---
title: kCVPixelBufferPoolAllocationThresholdKey
framework: corevideo
role: symbol
role_heading: Global Variable
path: corevideo/kcvpixelbufferpoolallocationthresholdkey
---

# kCVPixelBufferPoolAllocationThresholdKey

The key you use to set the auxiliary attributes dictionary.

## Declaration

```swift
let kCVPixelBufferPoolAllocationThresholdKey: CFString
```

## Discussion

Discussion Use this key to set auxAttributes in CVPixelBufferPoolCreatePixelBufferWithAuxAttributes(_:_:_:_:). The value for this key specifies that the system shouldn’t allocate a new pixel buffer if the pool already holds at least the specified number of allocated pixel buffers. This key doesn’t prevent the system from recycling allocated buffers. If this key causes CVPixelBufferPoolCreatePixelBufferWithAuxAttributes(_:_:_:_:) to fail, it returns the kCVReturnWouldExceedAllocationThreshold result code.

## See Also

### Constants

- [kCVPixelBufferPoolMinimumBufferCountKey](corevideo/kcvpixelbufferpoolminimumbuffercountkey.md)
- [kCVPixelBufferPoolMaximumBufferAgeKey](corevideo/kcvpixelbufferpoolmaximumbufferagekey.md)