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Guide to creating MP3 files:
• What are MP3 files?
MP3 – stands for 'MPEG-1 Audio Layer-3'
and
is
one
of
the
most
popular
compressed digital audio file formats
and they have become an almost
universal way to store music files on both
computers and portable devices. An MP3
file is a compressed version of a digital
audio recording, such as a track from a
CD. The original song data is 'encoded'
using
a
variety
of
techniques
that
reduce the size of the resulting file whilst
preserving much of the (perceptible)
sound quality of the original
Digitised audio is governed by bit-rate,
or the amount of song data that is
transferred per second to the device
that is playing the song. A digital audio
recording using the 'Redbook' audio
CD standard uses 1.4 million bits of
data per second. This is the amount of
information necessary to play a virtually
identical digitised version of the original
analogue music.
The MP3 format reduces this bit-rate by
a factor of ten or more, while retaining
much of the essential qualities of the
audio. The secret to this is analysing the
frequency of the sounds contained in the
CD track.
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Any audio recording is likely to contain
various noises, incidental or otherwise,
that are of a frequency we cannot
perceive. Likewise, any multi-track audio
recording is likely to have portions where
one track drowns out others due to its
volume at that point. MP3 encoders
analyse the frequency pattern of an
audio file and filter out sections of the file
which would be difficult or impossible for
us to hear.
Essentially, the MP3 format reduces the
size of audio files by 'biasing' them for
human hearing, stripping them down to
the essential, easily audible frequencies
which would be all we would generally
hear anyway. The resulting file is then
compressed
using
more
traditional
software methods.
We can levy some control over the
sound quality of an MP3 by adjusting
the sampling frequency (typically 44kHz)
and bit rate (64kb/s - 196kb/s, and in
some cases as high as 320kb/s) when
the MP3 audio file is originally being
encoded, which can dramatically impact
on the end result. Though just as vinyl
records are considered superior to the
Compact Disk, CDs are superior to most
MP3 recordings; though choosing the
right encoding settings narrows the gap
significantly.
Creating MP3 audio files requires the
use of a 'ripping' program; software that
can encode your conventional audio
files into the much more compact MP3
format. While Windows XP technically
provides this ability with recent versions
of Windows Media Player, it is strongly
suggested that you will find it much
easier using freely available third party
software.
MP3 encoding software can be either
downloaded for free or purchased online
from many web sites. Some of the
free versions have a limited number of
options and features.
Any modern computer fitted with a
sound card and speakers and loaded
with suitable software can create good
quality MP3 files.
• The Settings:
Good MP3 encoders give the user
total control over creating MP3 files,
with the many settings and functions
available with the software. But these
functions and setting of the software
could be confusing at first. Read the
documentation that accompanies the
software; take a tutorial offered by the
publisher (if offered) or simply go through
the software to familiarise yourself with
the different functions to overcome your
confusion and better use the software
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