Video on demand

今日在全球資訊網上傳遞著大量的文字、影像或動畫等不同的檔案格式，更由於聲音與視訊等檔案轉換技術的快速進展，使得聲音和視訊檔案的編碼和解碼，變得容易很多。然而傳統的全球資訊網架構，在網路上傳輸聲音與視訊資料是有其困難的。本文將討論如何建置一個穩定且能整合其他檢索系統的視訊伺服器。並介紹幾個國內、外頗著名的電子圖書館計畫。

Today, a vast amount of text, images, graphics, and animation are being hosted and delivered by the WWW. With rapid advances in audio and video technologies, more and more content will be encoded and delivered by means of audio/video in addition to texts and images. However, conventional Web servers are designed for data services and have no provisions for delivering continuous media such as audio and Vid-e-o. This paper presents the design and implementation of a stable digital video server which could display continuous-media along with traditional Web services. Finally, the paper gives some cases studies of an integrated electronic library, in order to propose an outline for the initiation of an electronic library.

「隨選視訊系統」為大學圖書館利用新興科技輔助教學的重要實例；而透過系統評估準則之建立，不僅讓已建置隨選視訊系統的大學圖書館能夠瞭解日後改進方向，更為其他圖書館提供客觀之參考資源。因此，本研究即以國內五所大學圖書館為研究單位，分別從管理者與使用者觀點，瞭解大學圖書館隨選視訊系統應具備的條件，藉此建置一套實際可行的評估準則，進而為其未來發展提出若干建議。

The new technology Video on Demand system (VOD) used in university libraries has proved to be a success. An evaluation of VOD system indicates that further improvement of this new technology is needed. This paper tries to establish some criteria of evaluation for this system in terms of its users and management. The criteria provided can eventually be used for other university libraries in Taiwan.