---
title: FreeBlock
framework: coremedia
role: symbol
role_heading: Instance Property
path: coremedia/cmblockbuffercustomblocksource/freeblock
---

# FreeBlock

A function to call once when the CMBlockBuffer is disposed.

## Declaration

```swift
var FreeBlock: ((UnsafeMutableRawPointer?, UnsafeMutableRawPointer, Int) -> Void)?
```

## Discussion

Discussion Pass NULL if you don’t want a function to be called after disposal. The function will not be called if no memory block is ever allocated or supplied.

## See Also

### Properties

- [AllocateBlock](coremedia/cmblockbuffercustomblocksource/allocateblock.md)
- [refCon](coremedia/cmblockbuffercustomblocksource/refcon.md)
- [version](coremedia/cmblockbuffercustomblocksource/version.md)