Research And Implementation Of The Digital Television Business Information And The Epg / Nvod's

Digital TV (DTV) Service Information (SI) standard is the basis of multi-program transmission, Conditional Access (CA), Charge system, Electronic Program Guide (EPG), multi-media system and other value added services. EPG is the graphic user interface which implements the interaction between users and DTV, it's a crucial part of DTV system. Users can be free to browse and query the program information and other service information effectively through EPG. Near Video On Demand (NVOD) is also a very important value added service in DTV system, it can store videos in servers and play them in more than one digital channels with time-shift, so users can order programs they want, and watch the program in several minutes.For the time being, DVB (Europe) is the most flexible and widely used protocol in all DTV standards. In this cable DTV Set Top Box (STB) project for degree, I choose DVB protocol, and ST Sti7710 as main MCU chip, ST-OS20 embedded operating system as software platform. Below is the process of my work:Firstly, build up service information database based on MPEG-2 Program Specified Information (PSI) and DVB SI standard, in which layer-orientated design of software module and tree style chain list architecture of SI database are highlights of this project. I obtain important service information by using the Programmable Transmission Interface (PTI) module of Sti7710 to parse PSI/SI tables and many important description symbols in the table.Secondly, use service information functions and database to query EPG data, and implement not only basic features like EPG browsing and notifying, but also extended features such as style choosing and dynamic data publishing. These extended features reveal that EPG will contain more and more features and will be more customized in the future.Finally, accomplish implementation of NVOD feature by using part of service information to query NVOD data, which can provide intact NVOD program to users.In software design of this project, I emphasized the design thought to be module and layer oriented, and used effectively the embedded operating system mechanism such as task, semaphore and message queue etc. to ensure the stability and sustainability of the software system.This project implements an integrated DTV system with SI, EPG and NVOD, which can make users not just receive TV programs but also interact with TV system. This project also provides a basis for implementation and application of other DTV services.