Apple's QuickTime is the technology your Mac uses to handle time-synchronized data. Time-synchronized data simply means data that must be managed so that its components remain "in sync" with each other. For example, when you're playing digital video, the video image must remain in sync with the sound track. When you're watching an animation or video, sound effects need to occur at the correct moments.
Since its introduction, Apple's QuickTime has been one of the most successful multimedia standards on any platform. In fact, it has been so successful that it is also widely used on Windows computers; QuickTime movies on Windows play the same way they do on the Mac. QuickTime has also been widely adopted on the Web. Many Web sites serve video and animation files as QuickTime movies.
Although it is natural to think of QuickTime in terms of video, you should also remember that QuickTime can be used for sound, animation, and other dynamic data (such as audio) as well. And not all components have to be present at all times; for example, you can have a QuickTime movie that consists only of a soundtrack.
You will encounter QuickTime movies in many places, including interactive games, reference titles, entertainment titles, learning tools, and, of course, Web pages.
Various files, folders, and resources are part of Mac OS X's implementation of QuickTime. These include the following:
QuickTime Preferences? The QuickTime pane of the System Preferences utility enables you to configure various aspects of how QuickTime works. The QuickTime preference file is stored in each user's Preferences folder within the user's Library folder.
QuickTime Player? As with previous versions of QuickTime, the QuickTime Player is the basic application you use to watch, create, and edit QuickTime movies. It is located in the Applications folder.
QuickTime Updater? Apple regularly updates QuickTime; this application can be used to ensure that all the QuickTime components on your Mac are in the current version. You can run the Updater from inside QuickTime Player, or you can run it from the Update tab of the QuickTime pane of the System Preferences utility.
Streaming is the capability to play QuickTime movies as they download from the Web?rather than having to wait until the movie is downloaded to your Mac before you can play it. If you have a fast Internet connection, streaming is very nice because viewing QuickTime movies on the Web is about as responsive as watching TV. If you use a phone modem, you still have to wait a while for most QuickTime movies.
QuickTime.framework folder? This folder provides the framework files for QuickTime (Mac OS X/System/Library/Frameworks/QuickTime.framework, where Mac OS X is the name of your Mac OS X startup volume).
To learn about Mac OS X's framework structure, see "Mac OS X Architecture and Terminology," p. 12.
QuickTime Plug-in? This plug-in (located in Mac OS X/Library/Internet Plug-Ins, where Mac OS X is the name of your Mac OS X startup volume) enables you to view QuickTime movies on the Web from within a Web browser.
Way back in version 3.0 of QuickTime (which was introduced as part of Mac OS 8.5), Apple added a new scheme for QuickTime distribution. QuickTime comes in two flavors: QuickTime and QuickTime Pro. With QuickTime, you get a basic set of capabilities that enable you to watch all sorts of QuickTime movies. But that is about all you can do with it. QuickTime Pro, on the other hand, enables you to create and edit QuickTime movies, along with various other useful things.
With the version of QuickTime included as part Mac OS X, you'll get substantive QuickTime capabilities. These features include the following:
Viewing all flavors of QuickTime movies on and off the Internet
Working with more than 30 audio and video file formats
Changing the size at which movies are played
Printing frames of movies
Watching QuickTime TV
When you pay for the QuickTime Pro upgrade, you'll get many more features. One of the most important features is the ability to create and edit your own QuickTime movies. QuickTime Pro provides you with all the capabilities of QuickTime "basic," plus much more, including the following:
Playing full-screen video
Viewing files in a wider variety of formats
Creating your own QuickTime movies
Editing and saving movies in various formats
If you do much work with multimedia files, just the ability to save files that you can open in QuickTime into other file formats makes the upgrade worthwhile.
Copying and pasting material from various formats into QuickTime movies
Preparing QuickTime movies for streaming delivery via the Web
Using sharpening, color tinting, and embossing filters on movies and images
Creating slideshows from a series of still images
The additional features in QuickTime Pro become part of the QuickTime framework. Therefore, any applications that use that framework, such as iTunes, iMovie, iPhoto, iDVD, Final Cut Express, and so on, also benefit from the additional QuickTime Pro features, such as the capability to apply custom compression schemes. In fact, a QuickTime Pro license is included with Apple's professional applications, such as Final Cut Pro.
As with other forms of multimedia, certain parameters govern how QuickTime movies appear on your Mac. To be comfortable with QuickTime, you should understand some of these basic specifications, which are described in the following sections.
QuickTime movies are composed with specific resolutions, just as still images are. The resolution of QuickTime movies is specified similarly to the way the resolution of your monitor is, that being X pixels wide by Y pixels high.
Although a QuickTime movie looks best in its default resolution, you can resize it in the QuickTime Player. Just as with still images, if you try to increase the resolution of a movie by making it larger, your Mac has to create pixels that aren't really there. This usually makes the movie look pixilated. Making a movie smaller usually does not detract from the way it looks because the Mac only has to remove pixels.
QuickTime movies created with larger resolution are better because they have a larger image to view and better definition of those images. The trade-off is in the frame rate at which the movie will play back (covered later in this chapter) and the size of the QuickTime movie file. The larger the resolution, the more information your Mac has to work with, and thus the harder it has to work to play back the movie and the larger the file sizes are. Sample resolutions for QuickTime movies are shown in Table 19.1.
Approximate Viewing Size on 800x600 Desktop (21'' Monitor)
Not So "Quick" Time
When QuickTime first appeared on the Mac, Mac hardware was underpowered; thus, the early QuickTime movies had to be pretty small so that playback could even approach smooth motion. The standard resolution for a QuickTime movie in those days was a paltry 160x120 pixels. This earned QuickTime the label of "postage stamp" size movies by its critics. A bit of an exaggeration perhaps, but the first QuickTime movies were awfully small. Fortunately, both Mac hardware and QuickTime technology have improved so that larger QuickTime movies are practical. In fact, with Web streaming and a broadband Internet connection, QuickTime movies can be full-screen and still have very fluid motion.
Just like still images, QuickTime movies are created with a specific color depth. Movies with a larger number of colors require more processing power and have larger file sizes. Plus, some Macs are limited in the color depth they can view, so creating a movie in 24-bit color can cause it to look different on those machines that cannot work with that many colors. Therefore, these Macs have to reduce the number of colors in the movie before the movie is played.
QuickTime movies?just like their analog counterparts?are actually a series of still images that are slightly different from one another. As these images are shown onscreen, you see the illusion of motion?QuickTime is really just the digital age equivalent of the flipbook. The faster these images "flip" on the screen, the smoother and more lifelike the movie appears. The speed at which the movie plays is called the frame rate.
As with all other aspects of QuickTime movies, there is a trade-off between the quality of the movie and the resources it requires to be played. The higher the frame rate, the smoother and better the movie appears. However, QuickTime movies with higher frame rates require more processing power to view and the files are larger, thus requiring more disk space and download time.
The resolution, color depth, and frame rate aren't the only factors that determine how well a movie plays. Other factors include processing power, video display hardware, hard disk or CD-ROM speed, and especially connection speed (for a movie over the Internet).
Apple maintains an extensive Web site dedicated to QuickTime. This site includes software and updates you can download, information on how QuickTime works, links to QuickTime showcases, and so on. The site is at www.apple.com/quicktime and has some great samples of QuickTime movies you can view.
QuickTime movies can contain multiple tracks, where each track contains certain information. For example, a movie can have a video track, text track, and soundtrack. You can also have multiple tracks of the same type in a single movie. Or, you can have a movie with only one track (for example, a music track can be its own "movie"). Using QuickTime Pro, you can manipulate the individual tracks of a movie.
In addition to its native format, QuickTime Pro works with various other formats, including the following:
The following list is for QuickTime Pro. The basic version of QuickTime can work with some of these file formats, but certainly not all of them.
Video? QuickTime can work with various video formats, including QuickTime, Audio Video Interleave (AVI, which is the Windows standard video format), Moving Picture Experts Group-1 (MPEG-1), MPEG-4, and Digital Video (DV).
Audio? QuickTime supports many audio formats, such as Audio Interchange File Format (AIFF), AAC, WAV (the PC audio standard), MP3, and more.
Image? Of course, QuickTime supports PICT and other Mac graphic formats, but it can also display BMP (Windows Bitmap), JPEG, and GIF images.
Animation? QuickTime also supports several standard animation formats, such as PICS files.
Mac OS X version 10.2 was the first version to include QuickTime version 6. Version 6 of QuickTime introduced support for MPEG-4. MPEG-4 is a revolutionary new compression scheme capable of delivering very high-quality video and audio in much smaller file sizes than is possible with other schemes. Plus, MPEG-4 is scalable, meaning that various quality and file-size trade-offs are possible. At its best, MPEG-4 provides quality equivalent to MPEG-2, which is the scheme primarily used for DVD movies. MPEG-4 can be used in many situations, but the most significant benefit?at least initially?is for movies broadcast over the Internet. MPEG-4 allows movies to be played over the Net in very high quality, even over relatively low-speed connections. In the not-so-distant future, MPEG-4 is likely to become a dominant standard for many aspects of video and audio content.
When you use the Pro version of QuickTime 6, you can produce content in the MPEG-4 format.