cvCreateCameraCapture returns null

Question

I\'ve got a webcam which is working perfectly in vlc, and is available as /dev/video0. However, whenever I use cvCreateCameraCapture, it returns null. I\'ve used 0,1,-1 as i

Answer 1

I also used OpenCV on Ubuntu (but from the standard repos). I had very similar issues and the solution I found was to compile OpenCV from source. I activated the --with-v4l option and it worked fine (you may also need some other flags, depending on your needs). If you compile OpenCV on your own, use CMake. There are also makefiles for "normal" make, but they are old.

Answer 2

I'm using OpenCV 2.1 on Ubuntu 9.04 and this works fine:

CvCapture* capture = NULL;
if ((capture = cvCaptureFromCAM(-1)) == NULL)
{
    std::cerr << "!!! ERROR: cvCaptureFromCAM No camera found\n";
    return -1;
}

Note that I'm using cvCaptureFromCAM() instead of cvCreateCameraCapture().