Video communication systems with heterogeneous clients

Modern wireless mobile devices have evolved to small computers that can render multimedia content, while desktop/laptop computers have become more computationally powerful with faster Internet access. As these computing devices getting more popular, users demand for more and higher quality videos in many communication applications, where clients are heterogeneous in terms of network bandwidth and computing power. The goal of this thesis is to improve client perceived-quality of various video communication systems by adopting scalable video coding tools that enable efficient rate adaptation. We seek to understand scalable coding standards and design optimization and streaming algorithms to make the best possible use of them in practical systems. We consider practical problems of video communication systems in three different environments: Internet streaming systems, TV broadcast networks, and mobile video communication systems. We propose efficient algorithms to solve the considered problems. We evaluate the proposed algorithms using numerical methods and/or simulations. Most importantly, we design and implement testbeds to validate our algorithms. The expected results of applying our algorithms to video communication systems are better video quality and higher user satisfaction as well as better bandwidth utilization and lower processing overhead.