The Application And Research Of The Key Technologies Of The Hard Disk Play System

The hard disk play system not only has excellences in simplifying matters, saving labor, higher signal quantity and good scalable ability, but also perfectly fuses computer technique and audio technology. From safe, practical and convenient point of view, during the designing process, we have taken considered the actual circumstance and the effective and concrete demands of our play and TV station, and obtained an integral system by harmoniously dealing with the demands of advanced technologies and the practical and concrete demands. At the same time, with a view to the developing trend of the computing technology and the improving trend of intelligence, reliability, and scalability of the hard disk play system, we have reserved adequate scalable capacity to satisfy the demands for more hardware and software in the future.In this dissertation, not only is the structure of the hard disk play system analyzed, but the main works are to chiefly investigate the key technologies related to it and to introduce the problems when it is implemented and propose the solutions.First, the hard disk play system and its key techniques are discussed. The basic knowledge and the advantages of the hard disk play system are looked back in brief, as well as the fundamentals which must be considered when the hard disk play system is to be designed, such as the main functions, the composing parts, the key techniques. After why compressing is necessary and feasible when the video data is digitalized is discussed, MPEG-2, one of compressing technologies for digital video data, is mainly analyzed. There are two kernels: discrete cosine transformation and movement compensation. The former can reduce the space redundancy and has a good energy compression property, and also can quantize the coefficients of DCT according to the person's eye vision model. The latter can cut down the time redundancy, and adopt the forward prediction and the backward prediction. It can also greatly improve the compressing ratio when only encoding the predicted errors is adopted. As to the RAID huge quantity storage technique, why it is necessary to select the RAID technique in the play and TV industry is discussed according to the definition, the advantage and the classification of the RAID technique.