Apple Final Cut Pro 7 - Manual (Page 713)

Doing Roll Edits in the Viewer
Final Cut Pro allows you to perform roll edits in the Viewer by setting In or Out points
while the Roll tool is selected.
To do a roll edit in the Viewer
1 Open a sequence clip in the Viewer.
2 Select the Roll tool in the Tool palette (or press the R key).
3 Do one of the following:
• Drag the In or Out point along the Viewer’s scrubber bar to roll the edit.
• Press I or O to set a new In or Out point.
Look in the Timeline to make sure the roll edit did what you expected.
713 Chapter 44 Performing Slip, Slide, Ripple, and Roll Edits