QuickTime Streaming vs. Progressive Download in Media Cleaner Pro

Apple introduced true streaming to its offerings with QuickTime 4.0, which requires a QuickTime streaming server and permits real-time delivery of content. Terran's Media Cleaner Pro offers presets for QuickTime streaming (QTS) and progressive download via the QuickTime WWW settings. There are several subtle differences in these delivery mechanisms that will be discussed in this section.

Figure 1: Preparing QuickTime for True Streaming

Figures 1 and 3 show the Output panel for a QTS stream and a QT-WWW movie, respectively. Two major differences are apparent, in the Hinting and Compress Movie headers. A QT stream must be "hinted" in order to deliver the content in real-time over less-than-ideal connections. If you click on the "Hints" option in this menu, the screen shown in Figure 2 appears. Here you can set up transport parameters such as packet size and packet duration. For more information on the QuickTime Streaming Server (QTSS) technology, go to Apple's QuickTime Site.

Figure 2: Setting Hint Options for QuickTime Streaming

Hinting a movie adds information to its header, so you never want to hint a progressive download movie. As shown in Figure 3, make sure the "Prepare for Streaming Server" box is unchecked for progessive downloads. On the other hand, you do want to compress the movie header for progressive download movies to reduce the wait time. According to Terran, this option may not be compatible with some third-party QT servers, so it should be turned off in the QTSS settings.

Figure 3: QuickTime Settings for Progressive Download

Another option available only for downloaded movies is the "Disable Saving" box. If this is left unchecked, the client will be able to save the movie to a hard drive.

The progressive download presets shown in Figure 3 do have some "real-time" settings. These will limit the data rate of the entire movie so that it will fit into a particular connection speed. Under ideal conditions, then, very little wait time will be required to view the movie on the client side. The difference between these movies and the QT streaming movies is that they can be served from any HTTP server, and the client can be allowed to save them to disk, if you so desire.