I am trying to use stereo cameras. I have two logitech c525s. The first camera opens fine and displays images but when I use the VideoCapture.open() command to open the second camera, the program hangs. I can access each camera individually.
I am using Windows 7, Visual Studio 2010 and C++ Windows device manager sees both cameras individually.
Is there something I am missing or neglecting to do?
sounds like you're trying to open both captures on the same device id(-1, the default), instead try :
VideoCapture cap0(0);
VideoCapture cap1(1);
// later:
while( cap0.isOpened() && cap1.isOpened() ) {
Mat frame0; cap0.read( frame0 );
Mat frame1; cap1.read( frame1 );
// stereo processing here
}again, all i'm saying is: 2 cams need 2 seperate id's
Are this USB camera's? It is possible that your hardware USB bus cannot power two camera's at the same time. If it are ethernet camera's then it is possible they have the same ip configuration in your network?
Was just debugging the same problem (but with Logitech C270's), and @StevenPuttemans comment was the solution. When both cameras were powered from the same USB hub, I saw the hang. The problem disappeared when they were powered separately.
Yep same problem here, you need seperate USB busses in order to address two cameras at same time. Else they are interleaved but thats not interesting for software purposes.
Hi! having two video input devices doesn't mean automatically that their IDs are 0 and 1, did you try to access the second camera alone with the ID 1 ? I have two cameras and here what I've tried and it worked :
int main (){
cv::VideoCapture cap(0), cap2(2);
int key = 0;
cv::Mat frame,frame1;
while(key != 27){
cap2 >> frame1;
cap >> frame;
cv::imshow("0",frame);
cv::imshow("1", frame1);
key = cv::waitKey(10);
}
cap.release();
cap2.release();
return 0;
}Asked: Aug 26 '13
Seen: 17,396 times
Last updated: Feb 06 '14
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Pls. post relevant code. It helps.