Design And Implementation Of Digital Media Center

Digital media is the information that presented in digital form including computer-generated text, graphics, video, audio and animation. With the rapid development of multimedia communication technology and economy, it becomes the popular form in interchanging information. It enhanced the communication between people and enriched people's moral life.Digital media center is a multimedia application system with the functions of storing and retransmitting digital TV, movie, music, text and image. CMMB is the abbreviation of China Mobile Multimedia Broadcasting. Its main business is video broadcasting business. Because of the limiting of terminal hardware configuration, only the device with CMMB module can receive CMMB video programs. This paper proposed a digital TV broadcasting solution based on CMMB system and solved the dependency of CMMB module problem in intelligent terminal and provided a new digital TV broadcasting solution to digital media center.This paper analyzed the current situation of Digital media center and mobile multimedia broadcasting, proposed the existing problems and introduced the technology architecture, standards and solution of CMMB, encoding, transmitting and synchronous playing technology of streaming media and the most popular embedded operating system with its features. This paper designed the digital media center system based on CMMB standards and streaming media technology and realized it. The system consists of the CMMB-based broadcasting subsystem, the streaming media service subsystem and the web subsystem. It realized the receiving, demultiplexing, decryption and retransmitting of digital TV, the VOD and broadcasting of streaming media and the receiving of images and texts. The architecture, modules and system configuration of CMMB are expounded. The key technologies, such as the packaging and unpackaging algorithm during transmitting, the packaging, invoking of decoder and the synchronous playing of H.264 and AAC in Windows, Windows Embedded CE/Windows Mobile, Linux and Symbian OS are explained in detail. This paper designed and realized the digital media center server in windows and client in multiple operating systems.Finally, it implemented the testing and verification of software function according to actual situation. It works well and stable and meets the demands of users.