View Full Version : problems with multiple capture sources

May 11, 2004, 12:47:16

I am currently evaluating MontiVision for use in our company and am trying to
build a multi-source capture filter with motion detection. I have tried several different configurations but none seem to work satisfactorily.

There are 4 cameras, but I'm only showing 2 for simplicity. The two configurations that come closest to what I need are:

(camera src) --- motionDetection --- colorSpaceConverter - mixingRenderer9
(camera src) --- motionDetection --- colorSpaceConverter /

where the camera color space is set at RGB24. In this configuration, the visualization of motion works but there seems to be a lot of 'interference' and noise in the rendered image.

The second configuration is:

(camera src) --- motionDetection --- AVI_Decompressor - mixingRenderer9
(camera src) --- motionDetection --- AVI_Decompressor /

where the camera color space is set at YUY2. This also has significant amounts of interference and the motion visualization is not rendered.

I am using high resolution on the (preview) pin in both cases of the camera properties, and the problem of interference is not apparent using either 1 or 2 cameras. However, it starts to appear after adding the 3rd (and subsequent) cameras.

Is there a resource issue or known limitation that I'm not aware of which prevents this from working or is there a problem with the graphs I'm using. Ultimately I will need to connect up to 16 cameras, so any help you can provide will be very much appreciated.

Thanks and regards,
Joe Johnson

Marc Cymontkowski
May 15, 2004, 21:34:53
Hi Joe,

No, there are no limitations in the software regarding the number of video sources, also your graph looks fine. To me this sounds like hardware (maybe bandwidth) issue. What kind of hardware are you using?

Best Regards,

Marc Cymontkowski

May 17, 2004, 14:59:57
Hi Marc,

thanks for the reply. I think you're right about the resources. According to documents I've read, the VMR9 primarily uses memory from the graphics card and not host memory. The card I'm using has relatively little memory which is probably the culprit. I did notice a continual degredation as I added more filters.

I have a new graphics card on order with 256mb onboard memory and will let you know if that solves the problem.

Thanks again,

Marc Cymontkowski
May 17, 2004, 15:26:46
Thanks for the update!