VCR Functionalities with Adaptive Rate Adjustment in Streaming Media Server

Due to the decoding dependency of MPEG coded frames, lots of dependent frames are transmitted at video cassette recording (VCR) operations, thus more computation resource, hard disk and network bandwidth are consumed on streaming media server, and higher decoding complexity on Set-Top Box (STB). To tackle this problem, our scheme of supporting VCR functionalities with adaptive rate adjustment in streaming media server is proposed. The scheme includes a general VCR functionalities supporting method called GVFR which selects frames based on Group of Pictures (GOP) and uses Variable Frame Rate (VFR). Selecting frames based on GOP can efficiently eliminate the transmission of dependent frames, and the realization of VFR leads to optional transmission rate. Then an intelligent decision mode is introduced which automatically picks the appropriate GVFR strategies with suitable transmission rate based on the congestion status of the link. The experimental results demonstrate that GVFR can greatly decrease the transmission rate of fast forward/backward, to 22% of that of normal playback at least, and by varying GVFR strategies, VCR with optional transmission rate is achieved.