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MP3: You can't stop the music ...

How MP3 went -- with a bullet -- from an obscure German compression technique to the music industry's current chart-topping controversy.
Written by Giancarlo Varanini, Contributor
With all the controversy currently surrounding the digital-audio format known as MPEG Layer III, or MP3, you might wonder how the digital-audio industry evolved from tinny-sounding MIDI files into near-CD-quality MP3 files.

With all the technical jargon, it's difficult to figure out why this breakthrough is so revolutionary. The reason is simple: MP3 dramatically reduces file size with only a small loss of quality.

In the late 1980s the digital-music industry stalled. Multimedia was outpacing the computer industry's ability to produce a large enough storage format that would let musicians store their digital work. The dominant compression scheme at the time, JPEG or Joint Photographics Expert Group, was only used for still images, and it couldn't handle the compression of high-quality movies or audio.

Out of the necessity to provide multimedia creators with better formats and standards, the Moving Pictures Expert Group was formed in 1988.

The group first met in May of 1988 with 25 experts. Since then, the group has grown to enormous proportions. Now, 350 experts from 200 companies and organizations in 20 countries are a part of the MPEG organization.

When a company or individual wants its technology to become an MPEG standard, it must first produce a verification model and submit it to the MPEG organization. The verification model explains how the multimedia encoder and decoder work through the use of programming code. This code is later used to test how the technology being proposed as a standard performs under actual conditions. If and when the MPEG organization believes that the technology has passed the verification model stage, the group producing the technology moves on to the working-draft phase of the process.

The working draft is essentially the proposed technology standard in its final form. The MPEG organization keeps the draft version of the technology within the organization for further evaluation. A series of evaluation stages follows. MPEG 1 and MPEG 2 both went through this process to become today's audio and video standards.

MPEG-1 was born in 1992 after the MPEG organization met with the International Standards Organization (ISO) and the International Electrotechnical Commission (IEC). It featured audio encoding in three different layers, with the third layer having the best encoding abilities.

The same three organizations -- MPEG, ISO, and ITEC -- met again in 1994 to announce the arrival of a new compression format known as MPEG-2. MPEG-2 was designed primarily for video, and it contains a number of new features, such as support for interlaced video signals. As an audio format, MPEG-2 continued to build off MPEG-1. MPEG-2 supports backward and forward compatibility for multichannel audio, so it supports both old audio technology, such as MPEG-1, and emerging digital-audio formats such as Dolby 5.1.

MPEG-2 also added a new feature to the MPEG standard: the ability to encode files with lower sampling frequencies such as 16KHz, 22.05KHz, and 24KHz. This allowed for better coding efficiency with lower bit rates. In other words, you get smaller files with little sacrifice in overall quality.

As MPEG-2 underwent continual evaluation, the MPEG organization learned that if MPEG-2 did away with backward compatibility and some of the additional features, encoding efficiency would be improved tremendously. As a result, in 1994 MPEG-2 Advanced Audio Coding was born. MPEG-2 AAC continued the trek toward providing digital-audio users with high-quality encoding and a small file size.

Even though the format is called MP3, it is not the third iteration of the official MPEG standard. The 3 in MP3 refers to the third layer of audio encoding, which is why it's dubbed MPEG Layer III. The original MPEG-3 was designed to deal with HDTV, but the organization knew that there were no tools built into MPEG-2 to handle HDTV. As a result, many of the features planned for MPEG-3 were incorporated into MPEG-2, while a new standard would be developed to handle HDTV.

MP3, MPEG Audio Layer III, still followed MPEG-2.

To completely understand how MP3 came into existence, the audio layers incorporated into MPEG-1 must be explained. Layer 1 is the most basic layer and was widely used by consumers until layer 3 emerged.

Layer 1 can encode audio files from 32Kbits per second up to 448Kbits per second. It was used mainly in theme parks and CD-I video. The problem with layer 1 is that it took a higher bit rate to produce a stereo-audio file, which resulted in a larger file.

Layer 2 took steps to remedy the problem of layer 1 by producing a stereo-quality file at 195 to 256Kbits per second. It could be used in a number of situations. Like layer 1, layer 2 was used in theme parks and CD-I video, but it was also used for video CDs, DVDs, cable TV, movie soundtracks, and a host of other multimedia formats.

Layer 3 offers the most compression of the three layers. Digital-audio encoders only need a bit rate of 112 to 128Kbits per second to get a stereo-quality audio file. Remember, the lower the bit rate, the smaller the file. Of course, layer 3 is being used primarily for encoding digital-audio files.

In conjunction with the University of Erlangen, the Fraunhofer IIS lab developed MPEG Audio Layer III -- or as the lab calls it "MPEG-2.5" -- in Germany.

The lab noted that, without compression, one second of stereo-quality music produces a file size of 1.4MB. Since the goal of MPEG was to reduce file size and maintain quality, the lab came up with a method known as perceptual coding.

Perceptual coding is actually the basis of all the MPEG audio formats.

Humans can only hear sounds within a certain frequency. If someone were standing next to a speaker that was playing loud music, he probably couldn't hear the person next to him speaking. The person speaking would be considered "masked;" his speech would be inaudible.

The same situation applies to digital audio; the human ear cannot hear every sound in a particular song. MPEG encoders read each audio file and determine which sounds are audible and which aren't before they encode the files, thus helping with the efficiency of the encoding.

Digital music has come a long way. With two simple ideas to drive it, the MPEG organization has created a music standard that's rocked the foundation of the music industry. If the recent past is any indication, the music industry may have a serious problem on its hands. The MPEG organization is currently working on MPEG-4, which will take a different approach to both audio and video.

MPEG-4, like MIDI, can generate music instead of simply playing it back. However, unlike MIDI, the sounds in the MPEG-4 program will not be ordinary samples. This technique of generating music has been dubbed "Kolmogorv encoding."

MPEG-4 will also combine two programming languages involved with digital audio. One is called SAOL, which is used for general computer audio, and the other language is called SASIL, which features support for MIDI. In its most basic form, MPEG-4 will generate sound in the same manner as a .WAV file, but the MPEG-4 file will not be nearly as large.

The MPEG organization is even currently discussing MPEG-7, but it appears that MPEG-7 will take yet another entirely different approach to encoding large audio and video files. Instead of generating audio and video files, MPEG-7 will be used to help search for multimedia files. The organization hopes the software will provide Internet users with a quick and efficient way to locate multimedia files.

Clearly, the MPEG organization has a lot on its plate at the moment. As audio files get smaller and smaller and quality improves, the controversy surrounding MP3 only increases. What will this do to the music industry? We'll have to wait and see, but it's apparent that MPEG can and will be put to good use in other mediums such as TV, radio, and video.

Only a few years ago, consumers were largely unaware of MP3. Talk of MP3s or those who knew anything about the technology was limited to a scant few people exchanging files. Indeed, even people who wanted to make MP3s couldn't, as the Fraunhofer lab wanted payment to use its MP3 encoder.

Now that MP3 technology has hit the Internet mainstream, everyone is getting into the act. People are copying CDs onto their hard drives and exchanging music files with people around the world. Who would've thought that such a miniscule portion of the Internet would erupt into the frenzy it is today?

Who can MP3 fans thank for that? If it weren't for the numerous lawsuits filed by the RIAA (Recording Industry Association of America) and other organizations, MP3 technology and awareness would never have reached so many people so quickly. Anyone who was curious could download a player, rip a few MP3s, tell a couple of friends, and so on.

Seeing its emerging popularity, a number of business-oriented people jumped on the MP3 bandwagon. Michael Robertson, CEO of MP3.com (mppp), was wise enough to register the most sought after domain name related to MP3s.

Robertson built an entire empire of unsigned artists who let their material be downloaded through the MP3.com site. Since then, MP3.com has moved into more unfriendly waters by offering the My.MP3.com service, which lets people store their music online at the MP3.com Web site.

An entire industry has grown out of the search for MP3s. Software that lets people exchange MP3 files in a more direct manner has started to appear. Led by Napster, this growing industry is not on solid ground, as these individuals and companies are essentially using pirated music as their foundation. Of course, the RIAA saw what Napster has done to the proliferation of illegal MP3s and filed a lawsuit, but this hasn't stopped other companies from developing, or at least attempting to develop, file-sharing software. (See: Napster creator Shawn Fanning.)

Nullsoft, the creator of one of the very first mainstream MP3 players, released its file-sharing software at the beginning of March. The program was quickly scrapped when America Online Inc. (aol), Nullsoft's parent company, found out about it and declared it an unauthorized freelance project. (See: MP3 players.)

Even now, GlobalScape -- the developer of the popular FTP software CuteFTP -- has released its own file-sharing software. Whether or not it will let people exchange MP3s and other forms of media remains to be seen, but it's clear that the threats issued by the RIAA against companies planning to develop software that lets people trade MP3s have fallen on deaf ears.

Perhaps one of the biggest questions surrounding MP3s is the question of legality. Depending on whom you talk to, MP3s are both legal and illegal.

On one hand, there are those who believe the Fair Use Act lets people do whatever they want with the music they own. Meaning, if someone wants to rip his entire CD collection into MP3 format, he has the right to do so.

However, people associated with the recording industry are quick to point out that when a person buys a CD, he is merely paying for the format it's being stored on. In effect, you're paying for the CD and not the music. Therefore, you have no right to do with it as you please. You do, however, have the right to use the CD to play Frisbee with your dog.

The industry also adds that the trading of MP3s couldn't possibly be more illegal, and it would be correct. Trading music without the consent of the copyright owner has been deemed illegal because it violates copyright law. If you don't own the music to begin with, you have no right to posses it or distribute it to others.

The lawsuits filed by the RIAA against Napster and MP3.com will help determine whether or not people own the music they buy or merely own the storage format it's printed on. Until then, it's not exactly clear here who's wrong and who's right.

It's obvious that the recording industry is worried about the potential effect MP3s could have on its bottom line, and is taking steps to ensure that record companies continue to make their enormous profits.

SDMI (the Secure Digital Music Initiative) has already arrived, but no one is really sure how it's going to affect MP3s, or if it will even work. An interesting side note is that the chairman of the SDMI is also the chairman of MPEG.

On the technological end, it's obvious that MPX will continue to evolve and produce smaller and smaller files with no quality degradation. Digital music will continue to spread, regardless of what happens between the RIAA and the major MP3 players.

The MPEG Audio Layer III format has a long history, and it will have an even longer future. Whether it will change to meet the needs of the industry, or if the industry will change to meet the needs of the format, remains to be seen. One thing is certain: We are all witnessing a possible shift in a huge industry. The situation can only get more interesting.

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