[AG-TECH] High End Portable Access Grid System

Douglas Kosovic douglask at itee.uq.edu.au
Thu Apr 19 02:44:13 CDT 2007


Fred Dech wrote:
> It's only 8K on the Macbook Pro.  Not sure about the MacPro.  I don't have
> one handy.  I assume it's the same.
>
> --fred
>
> On Tue, Apr 17, 2007 at 01:36PM, Joseph Stone said:
>> Speaking of all ears, how is the audio quality with the Mac setup?
>> Is it still limited to 8 K samples / sec? The Accumics do a great job of 
>> delivering but it gets lost to the lower sampling rate.  We've found that 
>> to be a drawback for recommending Mac's as a platform for now.

It's a limitation of the osx audio code in rat, it doesn't matter which Mac 
model is used. The code needs to be modified to make better use of the 
features provided by Apple's Core Audio API. If I get a chance, I might look 
into modifying the code.

>> On Apr 17, 2007, at 11:52 AM, Fred Dech wrote:
>>>My biggest disappointment is that the Mac Pro will not tolerate multiple 
>>>IEEE 1394a DV inputs of the type we had planned (DAC200 DV from  Sony EVI 
>>>D100 svideo source).  It will handle 2 iSights.  It will handle one DV 
>>>and one iSight.  But that's it.

It's been a know limitation with the Quicktime DV Video Digitizer for the 
last decade, it only supports a single connection, see:
    http://developer.apple.com/qa/qa2004/qa1365.html

note: vic uses the Quicktime SequenceGrabber to capture from video 
digitizers and the IIDC Video Digitizer is used with the Firewire iSight.

> Video capture cards for a Mac Pro?  I'm all ears.

There are a number of PCI-e analog video PCI-e capture cards for the MacPro, 
e.g:

LFG4 (with 4 x Bt878):
http://www.activesilicon.co.uk/products_fg_lfg.htm

http://www.aja.com/html/products_macintosh_kona.html

I can't say how well they work with vic as I haven't tried them.

I have used an older PCI-X  LFG4 in a PowerMac, but can't remember what 
issues it had, if any. I used the LFG4 to develop and test the NTSC, PAL and 
SECAM support in aqua AG vic.

Cheers,
Doug





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