---
title: kVTCompressionPropertyKey_TransferFunction
framework: videotoolbox
role: symbol
role_heading: Global Variable
path: videotoolbox/kvtcompressionpropertykey_transferfunction
---

# kVTCompressionPropertyKey_TransferFunction

The transfer function for compressed content.

## Declaration

```swift
let kVTCompressionPropertyKey_TransferFunction: CFString
```

## Discussion

Discussion If the video encoder enforces specific colorimetry, this property will be read-only (VTSessionSetProperty(_:key:value:) will return kVTPropertyReadOnlyErr). The value is set on the format description for output sample buffers.

## See Also

### Color

- [kVTCompressionPropertyKey_AlphaChannelMode](videotoolbox/kvtcompressionpropertykey_alphachannelmode.md)
- [kVTCompressionPropertyKey_ColorPrimaries](videotoolbox/kvtcompressionpropertykey_colorprimaries.md)
- [kVTCompressionPropertyKey_ContentLightLevelInfo](videotoolbox/kvtcompressionpropertykey_contentlightlevelinfo.md)
- [kVTCompressionPropertyKey_GammaLevel](videotoolbox/kvtcompressionpropertykey_gammalevel.md)
- [kVTCompressionPropertyKey_ICCProfile](videotoolbox/kvtcompressionpropertykey_iccprofile.md)
- [kVTCompressionPropertyKey_MasteringDisplayColorVolume](videotoolbox/kvtcompressionpropertykey_masteringdisplaycolorvolume.md)
- [kVTCompressionPropertyKey_YCbCrMatrix](videotoolbox/kvtcompressionpropertykey_ycbcrmatrix.md)