There is an increasing demand for the interaction between users and video streams. One example is the digital TV which will be popular in two years time. The advantage of digital TV is the interactivity it can do, not merely for a good picture. Users have a need to bring up the view in a special way. Another example is watching video in distance education scenario. There is a need to collect feedback from users and restructure the video presentation based on different responses. Video contains rich information. However, due to the organization of digital video streams, it is difficult to use hyperlinks similar to HTML links in Web pages. Video does not have the same hierarchical structure and organization as text.