使用HTTP協定的即時媒體串流重新導向伺服器

Abstract

目前的Streaming Server，在傳送資料給客戶端 (Client) 時，常會發生資料無法送達的情形。原因可能有很多，可是最大問題常常是在於防火牆根本就不給予通過。例如很多公司網路為了安全上等等的問題，UDP的封包 (Packet) 一律阻隔。然而目前絕大多數的防火牆都不會阻隔HTTP 通訊協定的封包，因為看網頁查資料是最基本的需求，所以根據這樣的優點，產生了HTTP Streaming Server這樣的構思。 本篇論文實做了一個HTTP Streaming Server，並且定位為媒體傳輸的中間站。由於某些環境中，防火牆只允許HTTP (TCP) 相關協定通過，這裡設計將影音資料由HTTP伺服器接收後，使用者再利用HTTP協定由伺服器接收影音資料就能通過防火牆等設定。目前實作是由Multicast接收廣播中的影音節目，暫存於HTTP伺服器記憶體中藉以突破防火牆的限制，未來也將定義由其他裝置輸入影音資料，例如數位攝影機、數位壓縮卡、電視卡等接收資料後傳送給用戶端。

While current streaming servers transfer data to client, data often do not arrive in client. Maybe there are many reasons, but the worst problem often is that firewall does not allow data to pass. For example, the network of many companies do not allow UDP packet to pass for the sake of some problems, like security, and so on. However, current most firewalls allow HTTP packet to pass. We have a design on HTTP Streaming Server according to such advantages because browsing web pages and researching data is the most basic demands. In this thesis, we implement a HTTP streaming server, and it is orientated as the intermediate depot of media streaming. We plan that streaming data is received by HTTP server, and then users receive streaming data through firewalls according to HTTP protocol. Now we implement that receiving streaming data of media program on broadcasting from Multicast and saving temporarily to memory of HTTP server using to break through the restriction of firewall. In the future, we will define that importing streaming data by other devices too, like digital video camera, digital encoding card, TV card, and so on. After receiving data, HTTP server will transfer data to client.