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dpat12
October 5, 2010, 04:50:30
i have 4 cahnnel PCI bt878 card . i wanted to display two video stream on screen at a time .

should i create two grabber object and then assign video channels to them . then how to switch between different video channels

Stefan Geissler
October 5, 2010, 07:40:32
Hello,

if your grabber board has only one digitizer, that means only one BT 878 chip on board, then you can display only one live video stream, not two at one point of time.

While the live video is running, you can switch between the input channels by using the setInputChannel() method:
http://www.imagingcontrol.com/en_US/support/documentation/class/meth_descGrabber_setInputChannel.htm
You do not need to call "stopLive()" and "startLive()" for changing the input channel.

Please keep in mind the change of the input channel requires the digitizer to synchronize to the video source, i.e. the camera. This takes some frames and can last up to 200ms, depending on the video source.

dpat12
October 5, 2010, 11:48:51
yes it has only one chip so i need to keep on switching input channels in some kind of timer ?

Stefan Geissler
October 5, 2010, 15:35:43
yes it has only one chip so i need to keep on switching input channels in some kind of timer ?
Yes, this is the only way.