Media Object Sequence Optimization for Reducing Presentation Lags in Automatically-Assembled Multimedia Presentations

• Main Authors: Feng-Cheng Lin, 林峰正
• Other Authors: Jen-Shin Hong
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/33955313233027119092

博士 === 國立暨南國際大學 === 資訊工程學系 === 96 === In a Digital Library/Museum system, media presentation is an important task that directly affects a contact with the user. How to transmit several media items effectively and accurately to reduce the user's waiting time (wait latency) is one of the main concern at this stage. Similar to a television broadcast, automatically and continuously present the media items in sequence enables the user to avoid downloading, and playing back repeatedly. This automatic presentation of the media is referred to as TV-like presentation and is user-preferred. According to this presentation, for reducing the wait latency, the server should be capable of deciding a proper order of the media items and effectively delivering. This dissertation focuses on optimizing the media transmission and playback technology by using the Prefetch mechanism under complicated environments. Aiming to seek the shortest time to arrange the sequence of the media items, this research applies the conventional scheduling algorithm to the multimedia file transmission and playback problem. First, an extensive discussion of the relevant issues related to reducing the presentation latency under various different types of constraints. Problems with object precedence constraints, objective due dates, and client-side buffer limitations are considered and solved with branch and bound solutions. In particular, the player-side buffer is “processing time dependence” and is different from the conventional item-based intermediate buffer constraints discussed in previous flow-shop scheduling problems; this new problem is then proven to be strongly NP-hard. In addition, various heuristic algorithms are proposed to approximate the optimal solution for the problem with the buffer constraint. From theoretical and practical 3G transmission experiments, a better scheduling algorithm can significantly reduce the wait latency efficiently.