Capturing 1080p at 30fps from logitech c920 with openCV 2.4.3

Question

I'm trying to capture the video stream off of my Logitech C920 in OpenCV. With Labview I can access an MJPG stream at 30fps 1080p. In opencv I am limited to either 5fps or 640x480.

Here is the code relevant to the camera settings:

this->camRef.set(CV_CAP_PROP_FRAME_WIDTH, 1920);
this->camRef.set(CV_CAP_PROP_FRAME_HEIGHT, 1080);
this->camRef.set(CV_CAP_PROP_FOURCC,CV_FOURCC('M','J','P','G'));

These all return 1, yet I get a 5fps stream of 1080p which corresponds to the YUY2 stream.
If I add the following line:

this->camRef.set(CV_CAP_PROP_FPS, 30);

This returns 0. I get a 30 fps stream at 640x480. To me it looks like the MJPG setting isn't be accepted but I don't know what to do or how to fix that.

EDIT: The following crashes the program.

 this->camRef.read(this->image);
 std::cout<< this->camRef.get(CV_CAP_PROP_FOURCC)                            << std::endl;
 std::cout<< this->camRef.set(CV_CAP_PROP_FRAME_WIDTH, config.width)         << std::endl;
 std::cout<< this->camRef.set(CV_CAP_PROP_FRAME_HEIGHT, config.height)       << std::endl;
 std::cout<< this->camRef.set(CV_CAP_PROP_FOURCC,CV_FOURCC('M','J','P','G')) << std::endl;
 std::cout<< this->camRef.get(CV_CAP_PROP_FOURCC)                            << std::endl;

Then in my run code I have the following:

void camera::run()
{
    while(true)
    {
        if(this->camRef.read(this->image) == 0)
        {
           if(this->capture)
            {
                cv::imwrite(fileName,this->image);
                this->count++;
            }
        }
        msleep(15);
    }
}

EDIT2: Solution is to set the fourCC codec before setting camera height and width.

Answer 1

As the author of the post already found the solution but didn't add it as an answer I will put the solution here.

You have to set the codec before you set the wanted resolution:

this->camRef.set(CV_CAP_PROP_FOURCC,CV_FOURCC('M','J','P','G'));
this->camRef.set(CV_CAP_PROP_FRAME_WIDTH, 1920);
this->camRef.set(CV_CAP_PROP_FRAME_HEIGHT, 1080);