[AG-TECH] AG Grid dream system
dbaggett at cise-nsf.gov
Fri Sep 27 07:38:03 CDT 2002
Broadcast quality in my mind is really just a much more broad fuzzy term
that means video that looks pretty good. Its pretty un-scientific :-)
I've been informed by some on this list that there is work being done to
try out HDTV quality video over the grid, which would be interesting. As an
AG operator, and not a researcher my interest is really seeing if current
hardware that I could easily integrate into my current grid setup would
make a qualitative difference that is worth going out and replacing what I
have (currently dual 1Ghz systems with Matrox cards and WinTV capture
cards). I'm sure people have other higher end systems that are better than
what I have. I'm just curious as to results.
10:38 AM 9/27/2002 +1000, you wrote:
>At 11:21 AM 26/09/2002 -0500, Robert Olson wrote:
> >At 11:59 AM 9/26/2002 -0400, Douglas Baggett wrote:
> >>Just starting a discussion for thinking of how to get the video REALLY
> good. I'm competing with H.323 devices that companies like Polycom make,
> and at 2 Mb/s the Polycom video is broadcast quality and looks very good.
> The AG has so much more to offer, broadcast video quality can't be that
> far behind concidering how fast PC's and devices are lateley....
> >Do you know what protocol the polycom is speaking at that rate? is it
> h.261 or h.263? Also, does it spec what resolution?
>I think it'd have to be h.263, at 4CIF (VGA). h.261 is limited to
>CIF/QCIF, at N*64kb, and maxes at 1.5Mb/s (and you don't get much beyond
>about 1.1Mb/s). h.263 has a lot more going for it, including much larger
>and more flexible image sizes (multiples of 8x8 I believe, to almost any
>size). Polycom and Tandberg both support h.263 at 4CIF (at the high end of
>the product range).
>"broadcast quality" is an interesting term :-). I'm not aware if anybody
>has actually developed an analyser that looks at a video signal and
>measures delivered colour depth, frame rate, contrast/fractal dimension,
>etc. I see claims for h.263 (and mpeg4, which uses one flavour of it) of
>'broadcast' quality or 'dvd quality'.
> >(the difference is that the polycom gets to use a hardware h26X codec
> with full motion estimation, etc. the vic h261 encoder doesn't do motion
> est. Anyone know an opensource h26x encoder with that?)
>Not that I've seen. I haven't looked at the ITU sample code for h.263 -
>has anybody here? It's meant to be freely downloadable if you can work
>your way through the ITU registration system. I've used it to download the
>written specs, but not the software.
>Markus Buchhorn, ANU Internet Futures Project, | Ph: +61 2 61258810
>Markus.Buchhorn at anu.edu.au, mail: Bldg #108 - CS&IT |Fax: +61 2 61259805
>Australian National University, Canberra 0200, Aust. |Mobile: 0417 281429
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