串流平台的程序控制

Abstract

串流伺服器的程序控制主要包含了連線建立、檔案處理及封包傳送三項主要任務。連線建立包含了socket間的資料傳遞以及透過一個狀態的機制來傳遞信令；檔案處理便是影音格式的解析以及訊框的切割與封裝；最後的部份便是封包傳送，此部分的重點在於時間的控制機制。 本論文主要是從單行程的觀點去探討串流伺服器的建構程序。一般來說，串流伺服器可分為多行程以及單行程架構，這兩種架構在表現上雖然差別不明顯，但是單行程細部的時間控制相較於多行程便困難許多，因為這牽涉到了影音格式的解編碼問題。 此外，本論文也實際修改一套開放程式碼的串流信令，使得改良後的串流系統能夠和市面上的商業串流系統得以溝通，其細部的修改重點也是本論文論述的核心所在。

Streaming systems consist of three big jobs which include connection setup, file processing, and packets sending. Connection setup consists of the socket setup and the state mechanism which is used to exchange signaling; file processing contains the file formats’ parser and the packetizer; packets sending focuses on the timing control mechanism.

In this work, we investigate how streaming servers are constructed in a single process’s view. Generally speaking, streaming servers can be categorized into two structures which are multi process structure and single process structure. Although the differences in the performance of the two structures are not obvious, the detail implementations of single process are more complicated in timing control since the coding problems of the file formats.

Besides, we also try to modify an open source streaming server so that it can connect to commercial streaming servers by RTSP signaling.