I refer you again to http://www.mathworks.com/matlabcentral/fileexchange/30849-image-mosaic-using-sift which shows calling SIFT to find matching points and then calls RANSAC to compute a model on the points.
If you want to perform the process on a video then you can put in a loop in which you read frames from the video and call the processing routine.
I note that your questions sound very much like you are working on an assignment or project. The volunteers are willing to guide you on assignments and projects but we expect you to do the real work. The code I linked to shows you that it can be done, and can be examined to figure out what the important parts are; you can then apply the ideas you have learned to writing your own code to do your specific assignment or project.
