這幾年，視訊與聲音串流的應用在業界一直受到重視，這些多媒體串流的應用包括網路電話、視訊會議與遠距教學。他們可以解決企業與企業間或企業與客戶間的溝通問題，為企業節省下大量的時間與金錢。另一方面，無線網路技術在近幾年內突飛猛進，許多的公司、快餐店、咖啡店等都已經有提供了無線網路的服務。最近更有廣範圍的都會區域無線網路(Wireless MAN)802.16，提供了更方便的無線網路環境。因此，無線網路的佈建將會越來越普及。並且這些室內或室外的無線網路頻寬都已經有足夠的能力能夠乘載多媒體串流的資料流量，因此使用無線網路環境之多媒體串流應用勢必是未來的趨勢。為方便無線網路的使用，目前市場上提供各種行動裝置像是PDA與smart phone。本論文的目標即是在行動裝置上實作一完整的適應無線網路環境之多媒體串流環境。由於對於行動裝置上實作多媒體串流的應用目前還在起步階段，因此我們的開發工具也受到了限制。目前Pocket PC上並未提供Microsoft DirectShow的開發支援，為了方便將來我們對任何多媒體串流與多媒體資料的處理我們開發一套DirectShow lite來解決Pocket PC未提供DirectShow的缺陷。此套DirectShow lite雖以完成一數位學習系統為目標，但是對於其他應用像是VoIP與視訊會議均可以支援。 In recent years, video/audio streaming applications play an important role in business. They contain VoIP, video conference and distant learning. They can resolve the communication problems between Business and Business or between business and customer; and saves lots of money and time for them. On the other hand, wireless network technologies are mature in recent years, now many places support wireless network. Like 802.11 and 802.16, they make wireless network more and more popular. And these wireless networks are capable of multimedia streaming. Multimedia streaming over wireless network will dominate the market in the future. The goal of this thesis is to implement a complete wireless adaptable multimedia streaming system over mobile devices. But the development tools of multimedia are limited on mobile devices. Microsoft DirectShow does not support Pocket PC. In order to simplify our implement of any multimedia streaming and multimedia data handling in the future, we develop a DirectShow lite to solve the lack of Microsoft DirectShow on Pocket PC. The DirectShow lite is used for an e-learning system, but it is also capable of any other applications, like VoIP and video conference.
