An Introduction to MP3
by Brett White <[email protected]>
What are they?
I'm sure that by now most of you out there have heard of the term 'mp3',
but do you know what it means? Well to put it simply, mp3s are just
another way of storing sound on your PC, but as you will see it has some
rather large advantages over conventional sound file formats.
Almost everyone will know of the wav file format (the format used to
store all the sound effects for Windows like that annoying error sound
you get every few minutes because of another 'stable' application
crashing). Due to the large size of these files (about 10MB/min) it was
near impossible to store lengthy or large numbers of these files. So, by
applying mpeg compression to the wav files mp3s (or MPEG layer 3) sound
files are created with a compression of around 10:1. The method of
compression exploits the properties of the human ear and produces CD
quality sound allowing you to store nearly 11hrs of music on a normal CDR.
Understandably so, this has caused some concern in the music business with
the possibility of an artists whole life's work being able to packed onto
one CD resulting in a large loss of revenue to the artist and the record
company. But not all musicians are against the mp3 revolution. David
Bowe's latest album is only available on his web site in mp3 format,
downloadable at a price of course.
How do I get them?
Well, there are 2 main ways that you can get your hands on mp3s. You
can either create the mp3s yourself or find them and download them from the
web.
Creating them yourself
Probably the quickest way to get your mp3s is to create them yourself
from your own music CDs (or other sound sources). To do this you first
need to get the music off the CD and into wav format, this can be done
using a 'ripping' program. Two of the programs that I have used in the
past are cdda2wav (comes in the cdrecord port) and cdparanoia (you'll have
to port and compile this one yourself). Once you have generated the wav
files you will need to compress them into mp3 files using an mp3 compressor
program such as bladeenc or mp3encoder. Personally I have found that the
FreeBSD/Linux based encoder software introduces a high end clipping
(difficult to detect, but once noticed becomes very annoying) in the
resulting file. The best encoder to mind was a Windows based compressor
called MP3 Compressor that is unfortunately no longer available on the
web.
One thing to be careful of when compressing wavs into mp3s is the high
CPU percentage required. On a newer system (PII/PIII) with a fair amount
of RAM this is not too much of a problem, but on older systems this can
render the system almost unusable during the compression.
Downloading them from the web
Due to the ability to convert music into smaller files without losing
quality, mp3 archives have popped up all over the place on the web. The
thing to be careful about if you choose to get your mp3s from the web is
that you are not allowed to own any mp3s that you don't actually own on
the original media (sort of like the situation with downloadable ROMs for
Nintendo emulators).
But that aside, there are a few different way of getting your mp3s on
the web:
- Download archives - these sites are usually an archive of links to mp3s
that you can download for free from other sites all over the web. A lot
of these do suffer from a large amount of 'broken links' though and can be
frustrating to use.
- FTP servers - a lot of FTP servers use the 'upload before download'
system where you have to upload a file that they want or don't have before
they will let you download from them. These are pretty annoying as most of
the files that you have will already exist on their server and hence it is
hard to get access to downloading from them.
- Email swap - a fair number of people publish on their sites a list of
mp3s that they own and mp3s that they want. This methodology is similar to
that of the FTP servers, where you email them an mp3 that they want and in
return they will email you your requested file. Can't say that I've ever
used these as there is just a little too much trust required.
- Online music stores - these have started to take off recently and as
you would guess, you have to actually pay to get the files that you want
from the store... bummer!
- Napster - this funky application allows you to log into a community of
users specifying that genre of music you are interested in. While you are
logged in, others can see what mp3s you have and they can download directly
from your machine (and visa versa). You can specify a maximum number of
connections to your machine so as to not clobber your bandwidth too
much.
How do I play them?
Once you have obtained your mp3s you will require an mp3 player. These
come in two flavors, console based and X based. Two of the more popular
console based mp3 players are amp and mpg123 (both ported to FreeBSD).
When it comes to X based players xamp and x11amp/xmms have been my
favorites. xamp has the one advantage that it is just a graphical front
end to amp so you don't end up having 2 players on your system for console
and X. x11amp/xmms is my current choice as it is a clone of Winamp and has
recently moved to support plugins as well as skins (to make it look
pretty) and many different sound file formats.
For a greater list of available rippers, compressors and players see the
Audio section of the FreeBSD ports archive.
Well, that pretty much covers all you will need to know to get your own
MP3 library up and running... happy ripping! >:-) |
