MPEG-4 the multi media format of the future ?


 
Would
you like to fit an entire DVD quality movie on a CD-R or would you like to
stream a movie to your mobile phone while you're travelling? Or do you prefer to
have your music compressed in a format that offers better quality, using less
space? Does that sound too good to be true? Well it's not! During Cebit several
companies announced products with MPEG-4 support and also companies like Ahead
are currently developing MPEG-4 related software products. Yes, MPEG-4 is the
new keyword that you should remember. This standard will likely be the next big
thing in the coming years. In this article we will try to explain why MPEG-4 is
important and how it works.

First of all it's important to understand
that MPEG-4 has nothing to do with MP3. MP3 is a part of the MPEG-1 standard,
just like the Video CD is part of the MPEG-1 standard. MPEG-4 is not really a
follow up of MPEG-1 either. It's a new standard that aims to become the standard
for digital media while MPEG-1 was mainly focussed to deliver content the way we
know it today.

The MPEG-4 technology works, simplified, by splitting the
content. A small movie can, for instance, be seen as Audio, Video, Titles, and
Subtitles. Four different objects that together form the complete movie. If you
want the best quality using the lowest amount of disc space you will need to
analyze each of these objects and choose the appropriate compression format. You
can imagine that if in the movie someone is only making a phone call you could
use an audio compression format that needs less quality than when you see an
orchestra playing in an opera house in the same movie. You can also imagine that
in case the person is making a phone call and he only moves his lips, you need
less movie quality than when you're showing an entire moving orchestra playing a
powerful song.

Important in MPEG-4 are the so called profiles. Profiles
describe somehow the content of an MPEG-4 object. E.g. the phone call would use
the Speech Audio Profile, while the orchestra would require the High Quality
Audio Profile. For video, the same rule applies and both movies would require a
different visual profile. The profiles are designed to make sure that a device
knows if it can play a certain MPEG-4 file. An MPEG-4 capable audio device is
for example unable to play an MPEG-4 compatible animation.

This phone
call/orchestra movie is only a small example. MPEG-4 objects can also appear
standalone. E.g. the audio format used in the phone call could also be used for
software that is able to set up phone calls over the internet. The audio format
that is used for the orchestra movie could be used for audiophiles to store
their music on their computer. Besides taped audio and video the MPEG-4 format
also allows drawn pictures and animations. Also, MPEG-4 content does not have to
be limited to movies or audio, it can also be used for interactive content and
games. By combining multiple MPEG-4 technologies, you make one .MP4-file that
contains everything you like and that can be played on a wide array of
devices.


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