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Smooth out a slow-motion clip with video quality presets
To smooth out the apparent motion of a clip playing back in slow motion, you can
apply frame blending or optical ow analysis to the retimed clip.
1 In the Timeline, select a range, a whole clip, or a group of clips whose video quality you
want to change.
2 Choose a Video Quality setting from the Retime pop-up menu in the toolbar.
 Normal: The default setting. Frames are duplicated, and no frame blending is applied
to the slow-motion clip. No rendering is required.
 Frame Blending: Adds in-between frames by blending individual pixels of
neighboring frames. Slow-motion clips created with Frame Blending appear to
play back more smoothly than those created with the Normal (duplication) setting.
Rendering is required.
 Optical Flow: Adds in-between frames using an optical ow algorithm, which
analyzes the clip to determine the directional movement of pixels and then draws
portions of the new frames based on the optical ow analysis. Only the portion of
the clip used in the project (the media between the clip start and end points) is
analyzed. Rendering is required.
Note: The more motion contained in a clip, the longer the analysis and
rendering takes.
Reverse or rewind clips
In addition to changing the speed of a clip, you can also add directional eects:
 Reverse: Reverses the order of frames in the clip, so that the last frame plays rst.
 Rewind: Appends a duplicate of the range selection or clip as a segment, rewinds the
duplicated segment at 1x, 2x, or 4x speed, and then plays the original clip segment
again in forward motion at normal speed.
Reverse a clip
1 In the Timeline, select a clip or a group of clips whose contents you want to reverse.
2 Choose Reverse Clip from the Retime pop-up menu in the toolbar.
The green bar with arrows pointing to the left above the selection in the Timeline
indicates that the clip is reversed.
332 Chapter 11 Advancedediting