Forcing the use of TCP as the transport layer with the "?tcp" suffix is great if your camera supports it (some do not). Otherwise, you're stuck with these smeared frames triggering lots of false motion detection alarms.
One possible workaround might be to do the motion detection on the camera itself if the camera supports it (and if the camera can be made to work with zmtrigger.pl). The alternative is to spend a little more money and buy a camera which can do MJPEG streaming over TCP.