Research And Design Of Terminal Players In Digital Media Distribution System

Media distribution systems have been increasingly popular thanks tothe rapid development of information society. At the same time, the re-quirements for terminal players in the system are growing continuously.Besides the capability to support various programs, user requirements alsoincludes automatic terminal management, remote control and extensibil-ity. For these demand, this thesis proposes a new architecture for digitalmedia distribution systems. The proposed architecture consists of a serverand terminal players. This thesis mainly focuses on the design and imple-mentation of the terminal players based on Android operating system.We choose to develop our terminal players on embedded Android de-vices due to its various functionalities, high potentials and low price. Ev-ery terminal player is an independent player, which can also communicatewith the server, accepting its control instructions. Terminal players shouldbe able to play web programs at the designated time according to theirplay lists, which are stored in the database on the terminal players. Theserver controls the behaviour of terminal players by remotely maintainingtheir play lists. The heterogeneous platform communication between theserver and terminal players utilizes the Web service technology, so that thesystem can handle requests from multiple terminal players.Apart from play control, terminal players must make smart planning onthelimitedlocalstorageinordertoincreasetheutilizationofstorageandprogramfles. Thisthesisproposedanewflereplacementalgorithmbasedon the fle storage scheme. The algorithm takes fle properties, historicalplaying records, and future playing plans into consideration to anticipatethe probabilities of programs being played in the future.The terminal player has been tested in the media distribution systemas a function component. The server succeeded in sending commands toand receiving information from terminals, distributing play lists and trans-mitting program fles. Programs in HTML format can play smoothly inthe Android terminal. We have also conducted simulation on the proposedalgorithm in our system. The result shows that the algorithm reduces theamount of downloaded data compared to conventional algorithms, whichin turn reduces the cost of network transmission.