SP-frame is a new picture type supported by H.264. The traditional usage of SP-frames is for switching between different compressed bit-streams. In this paper, we proposed and evaluated a scheme that uses SP frames as a mechanism to switch within a single compressed stream for the purpose of achieving error resilience and rate scalability. We have only considered the restricted but practical case in which only one secondary SP frame is allowed for every primary SP frame. Nevertheless, simulation results show that the technique can significantly increase the chance of video frames meeting their deadlines, and also improve overall PSNR.