MP3

MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is an audio coding format made by the Fraunhofer Society in Germany. It was created to use less space for audio while still sounding good to most people. For example, MP3 files can be much smaller than CD-quality digital audio, saving space.

MP3 became popular in the late 1990s because it let people share music easily over the Internet. This was helpful when bandwidth and storage space were limited. Many used services like MP3.com and Napster to share music.

Today, MP3 is still widely used. Even though newer formats like AAC exist, most devices, including portable media players and smartphones, can play MP3 files. Its ability to store music in a small size made MP3 important for how we enjoy music.

History

The Moving Picture Experts Group (MPEG) created MP3 as part of its MPEG-1 and later MPEG-2 standards. MPEG-1 Audio was approved in 1991 and published in 1993. MPEG-2 Audio was published in 1995.

MP3 uses a method called lossy compression. This helps make audio files smaller while still sounding good. MP3 files are often much smaller than files from CDs.

Many researchers and institutions helped develop MP3. Important work was done by the Fraunhofer Society in Germany, led by Karlheinz Brandenburg. Early tests used songs like "Tom's Diner" by Suzanne Vega to make sure the sound stayed natural.

In the 1990s, MP3 files became very popular on the internet. People could share music with friends, which sometimes led to discussions about copyright. Today, MP3 is still a common way to store and play digital audio.

Design

MP3 is a way to make audio files smaller while keeping most of the sound quality. It works by removing parts of the sound that most people can't hear. This makes MP3 files much smaller than regular audio files, like those on CDs.

MP3 files are made up of small pieces called frames. Each frame has a header and data that contains the audio information. There are also tags in MP3 files that hold extra information like the song title or artist. The quality of an MP3 file can change depending on how much data is used, called the bit rate. Higher bit rates usually sound better but take up more space.

Licensing, ownership, and legislation

The technology used to create and play MP3 files was once protected by special rights called patents. Patents let inventors control how their inventions are used. This caused some confusion when MP3 was first created, especially in places that allow software patents. But most of these patents have now expired.

In many countries, the main MP3 patents expired by December 2012. In the United States, the last big patent expired on April 16, 2017. This means that today, you can create and use MP3 files without paying special fees in most places. Some companies, like Technicolor, used to manage licenses for MP3 patents, but this happens less now. Because of this, many free software programs now include MP3 support without needing extra downloads.

Alternative technologies

Main article: List of codecs

There are other ways to make sound files smaller besides MP3. One common format is Advanced Audio Coding, or AAC. It was made to be better than MP3 at shrinking file sizes. Other formats like mp3PRO and MP2 are also related to MP3.

Some companies created their own formats. For example, Microsoft made Windows Media Audio, and Sony used a format called ATRAC for its MiniDisc players. Later, Sony added MP3 support.

There are also free formats anyone can use, like Opus and Vorbis (OGG). For people who want the highest quality sound without losing any details, there are lossless formats such as FLAC and Apple Lossless. These keep all the original sound but make files bigger.