User Guide

39
ADOBE AFTER EFFECTS 5.0
User Guide
Videotape If your final output will be videotape, set up your composition with a specific
video format in mind, such as NTSC or PAL. Using broadcast-safe colors and maintaining
frame size and compression ratios are also important considerations. These guidelines will
help in setting up a composition intended for videotape:
• Select a frame size in the Composition Settings dialog box that matches the frame size of
the destination video format.
• Use only NTSC-safe colors when adding or changing color in a project.
• If you will be using an MJPEG codec, keep in mind that the frame sizes and resolutions
available for rendering are determined by the specific MJPEG board you are using. Refer
to the specifications for your MJPEG board.
Animated GIF When you render an animated GIF, colors are dithered to an 8-bit palette.
Before rendering your final project, render a test composition so that you can adjust colors
if the results are not what you expected. If any source footage includes an alpha channel,
be sure that you know how it will affect your final project before you start rendering.
Streaming video over the World Wide Web Streaming video resembles a conventional
television signal in that video is sent to the viewer frame by frame, instead of by
downloading a large file to the hard disk. Streaming video on the Web is constrained by
the limited bandwidth (56 Kbps or less) of most consumer modems, which is even lower
than those used for CD-ROM playback. Use the same techniques that are listed for CD-
ROM playback, but adapt them for further reduction in file size and data-transfer rate.
You can export QuickTime streaming directly from After Effects. See “Exporting footage
using QuickTime components” on page 369.
Downloading video over the World Wide Web If your final output will be downloaded as
a file from the World Wide Web, the main concern is the size of the file, which directly
affects how long it takes to download the file. QuickTime and Microsoft Video for
Windows are formats often used when rendering final output that will be downloaded.
When you render a QuickTime movie, After Effects automatically creates a movie that can
play on both Windows and Mac OS without modification.
Intranet playback An intranet is an in-house or private network that uses Internet
network protocols. Intranets generally use higher-quality communications lines than
standard telephone lines, so they are usually much faster than the Internet. The data-
transfer rate for playback can be 100K per second or faster, depending on the speed of your
intranet.
UG.book Page 39 Wednesday, February 21, 2001 12:05 PM