---
title: kVTCompressionPropertyKey_FieldDetail
framework: videotoolbox
role: symbol
role_heading: Global Variable
path: videotoolbox/kvtcompressionpropertykey_fielddetail
---

# kVTCompressionPropertyKey_FieldDetail

Field ordering for encoded interlaced frames.

## Declaration

```swift
let kVTCompressionPropertyKey_FieldDetail: CFString
```

## Discussion

Discussion If a video encoder enforces specific field ordering, this property will be read-only (VTSessionSetProperty(_:key:value:) returns kVTPropertyReadOnlyErr). The field detail is set on the format description for output samples, and may affect source frame scaling. NULL is a valid value for this property.

## See Also

### Clean Aperture and Pixel Aspect Ratio

- [kVTCompressionPropertyKey_AspectRatio16x9](videotoolbox/kvtcompressionpropertykey_aspectratio16x9.md)
- [kVTCompressionPropertyKey_CleanAperture](videotoolbox/kvtcompressionpropertykey_cleanaperture.md)
- [kVTCompressionPropertyKey_FieldCount](videotoolbox/kvtcompressionpropertykey_fieldcount.md)
- [kVTCompressionPropertyKey_PixelAspectRatio](videotoolbox/kvtcompressionpropertykey_pixelaspectratio.md)
- [kVTCompressionPropertyKey_ProgressiveScan](videotoolbox/kvtcompressionpropertykey_progressivescan.md)