cold protection. In winter and spring when the temperature is low, if you put the VCD player in windward places such as doors and windows, it will inevitably be stimulated by the cold. This will make the VCD machine unable to work normally due to "cold", accelerate the aging of components, and thus lose its life.
The fourth is heat protection. VCD player is afraid of both cold and heat. It is best to put it in a cool and ventilated place, not in direct sunlight, close to heat sources such as stoves and heaters. Don't put the VCD machine on the power amplifier and voltage stabilizer, and avoid putting it on carpets, sofas and mattresses, so as not to hinder the heat dissipation of the machine.
The fifth is moistureproof. When VCD is wet, it is easy to blur the optical lens, and the laser beam cannot pick up the signal normally. Dewdrops or fog will be generated in the machine when the climate is wet or the weather changes suddenly. If used, the VCD player should be powered on for a few minutes, and then played. Keep the machine dry at ordinary times, and turn it on frequently in wet weather such as rainy season to drive away moisture. If the VCD machine is often wet, over time, the parts will rust and even the whole machine will fail.
Treatment of common faults of VCD player
1, it can't play normally after booting.
(1) CD is not clean. You can use VCD cleaner or soft cotton cloth dipped in pure distilled water to clean the CD, and then try again.
(2) The discs in the machine overlap, get stuck or slide out of the slot. Open the box, straighten the disc or take out the extra disc.
(3) If the ambient temperature is low and abnormal, you can start the machine while heating, and stop heating immediately after it is normal.
(4) There are foreign bodies on the laser head. You can clean the VCD player with a special cleaner, or open the shell and gently wipe the laser head with a soft cotton cloth dipped in pure distilled water. Be especially careful when operating, and ask professionals to repair it if necessary.
2. Suddenly out of control during playback.
(1) The button of the remote controller has not been reset, or the battery of the remote controller has failed. Check the remote control button or replace the remote control battery.
(2) The internal temperature of the machine is too high. It is caused by too long boot time or too high ambient temperature. At this time, stop and cool down before restarting, and use a fan to cool down if necessary.
3. Sudden stop during playback
(1) Poor contact between power socket and plug or power failure. Find out the reason and troubleshoot.
(2) Press the power off button by mistake. It should be restarted.
(3) Working in the playback timing state. Restart the machine and cancel the playback timer.
[Edit this paragraph ]VCD DVD player purchase
Pay attention to the size of discs (LD and VCD), and whether it is a CD player or a multi-disc (usually three-disc) player. A single disk drive is more economical, but multiple disk drives are more convenient. Compatible computers are a little more expensive.
(1) Pay attention to whether it has the functions of double microphone karaoke, digital reverberation, digital echo, tone change (language and tone change) and original sound canceller (multi-level noise elimination). It is a trinity of vision, hearing and singing, which is convenient and practical.
(2) See if there is a function of searching the program list. This function is the main symbol that distinguishes the modified car from the all-in-one machine. VCD players with this function all adopt the latest MPEG2.0 standard, which can directly display the program list on the screen. They are compatible with CDG, CD-DA and CD- 1, and are the most versatile models at present.
(3) Check whether there is PBC function. PBC is short for playback control. When playing 2.0 VCD discs, the machine with this function can realize man-machine conversation without a computer, and can insert high-resolution still images and enjoy VCD music in ordinary CD players. PBC function is an important symbol of VCD performance level.
(4) Check whether there is a system selection function. If you have this function, you can play NTSC movies on PAL TV manually or automatically. Otherwise, due to different formats, the image will be narrowed when playing. So this is also the most basic condition for purchasing.
(5) Check whether the S terminal has output. Large-screen color TV needs an S-terminal VCD player, and its high-definition characteristics will be shown.
(6) Pay attention to cost performance. The performance of foreign famous brand products is generally reliable, but the price is much more expensive than that of domestic products of the same grade; Some domestic films are good in quality, function, picture quality and sound quality, especially the error correction and playback of VCD- 10 old films, such as Anhui Wanyan CDK? 320, Shenzhen Xianke VCD- 10, etc. The price is much cheaper than that of foreign products of the same grade, so you should consider it when purchasing.
(7) Pay special attention to the model. Both imported and domestic VCD players should choose the models produced according to MPEG- 1 standard version 2.0, because the performance of VCD players produced according to brand specification 2.0 is much better than that produced according to 1.0 and1.
(8) Pay attention to the product origin and manufacturer. Imported machines must have instructions or certificates for commodity inspection and inspection; If it is a domestic machine, it must have a product certificate to confirm that it is a regular product. From the appearance, the formal product design is elegant, the technology is excellent, and the manual printing is exquisite and clear; The name, address and maintenance outlets of the factory are clearly introduced.
(9) Refer to the instructions in detail. Understand the technical indicators and various functions of DVD player. In addition to checking the above functions with instructions, we should also pay attention to multi-channel music selection, playback and memory, program pre-calibration, and wireless remote control. Displaying programs and high-definition freeze frames is an essential performance of MPEG- 1 Standard Edition 2.0. If the above requirements can be met, its performance is excellent. However, some VCD players have more than 15 functions, and there are single, three, five or even seven discs, which can be selected according to the actual situation and requirements of individuals.
There is a DVD series trial-produced according to MPEG-2 standard, which also uses 12cm diameter discs, and can record movies and TV programs with 130 minutes or more on one side, which is higher in definition than VCD and LD, but the technical feasibility and price have not met the appropriate requirements at present, so attention should be paid to it.
Finally, prevent inferior discs. They will overload the laser device, which will not only shorten the life of the laser device, but also easily damage the laser device, and the result is not worth the candle.
[Edit this paragraph]. Vcd file format
Virtual cd is a set of tool software for simulating real optical discs. It can create as many as 23 virtual cd or 1000 CDs, and compress the application software and data on the CDs into a virtual cd file (*. VCD) and store it on the designated hard disk, and notify the operating system after generating the virtual CD-ROM icon. This virtual cd can be used as a CD. Therefore, when you want to start this application after that day, you don't need to put the CD in the physical CD-ROM drive (it can be executed without a physical CD-ROM drive), and you don't need to wait for the CD-ROM drive to start slowly. Just double-click the virtual cd icon, and virtual cd will be loaded into the virtual CD-ROM immediately, which is quick and convenient. This version is multilingual, including Chinese, English and Japanese. When installing, the language version of the operating system will be automatically detected and installed.
[Edit this paragraph] The world's first VCD
When talking about VCD in China, we can't help but mention the once brilliant Anhui Wanyan Company, and even more, we can't help but mention its founder Jiang Wanmeng. In Anhui Modern Television Technology Research Institute, the reporter saw this legendary figure and the VCD player that still touches the eyes of the world. It sits quietly in the exhibition room of scientific and technological achievements that embodies the countless efforts of its owner, and its name is impressively written on a small cardboard made of printed paper-the world's first VCD machine.
1992, at the international radio and television technology exhibition held in the United States, an obscure MPEG (image decompression) technology exhibited by Gao Bai Company in the United States attracted the interest of Jiang Wanmeng, then general manager of Anhui Hyundai Group. He immediately intuitively thought that with this technology, images and sounds can be stored on one disk at the same time. Since then, Jiang Wanmeng has successively invested $570,000. 1September 1993, MPEG technology was successfully applied to audio-visual products, and a cheap audio-visual product, VCD, was developed. In 65438+February of the same year, he and Sun, a Chinese American, invested170,000 US dollars to set up Wanyan Company, and each took one of the names of Jiang Wanmeng and Sun as the company name.
In the 1993 VCD feasibility report of Anhui Modern Television Technology Research Institute, it is described that this is the only opportunity for China to take the lead in the field of consumer electronics at the end of this century. Therefore, Jiang Wanmeng conducted a series of market surveys, and got a series of figures: 1993 China, with the sales of 6,543.8+0.42 million sets of combined audio, 6,543.8+0.7 million sets of video recorders, 6,543.8+0.6 million sets of LD players and 6,543.8+0.6 million sets of CD players. At that time, the price of LD discs was four or five hundred yuan, while the price of VCD discs was only about 10%. Therefore, it can be predicted that the annual sales volume of VCD players will reach about 2 million units.
People in China didn't know about VCD until the end of 1994. This year, Wan Yan produced thousands of VCD players. Not only that, Jiang Wanmeng also wants to develop CDs, but he can't let ordinary people buy guns without bullets. To this end, he purchased the copyright from 1 1 audio-visual publishing house and distributed 97 kinds of karaoke discs. In less than a year after its initial establishment, "Wanyan" invested everything, created a market, established a famous brand, and formed a set of molding technology to dominate the VCD industry.
It can be said that Wan Yan's entrepreneurship is successful and brilliant. However, Wan Yan also brewed a cup of bitter wine for himself. What makes Jiang Wanmeng feel sad is that the first batch of 65,438+10,000 VCD players launched by Wan Yan were almost all bought by domestic and foreign home appliance enterprises as prototypes and became the objects of dissection.
Some people think that Jiang Wanmeng's biggest mistake is that he doesn't understand patent protection. When the reporter asked him about it, his answer was quite frank: "Under the circumstances at that time, I thought it was meaningless to apply for a patent. The key is to let the products occupy the market as soon as possible. "
Perhaps it is this difference that makes Jiang Wanmeng lose an excellent opportunity to lead the market, and at the same time makes China lose half of the country that should have taken the initiative in the development of this industry. Today, many years later, when the reporter asked him if he regretted it, he just smiled faintly, with a little helplessness, a little guilt and a permanent regret.
Jiang Wanmeng founded Wan Yan Shu and raised the banner of China VCD player. He should also be praised by Chinese people for this. But judging from the final outcome of Wan Yan, the rise and fall of Wan Yan is somewhat sad. If, when Jiang Wanmeng developed the first VCD player, he immediately applied for a patent; If the state invested 240 million at that time, the plan to make Anhui a national VCD production and development base became a reality; If we say ... the history of VCD development in China and even the world, maybe we should write it in another way-an epic of the main theme sung by China people!
Therefore, some people compare Jiang Wanmeng to a "revolutionary martyr" on the road of digital optical disc technology development in China.