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# kVTScalingMode_Letterbox

The source image buffer’s clean aperture is scaled to a rectangle fitted inside the  destination clean aperture that preserves the source picture aspect ratio.

```
let kVTScalingMode_Letterbox: CFString
```

## Discussion

The remainder of the destination image buffer is filled with black. If a destination pixel aspect ratio is not set, the source image’s pixel aspect ratio is used. The pixel aspect ratio used is set on the destination image buffer.

---

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