點對點影音串流系統的開發與研究

Abstract

目前有越來越多影音服務架構在peer-to-peer(P2P)系統中。然而，建立一個即時點對點影音串流系統充滿了許多挑戰。在本論文中，我們企圖建立一個穩定的點對點影音串流系統。首先，我們選擇了網狀結構當作網路拓撲的結構。因為有了網狀結構為基礎，使用者的高流動率對系統的影響較小；接下來，我們動態地選擇適合自己的父節點，挑選的標準由四個參數決定。此外在編碼方面，從原始資料依序進行影音編碼和信道編碼。藉由影音編碼，我們節省了全部要發送的總資料量；而經由信道編碼，讓我們節省了同儕之間資料溝通的訊息並加強了資料的保護。在我們實作系統的過程中，我們發現了一些實作上的議題，藉由這些議題，使我們的即時串流系統更加穩定。最後，在NS2模擬也顯示了我們方法的穩定性。

Nowadays, there are more and more video streaming services based on peer-to-peer architecture. There are many challenges to build a real time peer-to-peer streaming system. In this paper, we attempt to construct a stable peer-to-peer streaming system. At the beginning, we choose the mesh-based structure to construct the peer-to-peer overlay network. The whole system is more robust when dealing with peer churn because of the mesh-based structure. Next, we dynamically choose the parents that are suitable to us by four factors. Furthermore, the original data from source is encoded by video coding and channel coding sequentially. With video coding, we save the total size of data to send. With channel coding, we save a lot of data coordinate messages for peers and enhance the protection of data. During the process of building our system, we find some important implementation issues to make our peer-to-peer streaming system more stable. Finally, the NS2 simulation also shows the stability of the method we proposed.