Date: Tue, 8 May 2007 22:01:12 -0700 From: "Ted Mittelstaedt" <tedm@toybox.placo.com> To: "Gary Kline" <kline@tao.thought.org>, <usleepless@gmail.com> Cc: FreeBSD Mailing List <freebsd-questions@freebsd.org> Subject: RE: Another slightly OT q... Message-ID: <BMEDLGAENEKCJFGODFOCKEAOCAAA.tedm@toybox.placo.com> In-Reply-To: <20070509021840.GA41793@thought.org>
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> -----Original Message----- > From: owner-freebsd-questions@freebsd.org > [mailto:owner-freebsd-questions@freebsd.org]On Behalf Of Gary Kline > Sent: Tuesday, May 08, 2007 7:19 PM > To: usleepless@gmail.com > Cc: Gary Kline; FreeBSD Mailing List > Subject: Re: Another slightly OT q... > > > > So it *was* a hoax? Rats. Some weeks ago on Public > Broadcasting, a few sentences were spoken on the potential of > fractal geometry to achieve [I'm guessing] data-compression on > the order of what Sloot was claiming. So far, no one has figured > it out. It may be a dream... . > There's some cool math out there that explains all of this but I never liked math, but it isn't necessary to know the math to understand the issue. Just consider the problem for a while and you will realize that the compression ratio of a specific data stream varies dependent on the amount of repetition in the input datastream. A perfectly unrandom datastream, like a constant series of logical 1's, carries no information, but has a compression ratio that is infinite. A perfectly random datastream, on the other hand, also carries no information, but has a compression ratio that is zero. I believe that a datastream that is 50% of the way between either extreme carries the most information, and I believe your typical datastream is much closer to the perfectly unrandom side than the perfectly random side, compression is merely the process of pushing the randomness of the stream closer to the random side. Thus, if the input datastream is very close to the perfectly unrandom side - meaning it has a very high amount of repetition in it, you can get some pretty spectacular compression ratios. But as you move closer to unrandom, you carry less data. So, the better applications emit datastreams that are less unrandom, therefore compression does not work as well on them. This of course is completely ignoring the other data issue, is the application data efficient to begin with? For example, you can transfer about a page of information in ASCII that consumes about 1K of data, that same page of information in a MS Word file consumes a hundred times that amount of space - Word is therefore extremely inefficient with data. Probably the worst offender of this are the news websites like www.cnn.com. They insist on putting more and more news articles into videos rather than just a couple screens of text. I just do not see any benefit to the consumer of a video of an interview with someone like George Bush, when the video consists of 2 sentence fragments. The entire story could be written on a webpage, sans video. Do they really think the typical reader doesen't know what he looks like already? I see this a lot with audio files, also. For example, how many times have you come across an .mp3 file that was of speech only - perhaps a professor's lecture - that's been recorded in CD quality full stereo? A .wav file recorded at the lowest sampling rate in mono, which is perfectly acceptable for speech, would be smaller. Ted
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