Streaming Media Metafiles
QuickTime Metafiles
As we’ve seen, RealNetworks .RAM files and Microsoft .ASX files each have their own unique features, but the basic approach is the same. They are simple text files with simple syntax to describe all the ways you can control how your video plays. QuickTime, on the other hand, offers metafile-like features using a variety of different techniques:
—the QTSRC parameter
—RTSPtext
—QuickTime Media Links
—SMIL 1.0
—standard reference movies
—alternate reference movies.
Some of these approaches can be used together so you can combine their unique features. We’ll concentrate on the first three, the text-based formats that are similar to the .RAM and .ASX metafile formats used by RealPlayer and Windows Media.
QTSRC
If you’re embedding your QuickTime movie in a web page, then there’s an easy, no-metafile-needed way to point the QuickTime plug-in at the streaming server to get the file. You simply add a QTSRC parameter to your EMBED tag.
QuickTime supports many of the kinds of features found in RealPlayer and Windows Media metafiles by adding parameters to the embed tag itself. You can see the whole set of options supported by the embed tag in Apple’s QuickTime documentation.
RTSPtext
The simplest form of QuickTime metafile is a simple two-line text file. Just open your favorite text editor and type RTSPtext, followed immediately by the rtsp URL to the movie on your server.
RTSPtext
rtsp://myserver.com/mymovies/myquicktimemovie.mov
Save this with a .MOV extension and you’re ready to link to it from your web page. If you embed using an RTSPtext metafile, you should use the SRC parameter of the embed tag rather than the QTSRC parameter. It lets you change the video content on your page without having to edit the page. You can update RTSPtext file as needed without making any changes to the web page itself.
QuickTime Media Links
With QuickTime Media Links, we start to see an approach that’s more like traditional metafiles. You’ll usually use a .QTL file when you’re putting a link in your web page to launch the standalone QuickTime player (rather than embedding it in the page). It’s an XML file you can create with any text editor. Here’s a basic one: