Improved techniques for dual-bitstream MPEG video streaming with VCR functionalities

In this paper, a new dual-bitstream technique for video cassette recording (VCR) functionality and a transcoding technique of the motion vectors (mv) between dual bitstreams are introduced. In the dual-bitstream technique, a direct reference bitstream is proposed to replace the original reverse bitstream to reduce the required network bandwidth and decoder effort of VCR requests. In the transcoding technique, the mv in the forward bitstream are first reused to generate the mv in the reverse bitstream and the direct reference bitstream. If the obtained error is larger than a preset threshold, the mv are refined step-by-step from the inner to the outer of a refinement window.