Hello Jonathon,

We’ve been running Dell T5400 and Dell Precision 490 PC’s running WinXP SP3 for 
a few years.  We’ve tried both Spectra8 and Osprey 440 capture cards, but have 
been using Spectra8 most of the time.  AG3.1 worked well with 3 cams (Sony 
EVI-D100P’s) but adding a 4th on the Spectra8 caused black blocks of varying 
sizes to appear on 1 or 2 of the images. Sometimes these were about 1/10th of 
the image, other times ups to ½ of the image size. Since we generally only use 
3 cams that wasn’t a problem.  However with the low res of AG3.1 we were often 
pleased to use 3 cams so that we didn’t need to put very many people on each 
cam. 2-3 is about the most, as the faces become very much less distinct with 
more people in each shot.  We did find that using a Belkin S-video to USB 
adapter gave us noticeably clearer images than composite.  However we have only 
been able to use one adapter on these Dells.  Adding a 2nd causes one of the 
adapter images to freeze for 1-2secs about once per minute.  I’ve tried using 
different USB ports with no improvement, but haven’t tested with a powered USB 
hub.  However Tim Page at Auckland University Arts runs two Belkin adapters 
successfully on a Dell but I don’t remember which model. He gets no freezes.

Regarding audio:  We use the on-board audio using line input and outputs 
connected into a Nexia VC on several PC’s and Clearone Converge 560’s on 4 
other PC’s.  The on-board audio works well, but there is one aspect which needs 
to be allowed for:  Most on-board and consumer soundcards can take a maximum 
input level of about +1-2dBV (about 2Vpeak on many systems) before hitting 
digital clipping.  That means that if you don’t have a peak level meter, then 
-15dB is about the maximum you can run without hitting digital clipping.
Many of the soundcard manufacturers seem to use people of limited intelligence 
to design the on-screen controls, and many can be very tedious or frustrating 
to use.  Some feature “intelligent” configuration such that if you momentarily 
unplug a connector, everything will be reconfigured to another default. Allow 
plenty of time in configuration for sorting out the audio!
Regarding Creative: After several emails to creative to find out specs for 
their various soundcards, I’ve been told they won’t release that info because 
it is confidential.  Most other manufacturers have no problem displaying the 
tech specs for their cards, so Creative are totally off my list. Imagine buying 
a new car and the manufacturer won’t tell you how fast it would go or what size 
engine etc because that was confidential!

On the soundcard subject be aware that many consumer cards have very low gain 
on mic channels. Of six that I’ve measured, the gains ranged from 6dB (yes 
6dB!) to 40dB, which means they are not suitable for dynamic microphones.  
However since most use powered or electret types, that won’t be a problem.

We’ve used both Datapath Vision RGB Pro-02 and E1 capture cards. Both need the 
phase to be adjusted for each different source to eliminate the rainbow 
fringing. During testing with AG3.2 last year, we found we could only use one 
input of the Vision RGB cards, but this may have been corrected in subsequent 
updates.

There are several aspects of running HD video on AG3.2 which are yet to be 
clarified. In general terms, since AG only uses a single processor, video 
processing is likely to overload the system and slow it down when more than a 
few sources are being displayed.  Hopefully we’ll get some detailed results 
from testing over the next few weeks.

Regards,
Lloyd Pearson
AVCC Operator
University of Otago
Ph +64 3 479 8997
lloyd.pear...@otago.ac.nz<mailto:lloyd.pear...@otago.ac.nz>

From: 
ag-tech-boun...@lists.mcs.anl.gov<mailto:ag-tech-boun...@lists.mcs.anl.gov> 
[mailto:ag-tech-boun...@lists.mcs.anl.gov]<mailto:[mailto:ag-tech-boun...@lists.mcs.anl.gov]>
 On Behalf Of Jonathan Klubek
Sent: Saturday, 26 February 2011 3:30 a.m.
To: ag-t...@lists.mcs.anl.gov<mailto:ag-t...@lists.mcs.anl.gov>
Subject: [AG-TECH] Access Grid Hardware/Software Questions

My group at our university was recently tasked by one of our departments to 
construct an access grid facility (this facility will also function for other 
types of conferencing and classroom needs also).  After much reading we have 
determined many pieces we need to get including things such as several 
ClearOne, Crestron and Extron products to control the various audio and video 
pieces ranging from scaling windows on the projectors and switching sources to 
mixing and cancelling echo on the microphones on the various tables.   The 
problem we are running into in examining everything is with the access grid 
machine itself.  We have looked at the technology and many of the pieces of 
hardware are many years old and we are seeing possible issues with integration 
as things such as PCI are replaced with PCI-e.

We are looking at going with a Dell Precision workstation T7500 to be the 
access grid machine and have thought about adding more memory and a second 
processor to it (remember that it will serve multiple purposes. .  My questions 
are the following:


1.        I see that the software is listed for Linux, OS X, and Windows.  We 
most likely will be going with Windows so we can support Microsoft Link also.  
This software is listed for Windows XP but does it work with Windows 7 32-bit 
and 64-bit.  This is extremely important with Windows XP support coming to a 
close.  Also, with the increased resources we plan to use it may be necessary 
to use 64-bit to take advantage of things such as 4+ GB of memory.

2.       As mentioned before the technologies listed are out of date.  We are 
especially seeing this with the video capture cards and audio cards.  I was 
wondering if the following would be supported:

a.       SoundBlaster X-FI XtremeMusic (D)w/Dolby Digital 5.1 (this was the 
card option on the Dell) – if not is there a newer card than the one listed 
that is?  We will of course need to integrate with our other products.

b.      Datapath VisionRGB-E1 PCI-e RGB/DVI capture card

c.       Osprey Osprey-450e PCI-e Analog video capture card

If not we are looking for several recommendations of much newer technology that 
is supported as we see this to be extremely important.

Jonathan

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