Adobe After Effects CS4 - Manual (Page 708)

702 USING AFTER EFFECTS CS4
Rendering and exporting
Last updated 12/21/2009
Note: All files created with a color depth of Millions of Colors+, Trillions of Colors+, or Floating Point + have labeled
alpha channels; information describing the alpha channel is stored in the file. Therefore, you do not have to specify an
alpha interpretation each time you import an item created in After Effects.
Depth Specifies the color depth of the output movie. Choose from color or grayscale options. Certain formats may
limit depth and color settings.
Color Specifies how colors are created with the alpha channel. Choose from either Premultiplied (Matted) or Straight
(Unmatted). (See “ Alpha channel interpretation: premultiplied or straight ” on page 73.)
Starting # Specifies the number for the starting frame of a sequence. For example, if this option is set to 38, After
Effects names the first frame [file_name]_00038. The Use Comp Frame Number option adds the starting frame
number in the work area to the starting frame of the sequence.
Stretch Specifies the size of your output movie. Select Lock Aspect Ratio To if you want to retain the existing frame
aspect ratio when stretching the frame size. Select Low Stretch Quality when rendering tests, and select High Stretch
Quality when creating a final movie. (See “
Scaling a movie down ” on page 734 and “ Scaling a movie up ” on page 735.)
Crop Used to subtract or add rows or columns of pixels to the edges of the output movie. You can specify the number
of rows or columns of pixels to be added or subtracted from the top, left, bottom, and right sides of the movie. Use
positive values to crop, and use negative values to add rows or columns of pixels. Select Region Of Interest to export
only the region of interest selected in the Composition or Layer panel. (See “
Region of interest (ROI) ” on page 201.)
By adding one row of pixels to the top and subtracting one row from the bottom of a movie, you can change the field
order.
Audio Output Specifies the sample rate, sample depth (8 Bits or 16 Bits), and playback format (Mono or Stereo).
Choose a sample rate that corresponds to the capability of the output format. Choose an 8-bit sample depth for
playback on the computer, and a 16-bit sample depth for CD and digital audio playback or for hardware that supports
16-bit playback.
Post-render actions
You can use post-render actions to automate simple tasks that occur after a composition is rendered.
A common example of the use of post-render actions is with pre-rendering: Choosing Composition > Pre-render adds
the selected composition to the render queue and sets the Post-Render Action option to Import & Replace Usage.
Note: You choose Post-Render Action options in the Output Module group, so be aware that changing the Output Module
template could also change the Post-Render Action option. (See “
Output modules and output module settings ” on
page 700.)
1 Expand the Output Module group in the Render Queue panel by clicking the arrow to the left of the Output Module
heading.
2 Choose one of the following from the Post-Render Action menu:
None Performs no post-render action. This option is the default.
Import Imports the rendered file into the project as a footage item when the rendering is complete.
Import & Replace Usage Imports the rendered file into the project and substitutes it for the specified item. Drag the
pick whip to the item to replace in the Project panel to specify it.
Use the Import & Replace Usage option to create a chain of dependent render items. For example, you can set one
render item to use a watch folder and multiple computers to create a still-image sequence, and then the next render
item can render a single movie file from that still-image sequence. (See “ Network rendering with watch folders and render
engines ” on page 727.)