Real Time WEBCAM stitch

Real time video stitching-i need a source code for stitching together the inputs from four webcams and get the result in a single frame which contains the overlapped portion as well as the portions from the four [login to view URL] videos should be recorded and the results should be displayed in the time of recording [login to view URL] be implemented either in opencv or using matlab or EMGUCV, preferably EMGUCV. They could Use GPU for image sticthing and processing