I have an OpenCV program that is supposed to use a webcam (in this case the built in laptop camera). The program compiles fine without error but when I run it the program seems to hang on the line:
img_scene = cvCaptureFromCAM(0);
I have a different program that access the camera in the same fashion so I don't understand as to why this program seems to be having trouble.
Full capture code from non-working program:
Mat captureThread() {
if(captureOpen == false){
img_scene = cvCaptureFromCAM(0);
cvSetCaptureProperty(img_scene, CV_CAP_PROP_FRAME_WIDTH, 640);
cvSetCaptureProperty(img_scene, CV_CAP_PROP_FRAME_HEIGHT, 480);
}
while(1) {
image = cvQueryFrame(img_scene);
if(image.empty()) {
continue;
}
cvtColor(image, gray, CV_BGR2GRAY);
return gray;
}
}
This is the code that is being used in a different program that is working as expected:
img_scene = cvCaptureFromCAM(0);
cvSetCaptureProperty(img_scene, CV_CAP_PROP_FRAME_WIDTH, 640);
cvSetCaptureProperty(img_scene, CV_CAP_PROP_FRAME_HEIGHT, 480);
while(1) {
imageFrame = cvQueryFrame(img_scene);
if(imageFrame.empty()) {
continue;
cout << "image frame is empty" << endl;
}
cvtColor(imageFrame, gray, CV_BGR2GRAY);
What is causing the non-working program to have trouble access the camera? I have also tried plugging in a USB camera and setting `cvCaptureFromCam(-1)` but it does not work either.
EDIT: The non-working program uses multiple threads whereas the working program does not.
I should also point out that this program previously worked as expected on a desktop PC running debian based linux. I have only had these problems when trying to run the program on a macbook running OSX.
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