Adobe 65008009 - After Effects CS4 Using Manual page 79

Last updated 12/21/2009
Apply Interpret Footage settings to multiple footage items
You can ensure that different footage items use the same settings by copying interpretation settings from one item and
applying them to others.
1 In the Project panel, select the item with the interpretation settings that you want to apply.
Choose File > Interpret Footage > Remember Interpretation.
2
Select one or more footage items in the Project panel.
3
4 Choose File > Interpret Footage > Apply Interpretation.
Edit interpretation rules for all items of a specific kind
The interpretation rules file contains the rules that specify how After Effects interprets footage items. In most cases,
you don't need to customize the interpretation rules file. When you import a footage item, After Effects looks for a
match in the interpretation rules file, and then determines interpretation settings for the footage item. You can
override these settings after importing, using the Interpret Footage dialog box.
In most cases, the name of the interpretation rules file is interpretation rules.txt; however, some updates to After Effects
install a new interpretation rules file with a name that indicates the updated version number, and the updated
application uses this new file. If you've made changes to the old interpretation rules file, you may need to apply those
changes to the new file, too.
Locations of the interpretation rules file:
• (Windows XP and 32-bit Windows Vista) C:\Program Files\Adobe\Adobe After Effects CS4\Support Files\
• (64-bit Windows Vista) C:\Program Files (x86)\Adobe\Adobe After Effects CS4\Support Files\
• (Mac OS) Applications/Adobe After Effects CS4/
Quit After Effects.
1
As a precaution, make a backup copy of the interpretation rules file. By default, this file is in the same location as
2
the After Effects application.
Open the interpretation rules file in a text editor.
3
Modify the settings according to the instructions in the file.
4
Note: You must supply a four-character file-type code for each footage type or codec. If you don't know the code for a file
or codec in a project, press Alt (Windows) or Option (Mac OS) as you select the file in the Project panel. The file-type code
and codec code (if the file is compressed) appear in the last line of the file description at the top of the Project panel.
Save interpretation rules.txt.
5
Alpha channel interpretation: premultiplied or straight
Image files with alpha channels store transparency information in one of two ways: straight or premultiplied. Although
the alpha channels are the same, the color channels differ.
With straight (or unmatted) channels, transparency information is stored only in the alpha channel, not in any of the
visible color channels. With straight channels, the results of transparency aren't visible until the image is displayed in
an application that supports straight channels.
With premultiplied (or matted) channels, transparency information is stored in the alpha channel and also in the
visible RGB channels, which are multiplied with a background color. Premultiplied channels are sometimes said to be
matted with color. The colors of semitransparent areas, such as feathered edges, are shifted toward the background
color in proportion to their degree of transparency.
USING AFTER EFFECTS CS4
Importing and managing footage items
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