The camera will be deinitialized automatically in VideoCapture destructor.
Check this example from opencv docu:
int main(int, char**)
{
VideoCapture cap(0); // open the default camera
if(!cap.isOpened()) // check if we succeeded
return -1;
Mat edges;
namedWindow("edges",1);
for(;;)
{
Mat frame;
cap >> frame; // get a new frame from camera
cvtColor(frame, edges, CV_BGR2GRAY);
GaussianBlur(edges, edges, Size(7,7), 1.5, 1.5);
Canny(edges, edges, 0, 30, 3);
imshow("edges", edges);
if(waitKey(30) >= 0) break;
}
// the camera will be deinitialized automatically in VideoCapture destructor
return 0;
}
Also
cvQueryFrame
Grabs and returns a frame from camera or file
IplImage* cvQueryFrame( CvCapture* capture );
capture video capturing structure.
The function cvQueryFrame grabs a frame from camera or video file, decompresses and > returns it. This function is just a combination of cvGrabFrame and cvRetrieveFrame in one > call. The returned image should not be released or modified by user.
I hope this works for you. Best of luck.