---
title: mRefCon
framework: Core Media I/O
role: symbol
role_heading: Instance Property
platforms: [Mac Catalyst 13.1+, macOS 10.7+]
path: coremediaio/cmiodevicesmptetimecallback/mrefcon
---

# mRefCon

## Declaration

```swift
var mRefCon: UnsafeMutableRawPointer!
```