Two fast bitstream switching algorithms for real-time adaptive multicasting of video

Bitstream switching is an effective way to deal with the bandwidth variation issue in transmitting multimedia over the Internet or wireless networks. This paper proposes two new fast intelligent bitstream switching algorithms that aim to minimize the drifting error while avoiding the problem of long delay and high complexity that often occurred in prior solutions. The basic ideas are to choose a switching point in the most stationary neighborhood or in a neighborhood with the highest encoding quality, within a switching window determined by the switching delay constraint. We show that they can achieve performance that is closer or even identical to an off-line MSE-optimized bitstream switching solution, when compared to the algorithm we previously presented in B. Xie et al. (2003). They are especially useful in the scenario of real-time multicasting over heterogeneous networks, where multiple bitstreams with different bitrates are generated on the fly and dynamic bitstream switching is required for individual clients.