revVideoGrabber: stop preview doesn't hide video window

Richard Miller wow at
Sun Aug 8 08:48:26 EDT 2010


We limit grabs to 3 minutes now, but I suspect we could go longer. It 
really depends on the processor and camera involved (and probably the 
audio input source as well)... tremendous variability. Only testing will 

We sell a customized "kiosk" driven entirely by Rev. This kiosk now uses 
a dual-core Pentium and a machine-vision camera capturing at 60 frames 
per second, all under Windows 7. We had problems when using a slower 
Atom processor, but the new processor allows the videograb functions to 
work much more smoothly. For example, even during video capture, the 
live Preview screen still shows fluid motion. Before, it would be jerky 
and only show perhaps 1/4 of the actual frames.

We're not seeing any syncing issues with the audio using this 
configuration. No crashing. No problems.


On 8/8/10 5:05 AM, Ben Rubinstein wrote:
> Thanks, Stephen and Richard.
> Because I'm selfishly focused on my immediate needs, can you clarify 
> "long grabs" and "problems"?  Are long grabs like Stephen's two hours, 
> or would five minutes qualify?  Are problems sync drift, or crashing, 
> or memory leaks, or... something else?
> My application will probably not be doing more than a few minutes per 
> clip - but it will be doing lots and lots of them over a day. 
> Obviously I'll be testing this for myself - but it would be good to 
> have tips on what to look out for.
> Many thanks,
> Ben
> On 08/08/2010 01:54, Richard Miller wrote:
>> Yes. Long grabs are where we've encountered problems.
>> Richard Miller
>> On 8/7/10 11:35 AM, Ben Rubinstein wrote:
>>> Is it long grabs (my next set of tests) that is the problem?
>>> Many thanks,
>>> Ben
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