---
title: "VTCompressionSessionInvalidate(_:)"
framework: videotoolbox
role: symbol
role_heading: Function
path: "videotoolbox/vtcompressionsessioninvalidate(_:)"
---

# VTCompressionSessionInvalidate(_:)

Tears down a compression session.

## Declaration

```swift
func VTCompressionSessionInvalidate(_ session: VTCompressionSession)
```

## Parameters

- `session`: The compression session to invalidate.

## Discussion

Discussion When you finish using a compression session you created, call VTCompressionSessionInvalidate to tear it down, and then call CFRelease to release its memory. note: A compression session is automatically invalidated when its retain count reaches zero, but because sessions may be retained by multiple parties, it’s hard to predict when this will happen.  Calling VTCompressionSessionInvalidate ensures a deterministic, orderly teardown.