Adopting SP/SI-frames in dual-bitstream video streaming with VCR support

Abstract

Digital video cassette recording (VCR) operations such as fast-forward and fast-reverse playbacks enable quick and user-friendly browsing of video. However, the predictive techniques adopted in current video standards severely complicate these operations. One approach to implement the fast-forward/reverse playback is to store an additional reverse-encoded bitstream into the server. Once a client requests a fast- forward/reverse operation, the server can select an appropriate frame for the client from either the forward or reverse-encoded bitstreams to reduce the network traffic and the decoder complexity. Unfortunately, the forward and reverse-encoded bitstreams are encoded separately. The frame that has previously decoded by the client may not be exactly identical to the reference of the current selected frame and the mismatch problem occurs frequently. In this paper, a novel H.264 dual-bitstream scheme aiming at providing fast-forward/reverse playback based on SP/SI-frames is proposed to eliminate mismatch errors during switching between the forward and reverse encoded bitstreams. As a result, the proposed scheme enhances the performance of the conventional dual bitstream scheme.