Keyframe Stabilizer

When to use it

Think of a listening shot, a held smile or a pause between lines. The actor sways or breathes, so the head moves a little, but the expression doesn’t change. FaceTweak normally redraws the face fresh on every frame, and each redraw comes out very slightly different. On a held expression there’s nothing to hide those differences, so they show up as a fine shimmer around the mouth and eyes.

The Keyframe Stabilizer fixes that. FaceTweak fully redraws only some frames, called stabilizer keyframes, and builds the frames in between from them. It carries each keyframe’s redraw along with the actor’s real movement, then blends the two keyframes either side according to how close they are.

Where FaceTweak can’t be sure how the picture moved between frames, such as when a hand passes in front of the face or the mouth moves quickly, that frame keeps its own redraw instead.

Quick start

1. Find a held moment where the edit shimmers but the expression doesn’t change.
2. In the Temporal section, set Keyframe Stabilizer to 100.
3. Leave the other settings as they are to begin with: Whole Face, Every N Frames and an interval of 4.
4. Let the frame settle, then play the moment back. The shimmer should be gone.
5. Keyframe the strength if the moment ends in talking: set a keyframe at 100 on the last still frame and another at 0 where the movement starts.

Choosing the strength

With the stabilizer on, every in-between frame can be shown in two ways:

• Its own redraw, made fresh for that frame. It follows the actor exactly, but on a held expression it’s where the shimmer comes from.
• The steady version, built from the keyframes on either side as in the diagram above. It doesn’t shimmer, but it can only change as fast as the keyframes do.

The Keyframe Stabilizer slider chooses the mix between the two, like a cross-fade:

A few things it doesn’t change, which is where most of the confusion comes from:

• It isn’t the 75 / 25 split in the diagram. That split is how the steady version is put together from the two keyframes, and FaceTweak works it out for you from the frame’s position. The slider only decides how much of that finished steady version you see.
• It doesn’t change which frames are keyframes. That’s Keyframe Placement and Keyframe Interval. The keyframe frames themselves always show their own redraw, so the slider only affects the frames in between.
• It can’t force a bad result. Wherever FaceTweak can’t follow how the picture moved, such as a hand passing in front, the frame keeps its own redraw even at 100. That’s why 100 is a safe place to start.
• It only works inside the Stabilize Region. Outside it, every frame shows its own redraw.
• Lower values don’t render faster. Any setting above 0 builds the steady version, so 30 and 100 take about the same time.

Because you can keyframe the slider like any other control, you can switch the stabilizer on just for the still stretches: 100 while the expression holds, easing down to 0 over a few frames where the actor starts to speak.

The controls

Keyframe Stabilizer0 to 100 · default 0

The mix, on each in-between frame, between that frame’s own redraw (0) and the steady version built from the keyframes (100). 0 turns the stabilizer off. Start at 100 and keyframe it down to 0 where the actor talks or blinks. Choosing the strength explains it in full.

Stabilize RegionWhole Face · Eyes · Mouth · Eyes and Mouth · default Whole Face

Where the stabilizer applies. Outside this area, each frame keeps its own redraw. The region follows the features, including where your edit moves them, so a smile’s raised corners are covered. Choose Mouth, for example, if the eyes are blinking but the lips hold still.

Region Expand (%)0 to 50 · default 10

Grows the region beyond the features themselves, measured as a percentage of the face’s width. Raise it until the skin around the mouth or eyes stops wobbling too.

Region Softness (%)0 to 25 · default 5

Fades the stabilizer out gradually toward the edge of the region, so there’s no visible boundary between steadied and normal areas.

Keyframe PlacementEvery N Frames · Manual · default Every N Frames

Every N Frames places keyframes at regular intervals. Manual lets you choose them yourself (see below).

Keyframe Interval2 to 12 frames · default 4 · Every N Frames

How many frames apart the keyframes are. Longer intervals are steadier, but follow real changes, such as a slowly growing smile or a change in the light, more slowly.

Keyframe Offset0 to 11 · default 0 · Every N Frames

Shifts where the regular keyframes fall. With an interval of 4 and an offset of 2, keyframes land on frames 2, 6, 10 and so on. Nudge it if a keyframe happens to land on an awkward frame, such as the middle of a blink.

Manual KeyframesManual placement

Where you mark your own stabilizer keyframes, using the keyframe diamond beside it. Only the positions of the keyframes matter; the value is ignored.

KeyframesManual placement · read-only

Lists the manual keyframes FaceTweak found, the longest gap between them, and any frames too far from a keyframe to be steadied.

The controls you don’t need are hidden: Interval and Offset appear with Every N Frames, and Manual Keyframes and the Keyframes list appear with Manual.

Choosing keyframes yourself

Regular keyframes are quick, but sometimes a few frames look better than the rest: the mouth exactly as you want it, the eyes just so. Manual placement lets you build the moment from those frames.

1. Set Keyframe Placement to Manual.
2. Step through the moment. On each frame where the mouth and eyes look right, click the diamond beside Manual Keyframes. Click it again on a keyframe to remove it, and use the arrows beside it to jump between them.
3. Add a keyframe wherever the expression changes, for example where a smile starts and where it peaks, so the in-between frames have the right frames to blend.
4. Check the Keyframes list for gaps that are too long.

Each frame uses the nearest keyframe on each side, up to 24 frames away. Before the first keyframe or after the last, it uses the single nearest one. A frame more than 24 frames from any keyframe keeps its own redraw. Your manual keyframes also show up in Resolve’s keyframe editor, and they move with the clip.

Good to know

• You’ll see the steadied result a moment after you stop dragging a slider. The quick preview while you drag isn’t stabilized.
• There’s no jump on a keyframe: each keyframe frame simply uses its own redraw.
• Each in-between frame looks at its two keyframes, which adds render time. Changing a slider means the keyframes have to be redrawn.
• On close-ups, the stabilizer also steadies how the edit moves the real skin, which stops the skin around the lips wobbling (see Close-ups and 4K).
• Presets save the strength, region, expand, softness, placement, interval and offset. Manual keyframes belong to the shot, so they aren’t saved in presets.