Why a generated AI clip is letterboxed in your project

You generate a clip in AI Gen, then Video, add it to the timeline, and the preview shows bars around the picture. The clip is fine. Its shape differs from your project's shape, and the default framing shows the whole picture.

Where the bars come from

The video generator renders in one of two shapes: 9:16 or 16:9. Your project has more choices. The Aspect ratio tab in the left panel lists Widescreen 16:9, Vertical 9:16, Classic 4:3, Cinematic 2:1, Square 1:1 and Portrait 3:4, plus a Custom option.

When the Video panel opens, it picks the generator shape closest to your project. A Widescreen project gets 16:9 and a Vertical project gets 9:16, so those two match. A Square, Classic, Cinematic, Portrait or Custom project can only get the nearest of the two, and the clip cannot fill the frame exactly.

The preview frame always follows the project's shape, so the bars you see are the gap between that frame and the clip. Every new clip uses Fit framing, which keeps the whole picture visible. Where the shapes differ, Fit leaves bars. Picking the opposite shape in the generator gives the same result.

Fix 1. Fill the frame

1. Select the generated clip on the timeline.
2. Open the Framing tab in the right panel.
3. In the Framing row, choose Fill.

Fill scales the picture to cover the frame and crops whatever overflows. Drag the picture in the preview to choose which part stays visible. The Zoom slider in the same tab enlarges the picture further. If you drag too far, press Center, which appears in the Framing tab once the picture has moved.

Fill removes the bars and gives up the edges of the shot. Check that nothing important sits at the crop line, such as a face near the top or a caption area near the bottom.

Fix 2. Generate in the matching shape

If the clip is still a draft, regenerate it in the right shape.

1. Open AI Gen, then Video.
2. Press the sliders button labeled More settings.
3. In the Aspect ratio row, pick 16:9 for a Widescreen project or 9:16 for a Vertical one.
4. Press Generate video.

The compact row of icons under the prompt also holds an Aspect ratio menu with the same two choices.

Fix 3. Change the project shape

Sometimes the project shape is the thing to change. Open the Aspect ratio tab and choose Widescreen · 16:9 or Vertical · 9:16. Make this choice before you generate a batch of clips, so every clip starts at the same shape.

In a Square project, AI Gen, then Image offers Square · 1:1 in its own Aspect ratio menu. Square stills fill that frame without bars.

Before the next render

Check the shape in More settings before you press Generate video. Open DepCut and try Fit and Fill on one clip to see which crop you prefer.