The Design Of Real-time Multimedia Storage System

Security industry has developed rapidly. Because of the widely used of Embedded DVR, thevideo security storage technology as the core technology of DVR becomes more and moreimportant. The Standard File System has general characteristics, and not to consider the use of theplatform, easy extensions. So this paper design the Real-Time Multimedia Storage System based onthe General File System. The storage system is composed with the local storage module and thenetwork storage module, support for video storage and snapshot storage and has better portabilityand scalability.First of all, this paper describes the development of Embedded DVR from the video codectechnology to software technology. And then introduce the architecture of Embedded DVR fromhardware architecture to basic functions.The Data Storage of Embedded DVR has lots of features, such as long duration of data storage,data transmission capacity, low data access and low life cycle. So this paper designs the storage oflibrary to achieve these features. This paper use C/C++ language to design the library and theposition in the embedded system is application layer. Points from the data storage location, thestorage library can be divided ino local storage module and network storage module; And pointsfrom the level of architecture, the storage library can be divided into disk management module,remote directory management module, work directory management module, file watcher module,database module, media files module, index file module, query file module and FTP server module.In order to facilitate the centralized management of local disks, this paper designs diskmanagement module to complete disk partite, format and so on. And the remote directorymanagement module is used to achieve to login or mount the remote directory. This paper providesa local partition or one remote directory corresponds to a working directory. And this paper designsthe work directory management based on the disk management and remote directory managementmodules to the switch of the types of work directory, loop coverage and other functions. The filewatcher module and database module achieve the asynchronous operations between data storageand the information of file. Meanwhile, the database module provides fast query interface base onthe database. In order to achieve the functions of files read or write, repair, index file storgae forsnapshot storage, this paper desigms the media dile module based on the database module and filewatcher module. To support video playback skipping, this paper designs frame index module,storage I frame of video. Meanwhile, the paper design the query file module, support for record filequery and snapshot query. Finally, the paper provides simple interfaces for the upper users to call. Finally, the paper tests the system functions and performance of the storage library. After thetest of storage libraty, the library realizes the basic functons of DVR storage, and in terms ofperformances, in the resolution of CIF, 1024Kb/S stream encoding format, CPU is not higner than30% when 16 channels record at the same time, and CPU does not exceed 25% when 8 channelsrecord and snapshot at the same time. So the storage library fully meet the storage needs ofembedded DVR.