Dual-plan bandwidth smoothing for layer-encoded video

Traditional bandwidth smoothing techniques can be naturally supported by the renegotiated constant bit rate (RCBR) service model, but renegotiation failure in RCBR may cause buffer underflow and interrupt the playback of video. To address this concern, a novel dual-plan bandwidth smoothing (DBS) scheme is proposed in this paper by taking advantage of the SNR scalability of layer-encoded video. Upon renegotiation failure, the proposed scheme can adaptively discard certain enhancement layers to guarantee continuous video playback at the original frame rate. Experiments are carried out to demonstrate the validity of the proposed scheme. The impacts of renegotiation interval, granularity of enhancement layers, and playback buffer size on resulted video quality are also studied. From the simulation results, it is shown that the performance of the RCBR-based DBS scheme can be improved by 1) reducing the minimum time gap of renegotiation interval; 2) employing multilayer video encoding with finer granularity; and/or 3) increasing the playback buffer size.