This chapter introduces you to streaming media and shows you the different parts of a streaming media presentation. Although you do not need to know this information in order to use RealPresenter for basic tasks, it is recommended that you have a working knowledge of these topics.
Prior to streaming, you had to wait for a media file to download from an Internet or network server in order to experience it. When you create a streaming media presentation, users can view it almost instantly.
Streaming media allows you to send small packets of information over a network connection. The user receives the information packets and plays your media piece by piece. The process is almost invisible to the user, except for a small amount of buffering at the beginning.
RealPresenter is an integral part of the RealNetworks RealSystem. RealPresenter creates the presentations, either RealPresenter or a RealServer™ allows your audience to connect to presentations, and RealPlayer shows them to your audience.
A presentation created with RealPresenter can be as simple or as complex as you wish. It can include audio, video, and either PowerPoint slides or Web pages in a layout designed for streaming to RealPlayer. All of these media elements are synchronized together to create a rich, multi-media presentation.
This section introduces you to the different components that can make up a streaming media presentation created with RealPresenter.
The video portion of your presentation is captured from a video source, such as a video camera or video cassette recorder, to your computer via a video capture card or USB port. RealPresenter converts the video signal into RealVideo, which is then streamed to your presentation's audience.
A standard type of video clip that you will use with RealPresenter is a simple video camera shot of yourself talking through the presentation.
You can use RealVideo with your presentation if you are recording for high bandwidth users. See "About Bandwidth" for a description of bandwidth and how it affects your presentation.
Clear and good-sounding audio in a presentation can greatly improve your audience's experience. Your audio input, whether by microphone or a recording, is converted into RealAudio, and it is streamed along with your final presentation.
A PowerPoint file is a collection of slides combined to illustrate a presentation. RealPresenter takes these slides and converts them into RealPix™, which are streaming images. These images are combined with your narration (either audio or video) to create a streaming media presentation that can be shown with a RealPlayer.
Web PagesIn a Web Tour presentation, you can show different Web pages to your audience while you are describing them. RealPresenter allows you to automatically open the audience's Internet browsers and send them to whatever Web page you choose. The audio or video part of your presentation is played in the RealPlayer next to the audiences' browsers.
The way in which all of the above media elements are brought together is through a layout. RealSystem uses the SMIL (pronounced "smile") mark-up language to format layout. RealPresenter automatically creates the layout necessary to show your presentation, but if you wish to alter or customize how it looks, you will need to know how to program in SMIL. Refer to the RealSystem Production Guide, available from RealNetworks, if you want to learn more about the SMIL language.