MHP展示系統之設計實現

Abstract

MHP (Multimedia Home Platform)多媒體家用平台，為數位電視最新的國際標準，最早由歐洲數位電視廣播學會 DVB 所定義出來，其主要目的為提供一個發展DVB-Java應用程式 (Xlet) 的軟體平台。目前MHP 程式介面在應用上可分作三階層 : 第一層Enhanced Broadcast ， 第二層 Interactive Broadcast， 第三層Internet Access 。建構在Java虛擬機器(Virtual Machine)上， MHP扮演著數位電視中介層 (Middleware)的角色，利用 Java 語言物件導向，跨平台的特性與現有豐富的多媒體與網路支援，破除電視與電腦的分際，提供互動電視，多媒體電視應用，使得電腦軟體有移植到電視平台的可能。 此篇畢業論文大致上可區分為三個部分 : (1) 評估與研究MHP系統及其他相關數位電視標準 (2)開發工具的收集與展示系統的整體規劃(3)定義使用者介面 (User Interface)，並撰寫應用程式，經過不斷地測試與改進，實現MHP系統展示。 第一個部分，了解 MPEG-2 (ISO 13818-2)及 DVB-SI 的運作方式，MHP系統架構，數位電視中介軟體，資訊安全理論，條件接收系統 (Conditional Access) 等技術文件。接下來則是收集必要的開發工具及Java 函式庫。除此外，必須事先設計出MHP展示系統的結構與元件,使應用程式可以在MHP平台上順利執行。最後，運用 JDK 實現 MHP 應用程式，並在微軟Windows視窗平台上，完成程式開發及展示。利用 Java跨平台的特性，此展示程式亦可在 MHP 平台上執行。事實上，MHP最複雜之處，就是 Java 應用程式的建構，實體層與傳輸層資料的傳遞。使用適當的開發工具，經過不斷的努力與大量時間的投入， 我們終於成功的實現MHP 展示系統。

The main purpose of MHP (Multimedia Home Platform) is to provide a common interface for multimedia applications (Xlet) on the digital TV platform. It is defined by DVB (Digital Video Broadcasting), an European association organized for promoting digital TV. Three MHP profiles have been specified: Enhanced Broadcast, Interactive Broadcast, and Internet Access. MHP is an important international standard for the middleware used in DTV set top boxes. It is developed based on Java VM and thus has the Java advantageous features such as object-oriented, platform-independent, and its support to multimedia and Internet. There are three major parts in this thesis : (1) Survey MHP and other related standards for digital television; (2) Design an MHP application demo system using a good collection of available toolkits; (3) Implement the demo system by defining User Interface, writing and testing the demo programs. The first step in this research is to study and understand the various subjects related MHP such as MPEG-2, DVB-SI, MHP system, DTV middleware, information security, conditional access, and many other technical documents. The second step is to design the structure and components of our MHP demo system to show that useful applications can be built based on the MHP specifications. Also, we collect available tools and Java packages. Finally, JDK is used to implement our demo system which runs on the Microsoft Windows platform. Because Java is a platform-independent language, this demo system can run on any MHP-compatible platform as well. The most difficult part of an MHP application is the establishment of data delivery between the physical layer and the protocol layer. Using a number of tools and a great deal of time and effort, an MHP Demo System is finally completed successfully.