listDevices() without declaring an ofVideograbber variable?

I have an application where I check for all available camera devices and initialise them. Currently I do this:

    ofVideoGrabber tvid;
    allCameras = tvid.listDevices();

    cout << endl << "Listing camera devices:" << endl;
    for(int i = 0; i < allCameras.size(); i++){
        cout << allCameras[i].id << ": " << allCameras[i].deviceName;
        if( allCameras[i].bAvailable ){
            cout << endl;
        }else{
            cout << " - unavailable " << endl;
        }
    }
    cout << "Total number of detected cameras: " << allCameras.size() << endl << endl;

    vid = vector<ofVideoGrabber>(allCameras.size());
    for (unsigned int i = 0; i < allCameras.size(); ++i){
        vid[i].setVerbose(true);
        vid[i].setDeviceID(allCameras[i].id);
        vid[i].setDesiredFrameRate(30);
        vid[i].initGrabber(camWidth,camHeight);
    }

It's the first two lines that I find a bit ugly. Isn't there a prettier alternative? Why not make listDevices() a static member function?

Start by reading the ofVideoGrabber::listDevices() declaration and its current usage in the example shown. Check how device enumeration is exposed across the project before deciding whether the API can be called without an instance. Done means providing a consistent, documented way to list devices or documenting why the current pattern is required.