Due to high bandwidth resource requirement

how to support the digital video cassette recorder(VCR)functionality is a key problem in practical video on demand(VOD) systems.Based on the investigation of the impact of the frame rate on quality of perception(QoP)

an effective algorithm which selects frames by cooperatively adjusting the frame rate and position is proposed.The proposed algorithm presents a VCR operation model

and adds two constraints conditions to the fast forward and fast backward operations: bandwidth requirement and time limit.Based on MPEG dual-stream

the algorithm meets two constraint conditions by adjusting the frame rate and the frame’s position which would be displayed.Simulation results show that the proposed algorithm can effectively reduce the network bandwidth requirement of the VCR operation

while keeping good QoP.The proposed algorithm outperforms the dual bit-stream algorithm

which only needs about 90 percent of the mean bit-rate bandwidth.The method was already successfully deployed in Shanghai national high-tech research and development plan(863)IPTV systems.