現今資訊蓬勃發展，而資訊化的會議方式也逐漸被重視，目前市面上已存在多種多媒體會議系統，絕大多數的系統都以有線環境為主，雖然也能夠支援無線環境。然而，高品質的多媒體資料通常都夾帶著龐大資料量，導致頻寬較低的無線傳輸環境表現較差，往往必須降低其多媒體資料的品質。
本論文提出一套多媒體會議系統，主要應用軟體方式來實現傳輸高品質多媒體資料，以及維持高性能即時傳輸的表現。此系統採用Client-server架構，並提供了三種會議模組，分別為同聲傳譯、數位混音與畫面傳輸，各自對應了多語言翻譯、多人討論以及投影片演講等基礎會議室功能。本系統亦配合無線傳輸環境，多媒體資料皆使用低延遲的高品質編解碼，包含Opus的語音編碼以及H.264/AVC的影像編碼，並且為了加強混音的效率，使用非均勻波收縮混音來降低其複雜度。最後將系統實作且進行場域測試，得以證明本會議室系統能夠實際應用於基本的會議進程，而其中的實驗數據亦顯示本系統運行足夠穩定並擁有良好的用戶體驗。

In this thesis, a multimedia conference system is proposed to support the high quality multimedia processing. This system adopts the client-server architecture and consists of three conference modules: simultaneous interpretation, multi-channel audio mixing and video streaming respectively.
The goal of this thesis is to implement the proposed conference modules with a software solution. To perverse the performance of hardware solution, the multimedia data is encoded and decoded by Opus audio codec and H.264/AVC image codec. And the audio mixer uses Asymmetrical Wave-shrinking mixing algorithm to reduce the complexity. With the rigorous field trial, the results show the proposed system can be applied on a general conference to provide a good user experience.

論文審定書 i
誌 謝 ii
摘 要 iii
Abstract iv
List of Figures vi
List of Tables vii
1. Introduction 1
1.1 Background 1
1.2 Motivation 2
1.3 Contributions 3
2. Related Works 4
2.1 Conference System 4
2.2 Features of a Conference System 7
3. System Architecture 14
3.1 Server Unit 16
3.2 Client Unit 18
3.2.1 User Interface 20
3.3 System Modules 23
3.3.1 Simultaneous Interpretation Module 24
3.3.2 Multi-channel Mixing Module 29
3.3.3 Video Streaming Module 35
4. System Implementation 40
4.1 System Environment 40
4.2 Implementation 41
4.2.1 Simultaneous Interpretation Module Implementation 41
4.2.2 Multi-channel Mixing Module 45
4.2.3 Video Streaming Module 49
4.2.4 Field Trial Test 56
5. Conclusions and Future Work 58
References 59

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