Set execution speed
You can control the execution speed of the Clip via the executionSpeed property of it. executionSpeed can take positive or negative (reverse execution) numbers. The normal speed is 1.
myClip.executionSpeed = 1; // normal execution speed
myClip.executionSpeed = -1; // reverse execution with normal speed
myClip.executionSpeed = 2; // two times faster execution speed
myClip.executionSpeed = -2; // two times faster reverse execution speed