MP3 BASICS

MPEG-1 Audio Layer 3,
more commonly referred to as MP3, is a popular digital audio encoding and lossy compression format,
designed to greatly reduce the amount of data required to represent audio, yet still sound like
a faithful reproduction of the original uncompressed audio to most listeners.
It was invented by a team of European engineers who worked in the framework of the EUREKA 147 DAB
digital radio research programme, and it became an ISO/IEC standard in 1991.

mp3 cdS will only play on a computer or a CD player marked MP3. They can be download off the disc in to a file
on your computer and played with Windows media player, winamp, or any of the many other music player
made for computers. Some DVD player will play MP3 formated discs.

How many Programs will an MP3 Disc hold? That depends on the bid Rate and sampling Frequencys listed below.
The higher the bit rate and sample rate the better the quality but the more space taken up on the disc so
the disc will hold less programs. For old time radio shows that were recorded in mono a good bit rate is 40bps
and a sample rate of 22 which is radio quality. Most MP3s on the market today are at 32bps allowing about 100
programs to a 700mb disc.

BIT RATE
The bit rate is variable for MP3 files. The general rule is that more information is included
from the original sound file when a higher bit rate is used, and thus the higher the quality
during playback. In the early days of MP3 encoding, a fixed bit rate was used for the entire file.

Bit rates available in MPEG-1 Layer 3 are 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224,
256 and 320 kbit/s, and the available sample frequencies are 32, 44.1 and 48 kHz. 44.1 kHz is almost
always used (coincides with the sampling rate of compact discs), and 128 kbit/s has become the
de facto "good enough" standard, although 192 kbit/s is becoming increasingly popular over peer-to-peer
file sharing networks. MPEG-2 and [the non-official] MPEG-2.5 includes some additional bit rates: 8, 16,
24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 kbit/s.
SAMPLE RATE
A sound wave is continuous. Converting it to a form that can be stored as a digital sound file on your computer
or CD it must be converted . Your computer must record measurements of the sound a different moments
in time. This is called a sample. The number of samples that are taken per second is called the SAMPLE
RATE. The sampling rate is measured in kilohertz (KHz). The most commonly used rates are
11KHz (telephone quality) , 22KHz (AM Radio quality) 44Hz (Music CD quality).

Variable bit rates (VBR) are also possible. Audio in MP3 files is divided into frames
(which have their own bit rate), so it is possible to change the bit rate dynamically as the file is encoded
(although not originally implemented, VBR is in extensive use today). This technique makes it possible to use
more bits for parts of the sound with higher dynamics (more sound movement) and fewer bits for parts with lower
dynamics, further increasing quality and decreasing storage space. This method compares to a sound activated tape
recorder that reduces tape consumption by not recording silence. Some encoders utilize this technique to a great extent.

Non-standard bitrates up to 640 kbit/s can be achieved with the LAME encoder and the --freeformat option, however
few MP3 players can play those files.

More information can be found on the internet by typing in MP3 in the google or other search engines.