---
title: "replaceFormatDescription(_:with:)"
framework: avfoundation
role: symbol
role_heading: Instance Method
path: "avfoundation/avmutablecompositiontrack/replaceformatdescription(_:with:)"
---

# replaceFormatDescription(_:with:)

Replaces a format description with another or cancels a previous replacement.

## Declaration

```swift
func replaceFormatDescription(_ originalFormatDescription: CMFormatDescription, with replacementFormatDescription: CMFormatDescription?)
```

## Parameters

- `originalFormatDescription`: The original format description.
- `replacementFormatDescription`: A replacement format description.