[vorbis-dev] ogg pic format (again).. here's why
tme at 21rst-century.com
Fri Jan 26 21:09:50 PST 2001
Does anyone know how much a 3 or 4 D LOSSLESS compression could be
I have a feeling with video you could do a LOT better than Huffman encoding.
I remember that with Voyager, first pixel of each row was sent 16 bit (I
think), and then
each subsequent pixel was sent as a delta (from the previous pixel),
then runs were encoded, then
everything was formated in blocks with error correction,
with an average bit/pixel of like 3 or 4 or so, even over
landscapes (this was adopted originally as, for a pictures of moon
against black space,
long runs of black background could be in very few bits). (I may not
remember the steps in the
right order; it's been a long time.)
This is a 1-D lossless compression, with no fourier transforms or
I suspect that a factor of 10 would be easy,
and a factor of 100 possible, with lossless compression, if you went all
This, of course, would have some real attractions....
Multicast Technologies, Inc.
10301 Democracy Lane, Suite 201
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Phone : 703-293-9624 Fax : 703-293-9609
e-mail : tme at on-the-i.com http://www.on-the-i.com
Olaf van der Spek wrote:
> ----- Original Message -----
> From: <rillian at telus.net>
> To: "Gerry" <gerry at c64.org>
> Cc: <vorbis-dev at xiph.org>
> Sent: Friday, January 26, 2001 11:13 PM
> Subject: Re: [vorbis-dev] ogg pic format (again).. here's why
> > > The ogg video-format [...]needs a way to compress its
> > > frames. Are you going to use MNG for that ? :) ..
> > No. The advantage of MNG is that it offers lossless compression if you
> > it. Tarkin will be a (very) lossy encoder specifically for video; the
> > requirements there are quite different and are best implemented as a
> > format.
> > MNG can be used as a high quality "source" format for video such as one
> > for editing and effects work. Tarkin would be the final output format for
> > distribution.
> > It was also my proposal that we use MNG for overlays on top of tarkin
> > a la DVD subtitles. With text and other annotations the lossless nature
> > support of limited color palettes is a real win. And because of jng,
> > support for lossy continuous-tone images as well. (think "pop-up-video")
> AFAIK MNG doesn't support paletized images.
--- >8 ----
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