| Traditional technology on playing out TV programs focuses on VTR,therefore,it is called tape-based TV broadcasting mode. With the development of digital information technology,DVB comes into being. Hard disk automatic Digital Playing-out and Control Systems ( DPCS ) are the current hot issue in the field of TV broadcasting. This subject is built upon a good many kernel and key technic,each of which is a significant subject in theory and application. Based on this background,the research in the technic of DPCS on audio & video (AV) is put forward,which has been emphasized by international academe and enterprise at the present time.This dissertation has studied some key technologies in the field of DPCS on AV.First,this dissertation gives a summarize about the development status of the alteration and upgrade in the TV broadcasting system,in which a serious of key technologies of DPCS,including digital compression codec technology,large capacity storage and fault-tolerance technology,network connection technology,and systems security mode,are stressed.Second,this dissertation implements separately a MPEG-2 video decoder and a Dolby AC-3 digital audio decoder based on software mode,and gives a audio & video synchronization algorithm based on audio-clock-benchmark in MPEG-2 system decoder,whose feasibility and practicability have been proved by experimenting. It is an all-purpose algorithm,which can perform different decoder according to MPEG-1 or MPEG-2 system models,and can also be used for reference to the implementation of other multiplex stream decoders.Thirdly,this dissertation gives a Synchronization algorithm of double work-stations' playing out based on digital reference information. This algorithm can support multiform digital medias,which take advantages of the serial-ports and socket resource effectively. The successful simulate implementation proved its feasibility.Fourthly,this dissertation expatiates the principium and implementation of multimedia synchronization & chaining mechanism based on event-driven,and applies it in the project of DPCS software practically. This method leads to more flexible control,expansibility and friendly user interface based on the thought of object oriented.At last,this dissertation discusses the principium and application of RAID technology,and concludes a serious of theoretic expressions in order to support a justified evaluating system of the reliability of RAID. |
