RBLAB

function webcamSupportedModes(minW:Number, minH:Number, maxW:Number, maxH:Number, fps:Number, step:uint = 20)
{
    var cam:Camera = Camera.getCamera();

    for (var w:uint = minW; w < maxW + 1; w = w + step)
    {
        for (var h:uint = minH; h < maxH + 1; h = h + step)
        {
            cam.setMode(w, h, fps);
            if (w == cam.width && h == cam.height)
            {
                trace(cam.width + " x " + cam.height + " @ " + cam.fps);
            }
        }
    }
}

webcamSupportedModes(320, 240, 1280, 1024, 30, 100);