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# CVFillExtendedPixelsCallBack

Defines a pointer to a custom extended pixel-fill function, which is called whenever the system needs to pad a buffer holding your custom pixel format.

```
typealias CVFillExtendedPixelsCallBack = (CVPixelBuffer, UnsafeMutableRawPointer?) -> DarwinBoolean
```

## Parameters

`pixelBuffer`

The pixel buffer to be padded.

`refCon`

A pointer to application-defined data. This is the same value you stored in the [`CVFillExtendedPixelsCallBackData`](/documentation/CoreVideo/CVFillExtendedPixelsCallBackData) structure.

## Return Value

If `true`, the padding was successful; otherwise, `false`.

## Discussion

---

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