[AG-TECH] Have we looked at vBrick?
Markus.Buchhorn at anu.edu.au
Wed May 23 19:52:41 CDT 2001
At 06:54 AM 23/05/2001 -0500, Robert Olson wrote:
>At 11:20 AM 5/23/2001 +1000, Markus Buchhorn wrote:
>>I have some new cards here that I'm just starting to play with.
>>"Realtime" (we'll see) MPEG2 encoder for under $US1k, decoder for under
>Are these the kfir-based cards?
No - Sigma Designs (ex Creative RealMagic) who do the Hollywood+ card and
their Digital Video Recorder (DVR) (and offer OEM chipsets):
(which only writes to disk at this stage; give me time ;-) )
which apparently handles "streaming" video, without *any* indication of how
that video gets onto the network in the first place (MPEG/ATM,
MPEG/Ethernet, IP and multicast - they get mentioned, but no indication of
*how*). It may be that it uses one of the MPEG/Layer2 transports, with an
"out-of-band" IP channel for control. Great for the LAN maybe, not much
chop on the WAN.
They also have a set-top-box and developers kit, but again may be layer2
Their general decoder card is the Hollywood+ - I use it for my PC-DVD, and
it is excellent. Again, no hooks yet for receiving streaming content, but
I'm working on that too :-)
I hadn't seen the kfir card, I might grab one and check it out.
>The linuxtv folks
>have linux drivers for this mpeg2 encoder. Unfortunately, it has some
>issues on some motherboards, including the one on the machine I was
Sigma are quite linux friendly, and have linux drivers for (most of) their
various cards. The encoder is Windows specific at this stage, but I can
work with that. I haven't seen any motherboard issues raised on their
(news://news.sdesigns.com/) One of their techs hangs out there regularly.
>>MPEG1 would be a nice intermediate option, since you can go to decent
>>PAL/NTSC resolution at 30fps within 1.5Mb/s. The h.261 codecs are CIF
D'oh - Of course. Thanks!
>>and (are designed to) run well under 1.5Mb/s. (it's N*64kb/s to support
>>the ISDN world)
>There's a realtime MPEG1 software encoder available for Linux.
Do you have a URL for that?
>The issue there is integration with vic (the simple solution of breaking
>up the bytestream into packets and sending dumbly over the net breaks
>badly) and the MPEG over RTP profiles.
We really need somebody to develop a nice OSS library for rfc2250 - I can
generate mpeg1 and mpeg2 elsewhere, and all we then want is to dump it onto
a socket/pipe. Several bits are around, but nothing totally correct/useful yet.
There's an open source client (with multicast and sdp/sap support) at
http://videolab.uoregon.edu/mim/ . Cisco have apparently also made their
ip/tv client freely available, like IBM's videocharger client.
>>At the lower end, is anybody doing something with H.263 (very low
>>bandwidth)? It's a big area of interest now, as MPEG-4 uses it, and the
>>PDA/cell-phone companies are very keen on it.
>There's an h263 encoder in vic, but it is very slow. We have interested in
>H263 since it supports higher resolutions, something we'd like for doing
>some sci vis stuff.
Cool. My version of vic must be way out of date by now. I understand that
h.263 is more CPU-intensive to encode, clearly it needs a high-end box.
When you say 'slow' do you mean high-latency, and/or you drop the frame
rate? How high resolution-wise can h.263 go?
Does this vic also support m-jpeg? I had a feeling it did at one time, but
not at resolutions above CIF :-(
>>Conversely, some UWash/Stanford guys are playing with realtime HDTV
>>(40Mb/s at tolerable latency, 270Mb/s for pure I-frame low-latency :-) ).
>>Point-to-point only so far that I am aware of. There's also an
>>internet-draft for raw HDTV over RTP(modified) - 1.48Gb/s :-) Plus I know
>>NEC make some big (3 gun) projectors that have 2500x2000 display space
>Woo, cool. SC fodder :-). Is the HDTV gear all still way expensive, or is
>the market starting to bring the prices down?
Pass, but probably "yes" and "yes" :-). The projectors are certainly coming
down. At the I2-Members meeting in Seattle in Oct'99 they had two Sony
projectors, each around $US50k mark. Now NEC's are closer to $US10k. That's
a great start :-) Is anybody on this list at Stanford? They had a video lab
with HDTV video equipment (recorded and live)...
Hmmm, of course - does anybody want to play with real-time multi-camera
>>How flexible is the AG setup to putting in other codecs or indeed other
>Fairly flexible now, will become much more so in the next major turn of
>the crank. If someone had a new codec and RTP framing code it would be
>fairly straightfoward to add to vic.
Could it run in a completely separate process, say even on another box? My
initial interest is in developing a streaming (rtsp, mpeg) system, but it
will be used for live content as well. If there were some hooks in vic to
signal another process (or box) over the network it would be a very
flexible set up to bolt something new/unusual into the AG. Maybe some kind
of driver shim that fools vic's UI into thinking it is talking to a real
On a tangential topic - is anybody doing stereo video over the AG? Another
interest of mine :-)
Markus Buchhorn, Faculty of Engineering and IT, | Ph: +61 2 61258810
email: markus.buchhorn at anu.edu.au, mail: CSIT Bldg #108 |Fax: +61 2 61259805
Australian National University, Canberra 0200, Australia |Mobile: 0417 281429
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