In the prior article I discussed the fact that MIDI is the best choice when
adding background music to autoplay on your web site. Choruses of
favourite songs can be looped to play while images and text are
loading. MIDI is the best choice as it takes up very little space on your
web space(2-7k bytes).
Other types of sound files that are useful on web sites are MP3, au, wave,
real audio(.ra) to name a few. These are not practical as background sounds
due to their large file size but do have some unique features that make
them useful.
MP3
MP3(Moving Picture Experts Group1Layer3 Audio) is a type of sound file used
to compress large sound files. The most common use of MP3 files is to
compress a CD album. A complete CD album can be compressed into a file size
of 50MB. This has sparked a great deal of illegal copying on the web as
people can copy Cd albums into a MP3 and send it to others on the web.
Nevertheless, a good use for MP3 is as a 'download' on a web site. If you
have an audio speech or song album you want people to listen to, MP3 is
the way to go. Many musicians put their songs as wave files on their sites
for download which take just too long to download. A typical song might
take 35-50MB in wave form but saved as an MP3 would take only 3-5 MB. The
amazing thing about this type of compression is that it replicates the
quality of the wave file as well. However, even though a song in MP3
format takes only 3-5MB in file size, it still may take 15-20 minutes to
download for most people on a 28.8 modem line. Although with faster lines
this is becoming the best way to give downloads of music. There is a
faster way to broadcast your songs that will play a large sound file almost
immediately. This is the Streaming Audio File (.ra). Many web sites
wisely give the visitor a choice between a streaming audio or a MP3 download.
Real Audio
There are many types of streaming audio on the web but Real Audio seems to
be the most popular. A Real Audio file will play in seconds. The reason for
this is that the real audio file plays as it downloads. This is true of
even a very large audio file. The quality of real audio file can be poor
though on slower modem rates (28.8). It is excellent for talking but not
for showing off a musicians album unless you are using a faster line. In
which case the sound quality is quite acceptable. Many radio stations keep
archives of broadcasts so the visitor can go back to programs to hear a
certain person talk. Sometimes when there is net congestion a real audio
file will cut out and then come back which can be frustrating to a listener
if the net congestion continues.
The other problem with real audio is that it can cost the web owner to use
it. Anyone using real audio can go to someone owning a real server. They
are given a text file on their server(.ram) that connects to the real
server. This in turn connects to the real audio file(.ra). Most real
servers charge about 5$ to$40 US/month depending on the amount of space you
need. This same process can be done on your own server if it is configured
correctly. This is obviously cheaper but you will need large amounts of
space for the ra files. Many of the real audio options are not available on
your own server also. Real Audio Files compress well but still take up a
large amount of space if you're putting albums etc on your web space. Many
servers that offer free space limit the amount of streaming audio files on
their server.
There are many competitor's software available for the streaming
audio but Real Audio seems to be the most popular. Some you might look at
are Playstream, Beatnik, Quicktime and Windows Media Technology.
Wave
Wave files, although large in file size, can still be used on web sites. A
web designer may want to person to speak"Hello" or some phrase when a
button is pressed. This can done with a wave file. Provided the wave file
is less than a second this may provide a file size of about 10k.
You can download a free demo of programs like Cool Edit Pro or Cakewalk to
record the wave file. (The demo will not save nor print though.) After
recording the file, you need to change the sampling rate to about 11khz and
use an 8 bit resolution in mono. This greatly reduces the file size but
compromises a bit on quality.
Songs can alternatively be saved in the real audio format as an'.ra' file
as mentioned above.
There are other ways to record wave such as Beatnik, Windows Media
Technology to name a few but I have focused here on the most popular.
Sun's ".au" Files
Many web designers are now using java applets and scripts on the web. Most
applets use the.au format to put sound files into the applets. There is
often a chance to customize sounds in the applet's parameter tags. It is
important though in many applets to use a sampling rate of 8k when saving
the.au file. Otherwise the sound will not work in the applet. The new
swing jar java is opening up new sample rates.
I will talk focus on making MIDI for your web site next.
About the Author
John Rickey is an experienced MIDI arranger. He graduated from University
of Toronto with a degree in music and has worked from studio recordings to
Movies with his arranging. You can contact him at kingskid@netrover.com or visit his MIDI Design
Site at http//www.scugog-net.com/room108/midi/container.html