| The use of real-time streaming applications is expected to grow, and the lack of a quality of service (QoS) guarantee in current Internet poses many challenging issues that need to be addressed. Effective video streaming system is necessary to enhance resource utilization and the delivered stream quality. Because of its excellent rate adaptability and reasonably small server involvement, an embedded/progressive video encoding technique serves as an excellent framework for developing a video streaming application. The objective of the proposed research is to investigate new QoS support techniques for progressive video transmission.; First, a new rate-shaping scheme is designed to dynamically adjust the stream bitrate to varying network conditions. The video encoder can scale the spatial, temporal, or signal-to-noise ratio (SNR) resolution to decrease the bitrate. We study which particular combination of these three scalability options needs to be employed to maximize the perceived signal quality. The optimal rate-shaping procedure depends on the video compression scheme and the scalability it supports. We perform both qualitative and quantitative evaluation using MPEG coded video and video sequences coded with a 3-D subband coder. Next, we proposed a novel soft caching approach for streaming media over the Internet. Employing an embedded video coding technique, the proposed method allows video to be cached at various rates. A proxy server determines the optimum rate at which a video needs to be stored based on client capabilities, stream access frequency, and available network bandwidth, such that the delivered video quality is maximized under various delivery conditions. The impact of the caching algorithm on the delivered stream quality as well as the network load is explored under different access profiles and network conditions. |
