Patching is a cost efficient multicast stream scheduling technique to provide true VOD services. However, one patching channel is dedicated for serving one client and can't be shared by others. Therefore, the duration of patching streams is decisive to the performance of patching. When request rate is high, the scalability of patching is poor. In this paper, we present an adaptive segment-based patching scheme which provides maximum sharing of either regular multicast stream and patching streams. Our simulation results indicate that the ASP scheme offers better performance, especially for popular videos which have high request rate.