1 Introduction
On-demand refers to the active connection between the client and the server, in which the user initializes the client connection by selecting a content item. The user can start, stop, rewind, fast-forward, or pause the stream.
2 composition
2.1 Osproducer
OS producer uses OS encoder for file compression. According to user requirements will be a variety of audio and video files, such as AVI, VCD, DVD into the Han and Tang autonomous development of a variety of code rate of the MPF file, with a good expansion capacity.
2.2 OS Streaming Server
OS Streaming server is an OS Mpfsys system, which has been developed by Shanghai Han-Tang Technology Co., Ltd., which is a Cross-platform distributed video service system based on broadband and Narrowband network, which uses the MPEG 4 coding/decoding technology developed by Han-Tang technology independently. Used to provide a variety of streaming media services. The system adopts open design, which makes the extension of the system easy to implement, and also has the ability to support the new streaming format. OS Streaming server can provide services separately and through system configuration to form a large server farm, which brings great convenience to service provider maintenance and extension. The system, with its unique open structure, supports most of the existing coding techniques, and the codec can be embedded dynamically, which is suitable for a wide range of applications. As a cross-platform server software system, it supports a variety of operating system platforms and database systems. 2.3 osclient
OS player is a media player developed independently by Huntek. The player uses the latest MPEG-4 technology to support and play a variety of media formats including MPEG 4, DVD, VCD, DIVX, which can be used to directly play a variety of streaming media, as well as a variety of streaming media on the Web or live on the Internet.
At the same time, OS player can be embedded as ActiveX IE4.0 above version browser, when the user's browser security level is the default can automatically download and install, can solve the problem of program distribution and maintenance, users can update the system client in a timely manner.
3 Typical network architecture of VOD system
3. 1 Network architecture of mini-VOD system
Provide modules:
Production end Product (osproducer): Osproducer
Server-side streaming playback products (OS streaming server): Osstreamingserver
Client playback product (osclient): Osplayer
Application topology diagram:
Fig. 5.3 Mini-on-demand application system
3. 2 Network architecture of large-scale VOD system
Application module:
Production end products (OS Producer): OS Producer
Server-side streaming playback products (OS streaming server): OS clustermanager,,os streaming Server
Client Playback products (OS client): Osplayer
Application topology diagram:
Fig. 5.4 Application system for large-scale VOD
4. The protocols and standards used in the VOD system
OS Mpfsys implements the following four IETF standard agreements and the IRDP protocol developed by Shanghai Han-Tang Technology Co., Ltd, namely:
IRDP (Intelligent Resource Distributing Protocol)
RTSP (Real-time streaming Protocol, RFC 2326);
RTP (Real-time transport Protocol, RFC 1889);
RTCP (Real-time Transport Control Protocol, RFC 1889);
SDP (Session Description protocol, RFC 2327).
5 The main application of the VOD system
Telecommunication or broadcasting service provider, company, enterprise or service industry