What is playlist file?

Playlists are powerful and flexible. With playlists, you can schedule content to play in succession, or you can insert advertising or special-interest clips into a presentation after a specific period of time or at a specific point. Windows Media Services and Windows Media Player work together to play the clips in a playlist with minimal buffering time or interruption between clips.

The simplest playlists are created by adding multiple ENTRY elements to a metafile.

What is server or protocol rollover?

You can use metafiles to provide a means of automatically switching to alternate content sources when a stream cannot be accessed or played for some reason. This is called rollover, and you can use it to specify alternate content on different servers or even different types of servers. You can specify a first alternate on a different Windows Media server. If that content fails to play, the client can rollover to a second alternate on a Web server.

Windows Media Services 9 Series can use RTSP, HTTP, or MMS for streaming. It uses RTSP when trying to connect to Windows Media Player 9 Series or later. If that attempt is unsuccessful, the server uses HTTP to connect to the Player. Earlier versions of the Player do not support RTSP, but they do support MMS. If the server cannot connect to the Player by using MMS or RTSP, then the server tries to connect using HTTP. Windows Media Player automatically tries to rollover to different protocols according to its Windows Media property settings before trying the rollover URLs in the metafile. 

What is streaming audio or video?

Streaming audio or video is sound (as on the radio) or video (as on television) delivered over the Internet via a modem or broadband connection.

Why is it called "Streaming"?

It's called "streaming" because the sound and picture data flow in a digital stream from a server computer to your computer, ready to hear or view in real time, without having to download all of the content before you can enjoy it. It comes to you in a stream of digital bits... hence the term "streaming."

What kinds of Streaming audio or video are there?

There are three main streaming media companies: Real, Media Player (Microsoft) and QuickTime (Apple). All three provide streaming media players for the Mac and Windows platforms. All three also provide "basic" free players and optional "plus" players that offer extra features - at extra cost. The three media player types vary in cross-compatibility. Many Web sites also use Macromedia's Flash/Shockwave for audio and visual effects.

What difference does it make if content is streamed, rather than downloaded?

Audio and video files can be very large. You would spend many minutes or even hours waiting for them to be downloaded to your computer if they weren't streamed. Streaming media technology allows you to see or hear the content in just a few seconds, instead of having to wait for it. Your only wait is a few seconds for a "buffer" to be built up that helps avoid interruptions caused by Internet traffic problems.

What special equipment do I need to get streaming audio or video?

What are media players? 

A media player is a special type of software that recognizes the stream coming into your computer and displays it (video) on your screen or plays it (audio) through your speakers or headphones. There are three different formats of media players that are most commonly used. Your computer may or may not have one of them already installed. (You'll find download links in Q9 below.) Here are the various types (all with free and pay versions):

Windows Media Player™
Most computers that use the Windows operating system have Windows Media Player installed. If your version is getting old, you may need to download and install a more current one in order to use streaming. (We'll tell you how to do that below.) The Windows Media Player is also available for Apple computers and the Mac OS.

RealOne Player™
Real is another popular streaming format. Many computers/browsers come with the RealOne Player installed. Like the Windows Media player, you may need to download a newer version. Real offers the most compact media file format, even smaller than mp3. The RealOne Player comes in both Mac and Windows versions.

QuickTime™
Newer Apple computers (G5s, G4s, iMacs, PowerBooks, etc.) and many PCs come with the QuickTime player installed. As with all players, if your version is too old, you may need a new one. QuickTime is used for both audio and video streaming, but has additional capabilites, such as QuickTime VR, a panoramic picture display. QuickTime is also available for Windows.

Shockwave™
More and more Web sites are using Macromedia's Shockwave for audio and visual effects, but it's not a true streaming media player. It is popular because it can display short audio and video clips quickly (as in ads), without a long waiting period. The Shockwave browser plug-in is available as a short and free download. QuickTime can also display Shockwave.