Filename extension: .mp3
Internet media type: audio/mpeg, audio/MPA, audio/mpa-robust
Initial release: 1995
Type of format: Audio compression format, audio file format
Standards: ISO/IEC 11172-3, ISO/IEC 13818-3
MPEG -1/ 2 Audio Layer 3, more commonly known by its abbreviation MP3, is the specification of the standard audio MPEG-1/MPEG-2, of Moving Picture Experts Group (MPEG).
This is an audio compression algorithm that can drastically reduce the amount of data required to restore the audio, but for the listener is like a reproduction of the original uncompressed audio: with a good compression quality difference becomes hardly noticeable.
The file name extension is .mp3, and MIME type is audio/mpeg, audio/MPA, audio/mpa-robust or audio/mp3 (in Chrome/Chromium browsers). This file is called “MP3 file”.
A MP3 file is not subject to any technological protection measure.
By the early 2000s, exchange networks on the Internet via file sharing software such as Napster, have greatly contributed to the adoption of this format by consumers at the expense of competitors MPEG-4 Audio/TwinVQ and OGG Vorbis. At the same time, movies encoded in DivX (for video) and MP3 (for audio) have appeared. This is why manufacturers of electronic devices have begun to market CD- DVD- DivX, Audio CD Walkmans and CD Audio turntables players that can read a data CD containing MP3 audio files. Thereafter, the MP3 CD was less common with the advent of MP3 players such as iPod, which did not improve the situation of Super Audio CD and DVD- Audio.
Today the MP3 format has been adopted by the majority of sites selling online music such as Fnac or Amazon. Only iTunes Store sells music in MPEG-2/4 Audio/AAC. MP3 has also found its way to the audio stream online radio and other music listening sites and in video streams broadcast in Flash (FLV encoded in VP6) format. The majority of the PC games use it. MP3 is widely imposed against its direct competitors, the compression formats mp3PRO, WMA, OGG Vorbis and AAC.
On blank CD it says “80 minutes” to 737 MB (702 Mio). For audio the output is 2 (audio channels) * 44,100 Hz (sampling frequency) * 16 ( Number of bits per sample) or 1411.2 kbits/s. The popular audio compression format allows a reduction of 4.11 (320 kbit/s) at 176 (8 kbit/s). An audio file often occupies this way from 4.11 to 22 (64 kbit/s) times less space when compressed in MP3 format. Size reduction facilitates the transfer and storage of digital music data on a medium such as a hard disk or flash memory.
It has also been widely implemented in digital broadcast receivers in T-DMB Radio whose specification was adopted by ETSI in 2005 and is widespread in South Korea. Indeed, MP3 belongs to the same family of MPEG Audio MP2 MUSICAM that used in digital broadcasting (DVB-T for digital terrestrial television and T-DMB Radio). A simple binary format transcoding “MP2 audio broadcast” in format “MP3 recorded” can thus be achieved in the terminal T-DMB, so authorizing the placing on the market of portable / digital audio receivers that combine the functions of decoding audio MP2 (MUSICAM) and MP3.
Translated and adapted from Wikipedia under GNU Free Documentation License.