---
title: CMBufferGetSizeCallback
framework: coremedia
role: symbol
role_heading: Type Alias
path: coremedia/cmbuffergetsizecallback
---

# CMBufferGetSizeCallback

A client callback that returns a size.

## Declaration

```swift
typealias CMBufferGetSizeCallback = (CMBuffer, UnsafeMutableRawPointer?) -> Int
```

## Parameters

- `buf`: The buffer being interrogated.
- `refcon`: The client refcon. Can be NULL.

## See Also

### Data Types

- [CMSampleBuffer](coremedia/cmsamplebuffer.md)
- [Sample Buffer Flags](coremedia/sample-buffer-flags.md)
- [CMSampleTimingInfo](coremedia/cmsampletiminginfo.md)
- [CMBuffer](coremedia/cmbuffer.md)
- [CMItemIndex](coremedia/cmitemindex.md)
- [CMItemCount](coremedia/cmitemcount.md)
- [CMPersistentTrackID](coremedia/cmpersistenttrackid.md)
- [CMMuxedStreamType](coremedia/cmmuxedstreamtype.md)