The demand for applications like transmission and sharing of video is ever-increasing. Although network resources (bandwidth in particular) and coverage, networking technologies, compression ratio of state-of-the-art video coders have improved, unreliability of the transmission medium prevents us from gaining the most benefit from these applications. This thesis introduces a video coder that is resilient to network failures for transmission applications by using the framework of multiple description coding (MDC). Unlike traditional video coding which compresses the video into single bitstream, in MDC the video is compressed into more than one bitstream which can be independently decoded. It not only averages out the effect of network errors over the bitstreams but it also makes it possible to utilize the multipath nature of most network topologies. An end-to-end rate-distortion optimization is proposed for the codec to make sure that the codec exhibits improved compression performance and that the descriptions are equally efficient to improve the final video quality. An optimized strategy for packetizing the compressed bitstreams of the descriptions is also proposed which guarantees that each packet is self-contained and efficient. The evaluation of the developed MD codec over simulated unreliable packet networks shows that it is possible to achieve improved resilience with the proposed strategies and the end video quality is significantly improved as a result. This is further verified with subjective evaluation over a range of different types of video test sequences.
| Identifer | oai:union.ndltd.org:ADTP/258674 |
| Date | January 2009 |
| Creators | Biswas, Moyuresh , Information Technology & Electrical Engineering, Australian Defence Force Academy, UNSW |
| Publisher | Awarded by:University of New South Wales - Australian Defence Force Academy. Information Technology & Electrical Engineering |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://unsworks.unsw.edu.au/copyright |
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