Types of video and film – Adobe After Effects CS3 User Manual
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AFTER EFFECTS CS3
User Guide
68
A database retains links to each of the cached media files. This media cache database is shared with Adobe Premiere
Pro, Adobe Encore, and Adobe Soundbooth, so each of these applications can each read from and write to the same
set of cached media files. If you change the location of the database from within any of these applications, the location
is updated for the other applications, too. Each application can use its own cache folder, but the same database keeps
track of them all.
❖
Choose Edit > Preferences > Memory & Cache (Windows) or After Effects > Preferences > Memory & Cache (Mac
OS), and do one of the following:
•
Click one of the Choose Folder buttons to change the location of the media cache database or the media cache
itself.
•
Click Clean Database & Cache to remove conformed and indexed files from the cache and to remove their entries
from the database. This only affects footage items for which the source file is no longer available.
Note: Before clicking the Clean Database & Cache button, make sure that any drives that contain your currently used
source media are connected to your computer. If footage is determined to be missing because the drive on which it is
located is not connected, the associated files in the media cache will be removed. This will result in the need to reconform
or reindex the footage when you attempt to use the footage later.
Types of video and film
Some of the source footage you use may have been created digitally (for example, in Photoshop or Adobe Premiere
Pro), but other footage may need to be transferred to the computer from analog sources, such as film and videotape.
Understanding some of the media differences can help you decide how to handle footage as you transfer it between
digital and analog devices.
For introductions to digital video, digital audio, high-definition video, DVD, compression, and streaming video, visit
the Adobe website at
Analog video
Comes from an analog camera and carries picture and sound information by creating continuous
variations in an electromagnetic signal. Before you can import analog video into After Effects, you need to capture
it. Capturing transfers video from tape to your hard disk, and involves the conversion of the analog signal to a digital
signal.
Digital video
Comes from a digital video camera, and carries picture information by representing each pixel of a
video frame as discrete color and intensity values and transmitting and storing the pixel values in the binary data
format used by computers. Sound is also carried as binary data.
Digital video is not one format but a medium. There are many digital video file formats exist. Even if your source
footage was created digitally, you need to make sure that it is stored in a file format that After Effects can import.
If you plan to distribute the movie digitally, for example on DVD, you must render it in a file format appropriate for
your distribution method.
DV video format is a form of digital video that can be captured directly to your hard disk for editing in applications
such as After Effects and Adobe Premiere Pro. Most DV cameras and decks can connect directly to a computer using
an IEEE 1394 (FireWire/i.Link) interface.
Note: Some formats, such as Adobe Flash Video, have elements of conventional digital video, but represent an interme-
diate category between what has conventionally been thought of as a video format and what has conventionally been
thought of as computer animation format.
Analog film
Carries picture information by creating variations in colored pigments on a strip of acetate (the long reel
run through the traditional film projector). Examples include still transparencies and common motion-picture film.