基于DVB和IP雙結構傳輸模式的復合流式虛擬視頻點播系統設計

摘" 要： 當虛擬視頻點播系統遇到高訪問量時會使其服務器負荷過大，導致視頻傳輸速度下降、播放不連續。因此，設計一種基于DVB和IP雙結構傳輸模式的復合流式虛擬視頻點播系統，以適應用戶需求和網絡條件，動態調整視頻流的傳輸質量和分辨率。構建基于DVB和IP雙結構傳輸模式的復合流式虛擬視頻點播系統框架，終端用戶通過基礎服務層的Web頁面提交視頻點播申請后，從視頻編排層獲取點播視頻；控制層的播出控制模塊調取PBHS算法來實現網絡資源受限下的帶寬自適應分配，以動態地調整不同帶寬占用，優化網絡資源利用，提高傳輸效率。通過視頻傳送模塊輸出點播視頻，利用傳輸層的IP和DVB雙結構傳輸模式將其輸送到應用層，最終可視化呈現給用戶。實驗結果表明，所設計系統可實現虛擬視頻點播，視頻播放連續不卡頓、畫面分辨率高，信令延遲僅34 ms，視頻傳輸速度達到18 Mb/s，平均點播時間為1 320 ms，且拒絕用戶數少。

關鍵詞： DVB； IP傳輸； 視頻點播； 復合流； Web頁面； PBHS算法； 播出控制

中圖分類號： TN934.3?34； TP393" " " " " " " " "文獻標識碼： A" " " " " " " " " " " 文章編號： 1004?373X（2025）04?0063?05

Design of composite streaming virtual VOD system based on DVB

and IP dual structure transmission mode

LI Yuhua1， QIU Xinying2， ZOU Xuan1

（1. College of Science and Technology， Nanchang University， Jiujiang 332020， China; 2. Hefei University of Technology， Xuancheng 242000， China）

Abstract： When the virtual video?on?demand （VOD） system has high traffic， its server will be overloaded， resulting in a decrease in video transmission speed and discontinuous playback. Therefore， a composite streaming virtual VOD system based on DVB and IP dual structure transmission mode is designed to adapt to user needs and network conditions， and dynamically adjust the transmission quality and resolution of video streams. The composite streaming virtual VOD system framework based on DVB and IP dual structure transmission mode is built. After the end user submits VOD requests on the Web page of the basic service layer， they obtain the on?demand video from the video orchestration layer. The broadcast control module of the control layer can be used to call the PBHS algorithm to realize the adaptive bandwidth allocation under network resource constraints， dynamically adjusting different bandwidth occupancy， optimizing network resource utilization， and improving transmission efficiency. The on?demand video can be outputted by means of the video transmission module， the IP and DVB dual structure transmission mode of the transport layer is used to deliver them to the application layer， so as to visualize and present them to users. The experimental results show that the designed system can realize virtual VOD， with continuous video playback without lagging， high image resolution， signaling delay of 34 ms， video transmission speed of 18 Mb/s， average on?demand speed of 1 320 ms， and low number of rejected users.

Keywords： DVB; IP transmission mode; video on demand; composite stream; Web pages; PBHS algorithm; broadcast control

0" 引" 言

視頻點播（Video?on?Demand， VOD）作為一種重要的多媒體服務形式，已逐漸成為人們獲取信息、娛樂休閑的主要渠道[1?2]。傳統視頻點播系統主要依賴單一的傳輸模式[3?4]，如數字視頻廣播（DVB）或基于IP網絡傳輸。將虛擬視頻點播系統應用于計算機英語、虛擬教研室等領域，可滿足不同用戶需求。文獻[5]設計的廣電智慧云媒體系統建立在DVB傳輸模式基礎上，DVB模式覆蓋范圍廣，在大規模視頻內容分發上具有普遍應用性。……