Support Backward Interactive Functions of MPEG –2 Stream

In this paper, we present an efficient approach for supporting rewind operations in MPEG-based stream. This approach is based on transcoding the Predicted (P)frames of the original MPEG stream as intra coded (I)-frames in order to create an “interactive” stream. After a P-frame is retrieved, transmitted, decoded and played out, we encode this frame as a sequence of I-frames and store it back to an additional storage at the client. Transcoding only the Predicted (P)frames of the primary stream to generate the secondary “interactive” stream results in less frame rate of the secondary stream. The frame rate of the secondary stream can be artificially increased by including so called P (M) marionette frames .The effectiveness of our approach in terms of reducing the allocated bandwidth of the interactive stream is evaluated through extensive simulations. Moreover the visual quality during the interactive mode is analyzed. Key-Words: MPEGReverse/Backward Operations--VCR control -Scanning operationsVideo Browsing