2.5.3 Stream Content from Media Server - Media Player Client
In this use case, a media server streams content to a media player client.
Context of use: To stream content from a media server to a media player client for playback. This use case is illustrated in the following diagram.
Figure 10: Use case diagram for streaming content from a media server to a media player client
Goal: To stream content from a media server to a media player client.
Media player client
The media player client is the primary actor. It is the application that renders the media stream that is provided by the media server. This is the primary interface to the Media Streaming Server Protocols (MSS) system for the end user.
The media server is the supporting actor. It is the server that receives media from an encoder and streams it to the media player clients. The media server can act as an origin server or a distribution server.
Internet Content Providers (ICP)
Streaming media is generally intended to create the experience that is demanded by consumers or end users. In the corporate environment, the end user is the individual viewing the live broadcast of the company meeting or the individual watching the corporate compliance video at a convenient time.
To access content from the media server, the media player client is preconfigured to access the server.
In particular, the media player client has to have read permission to access the content on the server, and the media player client has to support the protocol that is providing the playback experience.
In addition, the network supports HTTP or UDP or multicast, depending on the protocol that is used.
Main Success Scenario
Trigger: The media player client requests a stream from the media server.
The media player client connects to the stream from the media server. The media player client will be notified with an error message, if the media player client cannot connect successfully to the server.
Note that the Media Streaming Server system uses packet-pair bandwidth estimation to optimize playback. Packet-pair bandwidth estimation is a technique for estimating the bandwidth of a streaming media connection over the Internet. The media server sends two or more consecutive messages, and the client estimates the bandwidth by measuring the difference between the times that it receives the messages. The Real-Time Streaming Protocol (RTTSP) Windows Media Extensions (RTSP-WME), the Microsoft Media Server (MMS) Protocol (MMSP), and Windows Media HTTP Streaming Protocol (WMSP) all support packet-pair bandwidth estimation. For more details, see [MS-RTSP] section 188.8.131.52, [MS-WMSP] section 184.108.40.206, and [MS-MMSP] section 220.127.116.11.
In the event that the media is not multicast, the media server evaluates the request, and then acts upon the request.
Depending on the configuration and settings, the media server might stream the file via unicast or multicast streaming to the media player client.
The media player client receives the content stream sent by the media server.
Web servers can host files that web pages and redirector files, such as .asx files and .nsc files, that are used to discover the media server content.
Logging is an extension to streaming, as described in section 2.5.5.
Enabling the Digital Rights Management (DRM) server to issue licenses to the media player client to enable playback is an extension to the streaming content from the media server as described in section 2.5.4.