No~~!!!!!

Dolby and DTS sound effects are one of the sound compression formats. MP3 is also one of the compression formats. CDs sold in the world The so-called DTS and Dolby sound effects on the disc are all deceiving! ! !

Dolby technologies commonly used in homes mainly include Dolby noise reduction systems and Dolby surround sound systems. Attention! ! It's the system! ! It refers to hardware equipment! ! !

The following are reference materials from Dolby Encyclopedia

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Dolby Overview

Dolby is the Chinese translation of Dr. R.M. DOLBY from the United Kingdom. The Dolby Laboratory he established in the United States has successively invented many technologies such as the Dolby noise reduction system and the Dolby surround sound system, and has had a profound impact on movie audio and home audio. Huge impact.

Dolby technologies commonly used in homes mainly include Dolby noise reduction systems and Dolby surround sound systems.

Dolby noise reduction system is mainly used to reduce the noise of recording or playback. It has been widely used in home recorders in the 1970s. At that time, we often found symbols marked on many recorders and original music tapes, which meant that the machine had Dolby noise reduction function, and the tape used Dolby noise reduction function. Recorded with noise reduction. Of course, this kind of audio tape can only achieve satisfactory noise reduction when played in a recorder with a Dolby noise reduction system.

Dolby Surround Sound System is a cinema sound system successfully developed by Dolby Laboratories in the United States to improve stereo sound quality. In a stereo cinema, in order to create an immersive spatial feeling for the audience, in addition to the left and right channels, a center channel that can enhance the sound effects on the screen and a surround channel that can allow the audience to feel the ambient atmosphere and special effects are also installed. vocal channel. This surround sound channel uses a number of loudspeakers arranged in parallel along the side walls and the back wall. Since direct multi-channel recording and transmission is expensive and inconvenient, Dolby Laboratories invented the Dolby Stereo movie system in 1976, which reduces the noise of the information from the left, center, right and surround channels in a certain way. Compiled and recorded into two channels. During playback, it is restored to four channels (i.e. 4-2-4 mode) in the opposite way, thus achieving compatible transmission of multi-channel and two-channel. In the "Star Wars" filmed in the late 1970s, the Dolby Surround sound system successfully synchronized the sound direction with the movement of the picture, allowing the audience to feel the direction and presence of the sound whizzing overhead, which aroused the attention of the film industry. vibration, so this system later became extremely widely used in movie theaters.

In order to enjoy effects similar to those in a movie theater in ordinary families, Dolby Laboratories has simplified and condensed the "Dolby Stereo Movie System" and successively launched the "Dolby Surround Sound System" and "Dolby Pro Logic Surround Sound System." The Dolby power amplifiers we often talk about now mostly refer to AV power amplifiers with "Dolby Pro Logic Surround" decoders and certified by Dolby Laboratories.

DOLBY Pro-Logic Surround is a second-generation home audio-visual surround sound system that has been improved on the first-generation "Dolby Surround System" and was released in 1987. From the late 1980s to the present, it has been widely used in recording sound effects of film and television programs such as video recorders, LDs, and VCDs. Of course, its decoding system has naturally been incorporated into AV amplifiers. The system has four channels, left, right, center, and surround, and adopts a specially designed directional enhancement circuit, which can make clever and adaptable adjustments to the relative strength of each channel according to the actual situation of the program signal. The sense of sound image positioning, direction, movement and reproduction of the original sound field are greatly enhanced, truly realizing the "theater" effect in the home. As a result, Dolby amplifiers have become the first choice for people to build home theaters. Of course, a disc with Dolby Pro Logic surround sound must be used in conjunction with a Dolby amplifier to achieve the desired effect.

Although Dolby Pro Logic Surround Sound has reached a high level of performance, it still cannot get rid of the limitations of analog technology. With the increasing maturity of digital technology, in order to meet the requirements of the next generation of television broadcasts, in 1994, Dolby Laboratories and Japan's Pioneer Corporation released a new digital system based on Dolby Prologic Surround Sound. Multi-channel film and television sound system: AudioCoding-3, named AC-3 based on its prefix. In 1997, it was renamed Dolby Digital: DOLBY DIGITAL. It can be equipped not only in movie theaters, but also in home theaters.

Dolby AC-3 is a compression/decompression system. It uses advanced digital compression technology and applies Dolby's original special technology to compress and encode the completely independent six channels (5.1 channels) of left, right, center, left surround, right surround and super bass into two Sound track, recorded on film or video disc. During playback, it is restored to six channels through the decoder for playback. In order to achieve wide dynamic range, high signal-to-noise ratio, high separation, and ensure signal fidelity, each channel is first recorded in a completely independent way, and then compressed and encoded. When compressing, Dolby Laboratories uses the basic principles of sound psychology to keep it quiet when there is no signal, and when there is an audio signal, it uses a stronger signal to mask the noise within the hearing range and delete what is inaudible to the human ear. or the signal part with similar frequency but small and negligible volume. In this way, the content that needs to be processed is greatly reduced, allowing AC-3 to achieve high digital audio compression efficiency, but still giving people an extremely complete and realistic feeling.

The AC-3 system is compatible with the Dolby Pro Logic surround sound system, and its effect is superior to that of THX. Future home theaters should use Dolby AC-3 as the mainstream system.

Dolby Laboratories

DOLBY

Dolby Laboratories was established by Dr. Ray Milton Dolby. Dr. Dolby was born in Portland, Oregon, in 1933, and grew up in the San Francisco Bay Area. When he was still in high school at the age of 16, he started working at Ampex Company. The company was one of the first manufacturers of tape recording equipment in the United States. Later, he was responsible for developing the electronic circuit portion of the company's world's first practical video recorder.

Dolby graduated from Stanford University in 1957 and received a Marshall Scholarship from the University of Cambridge in England to study long-wavelength X-rays. In 1961 he received his PhD in physics. In 1963, he accepted a United Nations appointment to serve as a consultant to India for two years.

As an amateur recording enthusiast, Dr. Dolby has recognized for many years the damage to recording quality caused by background noise when recording audio or video signals on tape. While in India he began thinking seriously about a way to reduce noise without compromising the quality of his recordings. These explorations of his became the basis for the later Dolby A noise reduction, B noise reduction and C noise reduction systems.

After returning to the UK in 1965, he established his own laboratory in London to implement the solutions he had thought of in India. In 1968, a company named "Dolby Laboratories" was established. Although the company's first 10 years of existence were centered in the United Kingdom, it has always been an American company. After 1976, the company's main work moved to San Francisco.

In 1965, the first Dolby Type A noise reducer (A stands for Audio) was produced. The system is designed to target a variety of audio noise reduction applications, particularly the noise produced by tape recorders when recording master tapes in the studio. By 1966, several noise reduction techniques had been developed, but they all somewhat compromised the quality of the recording. So the difficulty Dr. Dolby faced at that time was how to convince industry insiders and potential customers of his technology. At that time, multi-track recorders, from 4-track, 8-track, 16-track to 24-track, began to be used. When the multi-track recorded tapes were mixed, the noise level of the mixed two-track master tape was higher than that of the two-track direct recording. The master tape is much higher.

In January 1966, the British department of Decca Records believed that the Dolby A-type noise reducer could indeed function as described by Dr. Dolby, so it ordered 9 Dolby A301A type noise reducers. , was first used in a recording of some of Mozart's piano concertos performed by Ashkenazy in Vienna in May 1966. In November 1966, Decca released the first recording using Dolby Type-A noise reduction - Mahler's Second Symphony conducted by Soldi.

Subsequently, the recording industry began to recognize and use Dolby Type-A noise reduction systems extensively. At first, it was only used to record classical music. When multi-track recording technology was promoted, it became more widely used. Soon, professionals and non-professionals around the world began to associate "Dolby" with high-quality recordings.

As the desire to use the noise reduction technology invented by Dolby in civilian tape recorders continued to rise, at the urging of KLH Company, an American commercial tape recorder manufacturer, in April 1967, the Dolby Experiment The studio began developing a more practical noise reduction technology for civilian use, initially called the "Simplified Dolby System" and later becoming the widely known Dolby Type B noise reduction technology. When the development of Dolby B noise reduction technology was nearing completion, Dr. Dolby made the decision that Dolby Laboratories would not produce civilian audio products, or consumer electronics products, but would instead license Dolby's technology to manufacturers, and then use the already mature Manufacturers carry out application production. By the end of 1974, Dolby Laboratories had 47 authorized manufacturers, including all major manufacturers of consumer audio equipment.

Since then, Dolby Laboratories has developed a series of technologies: C-type noise reduction, SR (spectral recording), S-type noise reduction, HXPro, Dolby Stereo, Dolby Surround, Dolby Pro Logic , AC-1, AC-2, Dolby Digital (AC-3), Dolby E. These technologies are widely used in professional and consumer audio equipment, movie recording, theater playback equipment, digital broadcasting, etc.

In addition to its headquarters in San Francisco, Dolby Laboratories currently has branches or liaison offices around the world: Los Angeles, Wootton Barsay (UK), London, Brisbane, New York, Tokyo , Shanghai, Beijing, Hong Kong.

Dr. Dolby

Ray Milton Dolby was born in Portland, Oregon, in 1933, and grew up in the San Francisco Bay Area. When he was still in high school at the age of 16, he worked part-time at a company called Ampex. The company was one of the early manufacturers of magnetic tape recording equipment. At that time, the magnetic tape system, which had been brought to the United States from Germany after World War II, was still a new thing. But the biggest drawback of tape recorders is the annoying hissing noise. These noises are caused by friction when magnetic particles pass through the playhead, and there seems to be nothing people can do about it.

In 1957, Dolby received a bachelor's degree in electrical engineering from Stanford University, and then applied for a Marshall Scholarship to study at the University of Cambridge in England, where he studied long-wavelength X-rays. In 1961, he received his PhD in physics. In 1963, he served as a technical adviser to the United Nations and worked in India for two years.

While in college, Dolby still worked for Ampex. An amateur recording enthusiast, he began thinking seriously about a way to reduce noise without compromising sound quality while in India. Through research, he learned that human hearing is actually very "lazy". When two sounds, one large and one small, exist at the same time, the human ear will "hear but not hear" the quieter sounds. For example, if the neighbor's dog barks outside the house, we turn up the sound in the house so that the dog barks no longer. When taking a shower, the sound of running water will also prevent us from hearing the ringing of the phone. What if things were the other way around? What if the sound of the phone drowns out the sound of the water? Dolby realized that if the recording sound source greatly exceeded the tape noise, the noise would be negligible. Extending this idea, if you increase the signal strength of a silent track in a recording, you can make the tape noise "disappear" from our hearing during playback. The specific method is that through a mirroring process, Dolby designed a circuit device that can restore the mute signal that was enhanced during recording to normal levels during playback, thereby reducing noise.

In 1965, he returned to the UK and established his own laboratory in London to implement the solution he had thought of in India. In 1968, a company named "Dolby Laboratories" was established. After 1976, the company's main work moved to San Francisco. In 1965, the first Dolby Type-A noise reducer came out. This system is a great solution to the noise produced by tape recorders when recording master tapes in the studio. In 1966, Decca Records used Dolby noise reduction for the first time to record Ashkenazi playing Mozart's Piano Concerto in Vienna. At the end of 1966, Decca released the first record recorded with Dolby noise reduction - Mahler's "Second Symphony" conducted by Soldi.

What really brings Dolby technology to the masses is the Dolby B noise reduction system. It is widely used in home tape recorders and walkman products. When the development of Dolby B noise reduction technology was nearly completed, he made the decision that Dolby Laboratories would only focus on technology and not be involved in production. By licensing Dolby's technology to manufacturers, other professional manufacturers would then apply and produce it. Dolby and his lab built their business model on patents and technology licensing. This was quite avant-garde 30 years ago and set a precedent for many companies to follow in its footsteps.

Dr. Dolby’s technology-first concept is also reflected in the company structure of Dolby Laboratories. Ke Jieming, chief representative of Dolby Laboratories Shanghai office, told the author in fluent Mandarin that technical talents come first, and there are very few non-technical employees like him in the company. Only recently, due to the company's expanding business and the need to go public, has the proportion of non-technical personnel in the company increased slightly. Ke Jieming said that although Dr. Dolby is no longer on the front line of technology research and development, he still maintains a strong interest in technology research and development. He would quietly walk into a technical meeting of the company, sit inconspicuously in the back and listen to others' speeches, and finally stand up and express his own opinions. "The recording industry is the first big market for noise reduction technology, and movies will be next." Dr. Dolby later said when reviewing his technical decisions. In the 1970s, Dolby introduced cinema sound processing equipment into the cinema industry, and film sound effects technology became another major research and development area of ??Dolby. With the global release of "Star Wars: Episode III - Counterattack of the Sith", Dolby's recently launched Dolby Digital Cinema system has been put into use in some theaters around the world.

In the process of transitioning to digital technology, Dolby Laboratories' most successful step is to combine cinema sound technology with home applications. Through nearly free technical support and cooperation with upstream film companies, most current film productions use Dolby Laboratories' digital audio technology. At the same time, Dolby Digital Audio technology has become the international standard for digital TV and DVD in the future. Basically every DVD player has Dolby Digital decoding function. Therefore, DVD player patent fees have become Dolby's main source of profit.

Dolby's stock surged 35% on the first day of its listing in the United States. Dr. Dolby, the 71-year-old company founder, sold $300 million worth of stock, ending Dolby Laboratories' nearly 40-year history as a private company. The listing of Dolby Laboratories was also a last resort. Because Dr. Dolby is old, if he leaves Dolby Laboratories as a private company to his descendants after his death, according to U.S. law, his family will have to pay a huge estate tax that is enough to bankrupt the company. Going public can solve this problem.

Technical strength and forward-looking research and development are the core competitiveness of Dolby Laboratories. said Ke Jieming, Chief Representative of Dolby Laboratories Shanghai Office. So, what kind of next-generation sound technology is being researched at Dolby Laboratories? Who are Dolby Laboratories’ opponents? Ke Jieming smiled and replied that of course the company has new technology research and development, but even I don’t know the specific content. As for real competitors, it can be said that there are none at present. Because, after all, most of the top experts in the audio field have been recruited by Dr. Dolby in his laboratory.

When Dr. Ray Milton Dolby founded his company in 1968, Dolby Laboratories was just a small company dedicated to "noise reduction" technology. Today, Dolby Digital technology is one of the world's leading The most advanced audio coding system has pervasively affected everyone's life. Dolby Digital technology, originally designed for professional cinemas, has been transplanted into home theater systems, and consumers can also enjoy stunning sound effects in their living rooms. The digital TV wave that is sweeping the world is also inseparable from Dolby Digital technology. The United States, the European Union, Australia and other countries and regions almost all regard Dolby Digital as the first choice for the audio part of their digital TV transmission standards. Not only that, Dolby's latest Dolby Pro Logic II technology turns car audio into a flowing melody, and Dolby Headphone technology can give traditional headphones a surround sound effect.

Dolby technology has become a part of people's lives. Without it, even the sound world would become monotonous.

Dolby Certification

Dolby began cooperating with Chinese cinemas in 1982. In 1998, it established a representative office in Shanghai and began to provide authorization certification for the use of Dolby technology in China. Currently, almost every Chinese company that produces DVD products is using Dolby technology, and the "Dolby" trademark is marked on almost every DVD product in China.

In fact, Dolby not only provides technical certification services in China, but also relies on its nearly 40 years of technology accumulation to provide Chinese companies with a complete set of audio technology solutions, helping Chinese companies develop new products and expand New markets. Xinke Mobile DVD with built-in Dolby Headphone technology is a classic example of cooperation between Dolby and Chinese companies. Mutually beneficial cooperation and interdependence are Dolby’s philosophy in China.

Dolby not only provides a full set of audio technology services to Chinese companies, but Dolby will also help Chinese companies enter these markets. This is Dolby's recent development strategy in China. In fact, many consumer electronics products around the world use Dolby audio technology, and Dolby certification has become a necessary passport for companies to enter the international market. According to incomplete statistics, Dolby Digital technology has been used in at least 600 million consumer electronics products, including more than 55 million digital TVs and set-top boxes, more than 230 million DVD players and more than 39 million A 5.1 home theater system. Already, 58 major television stations around the world have upgraded their programming to Dolby Digital 5.1 audio.

Dolby Laboratories firmly believes that being able to provide 5.1-channel audio is crucial for any new consumer transmission format, and is suitable for DVD-Video, DVD-Audio, game consoles, and personal computers. Computer 5.1-channel audio systems have been widely recognized by consumers.

Dolby Applications

Multiple international standards have chosen Dolby Digital

The reason why Dolby can be widely used in various consumer electronics products and TV stations , cinemas and other fields, the key is that Dolby Digital technology has become the standard of various international industry organizations or enterprise alliances.

Dolby Digital technology was first selected as a standard by the Advanced Television Systems Committee (ATSC) in the United States. Dolby Digital has since become an International Telecommunications Union (ITU-R) standard. At the request of broadcasters in Australia and other countries, the European Digital Video Broadcasting Organization (DVB) included Dolby Digital in its standards in 1999. Equipment with built-in Dolby Digital decoders and digital TV broadcasters using Dolby Digital audio All outputs comply with DVB standards. Of course, the World DVD Forum also uses Dolby Digital technology as the audio standard for its DVD products.

Dolby Laboratories has made commitments to ATSC, ITU-R and DVB organizations to provide open and fair certification authorization. Due to the high degree of integration of the decoding chip, the cost of Dolby Digital decoding circuit application is almost negligible. In return for a modest royalty cost, Dolby Laboratories provides patent details and practical expertise (know-how) to consumer device manufacturers.

Working closely with Dolby enables these manufacturers to produce working products as quickly as possible, thereby significantly reducing development costs and shortening the time for new products to enter the market. The Dolby trademark on products is considered a symbol of high quality and reliability by consumers around the world, adding value to DVB products, especially retail set-top boxes that are very price-sensitive.

Dolby Digital has become the strongest driving force for car audio

Dolby ProLogic matrix surround technology can replace Dolby Digital audio (such as video tapes, analog TV broadcasts and Get a surround sound effect from a stereo source such as a music CD). Dolby Pro Logic II and Pro Logic IIx also enable multi-channel surround sound effects from all stereo programs without the need for special encoding. Similarly, after encoding games and broadcast programs, special directional effects can be obtained through the decoding function of Dolby Pro Logic II. Recently, Dolby Pro Logic II and Pro Logic Iix technologies are developing in the field of car audio.

ProLogicII's natural surround sound makes it perfect for use in car audio systems. Whether you are listening to FM radio, cassette tapes, CD records or MD discs, ProLogic II allows you to drive your car surrounded by five channels of sound. The ProLogic II decoder can be added to an existing car audio system (such as an FM radio/CD player) or used as a separate processor.

When you have a ProLogic II system in your car, you can enjoy a three-dimensional and natural sound image effect through its left, center, right and surround speakers, instead of just hearing the sound like many car audio systems. The horn is blaring. At the same time, some ProLogic II systems also provide sound field adjustment functions such as center channel width control, space control, and panoramic control. Using these functions, you can make special optimization adjustments according to your personal preferences.

Dolby Laboratories has become part of the car audio system since the promotion of Dolby B-type noise reduction technology in cassette players more than 30 years ago. Now, Dolby Laboratories is creating a new era of automotive entertainment equipment. You may have experienced the shocking sense of envelopment brought by surround sound in movies or at home, and today you can also experience it in car entertainment systems equipped with Dolby Surround ProLogic II, DVD, and even Dolby Headphones. It has the same shocking effect as in the theater, and some people vividly call it a "flowing melody".

Through the development of Dolby Surround ProLogicII, Dolby Digital, MLP Lossless compression (MLPLossless?) technology and Dolby Headphone technology, Dolby Laboratories has become the leader in this high-quality automotive entertainment The strongest driving force for equipment innovation.

Statistics

Certified products:

Certified products sold 1,499,475,600

Surround sound decoders sold 135, 365, 300 Pro Logic II decoders sold 15,000, 560

Products containing Dolby Digital (AC-3) sold 606, 690, 060

3,721,800 products containing AC-2 have been sold

3,618,880 products containing AC-1 have been sold

DVD products:

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DVD-Video player with Dolby Digital 234, 907, 200

DVD-ROM with Dolby Digital for PC 273, 540, 900

Other data:

·Dolby video can be mixed in 50 countries.

·170 distributors of cinema products in 61 countries. There are 52 distributors of professional audio products in 33 countries.

·Today, Dolby Laboratories has cooperative relationships with 1,821 certified media, 204 certified chip manufacturers, and 378 certified system (hardware) manufacturers in 50 countries.

·Dolby Laboratories was granted 731 patents in 27 countries and received 777 patents in 96 countries.