Reducing playback jitter for high quality audio and enhancing video bit-rate adaptability for multimedia streaming services

Abstract

In typical communication network environments, since message communication delays show jitter, that is, varying degrees of irregularity, it is necessary to realize streaming over a network in such a manner that the impacts of communication delay jitters appear in minimal forms in the play of the stream at a remote play site. On the other hand, the local delay jitter also can be introduced in end-systems because of scheduling irregularity of Operation Systems and time-stamping errors. Such reduction of the impacts of communication and local delay jitters is called the end-to-end jitter tolerance. It is a key issue in realizing high-quality streaming through communication network and end-systems. A fundamental approach that holds great promises in this area but has been minimally exploited by the research community is the global time based coordination of distributed actions. In this dissertation, we study and report the results of high-quality audio streaming by enhancing local jitter tolerance of the end-system in conjunction with compensating transmission jitter bounded within a predefined range. The Internet, meanwhile, is a best-effort network, which implies that the quality of service is not guaranteed in such networked multimedia systems in terms of minimum bandwidth, maximum jitter or delay, or loss. This requires that the end systems should properly react to the change of network situations, especially to congestion, to get the desired quality of service. There are two key points to maximize the effects of adaptive streaming. Firstly, fine-grained scalable storage is for the higher scalability of the video stream. Secondly, layered rate adaptation is for the precise selection of the sending layer to adapt the quality of service (QoS) requirement of the dynamically changing network. In this dissertation, we study a many-fold layered encoding mechanism that can provide fine-grained scalable storage, hence, improves the degree of QoS adaptability. Our schem...