Richmedia System Based On LASeR And The Streamer Of P2P Streammedia Live System

With the upcoming 3G age, communication network which is digital and IP besed has been developed into multimedia. However, multimedia technology could not been developed rapidly because of the differences in resolution of mobile end device, the constraint of resources and the shortage of relevant techniques. Currently, the screen of end devices is usually small, traditional pages don't perform well on it. In order to solve the problem, MPEG designed a lightweight SVG-based standard—LaSeR.LASeR employs richmedia ,which includes video, audio, cartoon, graphics, image, text and etc, as the basic elements of pages. Also, it makes use of scene tree to perform space and time layout of richmedia. Page could be zoomed freely according to the size of screens because vector graph could be scaled lossless. In addition, pefect transportation protocol stack, SAF, is designed in accordance with transportation of richmedia in LASeR in order to achieve the implementation of richmedia in 3G age.In this dissertation, LASeR based richmeida transportation system, is designed and implemented. The system achieves multiplex and transportation as well as playback of richmedia. In server, the system manages audio and video resources with help of database, MYSQL, so that program could make use of relevant resources expediently. Also, the system creates SVG scene layout file which organizes resources and utilizes space of screen efficiently to attain favorable visual performance. In addition, a new algorithm is designed to perform stream, synchronization, multiplex and transportation of audio and video resources in richmedia. It achieves little fluctuation of bit rate, ensures lip synchronization and maintains half fullness of playback buffer. After media stream is demuliplexed, the system adopts BATIK and JMF API to play back SVG scene file and streaming media, which achieve a good visual performance.The bandwidth of network is no longer bottleneck of development of streaming media as it increases rapidly. Nevertheless, server could not perform well because of consumers' rapidly increasing requirement of streaming media; therefore, the development of streaming media is slowed down. P2P as a new scheme to organize network decreases upload bandwidth of server and increases upload bandwidth so that network is more stable.In the dissertation, the streaming of P2P live sever is designed according to media file with ASF format. The semantics of ASF file is parsed so as to slice object and data unit. A loop buffer for publication is also proposed. Media is duplicated in the rate of playback according to the time stamp in data unit.