Changing Test Clip Duration
The playback duration of an Evenly Timed test clip can be changed using drag and drop. Mouse over the right-most edge of the test clip until the cursor becomes the resize icon. Single-click the right-most edge and drag the mouse to the left to shorten the test clip playback, or to the right to lengthen.
Additionally, for both a Manually Timed and an Evenly Timed Test Clip, the duration can be changed in the lower panel of the Composition Editor. Select the test clip you want to change by single-clicking it. Select the Properties tab in the lower panel of the Composition Editor. For an Evenly Timed Test Clip, you will also see input boxes labeled Duration and Start Interval. After you update the value, press the Enter key to change the duration.
Changing the duration of a non-sequenced test clip causes the timing of the clip elements inside of it to be adjusted proportionally. Increasing the duration causes the clip elements to be spaced out farther apart in time, while decreasing the duration causes their timing to be compressed.