RE: Data Compression

John W. Osborne (josborne@magna.com.au)
Sat, 6 Apr 1996 06:37:04 +-1000


Jay, et. al.,

<snip>

> With video/audio data like CU-seeme, it's useless, but for other
> peripheral data, who knows?

Not true. Video data is not random. It has very obvious patterns.
Compression works by looking at repeatable patterns and reducing the
information being sent in those patterns. Some forms of compression
are better than others, MPEG for example is a "better" compression
algorithm than is V42Bis for video, but V42Bis does still give some
compression on non-pre-compressed video. The same holds true for
audio.
<unsniip>

But then that begs the question, how much compressing, if any, is Cuseeme
doing the the video and/or audio data that it acquires before shipping it to
the modem? And, from comments made about compressing data via the
modem that has already been compressed before delivery to the modem
actually slowing things up: would one be better off, throughput-wise,
disabling compression when using CuSeeMe?

John