mpeg 1 layer 3:

history | mp3 format...

blah blah blah

introduction | lame mp3...

technical information | lame mp3...

the mp3 algorithm development started in 1987, with a joint cooperation of fraunhofer iis-a and the university of erlangen. it is standardized as iso-mpeg audio layer 3 (is 11172-3 and is 13818-3). it soon became the de facto standard for lossy audio encoding, due to the high compression rates (1/12 of the original size, still remaining considerable quality), the high availability of decoders and the low cpu requirements for playback. (486 dx2-66 is enough for real-time decoding). it supports multichannel files (although there's no implementation yet), sampling frequencies from 16khz to 24khz (mpeg2 layer 3) and 32khz to 48khz (mpeg1 layer 3). formal and informal listening tests have shown that mp3 at the 192-256 kbps range provide encoded results undistinguishable from the original materials in most of the cases.

mp3 uses the following for compression:

huffman coding
quantization
m/s matrixing
intensity stereo
channel coupling
modified discrete cosine transform (mdct)
polyphase filter bank

[there is a non-standardized form of mp3 called mp3pro, which takes advantage of sbr encoding to provide better quality at small bitrates.]

pros of mp3:

transparent quality at --alt-preset extreme (lame) in most of the cases.
iso standard
part of mpeg specs
fast decoding
anyone can create it's own implementation (specs and demo sources available)
nearly all portable players support it.
relaxed licensing schedule
lower complexity than aac or vorbis

cons of mp3:

problem cases that trip out all transform codecs
slow encoding (using lame vbr)
sometimes, maximum bitrate (320kbps) isn't enough.
no multichannel implementations.

here are some pre-made text files that should whet your whistle:

faq | frequently asked questions answered by the developers of lame || lame hp
usage | "directions" on how to use lame by the developers || lame hp
legal | a legal/technical question and answer document || lame hp

if you still have questions about lame, hopefully they can be answered here.

usability | lame mp3...

blah blah blah

encoder functions | lame mp3...

sonic:compression

an audio compression resource

navigation:

administrative...

introduction...

resources...

tutorials...

lossy formats...

lossless formats...