from
The Free On-line Dictionary of Computing (8 July 2008)
MPEG-1 audio layer 3
MP3
MPEG-1 layer 3
<music, file format> (MP3) A {digital audio} {compression
algorithm} that acheives a compression factor of about twelve
while preserving sound quality. It does this by optimising
the compression according to the range of sound that people
can actually hear. MP3 is currently (July 1999) the most
powerful algorithm in a series of audio encoding standards
developed under the sponsorship of the {Moving Picture Experts
Group} (MPEG) and formalised by the International Organization
for Standardization (ISO).
MP3 is very different from Layer 2, using an additional {MDCT}
layer to increase frequency resolution. Its scale factor
groups are more optimised for the human ear, and it uses
nonlinear {sample quantisation} and {Huffman coding}.
MP3 files ({filename extension} ".mp3") can be downloaded from
many {World-Wide Web} sites and can be played using software
available for most {operating systems} (also downloadable),
e.g. Winamp for {PC}, MacAmp for {Macintosh}, and mpeg123 for
{Unix}.
MP3 files are usually downloaded completely before playing but
{streaming} MP3 is also possible. A program called a "ripper"
can be used to copy a selection from a music {CD} onto your
{hard disk} and another program called an encoder can convert
it to an MP3 file.
(2001-12-04)