v.crop v.crop takes 4 arguments defining the left, top, right and bottom of a cropping rectangle. v.crop takes 4 arguments defining the left, top, right and bottom of a cropping rectangle. v.crop outputs a stream with the size of the crop rectangle, cropped to the rectangle. N.B. v.crop tags each video frame with the top and left of the crop rectangle. This allows v.composite to re-composite a fragmented stream without requiring extra position messages to each v.composite inlet. These (left, top) offsets persist in a stream until the stream is processed by something that makes the information irrelevant (i.e. a v.composite). There is an option to v.composite that turns this feature on and off.

from the library : softVNS Format : External Environment : jitter / max commercial Max 4.x http://homepage.mac.com/davidrokeby/softVNS.html