'**SUMMARY**
Get the current frame number of the video source.
Available for only video sources.
**RETURNS**
* *int* - number of the frame
**EXAMPLES**
>>> cam = VirtualCamera("filename.avi", "video", 120)
>>> i=0
>>> while i<60:
... cam.getImage().show()
... i+=1
>>> cam.skipFrames(100)
>>> cam.getFrameNumber()'

def getFrameNumber(self):

    if (self.sourcetype == 'video'):
        number_frame = int(cv.GetCaptureProperty(self.capture, cv.CV_CAP_PROP_POS_FRAMES))
        return number_frame
    else:
        return self.counter
