A novel decoder-downloadable system for content-oriented coding

In this paper, a new system architecture called decoder-downloadable system is described. The purpose of this system is to provide a uniform platform for the multimedia world based on image compressions using characteristics of the contents. This system enables dynamic decoder downloading by negotiation between servers and clients for seamless and minimum delay playback. This negotiation scheme is implemented by Java and CORBA (Common Object Request Broker). Thus, servers and clients in this system are independent from OSes and hardware specifications. This system is suitable for TV broadcasting as well as Internet streaming. We improve a decoder architecture in order to make the system more flexible. A decoder has some functions such as bitstream parsing, image compression algorithms (DCT, Wavelet, Motion estimation and so on). However, conventional decoders are monolithic software. Thus, it is impossible to share parts of decoders. The proposed method enables a module-based decoder and sharing some modules among some decoders. Consequently, the flexible decoder can make downloading time shorter by avoidance to download redundant parts of decoders. It also achieves scalability enabling this system to be used in some multimedia applications, such as a multimedia content search system, as well as a multimedia player.