Design And Realization Of MPEG4-Based Multiple Hard Disk For Video Storage

Among the existing video storage systems based on MJPEG algorithm, wavellet algorithm, MPEG1 and MPEG2 algorithm, the first two systems have low compress ratio and nonstandard format, while the last two systems need to be compromised between the compression ratio and the picture quality. Our analysis shows that these methods are either expensive, not reliable, complacated, or having low data rate. To accord with the ISO/IEC standard and meet the requirment of large storage, it is necessary to improve the present video storage system. This thesis aims at the design and realization of MPEG4-based multiple hard disk for video storage.By choosing hardware compression chips from VB Coporation (USA), the system can process the picture in high speed and real time. The system has variable bit rate, hence low bit rate for still pictures and high bit rate for moving pictures. In this way, the system achieves both the high picture quality and reduced storage space. By comparision with other video storage systems in the same enviroment, the result shows that this system has higher picture quality and realtime quality for web transmission.Based on the related research, this thesis proposes a new method in building multi hard disk storage system. With this method, a new storage system with 16 hard disk is realized by keeping the present computer hard disk design, adding a CPLD chip and three 74HC16245 gate drivers. The multi hard disk system improves the storage capcity with high stability and high efficiency since there is only one hard disk in operation at anytime, no additional CPU resource is consumed.