It has been commonly recognized that multiple bit-rate (MBR) encoding provides a concise method for video streaming over bandwidth-fluctuant networks. The key problem of the MBR technique lies in how to seamlessly switch one bit-stream to another one. To tackle this problem, we propose a bit-stream switching framework based on the Wyner-Ziv coding. Within the propose framework, the multiple bit-streams can be individually encoded without data exchange, which also supports the random switching at any desired frame without affecting the original coding efficiency of the regular bit-stream. In particular, two different implementation schemes under the same framework are presented. Different from the traditional switching schemes, the proposed method can use the same switching frame for the switching from any other bit-stream to the current one, which means less storage and less encoding efforts. Simulation results and comparison between the proposed method and the traditional switching m...