| Video on the internet could very well be the next big
thing. Whether this means 10,000 channels of television
or downloadable movies is uncertain. In order for
video to become ubiquitous on the net, significant
advances in video compression technology need to be made.
For example, an MPEG-2 movie requires approximately
6 gigabytes of storage which necessitates a DVD.
What if we could fit the same movie on a 600 megabyte
CD? This is the kind of claim that the recent
MPEG-4 and DivX proponents would make.
At the LML, we have found that it is possible to put
a full resolution movie on a CD using MPEG-4. So,
this much of the hype is indeed true. However, the
movie is not at the same quality standard as the
original MPEG-2.
So, one would logically ask how much gain the
MPEG-4 codec brings? At the same level of visual
quality, how much can a movie be compressed using
MPEG-4 beyond MPEG-2?
In our tests, a 6 gigabyte MPEG-2 movie can
be reduced to a 4 gigabyte MPEG-4 version with
negligible loss in quality. This is where DivX
would sell their hype. Specifically, on their
homepage they claim a 10 to 1 reduction at the
same quality level. Hype!
MPEG-4 is an advance in video compression, but
it generally is used in situations where the
video is degraded to a point where obvious
compression artifacts arise. You can put a
movie on a CD with DivX, but you may not
want to watch it afterwards. |
