Apple Motion 5.1.1 - Manual (Page 271)

Chapter 8 Timeline 271
Note: If an object has insufficient source media to complete the trim, the bar moves as far as it
can toward the new point.
Slip video layers
Slip a video layer when you want to use a different section of your source clip without changing
the layer’s duration or where it appears in the Timeline.
Important: Slipping is only possible after you have trimmed a video layer’s timebar.
For example, if you have a shot of a door opening that is three seconds long and you want to
trim it one second, you can use the Slip function to select which one-second section to use:
the first second as the door leaves the jamb, the next second where it is flying open, or the last
second where it bangs against the wall.
As with trimming, when you slip a video layer in the track area, Motion provides a visual
representation of how much additional footage is available in the object’s source clip: a dimmed
extension on either end of the object indicates that unused frames exist in the source video clip.
You can only slip an object as far as the existing unused frames in the source media.
Slip a video layer
1 With the pointer over the video layer’s timebar, press and hold down the Option key.
The pointer turns into the slip pointer.
2 Drag the middle part of the bar left or right.
Dragging to the left replaces the frames with a section from later in the source material, while
dragging to the right uses frames from earlier in the clip.
67% resize factor