臺灣博碩士論文加值系統

多人線上遊戲儼然已成為了現今遊戲的趨勢。而近來在多人線上遊戲上的一個創新就是利用VoIP技術來取代遊戲玩家使用鍵盤文字來做溝通。許多的線上遊戲已經在遊戲中提供了VoIP的功能，像是微軟近期推出的Xbox Live® [1]. 然而這樣的溝通機制通常只是提供給遊戲玩家聊天使用。
這篇論文提出了利用VoIP的群組語音服務來提供一個能夠讓使用者身歷其境的音效環境。所有不同來源的語音都會依據每個玩家在虛擬遊戲中的位置被調整近而做混合。對每個玩家來說，收聽到的語音將會因為其他玩家的相對距離而做出增減。這篇論文提供了一個更好的VoIP使用功能，並且可以帶給遊戲玩家在娛樂中有更好的感受。這篇論文是架構在中華大學陳建豪同學在2005間所提出的具有語音功能的多人線上遊戲碩士論文上[8]。

Multiplayer online games are the trend of the day. A recent innovation in multiplayer online game is the addition of technology that allows players to communicate with each using VoIP rather than typed text. Many of multiplayer online games have already support voice communication for players such as Microsoft Xbox Live® [1]. However, it merely provides voice channels for players to chat.
This paper proposes a use of VoIP conference, which it provides an immersive audio communication in multiplayer online game. The mix of voices from different sound sources according to player’s location in the virtual game space. For each user, the audios are attenuated according to distance from the listener. This provides a better use of VoIP function and players can also have better enjoyment in the game. This paper is based on the multiplayer online game with VoIP architecture from Chen’s thesis in 2005[8].

1. Introduction 1
1.1 Research background and motivation 1
1.1.1 Background 1
1.1.2 Motivation 3
1.2 Objective 4
2. Fundamental concept of voice and VoIP 5
2.1 Speech 5
2.1.1 Voice communication 5
2.1.1 Voice sampling 6
2.1.1 Quantization 8
2.1.2 Speech codec 9
2.1.3 How to calculate the bandwidth for an audio codec 10
2.2 Definition of decibel 11
2.2.1 Definition and example 11
2.2.2 Sound pressure, sound level and dB 13
2.3 VoIP (Voice over IP) 13
2.3.1 Generalization 13
2.3.2 H.323 16
2.3.3 Protocol structure - H.323 (ITU-T VoIP protocols) 18
2.5 VoIP solutions 23
2.5.1 H.323 based JCPPhone 23
2.5.2 OpenH323 project 23
2.5.3 OpenMCU 26
3. Server architectures 28
3.1 Early hybrid client/server architecture 28
3.2 Local voice server system infrastructure 29
3.3 OpenH323 project architecture 30
3.3.1 Maximum call density 31
3.4 System implementation 32
3.4.2 Implementation of audio normalization enhanced mixing 35
3.5 Voice Communication Working Flow 38
3.5.1 Local voice server initialization 38
3.5.2 Voice communication flow 39
3.5.2 Format of player list in packet transmission 40
4. Experiment result 41
4.1 Experiment I: feasibility 41
4.1.1 Resource allocation 41
4.1.2 Measurement 41
4.1.3 Experiment procedure 42
4.1.4 Local voice server analysis 42
4.2 Experiment II：game movement 45
4.2.1 Resource allocation 45
4.2.2 Measurement 46
4.2.3 Experiment procedure 46
4.2.4 Client data analysis 47
5. Conclusion 50
5.1 Conclusion 50
5.2 Research restriction 50
5.3 Future work 50
5.3.1 Enhanced algorithm 51
5.3.2 Codec changes 51
5.3.3 Solution with SIP 51

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