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# CMSampleBufferMakeDataReadyCallback

Client callback called by [`CMSampleBufferMakeDataReady(_:)`](/documentation/CoreMedia/CMSampleBufferMakeDataReady(_:)).

```
typealias CMSampleBufferMakeDataReadyCallback = (CMSampleBuffer, UnsafeMutableRawPointer?) -> OSStatus
```

## Parameters

`sbuf`

The sample buffer to make ready.

`makeDataReadyRefcon`

Client refcon provided to `CMSampleBufferCreate`.

    For example, it could point at info about the scheduled read that needs to be forced to finish.

## Discussion

This callback must make the data ready (e.g. force a scheduled read to finish). If this callback succeeds and returns 0, the sample buffer will then be marked as “data ready”.

---

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