Streaming
Applies To: Windows Server 2008, Windows Server 2008 R2
To deliver content to users by using a streaming method, you can save the content to a Windows Media server, and then assign the content to a publishing point. You can then provide users with access to the content by either creating an announcement file or by supplying users with the URL of the publishing point. You can embed the announcement file or the URL in a Web page or send it in an e-mail message. When the user clicks the link or the announcement file, the player opens and connects to the stream.
Streaming uses bandwidth more efficiently than downloading because it sends data over the network only at the speed that is necessary for the client to render it properly. This helps prevent the network from becoming overloaded and helps maintain system reliability. There is typically a delay between the time the stream is received by the player and the point at which it begins playing because the player must first buffer the data in case there are delays or gaps in the stream. Because data streaming and rendering occurs at the same time, streaming also enables you to deliver live content.
To stream content smoothly, the bit rate of the content must be lower than the bandwidth of the network. If the bit rate is higher than the available bandwidth, the player will try to thin the stream so it can render the stream properly by using a process called stream thinning. Because of this, the player may render only key frames of the video stream with audio so that the video is not in motion, creating a viewing experience similar to a slide show. If the bit rate requirements greatly exceed the available bandwidth, video playback may stop altogether and only the audio portion will be played.
The impact of inadequate available client bandwidth can be minimized if multiple-bit-rate (MBR) content is streamed. MBR content enables the player to request a lower bit rate stream from the server so that stream thinning is not necessary.