(.wav) Wave Form Audio File Format Wave files are used to
sample real analogue audio into a digital file format. The frequency
of the sample will determine the quality of the recording and
the size of the resulting file. At 44,000 Hz and 16-bits a WAVE
file will be close to CD quality but will generate a huge file.
Since their source is real, they can store a good representation
of the original sound. You could for example, distinguish Ringo
Starr's northern English accent in a recording of his voice
or the nuance of a good violin.
MP3 (.mp3) "Moving Pictures
Expert Group" Layer 3 This is not a new format but it
has significantly gained in popularity lately. Unlike WAVE,
MP3 uses a "lossy" algorithm in order to compress
the audio into smaller files. This type of compression essentially
throws information away so that a side-by-side comparison
between a high quality WAVE file and a highly compressed MP3
file will be quite noticeable. Even so, the loss of quality
is not very pronounced while the gain in compression is significant.
A 1.0 Meg WAVE file for example, can be compressed into as
little as 50K using MP3.
RA G2 (.ra,.rm) Real Audio Real Audio
is one of the oldest formats for distributing audio over the
Internet. Their initial objective was to provide voice transmission
over low bandwidth telephone lines. With G2 they are now moving
toward distribution of music. Real Audio can also be streamed
so that the visitor can start listening before the entire
file has downloaded. Unlike MP3, Real Audio is a proprietary
format but the Player is free and already installed on many
Video compression has been undergoing significant development
in recent years. The formats that are now available are a
lot smaller than in the past while still maintaining reasonably
good quality. Even so, there is really no such thing as a
small video file. They all require a significant amount of
bandwidth. When a typical movie on DVD requires over a Gigabyte
of space you will quickly realize that even short videos are
going to demand a significant amount of time to download even
with a fast connection.
There is a lot of talk about providing TV, Movies and Video
feeds over the Internet. The fact is the technology is just
not ready for it yet. In order to get real time video over
a fast connection, the quality has to be so low that it is
the equivalent of a penny whistle compared to a major symphony
orchestra. It may be able to carry the tune from Beethoven's
9th but wait until you hear what passes for the Choral Orchestra.
For those of you that have a valid reason to add video to
your web pages, these are the primary choices you have.
AVI (.avi) Audio Video Interleave
-Microsoft AVI was developed by Microsoft to add Multi-Media
capabilities to Windows. It is the most common Multi-Media
format if for no other reason than it is included on every
PC running any version of Windows. It is capable of combining
both Audio and Video into a relatively high quality file.
QUICKTIME (.gt,.mov) ISO standard -Apple. QuickTime
is a mature format that combines both audio and video into
a file that is significantly smaller than AVI at a slight
expense in quality. Apple was able to make the format popular
by offering a free player on PC's.
MPEG (.mpg,.mpeg) "Moving
Pictures Expert Group" This is one of the oldest and
most popular Audio/Video formats. MPEG is available on most
platforms and probably offers the best compromise between
file size and quality.
There are many other formats either in use, outdated but
still available or in active development. I have not attempted
to list them all since the topic is too extensive for a single
article. Some of the links below will provide additional information
for those of you that are interested in doing more research.
You can also try your favorite Search Engine or Index. I have
also not included links to sites that provide players for
these formats. The formats and players change often and are
Here are just a very few links to sites with additional
information on these formats. There are many more.