MP3 is the de facto standard
for storing and sharing music files on computers. On the surface
it is simply a file format,
like JPEG . However,
it is not any old file format, it is a highly sophisticated format
can require a great deal of computation to create. The main advantage
is that MP3 files are compressed - they take up less space than other
sound file formats (see "What's
it Good For").
The term MP3 is an abbreviation for MPEG I layer 3 (MP3 does not mean
MPEG III) .
MPEG (pronounced em' peg), in turn, is an acronym for Motion Pictures
Group which in practice refers to a group of international
for audio/visual file formats. MPEG I layer 3 (mp3) coding is an advanced
MPEG I layers 1 and 2. Essentially, it simply adds more steps in the
encoding processes of the other two layers.
MPEG I layer 1 was intended for the Digital Compact Cassette, but
is now virtually obsolete.
MPEG I layer 2 is used in live broadcasting. Because
it is simpler than layer 3, it takes a short amount of time to encode,
it useful for live transmission. It was intended to be high quality,
but to achieve this must be be used at high bit rates.
Finally, layer 3 was originally designed to offer
high quality at low bit rates. The main difference from the other
two layers is that
it adds a more sophisticated perceptual model.
More information on MP3