Interactive Compression Algorithms for Streaming Media Over High Speed Networks

This paper presents interactive compression algorithms for streaming media over high speed networks. An MPEG coded media sequence is typically partitioned into small intervals called GoP (Group Of Pictures). This structure allows a simple realization of forward (normal)-pay operation but imposes several additional constraints on the other interactive functions. Implementation of the rewind operations requires that the decoder either decodes the whole GoP and store it, or it decodes the GoP up to the current frame to be displayed. Both of these techniques lead either to the requirement for large storage at the client machine (to store a fully decoded GoP) or massive decoding processing power (to full), decode a GoP at required displayed frame rate). Neither of these options is desirable. Furthermore, Fast Play (Fast Forward/Jump Forward) functions of MPEG coded video present are problematic. When a P-/B-frame is requested, all the related previous P-/I-frames need to be sent over the network. This is likely to lead in considerable increase in communication bandwidth and decoding power compared to the normal-play mode. Several interactive algorithms are detailed with respect to server load /network bandwidth and decoder complexity. Finally an extensive comparative study has been carried out in order to determine the trade offs of the proposed approaches.