Apple Motion 3 - Manual (Page 327)

Chapter 4 Using the Timeline 327
Locked tracks still appear in the Canvas and are included in your final output. Although
you cannot make changes to a locked object, you can still copy or duplicate that object
or change the object’s layer order.
To lock a track:
m Click the lock icon at the right edge of the Timeline layers list.
Audio-Video Links
Ordinarily, objects that contain both audio and video are linked together so that they
always remain in sync. This link is represented by an icon in the Timeline layers list.
Note: To display audio in the Timeline, click the Show Audio button.
Objects that are linked are always edited together in the Timeline. Operations such as
cut, copy, paste, and split also affect both audio and video. However, if you ever want to
break that relationship so that you can move or edit the audio or video without the
other tagging along, you can disable that link and move either object freely. Beware
that this may result in your audio and video playing out of sync.
To manipulate audio and video elements separately:
1 Click the link icon to the right of the object name for either the video or audio element.
The link icon changes to a broken link.
2 Move, trim, or slip the audio or video bar.
The link icon also appears in the Layers list in the Project pane.
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