When you finish crafting your RealSystem presentation, you place the clips on RealServer for streaming. This chapter explains how to link your Web page to your presentation. It also describes how a Web server can play back some RealSystem G2 presentations.
A RealSystem presentation served by RealServer G2 involves the HTTP and RTSP protocols. If you have experience creating Web pages, you know that HTTP is the standard protocol Web browsers and Web servers use to communicate. Most Web page URLs begin with http:// to indicate that the file download occurs over the HTTP protocol.
As explained in "Hosting a Presentation on a Server", RealServer G2 and RealPlayer G2 communicate primarily with RTSP, a new protocol designed specifically for streaming media. When you assemble a RealSystem presentation, it's important to understand clearly which URLs should begin with http:// and which should begin with rtsp://.
Use rtsp:// in URLs in which RealPlayer G2 requests clips from RealServer G2. These URLs occur in SMIL files (.smi) and RAM files (.ram or .rpm). Use http:// in these URLs only if the clips are stored on a Web server instead of RealServer. Because a Web server doesn't use RTSP, you can't have rtsp:// in a URL to a clip stored on a Web server.
Links to a Web server or RealServer within a Web page (.htm) always start with http://. Like Web servers, Web browsers don't use RTSP and can't interpet streaming information sent by RealPlayer over RTSP. The Web browser can connect to RealServer through HTTP, though, because RealServer G2 uses HTTP as well as RTSP.
 |
Additional Information |
|---|---|
| For more on SMIL file URLs, see "Linking to Clips on RealServer" and "Linking to Clips on a Web Server". |
When you stream clips from RealServer, the RealServer administrator creates content directories and tells you the basic URLs to use. The administrator can also set up features such as password authentication and pay-per-view. When your media clips and SMIL file are ready, transfer them to RealServer and place them in the directories prepared by the administrator. Then link your Web page to your presentation as described below.
 |
Tip |
|---|---|
| Because earlier versions of RealServer do not support SMIL and RTSP, you need to ensure that RealServer G2 hosts your presentation. Also note that RealNetworks encoding tools can transfer files to RealServer automatically. See http://www.real.com for details. |
When you use RealServer, the RAMGEN utility can automatically generate the RAM file for you. Your Web page URL simply points to your media clip or SMIL file on RealServer and includes a ramgen parameter that makes RealServer generate the RAM file. The next figure illustrates the process of requesting a presentation through RAMGEN. The example uses a SMIL file that coordinates multiple clips, but you can also link to a single clip directly without using SMIL.