Adobe After Effects CS4 - Manual (Page 688)

682 USING AFTER EFFECTS CS4
Expressions
Last updated 12/21/2009
m = thisLayer.marker.nearestKey(time);
s = "time:" + timeToCurrentFormat(m.time) + "\r" +
"duration: " + m.duration + "\r" +
"key index: " + m.index + "\r" +
"comment:" + m.comment + "\r" +
"chapter:" + m.chapter + "\r" +
"URL:" + m.url + "\r" +
"frame target: " + m.frameTarget + "\r" +
"cue point name: " + m.cuePointName + "\r" +
"Event cue point? " + m.eventCuePoint + "\r";
for (param in m.parameters){
s += "parameter: " + param + " value: " + m.parameters[param] + "\r";
}
s
Because the XMP metadata in a footage item can be converted into layer markers for a layer based on that item,
expressions can interact with XMP metadata. For information, see “
XMP metadata in After Effects ” on page 626.
Dan Ebberts provides a tutorial on the After Effects Developer Center that includes an example of using XMP metadata
with expressions.
duration Return type: Number.
Duration, in seconds, of marker.
comment Return type: String.
Contents of Comment field in marker dialog box.
chapter Return type: String.
Contents of Chapter field in marker dialog box.
url Return type: String.
Contents of URL field in marker dialog box.
frameTarget Return type: String.
Contents of Frame Target field in marker dialog box.
eventCuePoint Return type: Boolean.
Setting for cue point type in marker dialog box. True for Event; false for Navigation.
cuePointName Return type: String.
Contents of cue point Name field in marker dialog box.
parameters Return type: associative array of String values.
Contents of Parameter Name and Parameter Value fields in marker dialog box.
For example, if you have a parameter named “background color”, then you can use the following expression to access
its value at the nearest marker:
thisComp.marker.nearestKey(time).parameters["background color"]