Adobe After Effects CS4 - Manual (Page 78)

72 USING AFTER EFFECTS CS4
Importing and managing footage items
Last updated 12/21/2009
The interpretation settings tell After Effects the following about each footage item:
• How to interpret the interaction of the alpha channel with other channels (See “ Alpha channel interpretation:
premultiplied or straight ” on page 73.)
• What frame rate to assume for the footage item (See “ Frame rate ” on page 75.)
• Whether to separate fields and, if so, what field order to assume (See “ Separate video fields and determine field
order ” on page 93 and “ Determine the original field order ” on page 93.)
• Whether to remove 3:2 or 24Pa pulldown (See “ Remove 3:2 or 24Pa pulldown from video ” on page 94.)
• The pixel aspect ratio of the footage item (See “ Pixel aspect ratio and frame aspect ratio ” on page 77.)
• The color profile of the footage item (See “ Interpret a footage item by assigning an input color profile ” on page 289.)
Important: In all of these cases, the information is used to make decisions about how to interpret data in the imported
footage item—to tell After Effects about the input footage. The interpretation settings in the Interpret Footage dialog box
should match the settings used to create the source footage file. Do not use the interpretation settings to try to specify
settings for your final rendered output.
Generally, you don’t need to change interpretation settings. However, if a footage item isn’t of a common kind, After
Effects may need additional information from you to interpret it correctly.
You can use the controls in the Color Management section of the Interpret Footage dialog box to tell After Effects how
to interpret the color information in a footage item. This step is usually only necessary when the footage item does not
contain an embedded color profile.
When you preview in the Footage panel, you see the results of the footage interpretation operations.
Jeff Almasol provides a script on his redefinery website that you can use to make guessing the 3:2 pulldown, 24Pa
pulldown, or alpha channel interpretation more convenient.
More Help topics
“ Footage (keyboard shortcuts) ” on page 745
Interpret a single footage item using the Interpret Footage dialog box
❖ Select a footage item in the Project panel and do one of the following:
• Click the Interpret Footage button at the bottom of the Project panel.
• Drag the footage item to the Interpret Footage button.
• Choose File > Interpret Footage > Main.
• Press Ctrl+Alt+G (Windows) or Command+Option+G (Mac OS).
Interpret a proxy using the Interpret Footage dialog box
❖ Select the original footage item in the Project panel and do one of the following:
• Alt-click (Windows) or Option-click (Mac OS) the Interpret Footage button at the bottom of the Project panel.
• Alt-drag (Windows) or Option-drag (Mac OS) the footage item to the Interpret Footage button.
• Choose File > Interpret Footage > Proxy.